1 INTRODUCTION The rationale of research Gam river is the largest tributary of the Lo river Its area in Vietnam's territory is 9.168/14.972km2 The human activities have a strong impact to the situation and evolution of natural resources and environment in the basin It also contains the risk of natural resources degradation and ecological environment That situation requires a comprehensive research for the rational exploitation and use of natural resources and for basin environmental protection Research objectives and purposes Research objectives: determine the use requirements and propose the use of three natural resources including land, forest, and surface water to contribute in research, rational use of natural resources, environmental protection of Gam river basin and the sustainability of Tuyen Quang hydropower plants Rsearch assignment: review of research trends in rational use of natural resources and environmental protection in basin in the world and in Vietnam; establish a theoretical basis, approach and methodology proposed to rational use of natural resources and environmental protection in the Gam river basin in the context of Tuyen Quang hydropower projects; analyze the characteristics of nature and socio-economic conditions related to natural resources and environment issues, and mining and use problem of the Gam river territory; analyze the situation and transformation of resources and environmental under the impact of Tuyen Quang reservoir; determine the requirements, propose rational use of land resources, forest resources, water resources and protecting the environment of the Gam's watershed; propose mining orientation of Tuyen Quang lake based on the basis analysis of its potential natural Research scope The territory: the Gam river basin in Vietnam's territory has a total area 9.168km2, accounting for 61,23% of the total basin area According to the administrative boundaries, Gam river basin spreads in the area of 17 districts, provinces of Ha Giang, Tuyen Quang, Cao Bang and Bac Kan Content: analyze the characteristics of nature and socio-economic conditions related to the situation and analyze the exploitation and use of the Gam river basin territory; determine the requirements and propose reasonable use of three main types of resources in the basin including land resources, forest resources and surface water resources; propose mining oriented and rational use of Tuyen Quang reservoir based upon the analysis of potential natural of reservoir Research viewpoints Thesis uses many key viewpoints in the research process, including: synthetic viewpoint, systematic viewpoint, historical and generating viewpoint, and ecologicaleconomic viewpoint Research methods The thesis uses specific method including data collection, statistics, data analysis; synthetic analysis; map and geographical information system (GIS); monitoring, field work and experts 2 Theoretical argument - Argument 1: Moutainous terrain occupies most of the area in Gam river basin Economic development has facilitated by the diverse distribution and complex of natural conditions, limited of socio-economic development, abundant of natural resources, advantage of forests, land, water, minerals and hydropower However, there is potential environment risk if it is lack of appropriate exploitation, use, and management in natural resources Along with the exploitation of natural resources in Gam river basin, the formation of Tuyen Quang lake is an agent leading the change in the entire system of resources and environment in the basin especially land, forest, and surface water resources Therefore, analyzing the characteristics of nature, socio-economic conditions, their impacts to to the situation, the transformation of natural resources and environment, and mining and resource use issues, is a pre-condition to propose rational use of natural resources and environmental protection in Gam river basin The center assignment is to propose rational use of three main natural resources of basin - Agurment 2: Study the rational use of natural resources and environmental protection in Gam river basin has accessed toward watershed/basin system analysis in the relationship between natural and human factors, between upper, middle, and down stream, and between level watershed, to determine the percentage of forest cover, land use structure, rational exploitation and use of water resources and Tuyen Quang lake Marks and contributions of the dissertation 1) The thesis has analyzed and clarified: the characteristics of natural, socio-economic conditions related to resources, environment and mining issues, the rational use of natural resources, environmental protection in Gam river basin; the situation and change of land resources, forest resources, surface water resources of the Gam river basin as a result of Tuyen Quang lake 2) The first time, the thesis proposed rational use of natural resources and environmental protection in the Gam river basin following basin analysis approach with specific findings include: proposed upstream decentralization protection, the direction used for different types of land use and land protection on the basis of the potential erosion classification of watershed; land capability assessment and classification of soil protection requirements; proposed reasonable use and forest restoration on the basis of assessment of imbalances cover and classification of forest resources in watersheds; proposed mining and rational use of surface water resources, hydrological flow changes, situation, demand and mining limitation, in Gam river basin based on analysis of potential surface water, the risks and causes of surface water resources degradation, shortcomings in the management of water resources in the basin; analyze natural conditions in Tuyen Quang lake for the purpose of aquaculture and tourism development Dissertation structure Besides the introduction and conclusion, the thesis includes chapters, with 147 A4 pages, 44 tables, 14 maps, 12 drawings, charts, diagrams and 156 references and 16 appendices 3 Chapter THEORETICAL BASIS AND RESEARCH METHODS OF REASONABLE USE OF RESOURCES, ENVIRONMENT PROTECTION IN GAM RIVER BASIN (VIETNAM TERRITORY) 1.1 Overview of the research trends in reasonable use of natural resources and basin environment protection in the world and in Vietnam Around the world and in Vietnam at present, research problems using appropriate resources, environmental protection is approached from the direction of future research: research landscape; assessment study soil erosion and protect soil from erosion; direction basin analysis study (including land-use planning based on an assessment of basin watershed decentralization, decentralization in the basin soil erosion); study integrated management of natural resources environmental and river basins studied the impact of hydropower, irrigation in the basin Several local authors have conducted research combined with landscape basin to the rational use of natural resources and environmental protection in the basin This is quite a new research direction in Vietnam should have only been a handful of authors implemented The research on the Gam river basin not only more focused and problem-solving impact of Tuyen Quang hydropower to the natural environment and the economy - society On the access point system and basin analysis, the thesis studies the rational use of natural resources, environmental protection Gam river basin, which focuses primarily on three resources as land, forests and surface water The results of a number of works have deployed on the Gam river thesis used as input data sources and references of the research process 1.2 Theoretical basis of the study of the reasonable use of natural resources, environmental protection in Gam river basin 1.2.1 The basic concepts Natural Resources: "natural resources are natural components of that at a certain level of development of productive forces are used or can be used as means of production and objects Consumers "[113] Environment: Environmental Protection Law in Vietnam in 2005: "Environmental factors, including natural and man-made physical factors related to each other, surrounded by people, affecting their life, the survival, and development of human beings " Between the environment and natural resources in general and natural resources in particular have a close relationship Therefore, protection of the environment always implies the exploitation and rational use of natural resources of the territory Basin: a natural spatial territory includes all natural objects and artificial on it, which receive storm water and ground water provides natural flow system, which is limited by the the watershed The entire catchment area is a unity and fulfillment naturally On each river basin exists close relationship between the natural and human components work The relationship makes both watersheds is a geographical territory, both as a dynamic system to adjust to the level of expression and different evolutions over time and space from the upstream to the mouth river Decentralized Watershed: the division of watershed area into different levels, reflecting the deterioration of soil erosion based on the geographical characteristics and their environment The most important objective of decentralization is to identify watershed areas need protection forests for water regulation, flood protection, erosion and landslides, limited reservoir sedimentation also such as the protection of downstream areas and bring economic benefits, ensure social security 1.2.2 The impact of hydropower projects in natural resources and the environment in the river basin Depending on the type and scale of development, hydropower projects have impacts on the environment at different levels For the natural environment, a system of dams - hydropower reservoirs are formed submerged part of the basin reservoirs The reservoir formation and operation of hydropower plants as well as changes in flow regimes, erosion