遥感方法应用于湖泊富营养化评价的研究

利用武汉东湖各子湖多年可靠的地面监测资料和1999年9月Landsat—7的TM各波段的卫星遥感数据,建立了各子湖的营养状态指数与TM各波段图像上灰度值之间的关系模型：一元线性模型、多元回归模型。运用这些模型对武汉各湖泊进行富营养化评价。同时基于地面监测资料,用日本学者相崎守弘提出的修正富营养化指数法对武汉主要湖泊的富营养化程度进行评价。结果显示,武汉湖泊多处于中富营养状态,遥感评价结果与地面监测结果基本一致。指出利用遥感方法进行湖泊水体富营养化监测评价是可行的、有效的、利用该方法可进行大范围的湖泊富营养化调查评价。

Study on Application of Remote Sensing to Assessment of Lake Eutrophication

Through analysis of the Thematic Mapper (TM) images in September, 1999, and reliable monitoring data for many years of several subdivision lakes of Lake Donghu in Wuhan, the authors discovered a good linear relation between the value of grey degree (GD) abstracted from TM band 5, band 7 images and Trophic State Indices (TSIM) of the lakes, and also established two regression models between TSIM and the value of GD, and evaluated all the main lakes in Wuhan according to the models. At the same time, based on the situ monitoring data, also evaluated the trophic status of lakes in Wuhan by other method "Amended Atrophic Indices" which was brought forward by Japanese scholar Morikiro Aizaki. The evaluated results by remote sensing models and situ monitoring data showed that most of lakes were mesotrophic. Some disparity existed between the results by different models. There are three reasons for the difference between the results of the different methods. First remote sensing technology reflects the average values of a certain corresponded with TM images in a certain period, but "Amended Atrophic Indices" reflects the annual average values of the monitoring spots. Second, the time of TM ' Images is later than that of situ monitoring data. And third, TM images are affected by cloud, water depth, suspension, such as sand, hyper-hydrophytes, etc. In a word, the result of remote sensing was almost agreed with the monitoring data. It means that sensing technology is feasible and effective to monitoring and evaluating the lake eutrophication in Wuhan and it can be also used to evaluate lake eutrophication in large scope.