The Estimation Of Surface Runoff And Precipitation In Chengdu Area

In this study,the surface runoff and precipitation as the research objects which arein Chengdu area, and the total amount of water resources are estimated by the corresponding methodin the area.Firstly,using Geographic Information System(GIS)technology from digital evaluation model(DEM) with 30 m resolution of Chengdu Area calculate and analyzethe natural watershed boundary and basin watershed extraction,It is divided into two parts which are the Tuojiang River and the Minjiang River basins,and then using the high-definition satellite combined with the administration boundaries of Chengdu citydelineate main river of the area, Finally,determine the Zipingpu hydro-stationwhich is on the Minjiang River Basin to be the water inlet,and determine the Pengshan hydro-station、Dongfengqu main canal、longquan mountain tunnelin Dongfengqu which are in Minjiang River to be the water point. Due to the limited data.In this paper, the study area is bounded in hydro-stations which are in the mountain watershed, and divided into the mountains and plains of two parts of the study area:The total amount of water resources in mountain area is composed by the mountain hydro-stationsof water runoff and obtain,The total amount of water resources in plain area is based on Thiessen polygons methodwith the 32 rainfall stations of annual average precipitation in plain area,and combined with the total area of the plain area calculation of total precipitation in plain area(unit: mm),finally, convert to the total amount of water resources(unit:million·m3).The totel amount of water resources of seven hydro-stations where are at moutains watershed by Zipingpu、Yangliuping、Yueziyan、Xinxinchang which are at Minjiang River and Shuguang、Xuri、Jianbing which are at Tuojiang River,there are eight years datas from 1968 to 1975, and the plain area’s is calculated according to the distribution of 32 rain-gauge stations’ data like Wenjiang station、Wangjianglou station、Shidiyan station where are at Minjiang River and Jinlun station、Huangxuzhen station、Majing station where are at Tuojiang River by Thiessen polygons method from 1968 to 1975.The results reflect:firstly, the main methods of water resources recharge is runoff in the study area.Runoff came from mountain area,and the average amount of water resources in mountain areas accounted for about 60% of the total water area.Secondly, Water resources in the mountain area is mainly from the upper reaches of Minjiang River, Zipingpu hydro-station locate in the area of the average years of transit flow is much larger,the average for many years of the total amount of water resources in mountain area average value accounted for 81.2% of the average annual total water resources;thirdly, Zipingpu hydro-station transit flow contribution to the total water resources in the study area is the highest.There are two rivers which are named Minjiang River and Tuojiang River in the area,the Zipingpu hydro-station is located in the Minjiang River area,the average annual runoff accounts for 48.5% of the total study area;fouth,the precipitation of Tuojiang River in study area is decreasing from the northwest to the southeast;fifth,The total amount of water resources in the study area is largerthe water resources of average annual value in this paper is 281 billionm3.