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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #350379

Research Project: Response of Ecosystem Services in Agricultural Watersheds to Changes in Water Availability, Land Use, Management, and Climate

Location: Water Management and Systems Research

Title: Rainfall variability on a small watershed: Implications for hydrologic modelling

item Erskine, Robert - Rob
item Green, Timothy
item KIPKA, HOLM - Colorado State University
item LIGHTHART, NATHAN - Colorado State University
item RAMIREZ, JORGE - Colorado State University

Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2018
Publication Date: 6/24/2018
Citation: Erskine, R.H., Green, T.R., Kipka, H., Lighthart, N.P., Ramirez, J.A. 2018. Rainfall variability on a small watershed: Implications for hydrologic modelling. Meeting Proceedings. 115.

Interpretive Summary: N/A

Technical Abstract: Rainfall is a key input to hydrologic models, and can vary greatly in both space and time. For small watersheds (areas of less than a few km2, for example), spatial uniformity is typically assumed, and temporal rainfall is often represented by a single rain gage. Rainfall variability is studied here on a 56-ha agricultural watershed in northeastern Colorado, where rainfall was continuously recorded at 5 locations beginning in 2001, and gradually increased to a maximum of 27 locations by 2017. Convective rain storms commonly produced significant spatial and temporal variability within this watershed. Effects of the spatial resolution of rainfall input on hydrologic model responses are quantified using the Agricultural Ecosystems Services (AgES) distributed watershed model. This daily model is calibrated to observed runoff and soil moisture using both uniform rainfall input from a single rain gage and spatially variable rainfall, as provided by the complete rain gage network and the climate interpolation tool in AgES. Changes to AgES are being implemented to incorporate sub-daily hydrologic components related to surface water infiltration, utilizing break-point rainfall input, which will better represent these processes in a small watershed.