Attribution of Eco-hydrological Responses in Anning River Basin to Climate Change and Land Use Change

The climate change and land use change are the two driving factors affecting hydrological cycle and sustainable utilization of water resources in rivers. Therefore, it is of great significance to effectively reveal the changes of land use and the climate change for ecological and hydrological response. Anning River Basin in southwest China is the second tributary of Jinsha River, which has experienced climate drought and water resources shortage. Based on the basic geographic information data, meteorological data and hydrological data, the semi-distributed hydrological model MIKESHE was used to simulate the ecological and hydrological status of the watershed, and the ecological hydrological response characteristics of the watershed with different ecological and hydrological conditions were compared. With the validated models, we discussed the potential eco-hydrological responses of land use and climate change by setting scenarios of extreme land use, precipitation reduction with 20% and temperature rise with 2℃. As hydrological impacts of land use change and climate change may be temporally varied, it is requisite to manage water resources adaptively to address future climate change and water resources shortage. Aiming at the complexities of water resources management, a multi-stage fuzzy stochastic programming model considering the ecological water demand of the vegetation by means of multi-stage, fuzzy, interval and other optimization techniques was developed. It is able to reflect dynamics of uncertainties and the related decision processes through constructing a series of representative scenarios within a multi-stage context under a set of fuzzy α-cut levels. The results indicate that the dynamic and complexity of water resources allocation can be reflected through the multilayer discrete context tree. Moreover, real-time correction for reducing the risk of water shortage and low economic penalty can be presented. They can seek water resources management programs that are coordinated and unified in economic, social and environmental benefits at different risk levels. Model optimization results can provide alternatives in different situations, which not only help decision makers to conduct in-depth analysis, but also contribute to the sustainable development of the ecological environment.