www.vncold.vn 1 WATER RESOURCES IN THE MEKONG DELTA: A HISTORY OF MANAGEMENT, A FUTURE OF CHANGE Dr To Van Truong a , Tarek Ketelsen b Introduction The Mekong Delta is characterized by change, which occur over a wide range of spatial and temporal scales. In the past the delta lay submerged below the sea and today it continues to accumulate sediments from as far away as the Himalayas so that the delta is constantly changing and reclaiming land from the sea. In fact, because of the delta’s dependence on a combination of ecosystem functions including tides, rainfall, and erosion that operate over a short timeframe, it is highly susceptible to human and environmental change. Now the Mekong Delta, a fringing ecosystem between terrestrial and marine environments, is facing perhaps the most devastating change of all, unique because Climate Change is bringing changes at a rate unprecedented in recent history. Whereas in the past change was a comparatively slow phenomenon with patterns set in motion over thousands of years, current changes require a sense of urgency as significant changes to the hydrologic regime are occurring over decades and even years requiring water management initiatives that are flexible and capable of evolving and adapting close to the speed at which climate change is occurring. Change has therefore become an issue because of the accelerated scale at which it is operating in both biophysical and socio-economic environments. Regardless of what mitigation efforts are taken internationally, climate change impacts for the next 40 years are inevitable (IPCC, 2007). After 2050, the impacts of climate change will largely depend on how we, as an international community, respond today, but changes to sea levels, rainfall regimes and storm frequencies before 2050 are determined by current levels of CO 2 in the atmosphere. This means that for the vulnerable communities in the world, adaptation is the most urgent issue. Furthermore, most impacts of climate change will be transferred to human and ecological communities via the hydrologic cycle, for example, through sea level rise, storms, flooding, and droughts. This places water resource management (WRM) at the front lines of human adaptation to climate change. A recent study by the World Bank (2007) identified Viet Nam as the most vulnerable nation in the developing world in terms of population, GDP, urban extent and wetlands, and the second most vulnerable in terms of percentage of total area affected. The Mekong Delta is one of the most vulnerable regions of Viet Nam. Therefore, planners and engineers working within the delta, face some of the most a Lead author and Director of the Southern Institute for Water Resource Planning, 271/3 An Duong Vuong Street, District . 5, Ho Chi Minh City Viet Nam b AYAD (Australian Youth Ambassador for Development) Water Resource Researcher at the Southern Institute for Water Resource Planning Deleted: Q www.vncold.vn 2 daunting and challenging problems of WRM in the world. The success of their response to this challenge will not only impact the livelihood of some 18 million local inhabitants and the national economic growth of one of South-East Asia’s development success stories, it will also serve as an example for other vulnerable nations. This places Viet Nam in a unique position, as a nation with strong technical capacity; it has the potential to become one of the world leaders in climate change adaptation. This chapter is divided into four parts. Section 1 provides an historic outline of water resources and management in the Mekong River basin and the delta in particular. It tracks the introduction of Integrated Water Resource Management (IWRM) and Participatory Irrigation Management (PIM) into the management superstructure, the rise of the Mekong River Commission (MRC) and the initiatives of the Vietnamese government in providing for the socio- economic development of the region and the preservation of vital ecosystem functioning in one of the most important and diverse river systems in South East Asia, if not the world. Section 2 then tracks the current debate and consensus on climate change (CC), culminating with a review of the latest findings by the Intergovernmental Panel on Climate Change (IPCC). Based on experiences of managing water-related extremes in the delta, the chapter then qualifies what the regional and local impacts of CC will mean to the current regime of water management in the delta. Section 3 continues by exploring the particular vulnerabilities of the delta community, the future directions of water resource management, and the important interaction between disaster preparedness and every day IWRM. In particular, this section discusses how these two fields, often considered mutually exclusive, are being brought closer together in a warming climate. The final section explores the relationship between national and international stakeholders and how these partnerships themselves need to adapt to CC, if the local communities are to successfully adapt to the rapid changes in our global climate. It also provides some recommendations to direct future efforts and improve the effectiveness of IWRM in the Mekong Delta. 