Assessing Future Water Availability and Water Use Impacts in Minnesota Using a Geospatial System Dynamic Model

Multiple environmental and social-economic variables can lead to increases in the uncertainty of water availability. Given that water is a regional resource, the absolute level of water availability estimated by the large-scale models is not an adequate indicator for local or state-level water management and planning. Additionally, water availability and withdrawal cannot be isolated from various socio-economic, technical, and demographic factors, but previous studies generally ignore such inherent linkages in planning. Therefore, to understand the future water availability and water use impacts, there is an urgent need to connect water use, its impacts, and the background variables from social-economic and environmental aspects.;This study focuses on investigating local water balance and use impacts in response to changes in population and climate. A spatially-explicit framework coupling system dynamic model and geographic information system was established to simulate daily water availability and withdrawal on a watershed level by taking climate and demographic factors into account. This study uses Minnesota as an example and applies the framework on all 81 watersheds. The results indicate that water withdrawal by 2030 would increase by 28% from the average level in 2000 under the designated climate change scenario, 126% under the population scenarios, and 134% under the joint climate-population effect. Approximately 80% of water use impact was caused by power generation and public supply sectors. Therefore water conservation planning should be prioritized in these two water use categories.