and sedimentation of lakes, rivers, and change the appearance of new ecosystems, deforestation and loss biodiversity, water pollution, changing climate conditions of the reservoir For the economic environment - social area submerged by the reservoir may be the place of residence, with the production of construction, aesthetic values, culture, and human sciences Therefore, the hydropower project also alter habitats and living conditions of a segment of the population, which may have a negative impact on the environment, such as deforestation, ecological housing for, cultivation, shifting cultivation, nomadic, erosion and desertification Space impact, including upstream and downstream reservoir dam, even estuaries Most of the impact is more long term, and could potentially manifest during operation of the project 1.2.3 Research approach Firstly, analyze the current state of resources, Gam river basin environment as a result of the relationship agreement, closely natural conditions, economic - and social impact of Tuyen Quang reservoir to the entire system natural - basin ecological environment Secondly, the proposed use of natural resources, environmental protection basin mainly focus on three types of resources as land resources, forest resources and surface water resources The approach of this project is to determine the required resources rational use of land, forest and water surface characteristics analysis based on natural conditions, economic - social, sexual exploitation, and use of resources the status of resources and environment as the basis of proposed use of the resources of this kind 1.3 Research method proposed reasonable use of natural resources and environment protection in Gam river basin 1.3.1 Methods of assessment of potential soil erosion in the basin Selecting assessment methods: These methods evaluate soil erosion mainly in the world are: classification, distribution territories on the extent of erosion on the basis of integrated assessment of the influence of natural conditions to and erosion modeling method based on empirical models erosion studies Due to widespread application of GIS tools with the advantages of the new technique in the process of erosion to study the thesis modeling methods used in studies evaluating the potential erosion of the basin Choosing evaluation models: Thesis using USLE model of Wischmeier and Schmid (A = R×K×L×S×C×P) to assess the potential erosion of the Gam river, after the kind of off coefficient C and P The selection USLE model allows to meet research requirements hierarchy erosion potential as the basis for the proposed decentralized protection in the basin Many authors in the world and the country has confirmed USLE model can be successfully applied to watershed erosion The parameters of the USLE equation can be modified to suit the specific conditions and can be completely calculated using GIS tools 5 1.3.2 DPSIR analysis method DPSIR (Driving forces-pressures - State - Impacts - Responses) is a cognitive model used to identify, analyze and evaluate the causal chain-result-response measures Thesis DPSIR methodology used to analyze general issues related to water resources of the Gam river basin, as a basis for determining the proposed solution to the rational use and protection of water resources basin 1.3.3 System analysis method System analysis method was applied dissertation solving research tasks in sequence content (steps) the following: Step 1: Analyze the characteristics of natural conditions and the status of natural resources and environment Gam river basin Step 2: Mapping erosion potential decentralized Gam river basin as a basis for the proposed decentralized protection, rational use and restoration of forest use and protection of land resources Step Assessment requires the use of water resources as a basis for proposing rational use of water resources of the Gam river basin Step 4: Identify strategies for aquaculture development and tourism Tuyen Quang reservoir area based on the analysis and evaluation of the natural conditions, natural lake Chapter CHARACTERISTICS OF NATURAL, SOCIO-ECONOMIC CONDITIONS, AND SITUATION OF NATURAL RESOURCES AND ENVIRONMENT IN GAM RIVER BASIN (THE TERRITORY OF VIETNAM) 2.1 The natural and socio-economic conditions and natural exploitation, environmental protection problems of Gam river basin 2.1.1 Geographical location On the territory of Vietnam, Gam river has about 217km long and a catchment’s area of 9.168,02 km2 On the administrative boundaries, the Gam river basin is located on the territory of 17 districts in the four provinces of Ha Giang, Cao Bang, Bac Kan and Tuyen Quang Due to the distribution in the territory should the vast natural basin characteristics are varied and complex The local catchment area has good economic conditions - poor social development in our country, especially in districts remote This is a major obstacle in the management of natural resources in general and land resources, forests, surface water in particular Gam river basin is 38,77% of the area of China to the basin management will encounter difficulties to reach consensus and ensure the interests of both countries 2.1.2 Natural conditions 2.1.2.1 Characteristics of tectonics - geological Gam river basin located mainly in tropical Gam structure, the North Vietnamese folded, form a graben in the Asian and enhanced meridional end Hecxini entirely Composition of tropical lava mainly terrigenous - carbonate Cambrian age - Ocdovic - Silua - Devon Magmatic activity is characterized by small intrusive bodies, penetrated the sediment Due in active tectonic region with varying intensity should basins strong differentiation of structure and stratigraphy of lava composition in space Activity of the tectonic phase motor with magma intrusion has created much destruction tectonic area in the basin 6 On the Gam river basin includes the formation and lava groups are: the ancient lava (igneous, sedimentary and metamorphic), the lava Mezozoi (including Lang Son Formation, Song Hien and Na Khuat); Cenozoic sediments (Quaternary material) Conditions geological tectonics is the primary basis of the continuous impact in the landscape basin crust, thereby controlling the direction and the extraction solution, using the territory for the purpose of economic development-society, especially for the use and protection of land resources History long territory along the tectonic movement created complex for catchment mineral resources are quite diverse The movement is made up of well defined areas hilly nature, and make a strong differentiation of terrain structures The richness of the composition of the lava flow has defined the diversity of the nature and type of soil cover 2.1.2.2 Terrain On the Gam river in the territory of Vietnam, it is possible to identify a level from low to high are: 100m (3,8%) and 100-200m (7,8%); 200-300m (9,9%), 300-400m (11,4%), 400-500m (11,3%), 500-700m (18,6%) 700-1.000m (19,6%); 1.000-1.500m (1,8%) in the 2.000m (below 1%) The area has a height of 500-1.000m majority with 38,2% of the total catchment area 1,000 or more places from small areas as peaks in the watershed South of the basin, along the Gam river mainstream popularity as a level below 200m elevation Overall, the Gam river basin topography is mainly low hills, with the fragmentation and separation complex Lower elevation terrain from north (above 1.000 m) to the south and southeast (200-500m) along the Gam river flowing mainstream Differentiation of terrain created by landscape diversity, and greatly influenced the direction exploitation and use of the territory Conditions mountainous terrain dominated resource extraction method primarily throughout history explored territory Farming practices have transformed the population structure of land use, exploitation of resources forms, form the system of shifting cultivation, terracing on slopes In the mountains upstream major advantage for forestry development with the protection of forests The model agroforestry farming, forestry and agriculture combined scale can only focus on the development of low hills and slopes In areas of low and flat terrain along the river were filled by new sediments should be very favorable for agriculture to help meet the demand for food, local food The process of long-term development of the basin's natural made adaptations and relative stability of the natural environment The exploitation and use of sloping land fragmentation and the distribution of production space is subjective reasons appear to increase the risk of natural disasters have been happening throughout the basin 2.1.2.3 Climate Climate of Gam river basin is nature tropical monsoon moisture, fertilizer complex, with cold winters and drier than other areas of the Lo river system - running warm and more humid than the Northeast The nature of the cold last winter due to the cold polar air masses due to the effects of tropical medium altitude terrain has made the annual average temperature is quite low (22-240C), but in a very large temperature range (12-140C) Geographical location and topographic structure also create favorable conditions for frequent intrusions in summer, bringing significant rainfall, ranging from popular and time 1.2002.500mm/nam rainy season prolonged, accounting for over 70% of the total annual rainfall 7 Temperature-humidity regime of the Gam river basin with the terrain and soil conditions arise, the development of the natural vegetation of the basin's rich This is one of the reasons that make the Gam river basin is home to the forest coverage rate much higher than the river basin and other localities of the country As the season of heat-moisture distribution and diversity of structure and basin topography to facilitate diversification of crops and livestock in agriculture at the local level with the garden hill farms, gardens forest associated with livestock and poultry Climatic conditions also brings significant difficulties for the