1. Water Resources in the Cuu Long Delta (CLD) 1.1 Water Resources in the Lower Mekong River Basin (LMRB) The Mekong River is one of Asia’s great rivers: it is 4,200km long with a catchment area of 795,000km² (KOICA, 2000). It flows through six countries (China, Myanmar, Thailand, Laos, Cambodia and Viet Nam), incorporates a massive lake system (Tonle Sap Lake) and downstream of Phnom Penh fans out into a series of channels, before discharging into the South China Sea. Due to geophysical and political differences, the Mekong River Basin is divided into two sub-catchments; the Upper Mekong River Basin, including China and www.vncold.vn 3 Myanmar, and the Lower Mekong River Basin (LMRB), considered as the area downstream of Laos and Thailand. The LMRB constitutes 77% of the total catchment area. Biodiversity and basin health Starting in the Tibetan plateau the river forms a wide variety of habitats, before ending in the sub-humid floodplains of the Mekong Delta. It is the size of the basin, the wide variety of ecosystems it supports and the minimal regulation of its flow, which contributes to its high levels of biodiversity and productivity. After the Amazon, the Mekong River basin is considered to have one of the highest levels of biodiversity on earth, including 1,200-1,700 species of fish (MRC, 2003; ARCBC, 2009). The LMRB is also home to some 60 million people, most of whom are agrarian farmers and fishermen and therefore dependent on the ecosystem services of the LMRB for survival. For instance, 90% of Cambodians rely on the fish for their protein intake, while Vietnamese fishermen harvest 400,000 tons of fish annually (Cornford et al, 2002; MRC, 2003; ARCBC, 2009). Most of the historic land clearing has been for agricultural purposes, most extensively in Vietnam and Thailand, while Laos and Cambodia contain the majority of the remaining forest systems and deforestation rates of 2-3% of the remnant forest cover (White, 2002). Climate & rainfall regime The LMRB has two seasons, the rainy and dry seasons. In mountainous regions of the catchment, rainfall is driven by changes in surface elevation, while the lower reaches of the basin typically experience rainfall in the afternoon/evening due to convective falls (White, 2002). Rainfall rates are highest in north-eastern Laos (3,500 mm/yr) and lowest in north- eastern Thailand (1,000 mm/yr) (White, 2002). Relative humidity exhibits a similar broad range across the LMRB (50-98%), while evaporation rates show smaller variation (1,500-1,800 mm/yr) (White, 2002). River morphology & flow The Upper catchment of the Mekong Basin is rugged, forested and mountainous, especially in China and Laos. It is characterized by steep gorges, narrow river channels and fast flows. Ground cover and surface gradients result in a high sediment content of run-off and river flows, which are transported downstream. As the river approaches Cambodia, the terrain flattens and the river slows and widens. The Mekong Delta starts south of Kratie (Cambodia). Tonle Sap Lake is one of the dominant hydrological features of the Mekong Delta. The lake is a unique system which regulates flows in the Mekong River by storing water in the wet season and releasing it in the dry season, providing the base dry season environmental flows and preserving the year-round integrity of biodiversity and productivity. In total, the annual discharge from the Mekong is about 450 billion cubic metres (4.5% generated within the Mekong Delta), with an average annual discharge of 13,700m 3 /s (Phuong, www.vncold.vn 4 2007; KOICA, 2000). During the wet season, the average discharge can peak at 25,400 m 3 /s, which results in widespread flooding as the river breaches its banks (Phuong, 2007). In general flood volumes are greater in the Mekong Delta, but more disastrous in the steeply sloped upstream sections of the catchment where areas’ water levels can reach up to 10 m. The Mekong Delta generally sees water levels of 4 m or less (Phuong, 2007). During the dry season flows in the upper catchment drop significantly and the flows in the Mekong Delta are sustained by drainage waters from the Tonle Sap system. Sediment dynamics and erosion are one of the key ecosystem functions of the LMRB, connecting sub-catchments thousands of kilometres apart. It is estimated that 150million tons of sediment is transported down the main channel into the Mekong Delta, where 138 million tons continues down the Mekong River towards the ocean, while 12million tons flows through the Mekong’s subsidiary