太湖平原地区不同土地利用类型对水质的影响

为探讨不同土地利用类型对太湖流域水质状况的影响,以太湖腹部平原区为例,基于典型年地表河流水质监测数据,结合TM影像解译结果所反映的土地利用状况,分别从区域和水质站点周边缓冲区两个方面,计算不同土地利用类型与水质状况的灰色关联序,以反映土地利用类型对地表水质的影响,为太湖腹部平原区的土地利用与水污染防治提供参考。结果表明:河流水质整体上与土地利用类型的灰色关联度最大的是城镇用地,其次是水田和旱地,水域和林地的灰色关联度最低;丰水期、枯水期的不同水质指标与土地利用的灰色关联序有一定区别,而水质站点缓冲区土地利用为样本时,水质指标受城镇用地影响最大,其次为耕作用地,最低为水域。

Effects of land use changes on water quality of the plain area in Taihu Basin

The water environment in Taihu Lake Plain has been getting worse in recent years. To improve the situation of this water environment, the effects of different land use and land cover(LULC) on water quality should be studied. Taihu Lake Plain was chosen as the study area because of its representativeness. Based on surface water quality monitoring data in a typical year and land use and land cover(LULC), the grey relational order between LULC and surface water quality was calculated through Grey Relational Analysis(GRA). The similarities between curves drew from the data of LULC and water quality indices were compared to determine the grey relational order. Circle buffer zones(200, 500, 1000, 1500, 2000 m) of sites and divided areas were set as samples to calculate the grey relational order which can reflect effects of LULC on surface water quality. The grey relational order between surface water quality and LULC was urban land> dry land or paddy field> forestland> water area. The grey relational orders of water quality indices were different between the dry season and the wet season. Surface water quality was affected by urban land most and by water area least when buffers of water quality monitoring sites were set as examples. This research provides references for land use change and water quality protection. Data with more details should be collected in a further study. A mechanism model is needed to explain how LULC affects surface water quality.