上海环城绿带水体水质与土地利用结构的响应研究

Changes in water quality and land use structure in the green-belt area around Shanghai

选取了上海环城绿带中30个水体,以现场实测数据和解译的缓冲区土地利用类型为基础,综合运用马尔科夫转移矩阵和相关性分析,揭示了环城绿带的土地利用变化规律及其与水质的响应关系.结果显示:绿带水体历年以Ⅳ类—劣Ⅴ类为主,劣Ⅴ类水体占比呈逐年下降的趋势;缓冲区内以建设用地、林地和草地为主,三者合计占比约84.37%;以建设用地的减少和裸地增加为主,两者分别占总减少面积的48.95%和总增加面积的50.85%;在300 m缓冲区尺度上,草地对DO、Chla呈现正效应;在500 m尺度上,裸地是引起CODMn恶化的主要因素,而耕地在两个尺度均与多个污染指标呈正相关.

In this paper,we study land use change and its effects on water quality for 30 water bodies in the green-belt area of Shanghai;the analysis is based on the Markov transfer matrix and Pearson correlation analysis of field data and interpreted land use types.The results show that:the water quality is dominated by GradeⅣand lower GradeⅤ;the proportion of water bodies with lower GradeⅤis decreasing year by year;the buffer zone is dominated by construction land,forest,and grassland,with a total proportion of about 84.37%;the increase in construction land and decrease in bare land,accounted for 48.95%of the total reduced area and 50.85%of the total increased area,respectively;on the 300 m buffer scale,grassland had a positive effect on DO and Chla;on the 500 m scale,bare land was the main factor for CODMn deterioration;and cultivated land was positively correlated with multiple pollution indicators at two scales.