Analyzing and forecasting water-land dynamics for sustainable urban developments: A multi-source case study of Lake Dianchi’s environmental challenges (China)

The delicate plateau lake ecosystem has been further damaged by extensive human construction projects, leading to water pollution in Lake Dianchi, China. This serves as a prominent example of urbanization and human interference, drawing global scholarly interest. Restoring Lake Dianchi’s water quality remains a global challenge despite 40 years of treatment, with unclear links to surrounding land development. Therefore, this study constructed a GIS database, combined with 2013–2023 landsat-8/MODIS, Land Use/Land Cover (LULC) remote sensing data and multi-year water quality monitoring, to conduct a multi-scale analysis of the plateau Lake Dianchi and its surrounding land, and implemented it through a Self-Organizing Map (SOM). The classification of lakeshore pollution source clusters was further analyzed through Redundancy Analysis to explore the interaction and future trends between lake water quality and land development in the lakeshore zone. Research indicates the following: (1) According to cluster analysis, water quality in semi-urban lakeside areas (cluster 2) had the highest correlation with lakeside land use, followed by urban areas (cluster 1) and rural areas (cluster 3); (2) Lake water pollution was difficult to improve through the optimization of land development in the lakeshore zone. Combined with the results from (1), although semi-urban areas had a certain impact on water quality, over time, there was a trend of decorrelation between the steady state of water quality pollution and the development of urban construction. This trend indicates that urban development consistently contributes to single pollution sources in water quality; (3) At different scales, the water pollution index in semi-urban areas responded significantly to construction activities, indicating signs of tele-coupling; the response to farmland was complex, while the response to green space was small; (4) In the process of decorrelation between lake water quality and land development, the rate in urban areas (cluster 1) and rural areas (cluster 3) was faster than that in semi-urban lakeside areas (cluster 2). To sum up, it is difficult to restore the water quality of Lake Dianchi through optimizing urban land layout. Meanwhile, it is necessary to further prevent and control the impact of remote pollution sources on the water quality of Lake Dianchi. Protection of the plateau lake environment cannot remain at the optimization level; it should further realize the principles of multi-dimensional governance. This is also the key to addressing the lack of results in Lake Dianchi management for many years.