土地利用和气候变化对四川省紫色丘陵区径流泥沙变化的影响研究  

Impacts of Climate and Land Use Changes on Runoff and Sediment Yield in Sichuan Purple Hilly Area

作　　者：曾赟[1] 魏琳 

机构地区：[1]四川农业大学信息工程技术学院,四川雅安625014 [2]四川省金堂县水务局,四川金堂610400

出　　处：《水土保持通报》2013年第3期1-6,90,共7页Bulletin of Soil and Water Conservation

基　　金：国家科技支撑计划项目"四川省新农村建设科技集成研究与示范"(2010NZ0105);四川省教育厅科研项目"李子溪流域水沙变化规律与计算模拟"(12ZB308);四川农业大学本科论文培育计划项目

摘　　要：嘉陵江紫色丘陵区的土壤侵蚀是造成该流域下游水土流失严重的主要根源。选取四川省紫色丘陵区的李子溪流域为研究区,根据反映"长治"工程实施前后的1986,1999和2001年影像数据,应用GIS技术解译得到了该流域3个时期的土地利用图,并利用SWAT模型对这3个时期的土地利用情形进行了产流产沙模拟。在1986年土地利用图的基础上,假设了7种不同土地利用情景以及9种不同气候组合,以评价土地利用变化和不同气候条件对李子溪流域径流泥沙的影响。研究结果表明:(1)1989年实施"长治"工程后,林地面积持续增加,水田、旱地面积持续减少,且林地增加的面积主要来自于水田和旱地;(2)林地覆盖率增加,耕地减少的土地利用变化对流域产流产沙量的减小影响显著,说明了"长治"工程实施后,以退耕还林和植树造林为主的理措施具有水土保持作用,且在大于25°的坡耕地上实施退耕还林措施对减少地表径流,拦截泥沙效果更显著。Serious soil erosion in the purple hilly areas of Jialing River basin is the major source of soil and water loss in the lower and middle reaches of the river.Lizixi watershed in Sichuan Province was chosen as the study area.Land use data were extracted by RS and GIS technology from remote sensing images（Landsat TM/ETM＋ and Spot Images） in 1986,1999and 2001representing the conditions at the three periods before and after implementing the key control project of soil and water conservation in the upper reaches of the Yangtze River（referred to as the ＂ Changzhi ＂ project）.The distributed hydrological model SWAT was used to simulate runoff and sediment yield based on the land use data at the three periods.Based on the land use map in 1986,the impacts of land use changes and different climates on runoff and sediment yield in Lizixi watershed were evaluated by making an assumption of 7different land use conditions and 9different climate combinations.The simulated results show that ：（1） After the implementation of the ＂ Changzhi ＂ project,paddy fields and dry land area continued to decrease,and forest area continued to increase from 1986to 2001,which was mainly transformed from paddy fields and dry land.（2） The land use changes of increased forest area and decreased farmland had an obvious influence on runoff and sediment yield,which showed that the control measures,mainly in the form of returning farmland to forestry and afforestation,had effects on soil and water conservation.In terms of conserving water and intercepting sediment,forestry was better than grassland,and grassland was better than farmland.Taking the measure of returning farmland to forestry andgrassland in25° farmlands had more obvious effects on reducing surface runoff and intercepting sediment than 15°～25° farmlands.

关 键 词：SWAT模型 土地利用变化 气候变化 径流 产沙量 李子溪流域 紫色丘陵区 

分 类 号：S157.1[农业科学—土壤学]