natural environment and economic - social activities of the basin Summer is usually the weather disturbance that causes widespread heavy rain Rainfall and unpredictable fluctuations in the rainy season are important factors leading to floods, landslides, rock succession occurs in many parts of the basin 2.1.2.4 Hydrology Gam river basin have long and narrow shape The small tributaries, but as feather structure is very convenient for the country to focus on the main line Low density of rivers (0.5-1km/km2), especially in the upland areas and paint the limestone On the territory of our country's territory, with Gam river is the largest tributary river and Nho Que river Energy Flood season in the Gam river basin extends from May to October, accounts for 7080% of the total annual flow Dry season lasts from November to April next year The seasonal distribution of basin flow regime increases the risk of water shortage, production in the dry season and the natural disasters of flooding The space division of the flow give rise to a conflict between the needs and potential of local water between the basin The construction of hydropower dams in the basin in recent years raises the conflict between water demand for irrigation and power generation However, the formation of Tuyen Quang lake also has facilitated the development of tourism and aquaculture, contributing to job creation and increased incomes for labours 2.1.2.5 Soils Covering of Gam river basin soil is formed under conditions of tropical monsoon climate mountains Therefore, yellow red soil on clay feralit and metamorphism (Fs) accounted for over 50% of tropical land basin Rule elevation and soil geomorphology is characterized by non-zonal soil mantle basin So, from a height of over 900m, and the weakening feralit appearance of the mulch, mulch Alit red loam soils with brown, yellowish red loam appear quite common, especially in the 1.500-1.800m Customary land from mining long pattern shown in the classic land-use and backward Method exploiting irrational slopes have accelerated erosion, leaching to the bare rocks in many places Soil structure coating the Gam river basin is quite diverse and rich The abundance, diversity of land resources to allow local catchment planning in the agro-forestry development towards product diversification, combining agriculture - forestry with tourism development eco tourism community Of the total land, soil feralit occupied the largest area, with nearly 70% of the total catchment area This is the kind of land capable of cultivation agroforestry and reforestation Groups gathered in upland watersheds Gam although small footprint but is valuable in agriculture to provide food, local food Most of the Gam river catchment area is hilly terrain with steep slopes to erosion, washout occurred powerful Each unit of land contained in the basin are at risk of developing the degenerative process The causes of land degradation can be caused by natural processes or by human impacts such as land use unreasonable, shifting cultivation, monoculture, deforestation, mining products Intensity erosion, runoff, soil degradation is enhanced by human activities Status monoculture, intensive burst structure and discolored soil, nutrient poor This is a very common situation in the district upstream Gam Coating structure and soil diversity basin but fragmented distribution, retail Meanwhile, agro-forestry farming is mainly based on the production of natural difficult to create focus and specialization Most of the agricultural products obtained from the extraction, land use is ultimately self-reliant Tuyen Quang Hydropower Project is built on the Gam river has flooded an area of arable land is quite large, mainly lowland soils capable river for farming already occupies the area very little of the total land area of the basin groups The process of migration and resettlement in the reservoirs to increase pressure on the resource type, the natural environment and the economy - society, especially for land resources The management of the State for land resources in time independent nature of each industry and in each locality should approach alone, and not inconsistent with the close coordination This raises the need to explore solutions, rational use of land resources and protect the environment in the basin 2.1.2.6 Creatures - The vegetation: Vegetation structure of the Gam river basin are quite diverse On most of the basin and sub-types of vegetation typical of the mountains in the North and North East In particular, the secondary vegetation of the area is mainly occupied, reflecting the strong human impact in the territory of the mining process - On the species composition of plant: Among 3.551 species of vascular plants of the Gam river, Tuyen Quang Lake area, about 1.159 plant species in sectors In the flora of about 470 species of plants, 75 species of trees and natural values of 50 species of wild crops Gam river basin has an area of significant SUF This is where the richness in species composition and biological reserves, including many rare species have scientific value Across the basin was initially counted 47 rare plant species listed in the Vietnam Red Book - On the composition of animals: According to incomplete statistics, there are about 840 species of Gam river basin higher animals Of these 163 species, 42 species of amphibians, 86 reptiles, 411 birds and 138 mammals In addition, the basin has 64 species of zooplankton, 44 species and 33 benthic taxa Tuyen Quang lake area alone, an estimated 344 species of wild animals in classes, including 48 mammals, 226 birds, 50 reptiles and 20 amphibians General biological resources, forest resources in particular have a huge role for both ecological and economic development - the local society of the Gam river basin Naturally, most of the Gam river basin area is hilly and plateau with large split level quite popular these sensitive ecosystems, easily degraded and difficult to exploit and protect In such conditions, forest resources have an important role in regulating the flow and soil protection, limiting natural disasters, contribute to stabilizing the basin ecological environment, especially in the local area upstream In economic terms - society, in general, biological resources have contributed to the development of certain economic - social Basin Production value of agriculture, forestry and often reaches 35 to 40% of the total production value of the sector in the local economy 9 Biological resources are the basis for the development of industries such as wood processing, food processing, food Since 2008 Tuyen Quang reservoirs in operation has facilitated the development of aquaculture and fisheries and eco-tourism zone of the lake due to the predominance of natural conditions However, so far, the extraction and use of biological resources in the basin is not really reasonable The forest exploitation and indiscriminate deforestation less strict management took place in many places for many years to increase the area of bare soil and risk of natural disasters due to deforestation From 2000 to present, the forest cover has increased, but mainly forest regeneration, recovery and upland forest The main reason degrade biological resources Gam river basin is affected by the increasingly powerful and diverse forms of community residents living in the basin In addition, the management and protection are neglected for a long time The education, raise awareness and mobilize people to participate in forest protection and forest resources are not really effective 2.1.3 The socio-economic conditions 2.1.3.1 Population and labor Gam river basin area of residence of many ethnics with a population of nearly 730.000 people (2010) Population structure by sex in recent years quite stable The population is not evenly distributed On the basin is 15 ethnic communities living in which people account for the largest number is Tay Number of employees in agriculture, forestry large proportion of the labor structure Population, labor and economic development - social Basin Gam relationship always closely linked By its manufacturing operations, human impact on the land, to transform it in the direction of positive or negative in order to serve their interests 2.1.3.2 Infrastructure Rural infrastructure in the basin of the district is very poor and backward The irrigation for production as well as ensuring clean water for life is limited Water shortages and production activities take place regularly at the local upland border 2.1.3.3 Soicio-Cultural Gam river basin is an ecological and cultural diversity The communities living together in conditions of strong natural division, with the customs and practices unique History of residence and production has long provided farmers with large capital experience in the production and exploitation of natural resources The mix of resident space, the production of the nation has created the interference of customs and production experience, creating knowledge systems of indigenous communities and ethnic minorities At a certain level, this is considered to be one of the advantages of implementing measures, advanced production model in accordance with the natural conditions in each local residents and practices, cultivation of particular ethnic groups The exploitation of cultural values from the traditional rituals associated with spiritual tourism, eco-tourism is one of the advantages to attract more tourists to the local basin However, the restrictions on the level of awareness of the people, which is the majority ethnic minorities in several years ago had a major influence on the selection method exploiting natural resources and protect environment 2.1.3.4 The impact of the Tuyen Quang hydropower resources, environment to the basin Tuyen Quang hydropower dam system has a major impact on both positive and negative directions to resource, environment Gam river basin The main positive impact of 10 Tuyen Quang Hydropower is: power supply, improve