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Infiltration in the Corgo River basin (northern Portugal): coupling water balances with rainfall—runoff regressions on a monthly basis

Author:
ALENCOÃO, ANA MARIA PIRES, PACHECO, FERNANDO ANTÓNIO LEAL
Source:
Hydrological sciences journal 2006 v.51 no.6 pp. 989-1005
ISSN:
0262-6667
Subject:
base flow, basins, environmental factors, equations, evapotranspiration, models, overland flow, rivers, rocks, runoff, surface water, temperate zones, water reservoirs, watersheds, Portugal
Abstract:
A combination of water balances and rainfall—runoff regressions is used to calculate infiltration, overland flow, baseflow and change to the surface water reservoir, on a monthly basis; evapotranspiration from the underground reservoir, on an annual basis; and a lag phase of maximum infiltration and maximum baseflow within a hydrological year. The water balance equations are written for catchment areas formed on crystalline rocks and located in temperate climates. The regression lines are fitted to precipitations and river flows. In a first run, the model is tested with the Corgo River hydrographic basin, a small watershed in the Trás-os-Montes and Alto Douro province, northern Portugal. The results compare favourably with results of other groups, working under similar environmental conditions. The sensitivity of the model to changes in the basin characteristics and climate is tested by a second run using data from the Terva River basin, a nearby catchment that is much smaller than the Corgo basin and has a much lower effective precipitation, defined here as a difference between precipitation and potential evapotranspiration. As a consequence of having a lower effective precipitation, the river dry-out starts earlier in the Terva (May) than in the Corgo (June).
Agid:
6363976