太湖叶绿素a浓度时空分异及其定量反演  

Spatio-temporal Distribution of Chlorophyll a Concentration and Its Estimation in Taihu Lake

作　　者：乐成峰[1] 李云梅[1] 孙德勇[1] 王海君[1] 黄昌春[1] 

机构地区：[1]南京师范大学虚拟地理环境教育部重点实验室,南京210046

出　　处：《环境科学》2008年第3期619-626,共8页Environmental Science

基　　金：国家自然科学基金项目(40571110);国家高技术研究发展计划(863)项目(2003AA131060)

摘　　要：利用2005年实测叶绿素a浓度数据分析了太湖叶绿素a浓度的时空分布特征,并利用同步光谱数据,分季节对太湖叶绿素a浓度的反演模型进行研究,从而分析叶绿素a的时空变化对反演模型的影响.首先分析1 a内叶绿素a浓度随时间的变化规律,然后利用反距离加权插值法绘制叶绿素a浓度不同季节空间分布图,分析叶绿素a浓度在不同季节的空间分布规律,在此基础上分春、夏、秋3个季节和中营养化、轻度富营养化、中度富营养化、重度富营养化4个营养状态进行叶绿素a浓度定量反演模型研究.结果表明,太湖叶绿素a浓度具有明显的时空分布特征.夏季叶绿素a浓度最高,冬季最低,平均浓度分别为56.29μg/L、13.61μg/L.秋季由于受到夏季高浓度的影响,叶绿素a浓度高于春季,平均值分别为26.43μg/L3、4.78μg/L;夏季叶绿素a浓度空间变化最大,冬季全湖叶绿素a浓度含量较为均一,空间变化不明显,秋季空间差异要大于春季;全年北部湖区的空间差异较大,而南部湖区相对较小.不同季节叶绿素a反演算法模型不同,春、秋季波段比值法反演效果较好;而夏季微分法反演效果明显好于其它反演算法,不同营养状态条件下反演算法差异相对较小.The temporal and spatial distribution of chlorophyll a concentration in Taihu Lake was analyzed using the data measured from January to October in 2005. Otherwise, chlorophyll a retrieval model was built using the synchronous spectrum data obtained in different season to evaluate the effect of chlorophyll a concentration temporal and spatial variation on the retrieval model. Firstly, temporal distribution of chlorophyll a concentration was analyzed. Then, chlorophyll a concentration was induced by Inverse Distance Weight method. Lastly, the chlorophyll a concentration estimation models based on spring, summer, autumn and different trophic states were built. An obvious spatialtemporal distribution was found for chlorophyll a concentration in Taihu. Chlorophyll a concentration had the maximal value in summer and the minimal value in winter, and the average chlorophyll a concentration was 56.29 μg/L, 13.61 μg/L respectively. Due to the effect of autumn, the average chlorophyll a concentration in autumn was higher than that in spring, and the average chlorophyll a concentration was 26.43 μg/L, 34.78 μg/L respectively. Marked spatial difference for chlorophyll a concentration was found in summer, while in winter the spatial variation was ambiguous. The spatial variation in autumn was greater than that in spring as influenced by summer. Spatially, the variation in north area was greater than those inthe other areas and the south area had less variation during the year. Because of the different chlorophyll a concentration, different season had different retrieval model. Band-ratio had better retrieval result in spring and autumn as there were lower concentration and less variation correspondingly. While in summer, because of the high chlorophyll a concentration and great spatial variation, among the arithmetic built in summer, the differential arithmetic was the optimal model, and the difference of Chl-a concentration retrieval model of different trophic state was minor.

关 键 词：太湖 Chl-a浓度 时空分布 反演模型 

分 类 号：X524[环境科学与工程—环境工程]