Understanding the water balance-modifying effects of urban forests is important for mitigating the impacts of climate change and urbanization. We established a paired plot-based hydrological research area in the Botanical Garden of the University of Sopron as part of a Slovenian–Hungarian OTKA project. The research area is designed for a paired plot examination of water balance (interception, transpiration, groundwater dynamics, infiltration, and runoff) with a forested plot and a grass-covered (control) parcel. Since the plots are located in the university's botanical garden, the proximity allows for diverse and frequent data collection and continuous monitoring. Long-term hydrological measurements offer significant opportunities for studying the water balance in forested areas (as is required for assessing the regime). The monitoring results based on only two years as the observational period can illustrate peculiarities and indicate the significant variability that must be captured, along with the factors required when designing such monitoring. The study presents a monitoring framework that provides insights into the complex water dynamics under the black pine canopy and compares the soil moisture and groundwater dynamics between grass and forest plots.

This study examines hydrological processes at the Zelenjak (1958–2023) and Rakovec (1926–2022) stations on the Sotla/Sutla River, analyzed on an annual time scale. The analysis includes time series of annual minimum and maximum mean daily flows and mean annual flows. Additionally, data on annual precipitation and mean annual temperatures measured at the climatological station Bizeljsko in the period 1951 to 2024 were used to calculate annual runoff coefficients at the Zelenjak and Rakovec stations. The New Drought Index (NDI) was calculated using precipitation and air temperature data measured at the Bizeljsko climatological station. All analyses indicated a strong variability of the analyzed parameters over the available data period. A clear downward trend in mean annual flows is observed. In the recent period, from 2000 onward, there has been a sharp increase in mean annual air temperatures and a decline in all other analyzed hydrological and climatological parameters. Particularly concerning is the notable rise in the frequency and intensity of droughts in the 2000–2024 period. The causes of these trends could not be reliably determined through an analysis conducted on an annual time scale. It appears that natural factors, particularly the sharp rise in air temperatures, have played a significant role. However, it is important to emphasize that the natural characteristics of the Sotla/Sutla River basin have, to date, remained largely unaffected by human interventions. Furthermore, the insufficient accuracy in defining peak flows must be considered, as the rating curves used to define maximum flows may not have been reliable in certain periods.

Municipal waste is a collection of residential, industrial, institutional, commercial, construction, and demolition waste collected by a municipality and disposed at a particular site. In poor urban areas, a large proportion of leachate is discharged, untreated directly into the closest water body. The Boragaon Garbage Dump is located inside the eastern part of Deepor Beel Wildlife Sanctuary, the only Ramsar site in Assam, Northeast India. The Boragaon Municipal Garbage dump directly releases its landfill leachate into the Deepor Beel, which increases the concentration of toxic substances in its water. In the present study, the water quality parameters and heavy metal concentration (EC, TDS, turbidity, pH, Na+, K+, Cl-, F-, BOD, DO, SO42-, PO43-, NO3-, As, Be, Cd, Ca, Cr, Cu, Fe, Mn, Mg, Ni, Pb and Zn) of the water in the outlets of Boragaon Garbage dump released into the Deepor Beel were assessed using standard methods for a one-year period. The results found were quite surprising, with very high levels of EC (8740±120 µScm-1), turbidity (693±1 NTU), BOD (458.6±1.86 mg/L), TDS (917.4±2.23 mg/L), K (53.9±0.24 mg/L), Cl- (502.28±2.96 mg/L), Al (7.21±0.06 mg/L), As (129.42±0.22 µg/L), Ni (0.102±0.002mg/L) and Pb (32.4±1 µg/L). These large amounts of physiochemical properties and heavy metals concentration in water may cause detrimental effects on the ecological communities of the Deepor Beel and the nearby human population. This Ramsar site needs an immediate solution such as the relocation of the dumping ground and better management of the existing waste to rectify the problem of deteriorating water quality, otherwise the water quality will be past the point of recovery within a decade.

Today, there are varieties of methods for determining the risk of flooding in different areas of a catchment. However, the use of GIS-based weighting is receiving increasing attention among researchers. In early 2019, severe and continuous floods occurred in some provinces of Iran. Khorramabad was one of the cities most affected by the floods. Regrettably, during the construction development of Khorramabad city, the minimum distance from roads was violated. In this study, flood risks in the area were zoned using a GIS-weighted overlay algorithm. Flood zoning was done based on various maps indicating factors such as rainfall, distance from the waterway, soil composition, waterway density, slope, soil permeability, land use, and vegetation. The flooding area then was parceled into six categories with return periods of 10, 30, and 50 years. As a result, the city was divided into three critical areas in terms of flood risk. The results indicate that the confluence of the Karganeh and Khorram–Rud rivers lacks sufficient capacity to withstand and repel floods. As a result, the city will suffer severe damage in future floods.

