内蒙古典型草原区土地利用动态变化及其对水质的影响  

Land use change and its effects on water quality in typical steppe region of the Inner Mongolia Autonomous Region,China

作　　者：项颂[1] 庞燕[1] 杨天学[1] 刁兆岩[1] XIANG Song;PANG Yan;YANG Tianxue;DIAO Zhaoyan(National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]中国环境科学研究院,北京100012

出　　处：《农业环境科学学报》2022年第4期857-867,共11页Journal of Agro-Environment Science

基　　金：国家水体污染控制与污染治理科技重大专项(2017ZX07301006006)。

摘　　要：探讨流域土地利用变化及其水质效应,有利于从源头控制水污染。以内蒙古自治区典型草原区河流海拉尔河为研究对象,综合GIS技术、多元统计及偏最小二乘回归模型,对2005—2015年间流域土地利用的动态变化及其对水质的影响进行分析。结果表明,2005—2015年研究区各土地利用类型面积发生较大变化,其中草地面积大幅锐减、水域面积明显萎缩,而林地、农田、城镇用地、未利用地面积增多,特别是在中上游流域土地利用类型变化较明显;土地利用格局整体呈现景观破碎化程度加剧、形状趋于复杂化、多样性增加、聚集度减弱的趋势,下游流域土地利用格局变化较明显。海拉尔河中上游水质基本满足环境功能区要求,下游水质污染物浓度大幅升高,高锰酸盐指数(CODMn)全年超标,研究时段内河流水质总体平稳改善。偏最小二乘回归模型显示,与水质呈显著正相关的主要土地利用指标为凝聚度(COHE)、蔓延度指数(CONTAG),负相关指标为农田面积占比(AGRI)、香农多样性指数(SHDI),主要水质污染指标CODMn对土地利用的显著响应均出现在雨季。研究表明,土地利用变化是影响区域非点源污染的重要因素,是海拉尔河有机污染的驱动因子之一,建议加强区域土地利用空间管控。The study of land use change and its effects on water quality is essential for controlling water pollution at the source.Using GIS technology,multi-statistics,and a partial least squares regression model,the changes in land use and their impact on water quality from 2005 to 2015 were analyzed in the Hailar River,a typical grassland river in the Inner Mongolia Autonomous Region.The results showed that significant changes in land use types occurred in the middle and upper basins,and grassland area and water area decreased sharply,while forest area,farmland area,urban land area,and unused land area increased.Furthermore,the land use pattern presented increasing landscape fragmentation,complexity,diversity,and a trend of decreasing aggregation,especially in the downstream catchment.The water quality of the Hailar River improved steadily during the study period.Water quality in the middle and upper reaches met the functional environmental requirements but deteriorated significantly downstream,where the permanganate index(CODMn)exceeded the standard throughout the year.The partial least squares regression model revealed that the key land use indicators showing predominantly positive relationships with water quality concentration were the cohesion index(COHE)and contagion index(CONTAG),while the proportion of farmland area(AGRI)and Shannon′s diversity index(SHDI)showed negative relationships.Moreover,the most dominant pollutant parameter,CODMn,was sensitive to land use change during the rainy season.This implies that land use change was an important factor influencing regional non-point source pollution and one of the driving factors of organic pollution in the Hailar River,suggesting that spatial control of regional land use should be strengthened.

关 键 词：土地利用 景观格局 水质效应 偏最小二乘回归模型 

分 类 号：S812[农业科学—草业科学] F321.1[农业科学—畜牧学]