Introduce
The west river belongs to a largest master stream of Lip river river, lie 1.5 kilometers west of the county town of Chengcheng county of Shaanxi Province, rise in the intersection of village and the intersection of township and the intersection of precipice and the intersection of side and the intersection of stockaded village and the intersection of things and ditch Zhao, left bank flow through village, the depression, the intersection of village and hair, outskirts,etc. Zhao, it is right bank flow through Liu depression, village Wang, on Ann, Yao is first class,it is for Lip river river to ask for by village. 36.8 of total length, 304.48 of drainage area, the intersection of average discharge and 0.61m3/s, average than lower 11.94‰, belong to and often flow in the river; The foot-path flow is about 1911.83 cubic meters in average year, account for 20.6% of the total amount of water resource in the whole county, and the main source of water of field irrigation that it is that the people and animals of a dozen villages and towns drink to the north of the thatch ditch of county town, it is the industry and agriculture of the whole county that develops one of the main routes of water, it is the lifeblood of main source of water that the people of the whole county depend on for existence and development. Both sides of west river belong to the water and soil intermediate loss area, the water erosion is serious, among them rely mainly on the fact that losing and ditch loses again, is the soil erosion modulus 1450t/km2? Annual, the soil corrodes total amount of 441,500 tons per year. Chemical fertilizer in the soil, pesticide, a large amount of organic matter, salt,etc. flow into the west river with the rainwash, have caused polluting to the water body seriously.
The gentle characteristic of west river is mainly influenced by atmospheric precipitation, the river flow is very large in seasonal variation, it is generally dry season in December – February, it is wet season in July – September, is period when a river is at its normal level in April – May and October. Silt content and precipitation intensity of the river are the positive correlation, environmental capacity and river quantity of the river are the positive correlation, the environmental capacity is relatively big in summer on the whole, it is relatively small in Winter-Spring.