The Rangeland Hydrology and Erosion Model: A Dynamic Approach for Predicting Soil Loss on Rangelands. Issue 11 (18th November 2017)

• Record Type: Journal Article
• Authors: Hernandez, Mariano; Nearing, Mark A.; Al‐Hamdan, Osama Z.; Pierson, Frederick B.; Armendariz, Gerardo; Weltz, Mark A.; Spaeth, Kenneth E.; Williams, C. Jason; Nouwakpo, Sayjro K.; Goodrich, David C.; Unkrich, Carl L.; Nichols, Mary H.; Holifield Collins, Chandra D.
• Is Part Of: Water resources research. Volume 53:Issue 11(2017)
• Page Start: 9368
• Page End: 9391
• Publication Date: 2017-11-18
• Subjects: rangelands -- soil erosion models -- soil conservation -- ecological sites -- sediment transport; Hydrology -- Periodicals; 333.91
• DOI: 10.1002/2017WR020651
• Languages: English
• ISSNs: 0043-1397

Abstract

Abstract: In this study, we present the improved Rangeland Hydrology and Erosion Model (RHEM V2.3), a process‐based erosion prediction tool specific for rangeland application. The article provides the mathematical formulation of the model and parameter estimation equations. Model performance is assessed against data collected from 23 runoff and sediment events in a shrub‐dominated semiarid watershed in Arizona, USA. To evaluate the model, two sets of primary model parameters were determined using the RHEM V2.3 and RHEM V1.0 parameter estimation equations. Testing of the parameters indicated that RHEM V2.3 parameter estimation equations provided a 76% improvement over RHEM V1.0 parameter estimation equations. Second, the RHEM V2.3 model was calibrated to measurements from the watershed. The parameters estimated by the new equations were within the lowest and highest values of the calibrated parameter set. These results suggest that the new parameter estimation equations can be applied for this environment to predict sediment yield at the hillslope scale. Furthermore, we also applied the RHEM V2.3 to demonstrate the response of the model as a function of foliar cover and ground cover for 124 data points across Arizona and New Mexico. The dependence of average sediment yield on surface ground cover was moderately stronger than that on foliar cover. These results demonstrate that RHEM V2.3 predicts runoff volume, peak runoff, and sediment yield with sufficient accuracy for broad application to assess and manage rangeland systems. Key Points: A dynamic model for assessing water‐driven rangeland soil erosion rates is presented and tested Application of the model to a small, hillslope‐sized watershed in SE Arizona showed improved predictive function over the previous steady state model for rangelands A case study of application of the model to 124 rangeland sites in the western United States illustrated the possibilities for using the model for broad‐scale assessments