Location: Water Management and Systems Research
Title: Rainfall variability on a small watershed: Implications for hydrologic modellingAuthor
Erskine, Robert - Rob | |
Green, Timothy | |
KIPKA, HOLM - Colorado State University | |
LIGHTHART, NATHAN - Colorado State University | |
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. |