基于GF-1号卫星WFV数据的太湖水质遥感监测

Remote sensing monitoring of Taihu Lake water quality by using GF- 1 satellite WFV data

为研究高分一号(GF-1)卫星数据监测太湖水质的可行性,基于新发射的GF-1卫星16 m分辨率的多光谱宽覆盖(wide field of view,WFV)相机和HJ-1A CCD数据,对太湖的叶绿素a、悬浮物、透明度和富营养化状况进行遥感监测,以评价GF-1 WFV相机的应用潜力。研究结果表明:GF-1 WFV与HJ-1A CCD数据对水质参数的反演结果具有一致性,可有效反映叶绿素a浓度、悬浮物浓度、透明度和富营养化指数的空间变化规律。其中,太湖西北部分布有少量水华蓝藻,在大面积蓝藻爆发区域附近,叶绿素a浓度明显高于其他区域的水体,平均浓度为62.46 mg·m-3;悬浮物浓度以竺山湾及西部沿岸湖区较大,沿西北向东南方向递减,平均浓度为26.07 mg·L-1;透明度整体从西北向东南递增,与悬浮物浓度的分布趋势相反,平均值为22.1 cm;富营养化指数整体从西北向东南递减,与叶绿素浓度的分布趋势相同,平均值为69.62。遥感监测指标的结果均符合常规监测规律。

The chlorophyll - a concentration, suspended solids concentration, transparency and eutrophication index for the Taihu Lake were obtained by using GF-1 satellite wide field of view （ WFV） camera and HJ-1A satellite CCD camera data with the purpose of evaluating the GF - 1 satellite ’ s application capability in environmental monitoring. The results show that the WFV camera data, consistent with the HJ -1A inversion results, could be used to monitor the distribution of the water quality parameters including chlorophyll - a concentration, suspended solids concentration, transparency and eutrophication index. It was shown that the algal blooming areas were found in the northwest of the Taihu Lake, the chlorophyll-a concentration was the highest near the algal blooming area, and the average of chlorophyll-a concentration in the whole lake was 62. 46 mg·m-3 . The suspended solids concentration was higher near the Zhusan Valley and the west coast area and decreased in the NW-SE direction, with the whole average value being 26. 07mg·L-1 . The transparency decreased in the NW-SE direction in contrast to the distribution of suspended solids concentration, with the whole average value being 22. 1 cm. The eutrophication index decreased southeastward, being the same as the distribution of chlorophyll-a concentration, with the whole average value being 69. 62. These results are consistent with the results of the routine surveying.