Keywords
hydrologic, hec-hms, hec-ressim, lake flooding, terminal lake
Start Date
1-7-2010 12:00 AM
Abstract
A dramatic phenomenon has been occurring in Devils Lake, a terminal lake inNorth Dakota: its inundated area has continually expanded since reaching its extreme lowin the 1940s. Devils Lake’s continual rise in water level has created immediate hardshipsfor local residents, particularly farmers who have lost large parcels of productive land andproperties. The search for solutions to the problems caused by the unique lake flooding hasmotivated our modeling of the lake basin’s hydrology, the lake processes, and climaticchange impacts. A distributed rainfall runoff model, HEC-HMS, has been calibrated forseveral major sub-basins that drain into the lake. A significant challenge has been theimplementation of Arc-Hydro within ArcGIS for a basin with relatively flat terrain (usingthe best available DEM of the region) which has undergone a lot of land-use changes in thepast century. Further complexities in modeling are introduced by a pumped-drainagescheme implemented by the state’s water commission to lower the lake level by pumpingand draining into an adjacent stream. The scheme operates whenever the stream’s waterquality is favorable. A reservoir simulation model, HEC-ResSim, which is coupled with theHEC-HMS model, is calibrated for the lake for a short period of time. For the modelcalibration, NASA’s remote sensing data, including the TRMM Multi-SatellitePrecipitation Analysis (TMPA) data, are used to supplement the limited ground data. Thecoupled, calibrated hydrologic-reservoir model allows a series of comprehensive climaticscenariosimulations to be carried out, a key feature of which is the use of future regionalclimatic conditions derived from GCM down-scaled ensembles. The described modeling isexpected to yield useful and usable results for planners and decision makers who set longtermsustainability plans for the Devils Lake region.
Modeling Hydrologic Regime of a Terminal Lake Basin with GCM Down-scaled Scenarios
A dramatic phenomenon has been occurring in Devils Lake, a terminal lake inNorth Dakota: its inundated area has continually expanded since reaching its extreme lowin the 1940s. Devils Lake’s continual rise in water level has created immediate hardshipsfor local residents, particularly farmers who have lost large parcels of productive land andproperties. The search for solutions to the problems caused by the unique lake flooding hasmotivated our modeling of the lake basin’s hydrology, the lake processes, and climaticchange impacts. A distributed rainfall runoff model, HEC-HMS, has been calibrated forseveral major sub-basins that drain into the lake. A significant challenge has been theimplementation of Arc-Hydro within ArcGIS for a basin with relatively flat terrain (usingthe best available DEM of the region) which has undergone a lot of land-use changes in thepast century. Further complexities in modeling are introduced by a pumped-drainagescheme implemented by the state’s water commission to lower the lake level by pumpingand draining into an adjacent stream. The scheme operates whenever the stream’s waterquality is favorable. A reservoir simulation model, HEC-ResSim, which is coupled with theHEC-HMS model, is calibrated for the lake for a short period of time. For the modelcalibration, NASA’s remote sensing data, including the TRMM Multi-SatellitePrecipitation Analysis (TMPA) data, are used to supplement the limited ground data. Thecoupled, calibrated hydrologic-reservoir model allows a series of comprehensive climaticscenariosimulations to be carried out, a key feature of which is the use of future regionalclimatic conditions derived from GCM down-scaled ensembles. The described modeling isexpected to yield useful and usable results for planners and decision makers who set longtermsustainability plans for the Devils Lake region.