infrastructure, enhance cultural life and facilitate the development of local industries, and flood control irrigation water as well as to limit the damage caused by flooding downstream These negative effects are mainly: the life of a disturbed residents in parts of the project area, agricultural land - forest submerged large; ecological environment changes etc 2.2 The situation of natural resources and environment in Gam river basin 2.2.1 The situation of soil resources in Gam river basin 2.2.1.1 The structure and distribution of soil cover Total area of natural watersheds is 916.802,1 Gam, including rocky area is 130.896,5 and is divided into 12 major soil types Properties, soil type Gam river basin is quite diverse and dispersed Land feralit gold on red clay and metamorphism (Fs) is the largest area of 494.104,0 (equivalent to 53,9% of Gam river basin), followed by yellow red loam over clay and metamorphic rocks (FHs) and land on the yellow sandstone feralit (Fq) has an area corresponding proportion was 8,5% and 8,4% of the total catchment area Smallest basin is gray with yellow loam where goods are potzon (Ha) and slope convergence (D) with both types of area less than 1% of the total area Gam river basin 2.2.1.2 Change in land area by the construction of hydroelectric lakes in Tuyen Quang Tuyen Quang lake has an area of 81,94 km2, formed by the expansion of water when the river bed The formation of the reservoir has 7.978 of land were flooded and converted to other uses when building the hydroelectric project items as well as changes in the nature and system of exploitation, land use after lake water Because the reservoir is characterized by steep slopes, narrow lake, the area submerged completely submerged area is big but small The submerged a large area of flat land along the river (over 60% of the total land area flooded) has lost agricultural land by residents This is one of the big changes of the natural environment and the economic environment - social sector, requires effective measures for the protection of the natural environment and especially in the resettlement planning for local residents Flooded land slopes up 38,28% of the land flooded, mainly red and yellow soils feralit Much of this land is forest land cover and land high above the rice terraces In addition, the construction of Tuyen Quang Hydropower also lost 440ha of land for the construction items A small portion of this area have been restored or converted to other uses after the completion of construction works 2.2.1.3 Land and rock slides in the lake and in the river bank in downstream of the dam Landslides occurred across much of the study area, but concentrated along the roads, along rivers and streams In recent years, the phenomenon of erosion is related to the operating performance of lake water and Tuyen Quang In the upstream dam, the water level rise and groundwater to increase the volume of soil while reducing the coherence of the material increased the slope processes on the slopes The volume of rock slides are mainly engaged in the process of sedimentation of the lake, taking part in the sandy mud flow downstream Corresponding to the sliding material, the lake will be deposited at a faster rate during the first 10 years of water then slowly due to reduced supply of raw materials However, reservoir sedimentation rate over time depending on changes in the rate of vegetation cover in the basin In the downstream of the dam, regional erosion process variation early and most powerful river from the dam to the town of Na Hang 11 Due to time and volume of the reservoir operation of Tuyen Quang Hydropower often should not impact the Tuyen Quang hydropower to the river bed erosion and riverbank erosion and sedimentation of lakes and should be followed continue to monitor and study the longer time to complete the assessment and accurate 2.2.1.4 Land use situation of Gam river basin The status of land use in 2010 Gam river basin is divided into groups as agricultural land, forest land, residential land use land, unused land and not rocky woods Farmland Gam river basin has an area of small (91.101,1 ha), accounting for 9,63% of the total natural area of the basin Due to topographical conditions, to land the Gam river basin has an area of forest land is very large (743.823,8 ha), including production forests, protection forests and special-use forests, accounting for over 80% of the total catchment area Group land and use land in an area of 30.000ha, accounting for 3,3% of the catchment area Unused land is 38.218,8 ha, accounting for 4,2% of the catchment area The whole basin to 13.833,6 non-forest mountains, accounting for 1,5% of the basin, most concentrated in Dong Van (5.550,3 ha), Meo Vac (3.558,2 ha) and Yen Minh (2.310,8 ha) 2.2.2 The situation of forest resources in Gam river basin 2.2.2.1 Forest cover situation Gam river basin coverage is relatively high compared to other river basins of North and North East As of 2011, the entire region 338.169,3 are forest land forest coverage rate reached 36,9% natural catchment area In particular, the natural forest area is 322.644,0 ha, equivalent to 95% of forest area and 35,2% of the total land area of the basin 2.2.2.2 Change of forest resources due to the impact of Tuyen Quang reservoir - On the positive side: rising water level increases the natural water supply for natural forest vegetation along the lake Ensure irrigation water also facilitates the expansion of plantation areas in the local reservoir area Rising water levels have enriched ecosystems and habitats - On the negative side: the construction, the entire forest area of the reservoir area to a height of 120m with artisanal mining This activity also facilitates illegal logging, as the Biodiversity and living space for many species decline When the lake water has submerged 7.987ha soil types In particular, forest land covers a large area with over 58% When the lake water has increased the risk of forest loss due to favorable mining conditions The relocation and resettlement of people in the lake as well as forest loss due to conversion purposes 2.2.3 Situation of water resources in Gam river basin 2.2.3.1 Surface flow As of Tuyen Quang Dam Gam total water year was 10.0 billion m3, with Qo = 319m3/s Due to the impact of the structure and topography climate Gam flow should be strong differentiation in space The seasonal climate classification did flow regime of the river Gam divided into two distinct seasons The flood season lasts from May to October, accounting for over 70% of the annual flow During the flood season, due to the combined effects of the floods caused morphology, structure and topography on a network of rivers to flood Gam usually fast and pulled up slowly, causing severe flooding across the downstream, especially the city of Tuyen Quang Dry season from November to April next year In the dry season, due to the relatively large amount of rain and the possibility of regulating the flow of the buffer should flow remained approximately 130m3/s corresponds to the flow module is 8,63 l/s/km2 12 Overall, the potential for surface water basin Gam large contribution to the Red river (accounting for 10,4% of the Red river in Shanxi) However, due to the higher flows in the river during the flood season should Gam often flooding downstream Therefore, the Gam river flood control will reduce the pressure of flood flows on the Red river in North Delta 2.2.3.2 River and reservoirs water quality Water quality is assessed by the major targets, including the mineralization, nutrient content, and trace ions, organic compounds, pH, coliforms bacteria Most indicators of chemical and biological water Gam general, Tuyen Quang lake in particular have changed markedly after Tuyen Quang reservoir is formed but still within the permissible limits of regulation Vietnam 08: 2008 (B1) However, a number of indicators of nutrients, organic compounds in the reservoirs tend to increase These are signs confirming the worse evolution of water channels, related to the human activities in the basin 2.2.3.3 Change the water flow in the Gam river in Tuyen Quang reservoir conditions Gam plays an important role in the appearance of large floods downstream Lo river The formation of the Gam river in Tuyen Quang lake has changed big flood situation downstream, reducing flood levels for Tuyen Quang town than before the dam The appearance of Tuyen Quang lake is an important agent makes the water level difference, and mode Gam flow upstream and downstream of the dam In the upstream dam, water level and water level fluctuation amplitude increases than in the absence of a reservoir In the downstream, the flood flow restriction and increased dry season flow, contributing to flood control, to ensure ecological balance and water resources in agriculture Role of lakes for flood control Tuyen Quang has been confirmed as participants and storing flood water for irrigation during the dry season from 2008 to present In summary, the natural conditions and economic - social characteristics of the Gam river basin has the dominant characteristics, evolution and current status of the resource, environmental and mining issues, resource use, Environmental Protection basin Chapter PROPOSED REASONABLE USE OF THE NATURAL RESOURCES AND ENVIRONMENT PROTECTION IN GAM RIVER BASIN (THE TERRITORY OF VIETNAM) 3.1 Proposed reasonable use of land resources in Gam river basin 3.1.1 Define requirements and the rational use of land resources protection 3.1.1.1 Basin potential erosion assessment a Classification of potential erosion for the basin Potential erosion map of the Gam river basin is built on the model of Wischmeier and Schmid USLE based on the following components map: map rain erosion coefficient R; map of soil erosion resistance coefficient K, DEM digital elevation model; map slope coefficient length L, the slope coefficient map S Potential soil erossion model of watershed land Gam established by Wischmeier and Schmid's