基于OLI遥感影像的叶绿素a质量浓度反演研究

为探究研究区叶绿素a质量浓度分布,更好的应对水体富营养化对东张水库水源安全的威胁。采用数学回归模型,利用OLI遥感影像,根据长期定点监测的叶绿素质量浓度数据与遥感影像光谱信息特征值的内在联系,构建叶绿素a质量浓度反演数学模型,应用GIS得出东张水库连续空间、离散时间上叶绿素a质量浓度的分布。结果表明,东张水库叶绿素质量浓度7月份明显高于11月份与3月份;东张水库沿库岸及进口位置叶绿素a质量浓度明显高于库心位置质量浓度;环东张水库截污工程前后相同月份叶绿素质量浓度有着明显的改善。遥感数据在空间、时间维度分布有差异的情况下,反演结果误差较小,精度满足管理决策需要,有着较好的适用性。

Study on the Inversion of Chlorophyll-a Concentration of Dongzhang Reservoir Based on OLI Remote Sensing Image

Chlorophyll-a was globally known as a key parameter for regular eutrophication mon.itoring dealing with the environmental crisis.Considering the inner link between the chlorophyll-a concentration and characteristic of spectra,the remote sensing technique was adopted as an efficient and accurate method for extracting chlorophyll-a.The aim of the study was used to map the spatio-temporal chlorophyll-a concentration changes in Dongzhang reservoir and analyze the fitness,as an indicator of eutrophication using readily available Landsat multispectral images (OLI) and GIS.The results indicated that the chlorophyll-a concentration in summer,particularly in July,was higher than November and March.The chlorophyll-a concentration where along the bank and inlet was higher than the center of the reservoir.In comparison to the former,the chlorophyll-a concentration was in a lower level when the sewage engineering was constructed.The precision of the inversion algorithm was considered to meet the requirement of management and have good applicability under different spatial and temporal conditions.