摘要
The paper deals with the impact of land use changes on water regime. An assessment was carried out in order to determine the extent to which the main components of the water balance on the experimental catchment Vseminka have been influenced by land use changes （region Vsetinske Hills, the Czech Republic）. For this reason, the water balance model WBCM-5 was implemented for the period of 30 years in a daily step, with particular focus on the simulation of the components of direct runoff and of subsurface water recharge. In the selected years of the period 1980-2009, major changes were made in land use and significant fluctuation of rainfall-runoff regimes were observed （e.g. dry year 1992, flood year 1997 and normal year 2009）. After WBCM-5 parameter calibration it was observed that some water balance components can change in relation to substantial land use changes, even up to dozens of percent in a balance-consideration, i.e. in daily, monthly and yearly or decadal values, specifically as far as the components of interception and also of direct runoff and of subsurface water recharge are concerned. However, a different situation appeared during the investigation of significant short-term rainfall-runoff processes. There were about seven real flood events during the same period on the same catchment which were analysed using the KINFIL-2 model （time step 0.5 hr）. Land use change, positive or negative scenarios, were also analysed during this period. As opposed to long-term water balance analyses, only a 10% difference in the hydrograph peak and volume was observed. In summary, the authors have shown that it is always important to distinguish a possible land use change impact on either long-term balance or short-term runoff. Otherwise, as often found in over simplified commentaries on flood events in the mass media, the actual impact of land use changes on water regime may be misunderstood.
