1995年以来贵州省土地利用变化对地表径流的影响研究

Study on the influence of land use change on surface runoff in Guizhou Province since 1995

为分析土地利用/覆盖变化对地表径流的影响,基于SCS水文模型,结合贵州省77个气象站1995年以来水文资料、土地利用变化情况、土壤数据,模拟计算地表径流。结果表明:SCS模型模拟误差在±15%以内,能够较为准确地模拟贵州省的地表径流分布特征;1995-2019年,贵州省土地利用结构发生了巨大变化,以耕地及林地的相互转化为主,灌木和草地主要向不透水面和水域转化;地表径流较大区域主要分布在省西南部、东南部和东北部,空间分布主要受降雨因子影响;在相同降雨情景下,不同土地利用类型的产流能力排序为:不透水面>耕地>草地>灌木>林地;1995年以来,相对于土地利用方式不发生变化区域,除灌木转化为林地区域,林地和灌木转化为其他土地利用方式区域地表径流量均增加,其中,转化为耕地区域地表径流量变化最大,变化率分别为-89.11%和169.31%;耕地和不透水面转化为其他地类区域造成地表径流量减少,其中,耕地转化为林地和不透水面转化为耕地区域地表径流量减少最大,减少率分别为168.49%和-177.02%。研究结果为贵州省水资源科学管理与土地规划提供一定参考。

To analyze the influence of land use changes on surface runoff,surface runoff was simulated and calculated based on the SCS hydrological model,combining hydrological data,land use changes and soil data from 77 meteorological stations in Guizhou Province since 1995.The results show that:the simulation error of the SCS model is within±15%,which can more accurately simulate the surface runoff distribution characteristics of Guizhou Province;From 1995-2019,the land use structure of Guizhou Province has changed dramatically,with the interconversion of arable land and forest land dominating,and shrubs and grasslands mainly converting to impervious surfaces and waters;The areas with larger surface runoff are mainly distributed in the southwestern,southeastern and northeastern parts of the province,and the spatial distribution is mainly influenced by rainfall factors;Under the same rainfall scenario,the flow production capacity of land use types are sorted:Impervious surface>cropland>grassland>shrubs>woodland;Since 1995,surface runoff will increase in both forest land and shrub conversion to other land use areas,except for shrub conversion to forest land areas,with the greatest change in surface runoff in forest land and shrub conversion to cropland areas,with rates of change of-89.11%and 169.31%;Conversion of cropland and impervious surface to other land use areas causes a decrease in surface runoff,conversion of cropland to forest land and impervious surface to the conversion of cropland result in the greatest decrease in surface runoff,with a decrease rate of 168.49%and-177.02%.The research results provide a reference for the rational planning and utilization of land and scientific management of water resources in Guizhou Province.