Evaluating potential impacts of land use changes on water supply-demand under multiple development scenarios in dryland region
Xueqiliu LIU, Beijing Normal University, China
Zhengjia LIU, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, China
Water scarcity greatly hinders sustainable development goal agenda and regional agriculture development in dryland regions. As we know, land use and cover changes are strongly responsible for spatial-temporal evolutions of water resource. However, there is little explicit understanding of how spatial patterns of future dryland use will affect the water supply-demand risk. To answer this question, this study took Yulin city of China, a typical dryland region, as a case study area, and firstly estimated its 2020-2050 land use patterns under three different scenarios, covering Natural Increased Scenario (NIS), Food Security Scenario (FSS) and Economic Development Scenario (EDS), with the help of the path-generating land use simulation (PLUS) model as well as Markov-chain model. Furthermore, this study employed InVEST model to explicitly investigate spatial-temporal evolutions of water supply, water demand and water supply-demand risk in all scenarios. The estimated results indicated that the largest expanding/shrinking land use types were grasslands/croplands in NIS, croplands/grasslands in FSS and built-up lands/croplands in EDS during 2020-2050, respectively. By 2050, all projected land use changes only slightly affected regional water supply (the fluctuation of ~5% compared to that in 2020), but greatly increased by ~57% regional water demand. Particularly, strong land use changes would likely put nearly 90% regions of Yulin city at endangered water supply-demand risk in 2020-2050. Ecological land and built-up land would easier suffer from critically endangered water supply-demand risk. On the basis of these analyzed results, this study proposed to develop water-efficient eco-agriculture, adjusting agricultural structure, enriching revegetation diversity, improving industrial water-saving technology and various mitigation strategies. These findings could provide some valuable information for dryland agricultural development and regional policy decision-making.
Mots clés : regional agriculture development|Water supply-demand risk|future land use patterns|mitigation strategies|dryland region
A103708XL