太湖梅梁湖湾蓝藻生物量遥感估算

本文利用陆地卫星TM数据和图像处理方法对太湖富营养化严重的梅梁湖区的浮游蓝藻生物量作了遥感估算。1992年夏季在海梁湖开展了星地同步浮游藻类监测,获得了湖中16个采样点的现场叶绿素a生物量(Q_a)和蓝藻生物量(Q_B)数据,并利用这两组数据分别建立了与差异植被指数DVI的遥感回归模型,从而得到水体中叶绿素a以及蓝藻生物量的空间分布信息。从遥感定量模型出发,运用逐个像元积分统计技术,估算出梅梁湖叶绿素a总量为2133kg、蓝藻总量为178.2t.与地面方法相比,遥感估算方法充分利用了TM数据中的浮游藻类含量分布与变化信息,具有较高的估算精度。

ESTIMATING CYANOPHYTA BIOMASS STANDING CROPS IN MEILIANG GULF OF LAKE TAIHU BY SATELLITE REMOTE SENSING

Landsat Thematic Mapper data were processed to estimate the biomass of Cyanophyta in Lake Meiliang, a gulf in the northern part of Lako Taihu. In the summer of 1992, on-the-spot sampling was taken in the gulf on the date of the overpass of Landsat-5 for 16 carefully selected sites to obtain chlorophyll-a and phytoplankton concentrations. With the ground truth data and Thematic Mapper images,two regression models were established between chlorophyll-a and DVI (Differential Vegetation lndex) and between Cyanophyta concentration and DVI. The regression models were the basis of the techniques of mapping the spatial distribution of chlorophyll-a or Cyanophyta concentration and integrating the whole pixels to estimate the total amount of chlorophyll-a and Cyanophyta.It was estimated that the lake contained 2133 kilograms of chlorophyll-a, or 178.2 tones in terms of Chynophyta.