channel (the Bassac River) entering the ocean. Figure 1. The Lower Mekong River Basin The energy potential One of the contributing factors to the regions biodiversity is the large amount of energy latent in the natural system. Changes in discharges, flow velocities and water levels are the fundamental drivers of the key ecosystem functions (flood pulse, the swelling of Tonle Sap Lake and the erosion/sedimentation processes), which in turn, create and support a diverse array of habitats and life. The river’s hydraulic potential is also essential for the agricultural and aquaculture activities of local communities who rely on the transfer of nutrients, sediments and freshwater driven by the basins ecosystem functions (ICEM, 2003). Interactions with non-MRC member states are a growing issue for water resource management, especially as development initiatives, such as hydropower escalate and the scale of anthropogenic influences on the rivers hydrology increase. The total hydropower potential of the Mekong River Basin is 54,234 MW (Nguyen et al, 2004). Currently there are 16 dams in the Mekong River Basin, 14 in the LMRB and 2 in China. There are plans for significant expansion of hydropower developments in the basin, and this is likely to generate complex conflict and cooperation linkages between riparian countries (Kummu et al (eds), 2008). China plans to Formatted: Font: (Default) Arial Formatted: Font: (Default) Arial Deleted: In total, the annual discharge from the Mekong is about 450 billion cubic metres (4.5% generated within the Mekong Delta), with an average annual discharge of 13,700m 3 /s (Phuong, 2007; KOICA, 2000). During the wet season, the average discharge can peak at 25,400 m 3 /s, which results in widespread flooding as the river breaches its banks (Phuong, 2007). In general, flood volumes are greater in the Mekong Delta, but more disastrous in the steeply sloped upstream sections of the catchment where water levels can reach up to 10m. The Mekong Delta generally sees water levels of 4m or less (Phuong, 2007). During the dry season flows in the upper catchment drop significantly and the flows in the Mekong Delta are sustained by drainage waters from the Tonle Sap system.¶ Figure 1. The Lower Mekong River Basin¶ Sediment dynamics and erosion are one of the key ecosystem functions of the LMRB, connecting sub- catchments thousands of kilometres apart. It is estimated that 150 million tons of sediment is transported down the main channel into the Mekong Delta, where 138 million tons continues down the Mekong River towards the ocean, while 12 million tons flows through the Mekong’s subsidiary channel (the Bassac River) entering the ocean less than 50km to the south of the Mekong. A large portion of this sediment washes out to sea where tidal and ocean currents transfer the sediments south-east along the coast to the Ca Mau Peninsula. Competing tidal and current interactions cause the sediment to be deposited on the peninsula fringe, which continues to expand by up to 50m a year in some parts. The depths of sediment layers in the delta vary between 20m in the inland areas to up to 500m at river mouths, supporting the hypothesis that most sediment is flushed out to sea before it re-enters the terrestrial environment some 150km to the south east.¶ www.vncold.vn 5 export a large proportion of the generated power, and Thailand, Laos and Viet Nam have all initiated plans for increased energy trade with China, while Thailand is also making plans with Myanmar and Cambodia, and Laos is undertaking similar efforts with Viet Nam and Cambodia (Kummu et al (eds), 2008). The environmental and social impacts of hydropower on downstream regions, as well as rising energy demands, are some of the key issues facing the Mekong Basin, and all riparian nations have a vested interest in both the positive and negative impacts of this energy source. Figure 2. Hydropower potential of the Mekong River Basin (%) (adapted from: White, 2002) Additionally, the nature of the impacts that the Chinese dams will have is not fully understood. A recent study on China’s existing Manwan Dam found that the infilling of the dam in 1992 caused record low water levels in various reaches of the Mekong River (Kummu et al (eds), 2008). A seasonal analysis comparing data from before (1962–1991) and after (1992– 2003) construction of the dam, revealed that while water levels and discharges were significantly lower during the dry season, during the wet season they increased slightly. Furthermore, there was no significant variation in the monthly means before and after the dam was built (Kummu et al (eds), 2008). The inter-seasonal variability is likely to be further amplified by the effects of climate change (see Section 3). Without question low flows are likely to be reduced further as the demand for water increases in all the riparian