formula: A=R×K×L×S Thesis conducted hierarchical level of erosion potential 13 based on the Gam river erosion potential value A On the scope of the Gam river basin is divided into potential erosion (Table 3.2): Table 3.2 The potential erosion of the Gam river basin Potential erosion level Level 1: very low potential erosion Level 2: low potential erosion Level 3: average potential erosion Level 4: high potential erosion Level 5: very high potential erosion A value < 15 15 - 30 31 - 45 46 - 60 > 60 In Gam river basin up to 117,276.5 of special-use forests, corresponding to 12.7% of the total catchment area If the area of special-use forests, the area of potential erosion of the basin is shown in the table (Table 3.3) Table 3.3 Areas of potential erosion of the entire basin Gam Potential erosion level Unit Area Level Level Level (ha) (%) (ha) (%) (ha) 341.865,8 37,3 242.212,0 26,4 62.803,4 Level Level (%) (ha) (%) (ha) (%) 6,9 52.508,8 5,7 100.135,6 10,9 Source: Analysis and statistics from the map of the basin and the potential erosion As the entire basin, the total area of potential erosion level and level has reached 584.077,8 ha, accounting for 63,7% of the natural area of the basin The area from potential erosion of average or higher (level to level 5) is 215.447,8 ha, accounting for 23,5% and the catchment’s area is mainly distributed in the watershed In particular, the area of potential erosion level and level has accounted for over 70% of the total area of all levels on the potential erosion b Decentralization erosion potential for watershed Gam river basin is divided into watershed level The results for the potential erosion of the river basin level is synthesized based on the statistical map of the area of the potential erosion map watershed boundaries (Table 3.5) Table 3.5 Areas of potential erosion of the basin of the river basin level Basin code Name of the river basin level Level (ha) (%) Level (ha) Level (%) (ha) Level (%) (ha) (%) Specialized forest land (%) (ha) 8,1 0.0 Level (ha) Nho Que 41.490,6 41,4 35.439,4 35,3 8.497,4 8,5 6.759,8 6,7 8.118,1 Nhiem-Tong Guong 51.047,4 41,7 30.111,8 24,6 7.425,0 6,1 7.291,7 6,0 22.764,2 18,6 3,847.1 Mainstream of Gam river 137.604,3 37,7 81.131,7 22,2 23.818,0 6,5 21.349,3 5,9 44.043,7 12,1 56,929.4 Nhi A 46.692,2 40,6 32.273,0 28,1 8.298,5 7,2 6.661,0 5,8 17.206,1 15,0 3,861.8 Nang 65.031,3 30,4 63.256,2 29,5 14.764,5 6,9 10.446,9 4,9 8.003,4 3,7 52,638.1 341.865,8 37,3 242.212,0 26,4 62.803,4 6,9 52.508,8 5,7 100.135,6 10,9 117,276.5 Total Source: Analysis and statistics from the map of the basin and the potential erosion From the above results show that, between the river basin level is quite clear differentiation potential for erosion In particular, basin 2, 4, and are required to keep the water Watershed Protection largest, requiring watershed protection in the most critical level The distribution of the degree of erosion potential of the watershed between the is the basis for the proposed decentralized watershed for the Gam river basin 14 3.1.1.2 Assessment requirements to protect land In order to decentralize the required level of land protection, theme based on the data including mapping of land degradation Gam river basin, soil depth maps and maps of erosion results potential Thesis made overlay on the map and determine the required level of land protection The area of land protection level requirements are distributed in the districts of the Gam river basin as follows (Table 3.8): Table 3.8 The level of protection required by the district land of the Gam river basin (ha) Province District Bac Me Bac Quang Dong Van Ha Giang Meo Vac Vi Xuyen Yen Minh Bao Lac Cao Bang Bao Lam Nguyen Binh Ba Be Pac Nam Bac Kan Cho Don Ngan Son Chiem Hoa Tuyen Na Hang Quang Yen Sơn Lam Binh Total % Natural area 82.315,0 3.418,7 39.165,8 54.683,2 13.461,8 58.596,2 94.910,4 80.214,0 34.651,7 63.308,1 48.670,0 38.926,3 14.627,0 107.735,3 81.250,1 22.716,3 78.152,2 916.802,1 100,0% Low 10.757,8 23,5 12.898,8 8.156,3 737,0 15.935,0 9.461,3 10.473,4 586,6 543,9 882,5 5.292,1 32,9 26.736,9 2.592,0 4.204,6 16.183,2 125.497,8 13,7% Land protection requirement Average High Very high 32.474,8 8.392,2 10.038,8 2.897,2 171,0 327,0 15.166,5 8.526,9 2.573,7 37.629,2 4.712,9 4.184,8 2.820,0 954,1 1.184,7 27.904,1 6.562,5 5.396,7 64.263,6 8.824,1 11.076,0 56.184,6 4.927,4 8.628,6 20.494,8 1.141,0 5.543,4 26.728,5 1.551,9 3.119,5 39.785,8 1.973,1 5.880,0 27.011,6 3.544,8 2.305,6 13.201,5 494,2 898,4 62.036,9 6.644,9 8.350,8 35.218,7 3.796,4 3.093,5 15.917,3 1.320,4 1.259,9 34.700,7 12.228,0 9.964,7 514.435,8 75.766,0 83.825,9 56,1% 8,3% 9,1% Specialized forest land 20.651,4 0,0 0,0 0,0 7.766,0 2.797,9 1.285,5 0,0 6.885,9 31.364,3 148,7 772,2 0,0 3.965,8 36.549,4 14,0 5.075,5 117.276,5 12,8% Source: Calculated according to the level map soil protection requirements and administrative map For the area of land required to protect high and very high, it is necessary to prioritize the development of forestry, especially headwater reforestation to curb soil erosion, soil protection For the area of land required to protect low and very low, developers need to implement a combination of forestry and agriculture in the form of agroforestry, forestry and agriculture combined to protect and increase efficiency land 3.1.2 Proposed rational use of land resources 3.1.2.1 Proposed upstream protected clasìication a Rationale and principles of decentralized watershed - The basis for the proposed decentralized watershed: zoning maps of the three existing forest Gam river basin; decentralization results in the potential erosion of tributaries of the river basin level Gam; Report report "master plan economic and social development in 2020" and report "Adjusting, additional planning, land use planning up to 2010 and orientations towards 2020" Committee of the provinces in the basin - The principles of watershed: 1) the level of protection area will be allocated according to recommendations and basin level 2, 2) hierarchical watershed basin Gam need to be planned in top-down approach and the bottom-up, and 3) the level of protection area and the proposed 15 allocation for the basin level must be based on the results of erosion potential of each proposed basin and area to inherit and protection based on the planning of the territory b Results decentralize headwater (types of land use management) Order decentralized watershed basin Gam done as follows: b1 Identify areas for watershed protection level b2 Decentralize headwater basin level Map decentralize headwater basin Gam is done by following these steps: 1) Develop potential erosion model for basin level 2, 2) Hierarchical Model A potential erosion of 100 the area for each river basin level and 3) Decentralization of protection for the basin level 2, 4) Determine the area of productive forest land for watershed 2, 5) Determine the area of forest land for the basin level 2, 6) hierarchical mapping for Gam watershed protection After the above steps, each river basin level will be assigned protection map Map of land use types of the Gam river basin is built based on the maps included decentralization of protection level watersheds in the basin Thesis using ArcGIS 9.3 software and Microsoft Excel to perform processing and analysis of spatial data, statistical data in the steps above b3 The results of protection The thesis analyzes the implementation of protective zoning map of the Gam river and district administrative map of the area to determine the type of land use management in the district The results shown in Table 3.13 Table 3.13 The area forms the main land use management in the Gam river basin Province Ha Giang Cao Bang Bac Kan Tuyen Quang District Natural area (ha) Total (ha) Forest land (ha) Other Protective forest land Productive Specialized agricultural Very Total Critical forest land forest land land (ha) critical Bac Me 82.315,0 70.993,6 20.557,2 Bac Quang 2.623,7 344,1 3.418,7 Dong Van 39.165,8 29.203,5 15.092,9 Meo Vac 54.683,2 38.648,3 10.504,8 Vi Xuyen 2.531,1 13.461,8 12.151,3 Yen Minh 43.368,7 16.755,6 58.596,2 Bao Lac 94.910,4 80.100,4 34.064,1 Bao Lam 80.214,0 64.147,9 20.025,9 Nguyen Binh 34.651,7 31.971,0 12.116,7 Ba Be 8.417,2 63.308,1 59.455,0 Pac Nam 48.670,0 40.966,6 15.178,0 Cho Don 9.834,8 38.926,3 32.944,5 Ngan Sơn 2.745,7 14.627,0 12.213,9 Chiem Hoa 107.735,3 77.544,6 14.611,4 Na Hang 9.554,2 81.250,1 74.246,0 Yen Sơn 2.444,0 22.716,3 15.932,6 Lam Binh 63.694,8 22.852,2 78.152,2 916.802,1 750.206,5 217.630,0 Total 18.698,6 251,6 13.516,3 7.736,1 2.405,3 12.756,6 23.485,2 12.066,8 8.988,9 4.556,3 9.661,3 6.326,6 1.072,1 10.019,2 6.389,9 1.015,4 20.007,8 158.954,0 1.858,6 29.785,1 20.651,4 92,5 2.279,6 0,0 1.576,6 14.110,7 0,0 2.768,7 28.143,5 0,0 125,8 1.854,2 7.766,0 3.999,1 23.815,2 2.797,9 10.578,9 44.750,9 1.285,5 7.959,1 44.121,9 0,0 3.127,8 12.968,4 6.885,9 3.860,9 19.673,5 31.364,3 5.516,7 25.639,9 148.7 3.508,2 22.337,5 772,2 1.673,6 9.468,2 0,0 4.592,2 58.967,5 3.965,8 3.164,4 28.142,4 36.549,4 1.428,6 13.474,6 14,0 2.844,4 35.767,1 5.075,5 58.676,0 415.300,0 117.276,5 11.321,4 795,0 9.962,3 16.034,9 1.310,5 15.227,5 14.810,0 16.066,1 2.680,7 3.853,1 7.703,4 5.981,8 2.413,1 30.190,7 7.004,1 6.783,7 14.457,4 166.595,6 Source: Calculated according to hierarchical protection map and administrative map Protected forest area accounts for 29,0% of the total forest area of the entire basin In particular, protection forest area accounts for 73% very important and vital forests accounted for 26,9% Special-use forest area accounts for 15,6% of the total forest area and 12,8% of the total catchment’s area naturally Production forests are the largest area (415.300,0 ha), 16 Tuyen Quang Bac Kan Cao Bang Ha Giang Province corresponding to 55,4% of the total forest area of the entire basin Agricultural land and other land not large (166.595,6 ha), equivalent to 18,2% of the total area of natural basin The results of the study are shown on the map hierarchy watershed protection In