The aim of the study was to evaluate the degree of pollution of bottom sediments from small water reservoirs with heavy metals on the basis of geochemical criteria: the enrichment factor and the geo-accumulation index. The investigations concerned sediment from eight small water reservoirs located in the Kielce Highland. Selected heavy metals, including cadmium, chromium, copper, lead and zinc, were determined using inductively coupled plasma-atomic emission spectrometry method. Additionally, particle size distribution and the content of organic matter expressed as loss of ignition were designated. The concentration of heavy metals in sediments was characterized by a great variety. The sediments of Morawica and Rejów show very high and extremely high enrichment in Cr, Zn, Pb and Cd. The values of EF>20 indicate also an extremely high enrichment in Cd of sediments in Mostki. In addition, over 50% of the samples of sediment from Suchedniów, Kaniów, Mostki and Jaśle reservoirs (the value of EF for Cr exceeded 5) indicate a moderately high enrichment of this element. Results of the analysis of the I_geo values indicate that the tested sediments are characterized by moderately high (2<I_geo<3) or high (3<I_geo<4) pollution. The differences in individual enrichment factor and geoaccumulation index values may result in the nature of heavy metals, their pollution loads, as well as speciation forms of trace elements occurrence in sediment-water complex. These findings indicate that the integration of geochemical methods is necessary for an appropriate ecological risk assessment of heavy metals in bottom sediments.

Various types of events and emergency situations have a significant impact on the safety of people and the environment. This especially refers to the incidents involving the emission of pollutants, such as ammonia, into the atmosphere. The article presents the concept of combining unmanned aerial vehicles with contamination plume modelling. Such a solution allows for mapping negative effects of ammonia release caused by the damage to a tank (with set parameters) during its transport as well as by the point leakage (such as unsealing in the installation). Simulation based on the ALOHA model makes it possible to indicate the direction of pollution spread and constitutes the basis for taking action. And, the use of a drone allows to control contamination in real time and verify the probability of a threat occurring in a given area.