countries of the Mekong, however downstream countries need to investigate thoroughly the interaction between their demand for imported Chinese hydropower and the water requirements of other sectors. Hydropower dams could either reduce or exacerbate the inter-seasonal variability in flow depending on the operational regime implemented. It should also be noted that discharge volumes are just one issue of many for a river basin with increasing hydropower development. Other issues – such as sediment transport, migration of fish species, bank erosion, water quality and land clearing – must also be considered when assessing the impacts of developing hydropower potential. Deleted: . www.vncold.vn 6 1.2 Water Resources in the Cuu Long Delta (CLD) The Cuu Long Delta (CLD) is the extent of the Mekong Delta within Viet Nam. It covers some 13 provinces and cities, with a total area of 3.9 million hectares and a population of approximately 17.5 million people (Phuong, 2007). The topography of the CLD is low-lying with gentle slopes, and an average elevation of approximately 0.7–1.2m above mean sea level. In general, sedimentation processes have built up the banks of the main river channels in the CLD forming a geographic hollow in the inland areas. These hollows form closed floodplains which store water after the wet season and support wetland and rice-farming systems. The socioeconomic development of the Mekong Delta, exacerbates stress on natural systems, particularly through agricultural development and living conditions of farmers. Upstream flows into the Mekong Delta Upstream flows into the Mekong Delta Regulation of the Greate Lake Regulation of the Greate Lake Rainfall in the Mekong Delta Rainfall in the Mekong Delta VIET NAM VIET NAM CAMPUCHIA CAMPUCHIA Flooding & Inundation Acid sulfate soils Salinity &Drought Erosion & Sedementaion Tides Strong winds Salt water Tides Strong winds Salt water Selection of land and water development scenarios Selection of land and water development scenarios Objectives for sustainable development: Ö Production Agriculture- Forestry-Fishery; Ö Stable resettlemnt; Ö Infrastructure development; Ö Environment protection. Objectives for sustainable development: Ö Production Agriculture- Forestry-Fishery; Ö Stable resettlemnt; Ö Infrastructure development; Ö Environment protection. Forest Fires Figure 3. Major impacts and development directions of the CLD (adapted from NN. Tran, 2004) The major constraints of the natural conditions include (a) flooding over an area of about 1.4-1.9 million ha in the upper area of the Delta; (b) salinity intrusion (greater than 4g/l) over an area of about 1.2-1.6 million ha in the coastal areas; (c) acid sulphate soils and the spread of acidic water over an area of about 1.0 million ha in the lowland areas; (d) shortage of fresh water for production and domestic uses over an area of about 2.1 million ha in areas far from rivers, and close to the coastline; and (e) the impacts of global climate change to the flow regime in the upstream areas, rainfall, and climate in the Mekong Delta and threat from sea level rise from the sea. Deleted: www.vncold.vn 7 Global climate change and its’ subsequent effects on ecosystems, flooding, drought, riverbank erosion, water pollution, salinity intrusion, animal and human disease are becoming more and more difficult to forecast, as well as seriously affecting the production and living conditions of local people. Therefore, in order to further sustainable socio-economic development including hunger eradication, and poverty alleviation, there is a need to direct the Mekong Delta towards a general vision of “effective management of natural disasters; wise use of natural resources for a prosperous and stable economy, and diversification and sustainable environment in the Mekong Delta" Climate & rainfall regime The CLD is under a semi-equatorial monsoon climate with rainfall distributed between two seasons: the dry season (November to April) and the wet season (May to November). The average annual rainfall is 1,600mm with 90% concentrated during the wet season. There is minimal seasonal variation in the average annual temperature, which remains about 26 o C throughout the year. Typhoons and storms are irregular events for the CLD under existing climate conditions. Generally low-pressure systems originating in the Pacific Ocean sweep west through the Philippines and past northern and central Viet Nam, however, occasionally some of these storms track further south crossing the CLD. In recent times major storm events have occurred and these events are likely to become more common for the CLD under a warming climate. River morphology & flow Flow in the Mekong is distributed between two seasons. During the wet season, it is driven by runoff in the upstream catchment, in particular the rugged Laos subcatchments. In the CLD