Linking a Land-Use Cellular Automata with a Water Allocation Model to Simulate Land Development Constrained by Water Availability in the Elbow River Watershed in Southern Alberta

Abstract

The availability of water resources in southern Alberta is under pressure, now and most likely even more so in the remainder of the 21st century if forecasts on climate change, economic development and associated population growth come true. Alberta Environment is mandated by the provincial Water Act to regulate most use of water through a system of water licenses. This department is currently using a water resource management model (WRMM) to support its planning, but wishes to expand the reach of its decision support tools by including additional factors such as the land-use dynamics. This paper presents the coupling of the WRMM and a land-use cellular automata (CA) model to constrain land development based on water availability in the Elbow River watershed in southern Alberta. Simulations were run with a calibrated CA model using a land-use map of 2006 as the starting year up to the year 2031, at a five-year interval and at a spatial resolution of 60 m. Two scenarios were tested: the business as usual scenario, which is a simple extrapolation of observed historical land development, expressed as the number of built-up cells, and a second scenario in which land development is constrained based on the WRMM water availability output. Results indicate that land development varies in terms of growth and spatial distribution when comparing the two scenarios. The potential benefits and limitations of the two models are discussed and further improvement needed to increase their usefulness in guiding water resource management is highlighted.