particular, differentiation in terms of catchment erosion potential is the basis for the thesis proposed land use types of the Gam river basin 3.1.2.2 Proposed land use orientation for different types of land use a Assessing the potential of land for different types of land use a1 Assessment Method: Based on the evaluation results soil erosion potential, thesis conducted hierarchical mapping of protection, thereby determining the protection requirements of water and soil conservation, erosion of Gam river basin On the other hand, based on the analysis of the topography, the soil characteristics and land use is associated with protection level results above a2 Evaluation results: On the basis of integrated protection hierarchical maps and topographic maps, slope maps, maps of land use status Gam river basin, the thesis has developed the ability to map land Perform statistical area of land capability maps with maps of administrative districts, the thesis has identified an area of land on the ability of the district as follows (Table 3.14): Table 3.14 Area of land in the district the ability of the Gam river basin (ha) District Bac Me Bac Quang Dong Van Meo Vac Vi Xuyen Yen Minh Bao Lac Bao Lam Nguyen Binh Ba Be Pac Nam Cho Don Ngan Sơn Chiem Hoa Na Hang Yen Sơn Lam Binh Toatl Natural area (ha) Protective forest land Very Critical critical 82.315,0 3.418,7 39.165,8 54.683,2 13.461,8 58.596,2 94.910,4 80.214,0 34.651,7 18.698,6 251.6 13.516,3 7.736,1 2.405,3 12.756,6 23.485,2 12.066,8 8.988,9 1.858,6 92,5 1.576,6 2.768,7 125,8 3.999,1 10.578,9 7.959,1 3.127,8 24.052,0 1.945,1 11.715,1 25.728,3 1.692,7 20.915,3 43.034,8 34.803,6 12.813,4 2.876,1 82,1 707,8 283,0 40,0 313,7 839,4 3.263,1 22,9 2.857,0 252,4 1.687,8 2.132,1 121,5 2.586,2 876,7 6.055,3 132,1 63.308,1 48.670,0 38.926,3 14.627,0 107.735,3 81.250,1 22.716,3 78.152,2 4.556,3 9.661,3 6.326,6 1.072,1 10.019,2 6.389,9 1.015,4 20.007,8 3.860,9 5.516,7 3.508,2 1.673,6 4.592,2 3.164,4 1.428,6 2.844,4 18.304,6 22.654,4 20.824,7 8.531,8 49.857,3 22.618,9 12.210,3 31.672,6 444,2 2.201,2 641,2 292,1 1.121,1 4.206,8 112,8 1.544,5 924,7 784,3 871,6 644,3 7.989,1 1.316,6 1.151,5 2.549,9 58.676,0 363.375,1 18.991,9 916.802,1 158.954,0 Productive forest land Productive Forestryforestry agricultural Agroforestry Specialized forest land Agricultural land, others Upland agriculture Lowland agriculture 20.651,4 0,0 0,0 0,0 7.766,0 2.797,9 1.285,5 0,0 6.885,9 9.364,3 614,8 8.235,7 14.527,7 539,4 12.038,2 12.218,0 12.007,6 2.048,8 1.957,0 180,2 1.726,6 1.507,2 771,1 3.189,3 2.591,9 4.058,5 631,9 31.364,3 148,7 772,2 0,0 3.965,8 36.549,4 14,0 5.075,5 2.472,7 6.134,3 3.812,8 1.309,4 7.980,9 5.306,4 1.312,9 6.494,2 1.380,4 1.569,1 2.169,0 1.103,7 22.209,7 1.697,8 5.470,8 7.963,1 32.933,1 117.276,5 106.418,3 60.177,3 Source: calculated according to hierarchy hedge maps, slope maps, soil maps Evaluation results on the ability of land is one of the basis for the mapping propose to use for different types of land use Gam river basin b Mapping propose to use for different types of land use b1 Method of mapping: Map propose to use for different types of land use Gam river basin is built based on the results of the assessment of land, forest status and class government, the land use of the basin by GIS technology 17 b2 The results suggest directions for use of the main types of land use * For protection forest land: forest land area of protection is crucial and accounts for 23,7% of the total basin area (Table 3.15) * For production forest: forestry production, forestry and agricultural land and associated land agroforestry corresponding proportion was 39,6%, 2,1% and 3,59% of the total catchment area Gam (Table 3.16) Table 3.15 Proposed land use for Gam watershed forest protection Main land use types Forest and land use situation Rich and medium forest Poor and regenerating forest Very critical protective forest land Bamboo forest Plantation forest Vacant land Total Rich and medium forest Poor and regenerating forest Critical protective Bamboo forest forest land Plantation forest Vacant land Total Area % nature area 9.746,3 41,801,9 4.759,5 590,8 102.055,4 158.954,0 1.508,5 13.709,9 2.975,4 473,1 40.009,1 58.676,0 1,1% 4,6% 0,5% 0,1% 11,1% 17,3% 0,2% 1,5% 0,3% 0,1% 4,4% 6,4% Forest use orientation Protection Reforestation and regenerating Reforestation and regenerating Protection, plantation Protective forest plantation Protection Reforestation and regenerating Reforestation and regenerating Protection, plantation Protective forest plantation Source: Calculated from the ability to map land, forest status maps Basin Table 3.16 Suggested directions for use of forest land producing Gam basin Forestry productive land Main land use types Area Forest and land use situation Rich and medium forest Poor and regenerating forest Bamboo forest Plantation forest Vacant land Forestry – Agriculture land Total Rich and medium forest Poor and regenerating forest Bamboo forest Plantation forest Vacant land Agricultural productive land Agro-forestry land Total Rich and medium forest Poor and regenerating forest Bamboo forest Plantation forest Vacant land Agricultural productive land 14.009,8 89.077,0 25.531,5 6.973,5 227.783,3 363.375.1 264,4 5.575,2 653,1 307,1 9.995,3 2.196,8 18.991,9 738,2 6,989.7 1,941.3 1,753.5 11,136.5 10,373.9 32.933,1 % nature area 1,5% 9,7% 2,8% 0,8% 24,8% 39,6% 0,0% 0,6% 0,1% 0,0% 1,1% 0,2% 2,1% 0.1% 0.8% 0.2% 0.2% 1.2% 1.1% 3,59% Forest use orientation Protection Reforestation and regenerating Reforestation and regenerating Protection, plantation Plantation, perennial fruit crops, industrial crops Protection Reforestation and regenerating Reforestation and regenerating Protection, plantation Plantation, perennial fruit crops, industrial crops Perennial fruit crops, industrial crops, plantation Protection Reforestation and regenerating Reforestation and regenerating Protection, plantation Plantation, perennial fruit crops, industrial crops Perennial fruit crops, industrial crops, plantation Source: Calculated from the ability to map land, forest status maps Basin * For agricultural land: Gam river basin has nearly 170.000 of agricultural land, including agricultural land and upland lowland farmland (Table 3.17) In fact, a small portion of land, including forest land and agricultural produce, especially lowland farmland in the provinces tend to use land gradually shifted due to the 18 increase in population, urbanization process and project development infrastructure mountainous areas etc 3.1.2.3 Identify strategies for rational use of land resources The solution proposed use of land resources is based on the unique natural conditions and economic - social Gam river basin, the diversity and sensitivity of land resources, and evaluation results decentralized watershed erosion Accordingly, the need to manage mining and land use in the basin uniform; land exploitation by the agro-ecological zones, land use rights over the long term, combined with the exploitation and protection of the land reform degradation and boosting the process of converting arable purposes on the steep slope areas, land fragmentation, consolidate and improve infrastructure, technical service and consumption of agricultural products; biotechnology applications associated with genetic conservation of plant varieties and animal breeds; measures applied biotechnology in soil improvement, expansion of forests, watersheds, improving public awareness on the economical use of land resources and reasonable Table 3.17 Propose land use for agricultural in Gam watersheds Main land use types Forest and land use situation Plantation forest Upland agricultural Vacant land Agricultural productive land Total Plantation forest Lowland agricultural Vacant land Agricultural productive land Total Area % nature area 13.844,6 1,5% 25.931,7 2,8% 66.641,9 7,3% 106.418,3 0,8% 6.541,5 0,7% 46.160,3 5,0% 60.177,3 Protection, plantation, soil enhancement, change land use purpose Plantation, perennial fruit crops, industrial crops Perennial fruit crops, industrial crops, rice, vegetable, plantation 11,6% 7.475,5 Forest use orientation 6,6% Protection, plantation, soil enhancement, change land use purpose Plantation, perennial fruit crops, industrial crops Perennial fruit crops, industrial crops, rice, vegetable, plantation, change land use purpose Source: Calculated from the ability to map land, forest status maps Basin 3.2 Propose rational use of forest resources in Gam river basin 3.2.1 Define requirements and the rational use of reforestation 3.2.1.1 Classification of forest resources To evaluate and classify forest resources Gam river basin, the thesis uses data maps of forest status and forest cover data in 2011 the Department of Agriculture and Rural Development in Ha Giang, Cao Bang, Tuyen Quang, Bac Kan Area of land, forest type is determined by district overlay map forest status in 2011 with map and administrative map Gam river basin Natural forest area of the Gam river basin is 322.644ha, accounting for 32,5% of the total catchment area naturally In Tuyen Quang is the local area's largest natural forest (accounting for 47,9% of the total natural forest area of the basin) Area planted area of 1,7% and 4,6% of the total natural land area forested watersheds, with 15.525,3 The land area is 338.169,3 forest basin, accounting for 36,9% of the basin Vacant area of the basin is quite large (374.946,9 ha, with 40,9% of the total catchment area) This is the area needed to implement new planting soil protection, erosion control 19 3.2.1.2 Classification of forest cover proportion by commune Forest coverage proportion is calculated according to the formula commune: Forest cover proportion = Forest area/Natural area (%) Forest cover ratio is divided by the following levels: (i) coverage rate below 10%, (ii) coverage rate from 10% to 30%, (iii) coverage rate of 30% -50 %, (iv) coverage rate of 50% -70%, and (v) coverage rate of 70% Gam river basin are 175 communes in 17 districts The results