C:\ Program Files\ CRHM\ QdroD QdfoD Qdro Qdfo SunMax global CalcHr Qsi calcsun hru_t hru_rh hru_ea hru_u hru_p hru_rain hru_snow hru_sunact hru_tmax hru_tmin hru_tmean hru_eamean hru_umean hru_rhmean hru_newsnow t rh ea u p ppt Qsi Qso Qn Qln SunAct form_data obs net_rain net_snow intcp_evap intcp net cum_net netall Rn Qg Qs net_rn hru_evap transp_on evap pb Hydrology of Prairie Droughts John Pomeroy, Kevin Shook, Robert Armstrong, Xing Fang Centre for Hydrology University of Saskatchewan Saskatoon, Sask www.usask.ca/hydrology
Non-Contributing Areas to Streamflow a Prairie Characteristic
Prairie Runoff Generation Snow Redistribution to Channels Spring melt and runoff Dry non-contributing areas to runoff Water Storage in Wetlands
Prairie Hydrology don t blink Smith Creek, Saskatchewan Drainage area ~ 450 km2 20 Average 1975-2006 15 Streamflow m 3 per second 25 1995 High Year 10 2000 Low Year 5 No baseflow from groundwater 0 27-Dec 27-Nov 28-Oct 28-Sep 29-Aug 30-Jul 30-Jun 31-May 01-May 01-Apr 02-Mar 31-Jan 01-Jan Hydrological drought can be viewed as the absence of prairie runoff
How to Characterise Hydrological Drought for the Prairies? River flows well gauged, but subject to abstraction, storage and do not reflect Prairie hydrological conditions. Streamflow network is more representative but is sparse, and subject to changes in land cover, drainage, abstraction, storage. Possibility to model prairie runoff generation and related hydrological processes to create a hydrological drought surface for the Prairies using atmospheric driving data and standardised representation of prairie snow redistribution, melt, runoff generation, infiltration and evaporation.
Modelling Objectives To Demonstrate the: differences between drought and non-drought hydrological cycling at the surface, evolution of hydrological drought over time and space Calculated Variables as ratios to non-drought conditions (~Hydrological Drought Indices~) Snow Accumulation peak SWE, duration Spring Freshet total, duration Actual ET/PET growing season Soil Moisture spring, summer, fall
Cold Regions Hydrological Model (CRHM) Drought Hydrology Simulation Model the effects of local drought meteorology on the hydrology of representative, first-order prairie basins Create virtual basin models, which can be applied to gridded datasets Allows comparison of basin response to drought conditions and to normal variability Requires high resolution driving data over entire Prairies for normal (1961-1990), non-drought (1962-1987) and drought periods (1999-2004) Snowfall, rainfall Incoming shortwave radiation, cloudiness or sunshine hours Temperature Humidity Wind speed
CRHM Prairie Hydrological Model Configuration Flow Chart in Cold Regions Hydrological Modelling Platform (CRHM)
CRHM Tests Creighton Tributary of Bad Lake -well drained semi-arid St. Denis National Wildlife Area -internally drained subhumid
Case Study at St. Denis, Sask (2007) Granger-Gray Evaporation module Validation site Eddy Cov E = 2.2 mm Granger-Gray E 2.6 mm Udir mm Aug 5, 2007
CRHM Hydrological Response Unit (HRU) Configurations Well Drained Fallow Stubble Grass Coulee Stream Creighton Tributary, Bad Lake Poorly Drained Cultivated Wooded Wetland Pond Wetland 109, St Denis
CRHM Hydrological Indices Snowcover duration Peak SWE Spring discharge (freshet) amount Streamflow duration AET/PET Soil moisture
NARR Variables All data required by CRHM are available from NARR Quality of data varies Incoming shortwave radiation is computed from modelled clouds, NOT from surface measurements
Edmonton 1979-2000
Winnipeg 1979-2000
Why not use all NARR data? Winnipeg daily Tmin & Tmax, 1979-2000
NARR precipitation Calgary 1999-2003 Unusable
CRHM Simulations Winnipeg and Calgary to date HRUs grass, cropped Evaluation of changes to drought hydrology
Calgary SWE on GRASS 1961-89
Winnipeg 2002 Drought SWE
Winnipeg Maximum SWE
Winnipeg Spring Freshet
CRHM Gridded First Order Hydrology Runs to be completed for all Prairies this winter, then mapped Will provide first physically based, comprehensive estimation of runoff generation from first order basins in Prairies Useful information for DEWS (soil moisture, SWE, peak flow, duration of flow, wetland level, actual evaporation) Actual evapotranspiration maps using remote sensing, splined observations, reanalysis Provides a hydrological modelling tool for general prairie application Advises application of VIC and MESH to Prairie environment