water levels rise slowly and peak at 4.0m in September/October, flooding ~1.2–1.9 million ha for 2-5 months (Phuong, 2007). The Tonle Sap Lake is a natural regulatory system for dry season water levels, and is connected to the Mekong by the Tonle Sap River which joins the Mekong mainstream at Phnom Penh. During the wet season, the high water levels in the Mekong main channel transfer water into the Lake, quadrupling its size. Then, as the channel water level drops with the onset of the dry season, the system’s hydraulic potential reverses the direction of flow in the Tonle Sap river, and the lake drains back into the Mekong Delta with an average downstream discharge of 3,000m³/s and an annual low flow of approximately 2,500 m 3 /sec. During the dry season, salt water intrudes into half of the CLD, and up to 50km up the main channel (Phuong, 2007). After Phnom Penh, the Mekong River fans out into a series of channels, with the Hau (Bassac) and Tien (Mekong) rivers being the two main branches. The distribution of discharge between these channels is important to the hydrologic regime in the upper reaches of the CLD. On average 83% flows through the Tien River (increasing up to 86% in the wet season and dropping to 80% in the dry season), which then forces lateral flow and flooding in the area Deleted: (NEED A REFERENCE). www.vncold.vn 8 between the two channels, such that, after the confluence with the Vam Nao River, the proportions of discharges between the two channels becomes approximately equal to each other (51%/49%) (Phuong, 2007). This redistribution of flow between the two main river channels has been enhanced by an irrigation canal network and is one of the reasons why the intra-channel riparian zone is some of the most productive land in the entire CLD. The Mekong river channel reaches a maximum non-flooded width of 1.2km at the Vam Nao confluence (White, 2002). Due to the low-lying topography and the fluctuations in the river’s flow regime, the CLD is affected by two distinct tidal regimes: the semi-diurnal tide in the South China Sea (max amplitude of 2.5–3.0m); and the mixed tide in the Gulf of Thailand (max amplitude 0.4–1.2m). During the dry season, the tides drive saline intrusion deep in land, while high tides during the wet season hinder the discharge of floodwaters in upstream areas, exacerbating inundation times and depths. Based on these hydrological factors, water resources are managed by dividing the CLD into three distinct areas (Table 1). Table 1. Hydrological Zones of the CLD (adapted from: Phuong, 2007) ZONE TYPE DESCRIPTION ZONE A Flood Zone Northern part of the CLD, ~300,000 ha including An Giang and Dong Thap ZONE B Flood and Tidal mixed zone ~ 1.6 million ha bounded by the Cai Lon River, Xeo Chit rivulet, Lai Hieu Canal, Mang Thit-ben Tre rivers and Cho Gao Canal ZONE C Tidal zone ~ 2.0 million ha along coastal areas, especially adjacent to the South China Sea The flood pulse The flood pulse is perhaps the most important process in the ecology of the floodplains, and the main reason for the delta’s high productivity. It facilitates the transfer of water to dry land and plant matter to the water, the latter provides energy and nutrients for the aquatic biota, while both facilitate biomass transportation (Phuong, 2007; Kummu et al (eds), 2008). The flood pulse is characterized by its timing, duration, amplitude, spatial extent, continuity, number of peaks and rate of inundation and subsidence (Kummu et al (eds), 2008). Most of these characteristics are vulnerable to changes in the flow of the Mekong River. In the future, flow in the CLD is likely to be affected by the dramatic escalation in upstream hydropower dams, conflict in water sharing based on increased agricultural activity in newly developing countries such as Cambodia, increased run-off in the mountainous catchments of China and Laos due to deforestation and other land-clearing practices, and also climate change. Furthermore, there will also be feedback between these impacts, for example climate change and hydrodams will increase inter-seasonal variability, or the dams could stagger their releases to synchronize with the dry season and thus curb reductions in the low flow of the Mekong River. www.vncold.vn 9 Human communities and their influence Over hundreds of years, farmers have built up a complex system of irrigation and drainage works in the CLD to support agricultural activity. To this day, fishing and farming remain the key economic activities in the Mekong Basin, making water resource management one the most important management issues. Rice crops dominate agriculture in the LMRB, with up to three crops a year in highly developed areas and just one rain-fed crop in less developed regions. However, other crops include maize, vegetables, mung beans, soya beans, sugar cane, fruit trees and coconuts (Phuong, 