小流域土地利用结构对氮素输出的影响  

Effects of Land Use Structure on Nitrogen Export in Hujiashan Watershed of Danjiangkou Reservoir Area,China

作　　者：罗璇[1] 史志华[1] 尹炜[2] 陈佳[1] 李璐[1] 伍世良[3] 

机构地区：[1]华中农业大学农业部亚热带农业资源与环境重点实验室,武汉430070 [2]长江水资源保护科学研究所,武汉430051 [3]香港中文大学地理与资源管理学系

出　　处：《环境科学》2010年第1期58-62,共5页Environmental Science

基　　金：国家科技支撑计划项目(2006BAC10B02);国家自然科学基金项目(40671178)

摘　　要：以丹江口库区的胡家山小流域为研究区,以资源二号卫星影像图为底图,通过实地调查获取胡家山小流域土地利用图,利用ArcGIS的水文模拟、空间分析模块提取15个集水区,并分析其土地利用结构.根据2008年1～12月各个集水区的出口的总氮、硝态氮浓度的监测数据,定量地分析土地利用结构对氮素输出时空变化的影响.结果表明,胡家山小流域内旱地、居民地对氮素输出起显著源作用,与TN、NO-3-N的Pearson相关系数分别为0.869、0.856和0.826、0.867.林地、疏林地、草地等对氮素输出起汇作用,其中林地、草地汇作用显著,与TN、NO-3-N的Pearson相关系数分别为-0.820、-0.851和-0.602、-0.518.土地利用结构是氮素输出空间变化的关键因素,土地利用类型的空间分布使得汇土地利用类型旱地、居民地对小流域氮素输出影响最大;在不同时间尺度上,土地利用结构对氮素输出浓度影响有所不同.年度上,对氮素输出影响最大的是旱地,季节上,春、夏、秋、冬四季对氮素输出影响最大的分别是旱地、居民地、居民地、旱地;土地利用结构对氮素输出浓度的影响受到降雨、气温、人为等因素的作用.Land use is one of the most important factors that determine the occurrence and pattern of non-point source pollution.This study selected 15 catchments of Hujiashan watershed to examine the effect of land use on non-point source pollution.Land uses of these 15 catchments were classified from Resources Satellite No.2 images.The total nitrogen and nitrate content of discharge were monitored from Jan.to Dec.of 2008.The relations between nitrogen export and land use were analyzed using the hydrological modeling and spatial analysis extensions of ArcGIS 9.2.The results showed that dry land and residential area exported significant amount of nitrogen,whilst forest and grassland could be considered as nitrogen sinks.Land use was a controlling factor that determined the amount of nitrogen export,although the effects varied with time.Annually,dry land was the top nitrogen producer.However,seasonally,top producers were dry land,residential,residential and dry land in spring,summer,autumn and win.ter,respectively.Rainfall,temperature and human activity are also important for influencing the nitrogen export.

关 键 词：土地利用类型 土地利用结构 氮素输出 时空变化 

分 类 号：X52[环境科学与工程—环境工程]