Effect Of Soil And Water Conservation On Wtaer Resources

Poyang Lake is the largest freshwater lake in China.It compiles the water of Ganjiang river,Fuhe river,Xinjiang river,Raohe river,Xiuhe river and becomes one of the most important water resource in our country. However, Jiangxi Province is one of the most serious soil erosion in southern provinces of our country. The soil erosion mainly distributes in "five rivers" on the upriver basin and middle reaches and the lakeside area of Poyang lake system.The existing soil erosion area is the approximately 32,000 square kilometers, occupying the entire province soil erosion area 95%. The serious soil erosion produces the runoff silt that not only fills up sea dykes and reduces adjusting and storing floodwater ability of sea dykes, but also is main carrier of surface source pollution. According to the investigation reckoning, Jiangxi Province because of the human factor, increases the soil erosion area to reach 53,300 hm2 every year at present, equaling area of water and soil conservation in the entire province 1/3. Soil erosion is an important point source pollution generated through, also contributed to the deterioration of water quality of Poyang Lake is one of the important reasons. The south of Jiangxi once was China Southern one of the most serious soil erosion, "Southern Red Desert", "Xingguo to subjugate a nation', Ningdu to want moved the capital'" to call out in alarm is at that time the soil erosion severely impair vivid portrayal. The rill river located at the Ganjiang River upstream, was the first-level branch of Ganjiang River basin, in the basin has developed experiment, demonstration and comprehensive management of the conservation of water and soil single item measure and the comprehensive program of public order measure from 1993. However watershed management for the quantitative evaluation of the effect was significantly less than, therefore, this article take the rill river basin's actual material as a foundation, using hydrology law as well as Xin'an river three water source model analysis and calculate influence of water conservation and soil measure to this basin water resources.The main research results of this paper are as fllows.(1) Study of water and soil conservation measures and rules of slope runoff and sediment yield:take slope district as testing unit,utilize rainfall and silt measurement data in 52-yard,and utilize the Usual Sole Loss Equation(USLE) to calculate backwards the eqution parameters the crop an vegetation management factors of three water and soil conservation measures(orchard+level terrace+bank before and ditch after,tree+shrub+grass+bamboo type contour trench,oil tea+bamboo type contour trench).(2) Soil and water conservation measures could retain the runoff and sediment effectively.This research calculate the effect of soil and water conservation on water resources by using Hydrological Method which include curve of double cumulate method,different series contrastive method and formula of experience method as well as Soil Conservation Method.The results show that soil and water conservation measures could retain the runoff and sediment effectively.With the gradual perfection of soil and water conservation in the Xiaoxi river watershed,the retention efficiency of water and soil increases constantly, which exceeded 85%.(3) The Xiaoxi riverwithstand the challenges of rainstorm many times.The analysis results under fifteen representative rainstorm at the different stage show that, soil and water conservation measures which make great contributes in ecological construction could retain the runoff effectively in strom flood.(4) Utilize Xin'anjiang(three waters)model to simulate the flood forecasting of Xiaoxi River.