鄱阳湖表层水体总磷含量遥感反演及其时空特征分析

Retrieval of Total Phosphorus Concentration in the Surface Waters of Poyang Lake Based on Remote Sensing and Analysis of Its Spatial-Temporal Characteristics

总磷是湖泊水质参数中的主要指标,从遥感数据中获得其时空上的分布信息对于理解、管理和保护湖泊生态系统是必要的。通过2009年4月至12月对鄱阳湖湖区和五河入口的表层水体进行采样分析,利用直接遥感反演算法和间接遥感反演算法,结合MODIS遥感数据择优反演鄱阳湖表层水体的总磷含量,同时分析总磷含量的时空特征和变化规律。结果表明:①从实验数据分析可知,总磷TP与总悬浮物浓度相关性较好,间接反演算法能够得到较好的反演结果;②TP是鄱阳湖水质的主要污染指标之一,TP含量在丰水期、平水期、枯水期三个时期呈上升趋势;③鄱阳湖三个时期TP含量的空间变化明显,中心湖区TP含量相对整个湖区较低,主航区和五河入口TP含量为全湖最高区域,常年处于高含量状态。

Total phosphorus （TP） is one of the most important indicators for water quality in a lake, and obtaining its spatial and temporal distribution from remote sensing data is necessary for understanding, managing and protecting lake ecosystems. By surface water sampling and analysis on the Poyang Lake and entrance of five rivers from April to December, 2009, adopting the direct and indirect inversion algorithms for remote sensing data, which can better algorithmically inverse TP content combining MODIS data for Poyang Lake, its spatialtemporal change characteristics are analyzed. The results are as follows： 1） The analysis of the experimental data shows that the concentration of TP and total suspended sediment have good correlation, indirect inversion algorithm can get better inversion results; 2） TP is one of the main pollution indicators in Poyang Lake, TP content shows a upward trend in the wet season, the level season and the dry season; 3） spatial variation of the TP content of Poyang Lake is apparent in the three seasons, TP content in central lake is relatively low compared with the entire lake, TP content is the highest in the main navigation areas and entrance of the five rivers for the whole lake area, maintaining a high level state throughout the year.