Land cover effect on water discharge, matter losses and surface temperature: Results of 20 years monitoring in the Šumava Mts

Abstract

Three small catchments (each c. 2 km2) with different land cover (drained pasture, wetland and spruce forest) located in the Šumava Mountains in the Czech Republic (altitude 780–1026 m) were monitored continuously for 20 years. The aim of the study was to evaluate the aging of different types of land cover landscape in terms of soil acidification (loss of alkalines). Average annual water discharge from the pasture catchment was c. 60 % of annual precipitation, but 38 % and 34 % of annual precipitation from the wetland and the forest, respectively. The relatively highest water runoff was from the pasture in all months. Daily runoffs during periods of heavy rain were 26 mm from the pasture, 16 mm from the wetland and 7 mm from the forested catchment. Water discharged from the drained pasture had two times higher electrical conductivity than water from the wetland and forest due to higher concentrations of bicarbonate, nitrate, calcium, magnesium, sodium and potassium. In the wetland and forest catchments, the amounts of nitrate, sulphate, chloride, TC, TN, TP and ammonium in the precipitated water were higher than that of the discharged with water (soluble matter losses). The amount of soluble matter discharged from the pasture catchment (matter losses) was in all cases higher than the amount in the precipitated water. On sunny days in the vegetation season, the pasture catchment had higher surface temperature than the wetland and forest catchments, which had higher evapotranspiration. Thermal pictures from satellites (e.g. Landsat) or taken by airborne thermal cameras can be used for identification of landscape areas of higher water outflow and higher matter losses.