土地利用变化对产流和产沙的影响分析

LUCC(土地利用覆盖变化)对径流的影响研究主要集中在对年径流量的影响,选用基于ArcviewGIS的SWAT模型,利用情景模拟来分析土地利用变化对产流量和产沙量的影响,并重点探讨森林对产流的影响。以黄河下游支流洛河上游卢氏水文站以上流域为研究区域,选取了1992～2000年24个雨量站的雨量资料和同期的气象资料,采用土壤类型图(1∶4000000)以及设定的不同土地利用情景,作为模型的输入,进行土地利用变化的产流量和产沙量的情景模拟。模拟表明:森林的存在增加了径流量,减少了产沙量;草地也能减少产沙量;农业用地的增加将会增加产沙量;平水年土地利用变化对产流量影响最小,降雨量的增大能弱化下垫面对产流量的影响。

Impact of Land Use Change on Runoff and Sediment Yield

The impact of Land Use and Land-Cover Change (LUCC) mainly on annual runoff yield, in this study through scenarios simulation of Lushi basin using SWAT(Soil and Water Assessment Tools), the impact of LUUC on annual runoff yield and sediment yield were analyzed, and stressed on the forest's impact on runoff yield. The subbasin upper to the Lushi hydrologic station in the lower reach of the Yellow River basin, the daily precipitation data of 24 rainfall station and the climatic data in this area from 1992~2000, soil type and the scenarios of the landuse, all of these data were inputed to the SWAT (Soil and Water Assessment Tool ) to simulate the impact of LUCC on the yield of runoff and sediment. The simulated results indicate that forest will increase the runoff yield and decrease sediment yield, grassland reduce runoff yield; with the increase of land use of agriculture the sediment yield will increase correspondingly; the least impact of LUCC on runoff yield was found in normal mean precipitation year, with the increase of the rain rate, impact of the basin condition on the runoff and sediment yield will be reduced.