引江济渭工程对渭河下游河道冲淤及降低潼关高程作用的初步研究

采用一维泥沙数学模型计算与分析了引江济渭工程不同引水方案对渭河下游河道和潼三河段冲淤及降低潼关高程的作用。计算方案考虑了1981-1990年的丰水系列和1991-2000年的枯水系列两种水沙条件，汛期引水量分别为30亿m^3、50亿m^3和100亿m^3的不同引江济渭工程规模及5种引水量分配方式。分析结果表明，引江济渭工程的实施对渭河下游河道减淤和潼三河段冲刷及降低潼关高程将产生一定的作用，随着引水量的增加和分配方式的优化，作用将更加明显。当引水量为30亿m^3和50亿m^3、调蓄水库采用汛期月调节（引水量分配方式4）时，计算10年末渭河下游河道由累计性淤积转为累计性冲刷甚至年内冲刷。丰水系列下渭河下游河道淤积量可分别比无引江济渭工程情况减少1．4334亿m’和1．7034亿m’。潼关高程可分别下降约0．53m和0．97m；枯水系列下渭河下游河道淤积量可分别比无引江济渭工程情况减少1．3056亿m^3和2．0415亿矗，潼关高程可分别下降约0．83m和1．16m左右；丰水系列所需调蓄库容比枯水系列的大。相应于引水量为30亿矗和50亿m^3，丰水系列所需调蓄水库库容分别为4．42亿m^3和5．59亿m^2。

Preliminary study on the effect of Changjiang River- to-Weihe River Water Transfer Project on the scouring and silting in Lower Weihe River and on the falling of Tongguan elevation

A 1-D sediment transport model was applied in this paper to study the processes of scouring and silting in the lower Weihe River and the river course from Tongguan Station to Sanmenxia Reservoir as well as possible falling of the Tongguan elevation due to the effect of the Changjiang River-to-Weihe River Water Transfer Project. In the study,2 hydrological sequences(covering the wet period of 1981-1990 and the dry period of 1991-2000),3 different annual diversion volumes(3 billion m~3, 5 billion m~3 and 10 billion m~3) with 5 different allocation scenarios,were taken into account.The study results show that the annual diverted water of more than 3 billion m~3 to Weihe River can even make erosion status in the lower Weihe River,hence enhance scouring in the river course from Tongguan to Sanmenxia,causing a falling of Tongguan elevation.Compared with the situation of no diversion,the water transfer project with the annual diversion-water quantities of 3 billion m~3 and 5 billion m~3,together with a monthly reservoir regulation(water allocation scenario 4),can decrease siltation of 0.143 billion m~3 and 0.170 billion m~3 in lower Weihe River during the wet period,respectively,and decrease siltation of 0.131 billion m~3 and 0.204 billion m~3 in lower Weihe River during the dry period,respectively.This means it will cause falling of Tongguan elevation of about 0.53m and 0.97m during the wet period and about 0.83m and 1.16m during the dry period.The storing capacities of the regulation reservoir during the wet period are 0.442 billion m~3 and 0.559 billion m~3 corresponding to the annual diversion-water of 3 billion m~3 and 5 billion m~3,respectively.These capacities are larger than those during the dry period.