Analysis of water quality conditions in Lake Hachiroko, Japan, using ALOS AVNIR-2 data

Remote sensing has been used to understand water distribution and pollution in recent years. In this study, water quality conditions were analyzed using the data collected by the Advanced Visible and Near Infrared Radiometer type-2 (AVNIR-2) of the Advanced Land Observing Satellite (ALOS). The method comprised three steps. First, the AVNIR-2 data was preprocessed using geometric correction and mask processing. Second, fuzzy regression analysis of the AVNIR-2 data and direct measurements of local water quality were performed. The relationship between the water quality data and the AVNIR-2 data was calculated by solving the min problem and the max problem. Finally, maps of estimated water quality were obtained using fuzzy level-slice processing. Comparison of the maps of estimated water quality with real distributions of water quality in the study area indicates that the proposed method makes it possible to derive water quality conditions effectively from the AVNIR-2 data.