嘉陵江流域整体设计洪水研究

Analysis on regional synthetic design flood in Jialing River Basin

为研究流域不同来水条件下的洪水组合情形,以干支流复杂的嘉陵江流域为研究区域,采用干支流控制性水文站的流量资料,开展了嘉陵江流域整体设计洪水研究。结果表明:北碚站年最大洪峰流量出现在5月中旬至10月上旬,主要集中在7~9月(87.0%),量级一般在10 000~40 000 m^(3)/s。渠江罗渡溪站占北碚站洪量的比例大于其面积占比,干流武胜站和涪江小河坝站占北碚站洪量的比例小于其面积占比。干流与涪江、干流与渠江洪峰遭遇的概率较高,渠江与涪江洪峰遭遇概率较低;随着洪水时段的增加,三江洪峰遭遇的概率略有增加。嘉陵江的洪水主要由干涪遭遇、干渠遭遇、三江遭遇和渠江来水较大导致,据此分别选取了1958,1975,1956,1989年及1981年7月洪水等5次典型洪水并采用同倍比法整体放大洪水过程。推求的整体设计洪水过程可为梯级水库群防洪调度决策和流域洪水资源化利用提供技术支撑。

In order to explore flood region composition in Jialing River Basin,we analyzed regional synthetic design flood using observed historical hydrological data.The results showed that annual maximum peak flow of Beibei Station occurred during middle of May to the early of October,and most occurred during July to September(probability of occurrence was about 87.0%),with amplitude of 10000 ~ 40000 m^(3)/s.The proportion of the flood volume at Luoduxi station to that at Beibei station was greater than the corresponding proportion of control area.While on the mainstream,the proportion of the flood volume at Wusheng station and Xiaoheba station to that at Beibei station was smaller than the corresponding proportion of control area.The probability of flood encountering between Jialing River and Fujiang River,and that of Jialing River and Qujiang River were high,while the probability of flood encountering between Qujiang River and Beijiang River was low.The probability of flood encountering among Jialing River,Qujiang River and Fujiang River increased slightly with the increase of the flood period.The flood in Jialing River was mainly caused by the flood encounters among above tributaries and the flood from Qujiang River.Therefore,flood in 1958,1975,1981 July,1956 and 1989 were selected as typical floods and homogeneous enlargement method was adopted to calculate design floods.The derived regional synthetic design flood could provide technical support for flood control operation of cascade reservoirs and flood utilization.