showed that levels throughout the basin with 27% having coverage below 10%, over 50% had coverage of 30% or less and 83,5% had coverage less than 50% Specific results in maps of forest cover rate in the commune of the Gam river basin 3.2.1.3 Classification of imbalance cover level by commune In order to balance the level of forest cover loss for the Gam river basin, based on the thesis imbalance indicators cover each commune This index is calculated by the following formula: The imbalance of coverage ratio = Current coverage proportion/Coverage under planning proportion (%) Specific results showed that the Gam river basin has 62 communes having unbalanced coverage ratio at high level, 43 communes at moderate level, 40 communes at low level and 30 communes balanced coverage, 15 communes and 12 villages of Tuyen Quang and Ha Giang 3.2.2 Proposed reasonable use and reforestation 3.2.2.1 Proposed reforestation priority (by commune) Evaluation results imbalanced coverage, the percentage of forest cover protection (according to the commune level) is the basis for the thesis proposed priorities of the local forest restoration in the basin Specific priorities in social rehabilitation as follows: - For the 83 communes having imbalance average and low coverage, need tending, protection and restoration of the area, the quality of existing forests, enrichment planting and afforestation to expand the coverage area - For the 62 communes with a high imbalance should cover new plantations to expand the coverage area and the regeneration, protection and recovery area of existing forest types, especially for with Cao Bang and Ha Giang provinces because this is the number of social imbalance in a high coverage the most 3.2.2.2 Identify strategies for rational use and restoration of forest resources Based on the natural condition, results of watershed protection, land capability, land use direction for the type of land use and the evaluation results imbalance basin cover, thesis propose solutions to protect and restore forests Gam river basin as follows: - For protection forest in the basin (217.630ha) It is necessary to have strict safeguards for local area large forests On the other hand, should take advantage of existing forest land to undertake afforestation, expansion of forests - For special use forests (117.276,5 ha): Ccong management and conservation of protected areas in the basin has relied heavily on international aid and rangers This requires measures and mechanisms to mobilize the participation of communities and local financial resources to manage and support organizations to protect the biodiversity of protected areas use in the basin Assessing and controlling the impacts of development projects in the basin are related to the special-use forests, especially the impact of eco-tourism activities lake Tuyen Quang Ba 20 - For the production forest (415.300ha): This type of land use involving direct management of a large segment of the local residents Therefore, the need to have policies and measures on capital, material and technical basis to support farmers in the plantations, the allocation of land, forest, agro-forestry ecological models Agroforestry - For vacant forest land, especially forest land without forests (15,5% of the total catchment area) to implement afforestation Take advantage of the resilience of vegetation to increase natural shrub cover 3.3 Propose rational use of water resources of the Gam river basin 3.3.1 Define requirements and the rational use of water resources protection 3.3.1.1 The situation of exploitation and use of water resources a The number and capacity of surface water harvesting irrigation works Surface water in Gam river basin is exploited for domestic, irrigation water supply, industrial water production and electricity generation, which mainly supply water for agricultural irrigation and power generation Currently, the Gam river basin has about 2.361 irrigation of all types, including 53 reservoirs, 202 dams, more than 2.100 temporary construction water extraction (approximately 90% of the irrigation works of note area) By design, the irrigation may irrigate about 7.015 and 16.240 of winter-spring crop But in practice, this works only ensure at 81,8% and was 91,5% of the cases respectively Operational capacity of the permanent buildings are generally low due to lack of proper planning, many items degraded investment fund repairs, maintenance, and may not be overcome in time b Demand for surface water By Thanh Ha, Nguyen Dinh Ky (2006) and Huynh Thi Lan Huong (2009), the need to use the Gam river basin tend to increase due to the increase in population size and growth of the industry health Specifically, the timelines in 2000, 2005 and 2010, the demand for surface water basin Gam 252,5 million m3, respectively, 257,6 million and 284,3 million m3 Forecast for 2020, will increase the amount of water needed to 335,7 million m3 Demand for water in the closely dependent on the structure of local crop and uneven in the region 3.3.1.2 Exploitation threshold of water resources Exploitation of water resources threshold is calculated by the ratio% between excess water during flooding from water potential Calculation results show that the threshold exploitation of water resources in a number of major stations on the Gam river basin ranges from 31 to 37% of total water potential With this result, it can be seen in both years, the amount of water needed in 2020 using the Gam river basin is much smaller than the allowed limit exploitation However, in the dry season, the amount of water needed in a number of localities in the Timeline 2010, 2020 have accounted for 10-25% of the water and is approaching the threshold of safe operation, while demand for irrigation water in the dry season is very large, many local water shortages occur locally 3.3.1.3 Risks and causes of surface water resources degradation The risk of water resource degradation Gam river basin is determined, based on analyzing the status and changes in surface flow and the need to use surface water basins, including the local water shortage, water quality degradation, increasing natural disasters related to water resources 21 Cause degradation of water resources Gam river basin is very diverse, is dominated by both objective factors and subjective factors The thesis has identified the causes of degradation of surface water resources Gam river basin include: due to climate change, due to the exploitation of natural resources basins, the development of economic sectors and photos system effects of hydroelectric dams in the basin 3.3.1.4 Difficulties in the management of water resources So far, no Gam river basin planning model and integrated management of water resources This is one of the major difficulties in the management of water resources of the basin today Despite Basin Management Hong - Thai Binh, but because the space is too large to manage effectively managing water resources in the specific conditions of the Gam river ineffective Basin water resources are being managed by Gam administrative boundaries of provinces and less emphasis on the participation of water users The staff responsible for the management of water resources in the basin of the province Gam too little, usually only about 3/province Gam river basin over 30% of the area is located in Chinese territory However, the lack of cooperation between the two countries in the management and protection of water resources This requires the need for a watershed management organization uniform And potential exploitation and use of water resources and the difficulties and shortcomings in the management of water resources Gam river basin poses requirements necessary to have the total solution to exploit, rational use and protection of water resources of the basin 3.3.2 Proposed the use of water resources From the results of assessment requires the use and protection of water resources of the basin The thesis has identified the challenges of water resources Gam river basin include: (1) groundwater extraction efficiency is not high, (2) Lack of production and living water in dry season (3) The contradiction the use of surface water, (4) degradation of water resources and (5) Restriction of water resources management On the basis of the above issues, using the DPSIR analysis, the thesis analyzes the causes, impacts and proposed solutions to the rational use and protection of water resources of the basin DPSIR analysis result, may synthetic solutions using integrated water resource management solutions include groups: group solution and water demand management solutions for group management capabilities a Group management solutions needs water a1 The solution works, techniques: 1) the construction of irrigation in the basin; 2) repair and upgrade irrigation works have been degraded, damaged, and 3) improve ability to regulate the existing reservoirs; 4) river dyke system upgrades a2 The non-structural solutions: 1) use planning and integrated water resource protection Gam river basin, 2) inventory and assess the potential for surface water basin, and 3) develop a production model water savings; 4) monitoring surface water quality in the basin; 5) enhance forest cover watersheds; 6) issued regulations on the exploitation, protection and sharing of water resources; 7) strengthening education; 8) international cooperation in the exploitation and protection of water resources 22 b Group solutions related to capacity management: 1) Develop integrated management of organizational resources Gam river basin; 2) exchange and learning experience of water resource management in the basin in the world, and 3) enhance staff management of water resources at the local level 3.4 Orientation mining Tuyen Quang reservoir area Tuyen Quang reservoirs have two important tasks that contribute to downstream flood control and power generation The creation of water reservoirs open up new development opportunities based on the advantages of natural