An integrated modeling system to simulate the impact of land-use changes on hydrological processes in the Elbow River watershed in Southern Alberta
Date
2013-01-25
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Abstract
The Elbow River watershed (ERW), in southern Alberta, Canada, covers an area of 1,238 km2 and is subjected to considerable pressure for land development due to the rapid population growth in the City of Calgary. In this study, a comprehensive modeling system was developed to investigate the impact of land-use change on hydrological processes considering the complex surface-groundwater interactions existing in the watershed. Specifically, a spatially explicit land-use change model was coupled with MIKE-SHE and MIKE-11, a distributed physical based catchment and channel flow model. The modeling system was designed such that it has the following unique features: simulate dominant land-use changes in a spatially distributed way using a spatially explicit land-use change model, integrate spatially distributed land-use based parameters through the coupling of the land-use change model and the hydrological model, use comprehensive mechanisms to simulate the surface water and groundwater processes and their interactions, and incorporate a flexible design so that new land-use change plans can be incorporated easily for scenario analysis. Following a rigorous sensitivity analysis along with the calibration and validation of the integrated models, four land-use change scenarios were simulated for the period 2016-2031: business as usual (BAU), new development concentrated within the Rocky View County (RV-LUC) and in the Hamlet of Bragg Creek (BC-LUC) respectively, and development based on projected population growth within the ERW (P-LUC). The simulation results reveal that the rapid urbanization and deforestation create an increase in overland flow, and a decrease in evapotranspiration, baseflow, and infiltration mainly in the east sub-catchment of the watershed. Furthermore, BC-LUC is the most preferable scenario, while the BAU scenario with the same amount of new built-up area is found less preferable in terms of the impact on overland flow and baseflow. The scenario P-LUC is found the least preferable out of all scenarios mainly due to the aggressive new development associated to the high population growth. The land-use/hydrological modeling system described in this study is resourceful and could be used to reduce the negative impact of land-use changes on the hydrological processes in the Elbow River watershed. This study is the first of this nature carried out in the Elbow River watershed, and is unique mainly due to its comprehensive framework that facilitates spatial explicit land-use change modeling, physical based and distributed hydrologic modeling, and the connection between these via distributed land-use based parameters. Furthermore, the design of this modeling system is flexible enough to extend this study to consider more aspects of the environment, e.g., incorporate climate change data to evaluate the impact of land-use and climate changes on hydrological processes.
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Hydrology, Environmental Sciences, Engineering--Environmental
Citation
Wijesekara, G. N. (2013). An integrated modeling system to simulate the impact of land-use changes on hydrological processes in the Elbow River watershed in Southern Alberta (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/24908