基于土壤地形指数的流域水文敏感区空间分布研究

Study on Spatial Distribution of Hydrologically Sensitive Areas in the Watershed Using Soil Topographic Index Method

以丹江口水库上游堵河流域为研究区,借助SAGA GIS和R平台,以ASTER GDEMV2为数据源,在获取流域土壤地形指数及其阈值设定的基础上,利用Python获取3种情景下(STI≥9、STI≥10和STI≥11)水文敏感区内不同土地利用类型及其面积和空间分布。结果表明:利用土壤地形指数识别,提供了更为详细表征的水文敏感区,可合理预测径流产生的空间分异性;3种情景下,林地均是水文敏感区内最主要的土地利用类型,约50%水体均位于水文敏感区;不同情景下,识别的水文敏感区内农业景观和开发景观应禁止开展高强度的土地开发,并优先布置植被缓冲带等保护措施以保护水质安全。

This study was conducted in the upstream watershed of Du River,central China,and ASTER GEDM was processed in the system for Automated Geoscientific Analyses（SAGA GIS）package in the R-platform.On the basis of obtaining watershed soil topographic index（STI）and its threshold setting,using Python module programming,three different scenarios（STI≥9,STI≥10,and STI≥11）were selected to delineate and understand the land use types and their areas and spatial distributions within hydrologically sensitive area（HSAs）in the watershed.The results showed that STI technique improved the identification of HSAs,which could reasonably predict the spatial differentiation of runoff in the watershed.Forest land was the major land use in the HSAs under all three scenarios,and about 50% of water was identified as HSAs.Under the three scenarios,the agricultural landscape and development landscape in the HSAs should be prohibited from carrying out intensive land development,and should arrange in priority vegetation buffer zones to protect water quality.