Land use change and classification in Chaohu Lake catchment from multi-temporal remotely sensed images

ABSTRACT Chaohu lake and its surrounding have received considerable attention in terms of water and sediment pollution investigations. In this study, the trend of changes in four key land uses in the catchment area was examined. Maximum Likelihood Supervised Classification (MLC) in ESRI？ ArcGIS was applied to subsets of Landsat MSS, TM, ETM and OLI/TIRS images of 1979 to 2015. The results showed that the water bodies’ position remained relatively stable, while the portions of land used for urban activities and agriculture consistently increased. The built-up areas increased from 3.5% in 1979 to 25.1% in 2015. Similarly, the agricultural land use increased from the area coverage of 29.8% in 1979 to 45.2% in 2015. Forested/vegetated land of the catchment substantially decreased during this period, from 59.8% in 1979 to 22.9% in 2015. Decades of improper land use activities and resource utilisation have led to ecological degradation of the basin which has manifested in serious eutrophication of the lake. The conflict between the economic development and the need to protect the ecosystem of Chaohu catchment has now become a management issue. Deliberate planning should be made to reduce the rate of conversion of the forested land area to agriculture and urban use