Human activities affecting hydrological processes in a catchment have many forms and the effect of those activities on the propagation of drought in a catchment depends on the relevant scales of the processes involved. The research presented focuses on the influence of reservoir and land use on drought dynamics. As a case study, we use the River Kamienna, Swietokrzyskie mountains, Poland. The Kamienna River has a mountainous character, with several water retention reservoirs and a history of industrial activities in the region. Annual water balance is also affected by water withdrawals in the catchment. Modeling tools in the form of lumped and semi-distributed hydrological models are applied to analyze hydrological processes in the catchment and to separate climatological and human-related factors affecting them. Two main goals of the modeling can be summarized as an investigation of the effects of reservoir operation on hydrological processes, especially dry season runoff, and an analysis of impacts of land-use change on the spatial-temporal characteristics of hydrological drought propagation. We apply three different models to simulate the catchment hydrological processes: two semi-distributed models, SWAT, and TOPMODEL, and the lumped hydrological model HBV. We present the calibration and verification of the models applied and a comparison of results using the goodness of fit criteria. The simulated flow at the gauging station along the Kamienna River is compared with the observed flow. The study applies several flow-related indices to understand how the climate and human-induced changes are affecting flow patterns in the region. The flow regime is described using a baseflow index and the runoff coefficient. The standardized runoff index (SRI) and runoff coefficients are also derived for the catchment. The results indicate that human activities dominated the decrease in runoff over the Kamienna River. The main finding shows that man-made activities such as the construction of reservoirs, land-use changes, mining, etc. have led to a more severe hydrological drought than under natural conditions. The research is part of the project “Human and climate impacts on drought dynamics and vulnerability” HUMDROUGHT (http://HUMDROUGHT.igf.edu.pl).

The main objective of the study is to evaluate the roles of climate change and human factors on runoff, baseflow, and hydrological drought characteristics at a watershed scale. The novelty of the study is to assess separately the cascading, indirect, accumulative effects of climate change and human factors on hydrological drought, i.e. runoff and baseflow. This involved analyzing change points to divide the available hydrometeorological data into a baseline and a perturbed period. We applied two hydrological models, SWAT and HBV-light, and two nonparametric climate elasticity of runoff to identify the contribution of climate change and human factors in influencing runoff and baseflow processes. The hydrological models were used to simulate naturalized runoff and baseflow during the perturbed period. The temporal variation in the characteristics of the baseflow regime is expressed as baseflow index. Drought indices, standardized runoff index and standardized baseflow index were used as hydrological drought indicators. A significant change in runoff reduction in the Kamienna watershed began in 1982, suggesting that human factors play a dominant role in influencing runoff. In addition, we found that an increase in baseflow and a decrease in hydrological drought events in the 2010s are a positive long-term effect of human factors such as construction of dams in the watershed. Finally, analyses of changes in land cover dynamics in the watershed over the past four decades using satellite imagery are used to confirm the presence of human interventions.