EFFECT OF PERI-URBAN DEVELOPMENT AND LITHOLOGY ON STREAMFLOW IN A MEDITERRANEAN CATCHMENT

摘要: Predicting the impact of urbanization on hydrology peri-urban catchments remains a challenge. Using data from nine streamflow gauges installed in small Portuguese catchment, this study investigates responses over three-year period. The catchment comprises unique nested sub-catchments, characterized by (1) varying proportions non-urban land-use (17-97%) and impermeable surfaces (6-36%), distances between urban areas stream network, storm drainage systems (piped vs dispersed); overlying distinct lithologies consisting sandstone limestone. The results show that (39% 22% impervious surfaces), most water infiltrated annual runoff varied 9-13% rainfall. In sub-catchments (≈50% urban), 29% rainfall became 17% limestone. with more than 80% forest, coefficients were averaged 6% independent lithology. Sub-catchments downslope had shorter response times (<20 min) dispersed which part infiltrated, time was up to 1h. Baseflow contributed 25-33% upstream 37-38% downstream total runoff, but less 5% limestone location. Hydrological impacts may be minimized planning through disconnecting network thereby enabling infiltrate into soil forest patches before reaching stream.