[...]... vulnerability of the economic life of a water resources project to reservoir sedimentation stems from the nonlinear relationship between yield of water and reservoir capacity Severe reductions in yield of water from a reservoir can result from relatively small changes in reservoir volume A conflict therefore arises in areas where reservoir sedimentation is a problem, and the water resources engineer must... also result in other environmental damage Anticipating the effect reservoir sedimentation will have on flood lines upstream of reservoirs is very important, as inaccurate assessment can result in unplanned inundation, which could lead to considerable losses of both crop and wild plant life Deposited sediment can also, in cases where reservoir levels are often low, result in damage to the surrounding... discharge patterns downstream of a reservoir, information which is required to reliably determine the potential influence of a reservoir on the original river system The effect of degradation as regards l o s s of fertile soil and changes in aquatic environment due to changes in river geometry, also require rigid calculation procedures In the region upstream of the reservoir sediment deposition can,... sediment d e p o s i t s r e q u i r e s a q u a n t i t a t i v e a n a l y s i s of sediment p r o c e s s e s , t h e s u b j e c t matter of t h i s book In o r d e r to appreciate the influence reservoir of sedimentation on the environment i t i s i m p o r t a n t t o view t h e r e s e r v o i r a s p a r t of a r i v e r system Before t h e e x i s t e n c e of a r e s e r v o i r , t h e r i v... y approach 9.2.2 Probability approach SCOUR 9.3.1 Komura a n d S i m o n s ( 1 9 6 7 ) 9 3 2 Aksoy ( 1 9 7 0 ) CONCLUSION 191 192 192 196 201 202 206 211 212 220 T Chapter 1 PROBLEMS RELATED TO RESERVOIR SEDIMENTATION The r o l e of t h e w a t e r r e s o u r c e s e n g i n e e r i n a c o u n r r y ' s economy o f t e n goes unnoticed b u t i s of v i t a l i m p o r t a n c e , e s p e c i a l... on a community or country The influence of sediment deposition on reservoir design affects decisions regarding the placement of sluices in dam walls and estimation of excess pressure due to deposited sediment on structures such as dam walls and intake towers It is therefore very important to accurately predict sediment distribution in a reservoir Large volumes of deposited sediment will not necessarily... discharge (2.46) Equations ( 2 4 1 ) to are therefore very useful for determining initial conditions in backwater calculations, a requirement for the assessment of stable sediment profiles in reservoirs subject to sedimentation A method for calculating backwater curves will be presented subsequent to the review of basic principles of uniform flow The latter is dealt with first as some of these concepts... 8.3 119 120 121 122 129 129 132 134 140 146 148 148 159 164 167 173 173 177 180 186 190 SCOUR DOWNSTREAM OF RESERVOIRS 9.3 9.4 REFERENCES INDEX 9.1 9.2 118 STREAM POWER THEORY STABLE NON-EQUILIBRIUM CONDITIONS 8.1.1 Theory 8.1.2 V e r i f i c... accurately predict sediment distribution in a reservoir Large volumes of deposited sediment will not necessarily mean that pressures due to sediment on a dam wall will be 3 considerable The shape of the reservoir basin and sediment transport c h a r a c t e r i s t i c s may b e such t h a t most of t h e sediment i s d i s t r i b u t e d i n t h e In other cases upstream r e a c h e s , perhaps n o... e r e s t of t h e book has been o r g a n i z e d to e n a b l e t h e w a t e r r e s o u r c e s e n g i n e e r t o q u a n t i f y most of t h e phenomena a s s o c i a t e d w i t h reserv o i r sedimentation o m i t t e d by Chapter 2 reviews b a s i c h y d r a u l i c p r i n c i p l e s and can be those f a m i l i a r with the d e t a i l s Chapter 3 d e a l s w i t h morpho- l o g i c a . appreciate the influence of reservoir sedimentation on the environment it is important to view the reservoir as part of a river system. Before the existence of a reservoir, the river in. resources project to reservoir sedimentation stems from the nonlinear relationship between yield of water and reservoir capacity. Severe reductions in yield of water from a reservoir can result. of reservoir sedimentation are generally lacking. There is however a need for collecting, documenting and evaluating the knowledge available in this field of engineering. Research on reservoir