2007). Aquaculture and fisheries in the LMRB are two of the oldest and most important sectors. Inland areas are dominated by fishing, especially in the Tonle Sap system, while coastal areas utilize estuarine environments to support shrimp farming. Of the 17.5 million people in the CLD, nearly 80% live in rural areas (Phuong, 2007). Population density is strongly correlated to proximity to fresh water sources, highest densities occur along the Hau and Tien rivers (i.e. Zone A and B), while areas of Zone C (Ca Mau, Bac Lieu and Kien Giang) have some of the lowest population densities. Farm land per capita follows a reverse pattern, along and between the Hau and Tien rivers the average farmer has 0.1 – 0.2ha, increasing to 1ha per farmer in more remote areas (Phuong, 2007). The economic basis of the CLD remains in the sectors of agriculture and aquaculture (generating 70%-90% of the income), however recent years have seen the diversification of the local economy, especially with the growth of the industrial and manufacturing sectors. Average income per- capita is estimated at 400 – 470USD, however distribution is uneven, with 20 – 30% of the population living in poverty (Phuong, 2007). Most of the existing irrigation works in the CLD were built during the 1960s, and 1970s. In 2002, the system supplied water to only 50-60% of the design command area (Molle, 2005). The Government of Vietnam, recognizing the massive outlay required for infrastructure works, estimates that USD $750 million is required for repairs and improvements to the existing system (Oxfam, 2008). It should also be noted that currently, sediment deposition is not transferred to the floodplains concentrating in the bottom of river channels and canals, due to inefficiencies in the water distribution network. Development plans, especially in the deltaic areas of Cambodia and Viet Nam, aim to increase food production through a combination of expanding crop areas, intensifying production and improving yields (KOICA, 2000). In Viet Nam, development plans also include expansion of aquacultural production, enlargement and specialization of fruit tree growing areas and the controlled expansion of industrial and shipping activities. The main issues facing agricultural communities in the LMRB are; acid sulphate and saline soils, flooding, drought, freshwater shortages, storm events, sedimentation, bank erosion, and saline intrusion. Deleted: ¶ www.vncold.vn 10 Wetlands There remain several key wetland areas of high regional significance. These include Dong Thap Muoi, Mekong River Estuary, Minh Hai melaleuca forest, Bac Lieu coastal marshes, Dam Doi bird colony, Cai Nuoc bird colony and Nam Can mangrove forest (ARCBC, 2009). Six reserves have consequently been established protecting some 20,671 ha of the total 290,000 ha of remnant wetlands (ARCBC, 2009). The support and expansion of these areas is crucial for survival of the deltaic flora and fauna, and efforts to establish the Tram Chin Nature Reserve in the 1980s have already seen the return of the Sarus Crane, once thought to be near extinction (Pacovsky, 2001). Water quality Currently, the high volumes of flows in the Mekong system possess very efficient flushing properties; consequently there are no significant problems with water quality in the CLD. However, the continued intensification of agricultural activity will see continued growth in use of pesticides and fertilizers, new industrial developments are likely to increase the pollutant loading of the delta’s waterways and population growth will increase domestic waste loads, the combination of which may pose serious risks to water quality. Water quality will also be affected by the timing of river flows. Changes to the flood pulse and inter-seasonal variability could increase wet season erosion, while increased water scarcity in the dry season could result in concentrated contaminant pulses (DWR, 2008). 1.3 Water-related extremes & management issues According to the Asian Disaster Reduction Centre (ADRC), the main natural disasters facing Viet Nam include windstorms, floods, epidemics, droughts, insect infestation, landslides, wildfires, with floods droughts and windstorms affecting the most people in recent years (ADRC, 2006). Floods, other high rainfall storm events and droughts dominate water-related extremes in the CLD. Water management issues are determined by the season, during the wet season the main problems are flooding, erosion and the leaching of acidic soils, while drought, fresh water shortages and saline intrusion are the main issues for dry season water management. Flooding The main factors influencing flooding are; topography, upstream precipitation, regime flow and run-off, regulation of Tonle Sap Lake, the two tidal regimes, local rainfall and the existing infrastructure system. All of these factors undergo continual changes between seasons and even between days, resulting in a complex flood signature in the CLD, forcing communities to develop a high level of resourcefulness and adaptability in order to prosper, even without climate change. [...]