摘要
以杭州城区五条典型河流为研究对象,利用与水质监测数据相同年份的SPOT-5高分辨率卫星遥感影像,采用非监督分类与监督分类相结合的方法获取河流两岸土地利用信息;运用GIS的空间分析功能和景观生态学的原理,计算了河道两岸不同距离缓冲范围区内的土地利用结构和景观格局指数;从小尺度上研究和分析城市内部土地利用结构和景观格局与河道水质的关系,及其空间变化对水质的影响。结果表明,河道两岸土地利用结构中典型城市用地(商业及工矿用地和居民住宅用地)占主导地位,而耕地数量极少;河流两岸的土地利用类型与河流水质污染指标有强烈的相关性。当缓冲区距离为100m时,土地利用结构和格局与水质呈现出显著的相关性,其中典型城市用地与水质表现显著正相关,它是造成城市河流污染的最主要的因素,绿化用地与CODMn、BOD5,优势度指数与DO都有着显著的负相关;而随着缓冲区距离增大至200m和300m时,土地利用结构和格局与河流水质的相关性明显下降,甚至消失。
Land use is one of the most important components of urban environmental change research. Urban land use changes have both natural and human causes, but social and economic factors are the main driving forces. With its expanding, dense population and developing economy, some of China＇s urban ecosystems are increasingly fragile, with persistent environmental problems that cannot be ignored. Water pollution of urban rivers is one of the most serious environmental problems. This paper addresses the relationship between urban river water quality and land use structure and landscape pattern within the city boundaries of Hangzhou, using five rivers as a case study. GIS and RS techniques were applied to describe the land use structure and landscape. SPOT-5 satellite data, acquired for the same year as the water quality data, was classified into six land use types in ERDAS. Field investigation of land use was used to evaluate the classification. Land use structure and landscape pattern within buffer zones of different distances were analyzed using spatial analysis and landscape ecology methods. Based on fieldwork on land use and spatial characteristics, the minimum buffer distance of 100 meters and the maximum buffer distance of 300 meters were selected, and correlation and regression analysis methods were used to analyze the relationship between land use structure and river pollution. Results show that the composition of land use along all five rivers is similar, with urban land use （including commercial, industrial and residential land） occupying more than 75 % of the area, and minimal amounts of farmland. However, landscape characteristics of evenness, diversity and dominance are highly variable. There is a strong relationship between river water pollution and land use/land pattern within the 100-meter buffer. As the buffer distance increases to 200 and 300 meters, the correlation between water quality and land use structure and landscape pattern declines. Urban land use shows a distinct correlation with organic pollution of river water and is the dominant factor for most river pollution. Greenbelts reduce the organic pollution of rivers due to improved absorption capacity. Cultivated land and bare land are also important pollution sources. This suggests that protection of natural vegetation should be strengthened in urban environments, with limitations on urban land use and greenbelts on both sides of rivers to reduce pollution discharge. Sewage interception along urban areas is also critical for reducing pollution discharge, and pollution from cultivated and bare land areas should be controlled.
出处
《资源科学》
CSSCI
CSCD
北大核心
2008年第6期857-863,共7页
Resources Science
