A bacia hidrográfica do rio Leça : estudo hidroclimatológico

• Author(s): Velhas, Edite
• Date: 1991
• Persistent ID: http://hdl.handle.net/10216/8859
• Origin: Repositório Aberto da Universidade do Porto
• Subject(s): Rio Leça - Bacia hidrográfica; Bacia hidrográfica - Rio Leça; Hidrografia
• Document Type: Article
• Language: Portuguese

Description

In Northern Portugal, the study of streamflow characteristics in small drainage basins is made difficult due to an insufficiency or even to an absence of records on stage or discharge data. The purpose of this study was to develop and test a methodology applied to Leca river basin, which relied on the calculation of water balances through the analysis of the main climatic elements. The study of the rainfall areal variation and its monthly pattern, as well as the estimation of the potential evapotranspiration for the main weather stations in the basin, provided useful background knowledge about the atmospheric component of the hydrological cycle. Having taken into consideration landform, lithology, vegetation and land use characteristics we defined an approximate value for the soil moisture storage. The analysis of the soil moisture deficit values, obtained by a calculation procedure based upon the water balance concept, and of the other variables mentioned above, enabled us to establish the most favourable conditions for the occurrence of the greatest runoff volumes. Finally, we applied a general method for estimating rainfall intensity - duration - fequency relationships in order to calculate the flood peak flows and to map flood prone areas in the Leca river basin.