The transboundary influence of environmental change is a critical issue in the Lancang-Mekong region.As the largest river-connected lake in the lower Mekong,the ecological change and influence of Tonle Sap Lake have received widespread attention and discussion,especially after 2008,when the hydrological regime of the Lancang-Mekong River mainstream underwent distinct changes.However,the linkage and coupling mechanism between the lake riparian environment and mainstream water level change are still unclear.In this study,the interannual spatiotemporal changes in land cover in the Tonle Sap Lake riparian zone(TSLRZ)and their relationship with mainstream water levels were analysed.The results showed that the expansion of farmland was the most notable change in 1988–2020.After 2008,the land cover changes intensified,manifested as accelerated farmland expansion,intensified woodland fragmentation and significant water body shrinkage.Furthermore,the responses of the water body,degraded land,wasteland and grassland areas to the mainstream water levels weakened after 2008.Evidently,the land cover changes in the TSLRZ in the last 30 years were less related to the mainstream water level change than to local reclamation and logging.These results can offer a new scientific basis for the transboundary influence analysis of hydrological change.
The evolution of land use/land cover(LULC)patterns significantly influences the dynamics of carbon storage(CS)in terrestrial ecosystems.In response to future environmental changes,however,most studies fail to synthesize the effects of policy pathways and evolving core driving factors on LULC projections.This article presents a systematic framework to assess the dynamic response of the terrestrial ecosystem CS to future LULC changes.After investigating spatiotemporal characteristics and driving forces,policy effects and future core driving factors are integrated into the improved Markov–future land use simulation model to project LULC across diverse scenarios.Then the Integrated Valuation of Ecosystem Service and Tradeoff model is coupled to explore CS dynamics with LULC changes.This framework was applied to the Weihe River Basin.The finding reveals that the overall proportion of cultivated land,forestland and grassland is above 85%and is significantly influenced by policy effects.Precipitation,temperature,population density and gross domestic product are core driving factors of LULC changes.Equal-interval projection is a viable approach to mitigate policy impacts by avoiding error propagation while coupling future core driving factors to improve LULC projection accuracy.Ecological protection should be emphasized in the future.The rate of increase in CS is 1.25 and 1.63 times higher than the historical trend and economic development scenario,respectively,which alleviates carbon loss from the expansion of built-up land.This research provides a valuable reference for future insight and optimization of ecological conservation strategies.