... on research and initiating studies indicates that Vietnam’s response are still in their infancy In this regard the international community plays a vital role in helping Vietnam ol adapt to the pressing concern of climate change, through technical, strategic and financial support for adaptation initiatives nc The structure of the AP in particular, and the nature of development in Vietnam in general, give... and rehabilitation While the management initiatives for many of these issues may overlap, and others may already exist, v climate change will force better coordination of efforts at all spatial and temporal scales Lastly, Viet Nam and the CLD in particular, must acknowledge that while they played w only a minor role in the escalation of human-induced climate change, they must take control of adaptation... knowing what to do in droughts and v insufficient water storage capacity were considered to be major limitations in drought-risk management Predictions suggest that climate change will increase the inter-annual variability in w weather patterns, increasing rainfall in the wet season, decreasing rainfall in the dry season, shifting the timing of the flood season and prolonging the duration of drought... had some effects on the inundation regime Specifically, in deep inundation areas they have changed the direction and water level in the fields at the beginning of the flood season, and altered the signature of the main flood in shallow inundation areas 11 One of the key changes in WRM in the CLD is the acknowledgement that communities must live with floods, and that flooding brings both negative and... al, 1997) The damage was amplified by the fact that the CLD was largely unprepared for such a disaster and therefore had minimal disaster response systems in w place Because storms originate in the Pacific Ocean, the impacts are concentrated around the coastal areas of the CLD These areas also correspond to some of the highest levels of poverty and isolated communities Table 4 Damage cause by Linda... Climate Change and Water (Bates et al, 2008) outlines the effects that Climate Change is having on the hydrological cycle By the middle of the 21st nc century water availability is expected to shift away from arid, semi-arid and dry tropical areas towards wet tropical and higher altitude areas Therefore, river run-off is expected to increase in parts of the LMRB, and there is a likely increase in the. .. is also consensus amongst the scientific community that global temperatures are increasing Furthermore, most research indicates that human activities have played a decisive role in accelerating this process stage in the earth’s history .v during the last century, such that climate change is now happening faster than at any other The Intergovernmental Panel on Climate Change (IPCC), one of the leading... polarization of rainfall Flows in the Mekong to increase 7-15% in the wet season, decrease 2-15% in the dry season Increased erosion Decreasing water and soil quality, and poorer plant health Floods last longer and arrive earlier (especially in Long An province), with higher levels of inundation in and along the Cambodian border Increased areas with flood control (i.e three crops and inundated all year) which... as reflected in Viet Nam’s remarkable progress towards satisfying the Millennium Development Goals and economic development in general, however, it also means that the system remains somewhat inflexible to changes in the way plans are d formulated, making new paradigms such as participatory planning unpopular The response to climate change requires a system wide rethinking of water ol management, and... climate change, human land use and clearing practices) and also because of increasing vulnerability to the 32 impacts of floods This is the multifarious nature of planning for the future which climate scientists do not usually consider On the one hand the risks facing human communities are increasing, due to changes in the earth’s temperature and consequently the hydrological cycle, on the other hand . climate change will increase the inter-annual variability in weather patterns, increasing rainfall in the wet season, decreasing rainfall in the dry season, shifting the timing of the flood season. Upstream flows into the Mekong Delta Upstream flows into the Mekong Delta Regulation of the Greate Lake Regulation of the Greate Lake Rainfall in the Mekong Delta Rainfall in the Mekong. over a wide range of spatial and temporal scales. In the past the delta lay submerged below the sea and today it continues to accumulate sediments from as far away as the Himalayas so that the