condition and economic - social condition Aquaculture development and tourism in the direction of Tuyen Quang reservoir is likely to yield high economic efficiency, create jobs and contribute to poverty reduction for local reservoir area - For aquaculture development: The increase of floor area and the depth of the water after the water reservoir and creating stable water levels of dams regulated by the Tuyen Quang not create the conditions for aquaculture on a large scale, but also allows the development of diverse species adapted to the marine waters of the region The chemical criteria reflect water quality in Tuyen Quang lake despite the increase in recent years but still fully meet the requirements of natural surface water for aquaculture The diversity of species composition and strong development of aquatic fauna and flora of Tuyen Quang reservoir area is a source of food plays an important role in the development of fisheries resources On the other hand, natural food sources are abundant with natural conditions typical of mountain streams flow has created a rich diversity of aquatic species with high economic value, formed the basis for the development of aquaculture Besides the above advantages, the development of Tuyen Quang reservoir fisheries also experiencing some difficulties Content of chemical indicators of water pollution tends to increase The water regulation in the pond submerged area difficult, especially in the rainy season The awareness of the people and the local authorities in a number of incomplete and potential economic effects of aquaculture on the reservoir should not invest adequately The management of aquaculture, fishing is not tight Operational capacity of the fisheries cooperatives is weak and uneven, narrow market and has not been extended - For the development of tourism in the reservoirs: Tuyen Quang lake natural potential for development of tourism, especially eco-tourism products based on the diversity and unique geologic structures - topography, hydrology, biological resources and favorable climatic conditions History long territory of the region is one of the fundamental elements create structural diversity of terrain - geomorphology, hydrographic network and the uniqueness of the terrain along the lake Most of the elements of weather, climate Tuyen Quang lake is very convenient for tourism and resort people The formation of the water reservoir has the advantage of creating natural landscapes, hydrological conditions for tourism development purposes The water surface was created to expand the space required for the tour activities, explore the lake The richness and diversity of biological resources Tuyen Quang lake is not only a source of precious biosphere reserve that is also much potential for development of tourism, supply of food and medicinal herbs in place for visitors The development of 23 aquaculture, fisheries based on the favorable conditions existing natural reservoir area is also one of the key advantages to promote the development of tourism activities CONCLUSION On the one hand, the results of the thesis contributes to complete the methodology and research method modern physical geography On the other hand, it is the scientific basis to propose orientation of mining and use of territory From the contents of the thesis on the Gam River basin, author draws a number of conclusions and recommendations following: The research results Thesis overview the research in rationable use of resources and environment protection in the basin in the world and in Vietnam as a basis for establishing the theoretical basis, approach, and research method proposed rational use of natural resources, environmental protection Gam River basin Analyze the characteristics of natural, socio-economic conditions, impacts of these factors to the situation, resources and environment change, and mining and use of natural resources issues, particular in land, forests and surface water, as the basis to propose the rational use of natural resources, environmental protection in Gam River basin Basin analysis approach to determine the relationship between the natural and the human components, between the upstream, middle and downstream, and between level basins to propose the rational use of land resource, forest, surface water and Tuyen Quang lake area This is a central task in the study of resource use and environmental protection in Gam river basin For land resources: Assess the decentralization of erosion potential for the basin and river basin level by erosion potential level as the basis for the proposed decentralized watershed for Gam river basin Classification the levels of protection requirements based on soil mapping degradation situation; soil depth maps and watershed potential erosion classification map Proposed allocation area forms the main land use management for the entire basin and the basin with an area of forest land is 217 630 ha, forest land production is 415300 ha, forest land use is 117276.5 ha, area and determine the type of land use management in the river basin district of the Gam The thesis proposes land use orientation for different types of land use based on land capability map and orientation proposal map for main types of land use in Gam river basin These include very important protection, important protection, specialized forest land, forestry production land, combined agricultural and forestry land, forestry land, low lying agricultural land and upland agriculture The research propose some rational use orientation of land resources based on the natural and socio-economic conditions in Gam river basin, the diversity and sensitivity of land resources and the assesment and erossion classification results in Gam river basin For forest resources: This thesis assesses the requirements of rational use and forest restoration based on the classification of forest resources and decentralization of forest cover rate according to communes: statistics and classification of forest resources according to districts based on the map of forest status and forest cover data in 2011 of watershed localities; classification of forest cover for over 175 communes in watershed area with 27% 24 of communes having cover rate below 10%, over 50% have cover rate from and less than 30% and 83.5% of communes have cover rate less than 50%; hierarchical level unbalanced coverage by index-based social imbalance cover government social imbalance, with 62 high cover, 43 cover social imbalance in the average, 40 social imbalances and lower cover 30 cover social balance This study proposes rational use and forest restoration on the identifying the priorities for forest cover of communes, the natural condition of watershed, results of classification of watershed protection, land capability, directions of land use for different types of land use and the results of imbalance evaluation for basin cover For surface water resources: This study identifies the requirements of water resources rational use and protection based on the of analysis of the flow characteristics, the current status of water resources of the Gam River basin; changes in surface flow Tuyen Quang reservoir conditions, changes in demand for and utilization of water resources threshold of the basin as a timeline from 2000 to 2020; risk and causes degradation of water resources, the difficulties, exists in the management of water resources of the basin From the results of assessment requires the use and protection of water resources, the thesis has identified the challenges of water resources in Gam River Basin including water extraction efficiency is not high, lack of water production and active dry season, the inconsistency in the use of water resources, degradation of water resources and limited water resources management Applying DPSIR analysis methods to analyze the causes, impacts and proposed solutions to the rational use and protection of water resources of the basin Since then, synthetic solutions using integrated water resource management solutions to the groups of water resource issues including water needs management solutions group and water resource management capacity solutions group For Tuyen Quang reservoir area: The thesis analyzes the natural conditions of Tuyen Quang Lake for the purpose of tourism and fisheries development to create jobs, incomes increase and life stability for employees Recommendations The findings and results of the thesis are credible scientific basis for proposing rational use of natural resources and environmental protection in Gam River Basin However, the rate of the basin studies is 1/50.000 so generalized level remains high Therefore, there is a need to continue research with approach to basin analysis of rational resource use and environmental protection in Gam River in greater proportion to increase the specific of proposals in research results Basin analysis with extensive application of GIS technology in data management, spatial analysis and modeling of the quantitative indicators, to rational exploitation and use of natural resources and environmental protection is hereby integrated approach, in accordance with the conditions of dissected mountainous terrain and rainy seasonal climate like in our country so it should continue to be studied in other river basins in the country to develop a completely improved methodology and research methods  ... CONDITIONS, AND SITUATION OF NATURAL RESOURCES AND ENVIRONMENT IN GAM RIVER BASIN (THE TERRITORY OF VIETNAM) 2.1 The natural and socio-economic conditions and natural exploitation, environmental protection... USE OF THE NATURAL RESOURCES AND ENVIRONMENT PROTECTION IN GAM RIVER BASIN (THE TERRITORY OF VIETNAM) 3.1 Proposed reasonable use of land resources in Gam river basin 3.1.1 Define requirements... investment fund repairs, maintenance, and may not be overcome in time b Demand for surface water By Thanh Ha, Nguyen Dinh Ky (2006) and Huynh Thi Lan Huong (2009), the need to use the Gam river basin