1981—2013年桃江流域径流与泥沙模拟研究

Simulation of Runoff and Sediment During 1981-2013 in Taojiang Basin

[目的]探讨人类活动对桃江流域水文过程的影响,为赣江源区的生态保护与可持续发展决策提供一定依据。[方法]利用1980,2000,2015年3期土地利用数据,结合SWAT模型模拟桃江流域1981—2013年的径流与泥沙,分析土地利用方式对土壤侵蚀的影响,并定量评价居龙滩水电站的拦沙效应。[结果](1)SWAT模型能够较好的模拟桃江的径流与泥沙,其中月径流模拟的Ens为0.92,月泥沙模拟的Ens为0.8;(2)1980—2013年土地利用变化对桃江径流和泥沙的影响很小;(3)桃江流域以轻度侵蚀为主,草地侵蚀模数最大,林地绝对产沙量最大;(4)居龙滩水电站对桃江的泥沙具有较强的拦截作用,2007—2013年预计拦沙量为7.78×10~6 t,约占桃江流域输沙总量的77.5%。[结论]土地利用变化不是引起桃江流域径流和泥沙变化的主要原因,但居龙滩水电站的建设对桃江泥沙影响显著。

[Objective] To explore the effects of human activities on the hydrological processes in order to provide a certain basis for decision-making regarding ecological protection and sustainable development in Ganjiang River headwaters region.[Methods] SWAT （soil and water assessment tool） model was used to simulate the runoff and sediment in Taojiang basin during 1981-2013 based on the land use data of 1980, 2000 and 2015. And the effect of land use change on soil erosion was analyzed. The effects of sediment retention on Julongtan water conservancy project were analyzed quantitatively.[Results] ① Monthly runoff and sediment obtained from SWAT model were agreed with the observed data in Taojang basin, with Ens was 0.92 and 0.8, respectively. ② Land use variations during 1980-2013 showed little effects on the runoff and sediment output in Taojiang basin. ③ Soil erosion in Taojiang basin was mainly light ersion. Soil erosion modulus in meadow was the maximum, and the sediment yield in woodland was the maximum. ④ The Julongtan water conservancy project effectively intercepted sediment Taojiang basin. It was estimated that about 7.78×106 t sediment was retained druing 2007-2013, accounted for 77.5% of the total amount of sediment transported into the Taojiang basin.[Conclusion] Land use change is not the main reason that causes runoff and sediment change in Taojiang basin. In contrast, the construction of Julongtan water conservancy project shows a significant effect on the variation of sediment in Taojiang basin.