A Study on Retrieval Algorithm of Black Water Aggregation in Taihu Lake Based on HJ-1 Satellite Images

35th International Symposium on Remote Sensing of Environment

地球科学;生态环境科学

Lei, Zou^1 ; Bing, Zhang^1 ; Junsheng, Li^1 ; Qian, Shen^1 ; Fangfang, Zhang^1 ; Ganlin, Wang^1

Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100190, China^1

关键词: Black water aggregations;    Climate condition;    Digital numbers;    Empirical algorithms;    Environmental satellites;    Retrieval algorithms;    Retrieving algorithms;    Satellite images;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/17/1/012100/pdf
DOI  :  10.1088/1755-1315/17/1/012100

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The phenomenon of black water aggregation (BWA) occurs in inland water when massive algal bodies aggregate, die, and react with the toxic sludge in certain climate conditions to deprive the water of oxygen. This process results in the deterioration of water quality and damage to the ecosystem. Because charge coupled device (CCD) camera data from the Chinese HJ environmental satellite shows high potential in monitoring BWA, we acquired four HJ-CCD images of Taihu Lake captured during 2009 to 2011 to study this phenomenon. The first study site was selected near the Shore of Taihu Lake. We pre-processed the HJ-CCD images and analyzed the digital number (DN) gray values in the research area and in typical BWA areas. The results show that the DN values of visible bands in BWA areas are obviously lower than those in the research areas. Moreover, we developed an empirical retrieving algorithm of BWA based on the DN mean values and variances of research areas. Finally, we tested the accuracy of this empirical algorithm. The retrieving accuracies were89.9%, 58.1%, 73.4%, and 85.5%, respectively, which demonstrates the efficiency of empirical algorithm in retrieving the approximate distributions of BWA.