摘要
分析认为 ,小浪底水库逐步抬高主汛期水位拦沙和调水调沙运用 ,库区为锥体淤积 ,由下而上、由低而高逐步淤积 ,比降变小 ,主汛期运用水位 2 5 4m ,形成高滩高槽形态 ,不影响三门峡坝下水位 ;支流拦沙库容充分淤积 ,拦沙库容约80亿m3。若水库一次抬高水位或主汛期高水位蓄水拦沙 ,水库为三角洲和带状淤积 ,在淤积向坝前推进过程中 ,洲面淤高 ,淤积上延 ,河床比降增大。为了不影响三门峡坝下水位 ,主汛期运用水位要降至 2 40～ 2 46m ,干流拦沙库容减少 15～ 2 5亿m3,支流河口拦门沙坎高 ,支流淤积面低 ,大量损失拦沙库容 ,因此应予避免。水库拦沙后 ,逐步降低主汛期水位至 2 30m ,形成高滩深槽的平衡形态 ,平均河床比降 3 .3 ,不影响三门峡坝下水位。小浪底水库选择最高水位 2 75m ,主汛期限制水位 2 5 4m ,死水位 2 30m ,总库容 12 6 .5亿m3,有效库容 5 1亿m3,其滩库容 41亿m3,槽库容 10亿m3,拦沙容积初期 80亿m3、后期 72 .5亿m3,下游平均减淤 78.
It is recognized from analysis that there will be no impact on water level at sanmenxia through the operation of the reservoir lifting water level in main flood season step by step to store sediment and adjust water and sediment, and in the way sedimentation in the reservoir will be cone shape and sedimentation happened from lower reaches to the upper, from lower position to the higher, which leads to lower river gradient, high enough sedimentation depth and the river regime of high beach and high channel with operation water level of 254?m in main flood seasons; the storage capacities in tributary reservoirs should be full used by sedimentation; the total sediment storage capacity is 8 billion m 3. If the reservoir lifts water level in one time or store water and sediment under high water level in main flood seasons, the sedimentation shape will be delta and belt, and during develop forward to the dam, the delta surface will be getting higher and higher with sedimentation getting upper reaches, the river gradient become steeper, which should be avoid through best effort in order not to influence the water level in front of Sanmenxia dam and loss of reservoir sediment storage capacity, besides, the operation water level in main flood seasons should be decreased to 240 to 260?m, sediment storage capacity in stem should be decreased by 1.5 to 2.5 billion m 3, high threshold may form at mouths of tributaries and lots of sediment storage capacity may loss because lower sedimentation bases, which must be avoided too. After sediment stored in the reservoir, water level in main flood seasons will go down till 230?m step by step, a balance of high beach and deep channel will reach with average river gradient of 0.033%, which is of no influence on Sanmenxia water level. The selected highest water level for Xiaolangdi is 275?m, restricted water level in main flood season is 254?m, dead water level 230?m, total storage capacity 12.65 billion m 3, effective storage 5.1 billion m 3 for which 4.1 billion m 3 is on beach and 1 billion m 3 is in channel, sediment storage capacity is 8 billion m 3 in initial stage and 7.25 billion m 3 in later stage with average sedimentation reduction of 7.87 billion in the lower Yellow River.
出处
《人民黄河》
北大核心
2000年第4期20-22,共3页
Yellow River
关键词
库容规划
淤积形态
拦沙库容
槽库容
小浪底水库
storage capacity scale
reservoir sedimentation regime
sedimentation reduction effect
sediment storage capacity
storage capacity in channel
reservoir operation model
Xiao Langdi reservoir
