Impact of landscape management and vegetation on water and nutrient runoff from small catchments for over 20 years.

Abstract

Land cover, vegetation, and landscape management have a large impact on surface water conditions. We analyzed the quantity and quality of surface waters draining from forest catchment with high vegetation and agricultural catchment with low or no vegetation. The following parameters were assessed: specific water runoff, precipitation totals, electrical conductivity in the surface waters, the content of suspended solids, nitrate nitrogen (N-NO₃^-), and phosphate phosphorus (P-PO₄^3-) in the surface waters. Measurement of the specific water runoff took place over one hydrological year. Measurement of the water quality took place over twenty years and captured changes in the land cover. Hydrological and hydrochemical data from both sub-catchments were compared and statistically analyzed. The results showed that forest landscapes with high vegetation can retain up to twice as much rainwater compared to agricultural landscapes with low vegetation and bare areas. However, in episodes with intense short-term rainfall, forest landscapes can hold even several times more rainwater than landscapes with low vegetation. In dry periods, landscapes with large amounts of high vegetation can retain more water for longer periods than landscapes with low vegetation and bare areas that dry out relatively quickly. The runoff of nutrients and other substances from forest landscapes is much slower due to the high vegetation and thus contributes to the protection of water quality in watercourses. The main findings of this research show that as vegetation increases, the landscape holds more water and other substances, reducing the risk of floods, droughts, and water pollution. Other research results show that even a small change in vegetation cover has a significant impact on the water runoff and quality of surface waters. The work emphasizes the importance of supporting vegetation in temperate zone landscapes in landscape planning and management.