Slovenia is one of the most forested countries in Europe. More than half of its territory is covered by forest. The forest certainly influences on water balance and hydrologic conditions in the river basin. Urban forests and other green areas in cities have also impact on water balance. In comparison with other urbanized areas, they have a positive effect since they can reduce the surface runoff by rainfall interception and increasing infiltration below the trees.
The forest hydrological cycle is in general represented by precipitation (intercepted or direct), its infiltration, surface runoff and evapotranspiration. If we have enough measured data about hydrological processes, we can estimate the forest water balance using different types of models. In master thesis we tested the Brook90 model in order to estimate the water balance in urban forests.
In the practical part of the thesis we developed water balance models for four urban research areas (Gameljne-leaflets, Gameljne-pine, Gameljne-island and Rožnik-mixed forest) with the help of field measurements. We estimated the amount of surface runoff, throughfall and evapotranspiration for each considered research area and compared them with measured values.
The Brook90 model proved to be a suitable tool for simulating and modeling of the water balance in considered urban research areas. Comparision of measured and modeled values yielded good results. The largest percentage of the water balance presents surface runoff. Nevertheless, its amount in the last few years has been falling and consequently the amount of evapotranspiration has been increasing.