Thursday, March 31, 2016
University of New Mexico Researchers Model Precipitation and Evapotranspiration
University of New Mexico Researchers Model Precipitation and Evapotranspiration by Ricardo González-Pinzón, UNM Accurate statewide water budgets are dependent on the quality, quantity and availability of measured information in catchments. Given typical data acquisition constraints, water budgets rely on the measurement of a limited number of water fluxes (e.g., precipitation and streamflow) and on modeling tools that allow for estimation and scaling of other relevant, unmeasured fluxes. In our study, we used a parsimonious modeling technique (Doing Hydrology Backward (DHB) from Kirchner (2009)) that utilizes discharge data alone to estimate catchment-averaged precipitation and evapotranspiration rates in New Mexico. Discharge fluctuations were analyzed for three New Mexico basins: Canadian River, Rio Grande, and the Pecos River. We developed an open source MATLAB code capable of estimating catchment-average precipitation and evapotranspiration rates. We successfully validated the code using the original data presented by Kirchner (2009). Despite providing accurate estimates of hydrologic processes in humid catchments, the standard DHB model did not accurately represent precipitation rates observed in three dryland basins in New Mexico. As it is, the DHB code that we developed in MATLAB will be useful in humid catchments. However, it requires the addition and validation of snowmelt terms before it can be used in our characteristic New Mexico dryland basins. The study was funded by the NM WRRI. To view the final report click here.