TITLE:
Modeling the Effect of Irrigation Practices in Flash Floods: A Case Study for the US Southwest
AUTHORS:
Cesar Canon-Barriga, Juan Valdes, Hoshin Gupta
KEYWORDS:
Irrigation Practices; Flash Flood Events; Reference Crop Evapotranspiration; Soil Saturation; Streamflow Forecasts
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.4 No.7,
June
18,
2012
ABSTRACT: Conventional streamflow forecasting does not generally take into account the effects of irrigation practice on the magnitude of floods and flash floods. In this paper, we report the results of a study in which we modeled the impacts of an irrigated area in the US Southwest on streamflow. A calibrated version of the Variable Infiltration Capacity model (VIC), coupled with a routing algorithm, was used to investigate two strategies for irrigating alfalfa in the Beaver Creek watershed (Arizona, USA), for the period January to March of 2010, at a resolution of 1.8 km and hourly time step. By incorporating the effects of irrigation in artificially maintaining soil moisture, model performance is improved without requiring changes in the resolution or quality of input data. Peak flows in the watershed were found to increase by 10 to 500 times, depending on the irrigation scenario, as a function of the strategy and the intensity of rainfall. The study suggests that both flood control and irrigation efficiency could be enhanced by applying improved irrigation techniques.