Impact of antecedent soil moisture on runoff from a semiarid catchment

JOURNAL OF HYDROLOGY

卷:569

Article

Schoener, Gerhard¹  Stone, Mark C.² 

[1] Southern Sandoval Cty Arroyo Flood Control Author, 1041 Commercial Dr SE, Rio Rancho, NM 87124 USA

[2] Univ New Mexico, Dept Civil Construct & Environm Engn, Albuquerque, NM 87131 USA

关键词: Soil moisture;    Runoff;    Arid;    Scaling;    Curve number;    Green and Ampt;   

DOI  :  10.1016/j.jhydrol.2018.12.025

来源: Elsevier

【 摘 要 】

Antecedent soil moisture is an important factor in the generation of runoff, but guidance for modeling moisture conditions in semiarid catchments is limited and conflicting. In this study, the impact of antecedent moisture was assessed at the plot scale (2.8 m(2)) using a portable rainfall simulator, and at the catchment scale based on observed precipitation and discharge for a 2.8 km(2) watershed in central New Mexico. Performance of three loss models commonly used for hydrologic analysis in the southwestern U.S. was tested at both scales. High initial moisture content led to substantially higher runoff ratios at both scales, confirming the importance of antecedent soil moisture for runoff predictions in semiarid drainages. Hydrologic parameters estimated based on plot experiments, however, were highly variable and cannot easily be upscaled to the catchment scale. Loss model performance was clearly scale dependent more simplistic (one- and two parameter) loss methods out-performed a more complex (four parameter) model at the watershed scale, while the opposite held true for test plot simulations. At the catchment scale, all models performed poorly for small runoff events, but yielded acceptable results for storms causing large discharges if antecedent soil moisture was considered. Failing to account for antecedent moisture led to simulated runoff volume errors up to one order of magnitude.

【 授权许可】

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