汾河上游土地利用变化对径流的影响研究

Effects of Land Use Change on Runoff in the Typical Areas in Upper Fenhe River Basin

为研究土地利用变化对流域径流的影响,以汾河上游为研究区,利用1951—2016年的水文气象资料,结合不同土地利用类型的时空变化特征,进行SWAT模型的构建,设置1978年、1998年和2016年3种土地利用情景,模拟土地利用变化与径流的关系。结果表明:模型在研究区具有很好的适用性,可以精确地模拟汛期月径流量及全年径流量,年平均径流量呈下降趋势;1978—2016年研究区林草面积占比显著提高,农用地面积占比呈下降趋势;土地利用变化使汛期径流量、最大月径流量减小以及汛期径流系数减小。

In order to research the reaction of the runoff of Fenhe River Basin towards the change of land use,the upper Fenhe River Basin were regarded as the research area and the data of hydrometeorology from 1951 to 2016 were combined to analyze the characteristics of tempo⁃ral and spatial changes of different land use.Moreover,three scenarios of land use were set in combination of SWAT(Soil and Water Assess⁃ment Tool)model and influence to the runoff by the change of land use types was evaluated.The result shows that this model can better simu⁃late monthly flow process of the whole year as well as in flood seasons.The runoff has experienced a gradual decrease for many years.The transformation in time and space among different types of land use presents the reversibility and major changes include an increase in forest,a decrease in grassland and a little increase in agricultural land.The increase of forest and the decrease of grassland will cause a decrease of runoff in flood season and the maximum monthly peak discharge.The coefficient in flood season is decreased with the increase of forest area.Therefore,it is very important to properly plan land use pattern so as to control watershed hydrological events.