中文摘要：

为探索异质景观内不同土地利用格局与水质之间的相关关系,以太湖流域为对象,根据地形条件、土地利用状况及主要水系的流向,将太湖流域分为13个水文生态单元,并对各水文生态单元内主要土地利用/覆盖类型的相对面积占比与水质等级之间的相关性进行了研究。结果表明：各水文生态单元水质等级2006年的变异系数与其林地面积占比呈正相关,与农田和聚落用地的面积占比呈负相关,其中与聚落用地占比在非汛期时具有显著性,体现了不同土地利用方式对水质改善能力不同,林地对水质改善能力较强,而农田和聚落用地相对较弱;各水文生态单元水质等级与农田、聚落用地的相对面积占比呈正相关,并分别在汛期和非汛期表现出显著性;与林地面积占比呈负相关,与各单元湿地面积占比在非汛期时呈弱负相关,汛期和全年为弱正相关;4类主要土地利用方式对水质等级改善的效应在汛期为林地〉湿地〉聚落用地〉农田,非汛期为林地〉农田〉湿地〉聚落用地。林地对水质的正贡献最大;农田和聚落用地分别对汛期和非汛期水质负贡献最大。

英文摘要：

Aimed to explore the correlations between land use pattern and water quality in heterogeneous landscapes,Taihu Lake basin was taken as a case,and was divided into 13 hydro-ecological units based on topography,land use pattern,and flow direction of major hydrological systems.The correlation analysis on the area proportions of different land use/cover types and water quality grade across the hydro-ecological units showed that the coefficient of variation of the water quality grade had a positive correlation with the area proportion of woodland,but a negative correlation with the area proportions of farmland and settlement,being significant for that of the settlement in non-flood season,which suggested that different land use types had different effects on water quality,i.e.,woodland could improve water quality more effectively than farmland and settlement.The water quality grade of the hydro-ecological units was significantly positively correlated with the area proportion of farmland and of settlement in the flood season and non-flood season,respectively,but negatively correlated with that of woodland.There was a weak negative correlation between the water quality grade and the area proportion of wetland in the non-flood season,but a weak positive correlation in the flood season and in the whole year.The effect of the four major land use types in improving water quality in the flood season was in the order of woodland wetland settlement farmland,and that in non-flood season was woodland farmland wetland settlement,suggesting that woodland had the greatest positive contribution to the water quality,while farmland and settlement had the greatest negative contribution to the water quality in the flood season and non-flood season,respectively.