Anaerobic digestion is a process by which energy from organically degradable waste can be recovered in the form of biogas. The uncontrolled disposal of such organic waste is very burdensome to the environment. In Slovenia, large quantities of waste edible oils are produced every year, which could be used for biogas production. In this study, we investigated the methane potential of waste edible oil in a batch reactor. Further in the pilot scale in a semi-continuous experiment we evaluated the use of waste edible oil in anaerobic digesters of wastewater treatment plant. The results show that the quantity of oil per day that is fed into the anaerobic reactor is limited due to the process's instability and lower biogas production. The optimal daily organic loading of waste edible oil was between 1.6 and 2.4 g VS/L inoculum. During these conditions, the process of anaerobic digestion was stable and methane production was highest. At higher organic loading, the process became unstable, pH was reduced, volatile fatty acids increased, COD at the outflow of reactor increased, and biogas production was significantly reduced.

In the paper, the determination of nitrate nitrogen (NO3-N) export regimes from the Kuzlovec catchment during rainfall events is presented employing various determination methods: the ratio of coefficient of variation of NO3-N concentration and discharge (CVC/CVQ), the slope of the regression line to the points of concentration and discharge logarithms (b), both mentioned indices together, and the relative change of the NO3-N concentration during the event (Crs). According to previous analyses, the amount of exported NO3-N during rainfall events comprises approx. 30% of the total export amount, while from a temporal point of view, rainfall events represent only 10% of the time. Export regimes were identified as chemostatic (concentration does not change with discharge) and chemodynamic (concentration changes with discharge). The latter were further divided into dilution and flushing regimes. 43 rainfall events from the period April 2018–April 2020 were included in the analysis. For these events, high-frequency data of 20-minute intervals were available for concentration and discharge. All applied indices showed that the catchment responds differently from a concentration-discharge perspective and that chemodynamic behaviour is predominant, with flushing most frequently prevalent. A possible seasonal connection with regime diversity was tested using the non-parametric, statistical Wilcoxon test. A statistically significant difference was not found for any of the indices. Nevertheless, a detailed analysis of CVC/CVQ revealed that the ratio is likely related to seasonal variability in rainfall characteristics and consequently to the hydrological conditions in the catchment. Hence, it would be of great importance to include data about rainfall and hydrological properties in future studies.

The use of ultrasound (US) to control algal growth in natural water bodies raises concern about the undesirable effects of US on non-target organisms. In this study a lab-scale experiment was performed to evaluate the effects of low-power US to counteract algal growth on adult and juvenile Daphnia magna. The 48-hour experiment was conducted in a 200 L glass aquarium with three fish nets, each filled with five D. magna. Each net was inspected for immobilized D. magna on different times during ultrasonication; additionally, basic physical-chemical parameters were measured. The results showed that tested low-power US device had no acute effect on the mobility of adult or juvenile D. magna, since after 48 h of ultrasonication 87% and 82% of adult and juvenile organisms remained mobile, with the same or higher percentage of mobile D. magna in the control groups. Additionally, no statistically significant effects were noticed on the measured physico-chemical parameters. However, when applied for algae control in field conditions, US is in operation constantly or at least for a long period of time (several weeks or months); therefore, the effect of long-term exposure to ultrasonication on zooplankton should be tested to ensure that US devices are safe for zooplankton.

The 2000 Stože Landslide with the consecutive wet debris flow with a volume close to 1 million m3 that hit the village of Log pod Mangartom in November 2000 had many consequences. It triggered vast efforts not only for the mitigation of the devastated area but also sparked many studies in several scientific disciplines. Various studies were performed in order to better understand this type of natural hazard and its consequences for the natural and built environment, and for society as a whole. After two decades since the disastrous event in 2000, this paper provides an aggregate survey different studies on this event performed by researchers and engineers, summarising this event’s impact on in-depth landslide research in Slovenia. The advancement in this field in Slovenia since 2000 is obvious.

We discuss modeling of the transport and decease of bacteria Escherichia coli in marine environments. We calculated the spatially variable decease coefficient of E. coli from the extrapolated measurement data on environmental parameters in accordance with Mancini's equation for bacteria stemming from the Rižana River and entering into the computational domain – the eastern part of the Koper Bay. Using pre-computed circulation data and the modified particle-tracking model Nafta3D we performed two-day simulations of an instantaneous and a continuous release from a single source. We analyzed locations of two particle types: free E. coli (ECF) and E. coli bound to suspended solids (ECA). We then analyzed the ECA and ECF activity decrease with a newly developed decease model, applying a first-order kinetics equation. In the given conditions a vast majority of ECA remained in the second basin of the Port of Koper and sank to the bottom layers. The decease time of 90% of the ECA (T90) was about 48 hours. The ECF remained closer to the surface; they moved more quickly and for the most part abandoned the second basin. The determined T90 was 6 and 10 hours in instantaneous and continuous release, respectively.