Hydrology of the Delta Marsh Watershed: water balance characterization and analysis of land use changes
Schellenberg, Gregory John
MetadataShow full item record
A hydrological model was used to examine the water balance of the Delta Marsh Watershed (DMW) currently and as impacted by land use changes. Understanding DMW hydrology can help to improve conditions in the Delta Marsh. MIKE SHE model results showed that the water balance is typical of prairie conditions with limited wintertime activity, significant spring melt runoff, and high summertime evapotranspiration and infiltration. Results showed that the DMW contributes approximately 40 million m3 of water to the Delta Marsh in an average year, or 710 m3/ha/yr. Portage Creek is the single greatest inflow from the watershed (31% of total) and the West Marsh area also receives large runoff volumes (combined 37% of total). Analysis of land use changes showed that urban expansion in the DMW would increase annual marsh inflows by over 50% under one urbanization scenario due to associated decreases in infiltration and transpiration. An agricultural shift towards row crop predominance would have minimal impact on the DMW water balance. Conversion of cropland to natural vegetation would decrease annual runoff by 12% to the marsh due to increased surface ponding, infiltration, and transpiration.