Publikationsdatum:
2013-09-10
Beschreibung:
Land use change as conversion pasture to forest produces several changes on hydrological cycle. In this paper we analyze the effects on stream discharge of afforestation of a small watershed devoted to pasture using the HBV hydrological model. Streamflow data obtained over the first ten years after planting were employed to evaluate the capacity of HBV model to simulate hydrological behavior of catchment after afforestation. Obtained results indicate that the estimation of streamflow was accurate as reflected by statistics (R 2 = 0.90, NSC = 0.89 and PBIAS = 0.34). Afterwards, streamflow under pasture land use (if afforestation had not occurred) was simulated using hydro-meteorological data collected during the period of study and model parameters optimized previously, together with two parameters, pcorr and cevpfo , that were adjusted for pasture conditions. HBV model results indicate that afforestation produced a water yield reduction around 2000 mm (22% of total stream discharge) during the first ten years of planting growth. The differences between forest and pasture land cover are increasing in all seasons year by year. The greatest streamflow reduction was observed in wet period (autumn and winter) with 76% of total reduction. In summer, streamflow reduction represents only 3% of total, however, represents 24.7% of discharge in this season. Streamflow reduction was related to increase of rainfall interception (mainly in wet periods) and the increase of evapotranspiration by plantation in dry periods. This article is protected by copyright. All rights reserved.
Print ISSN:
0885-6087
Digitale ISSN:
1099-1085
Thema:
Architektur, Bauingenieurwesen, Vermessung
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Geographie
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