The hydrochemical properties of groundwater play a crucial role in crop growth and soil health, as well as the maintenance of irrigation equipment. To ensure suitable water quality for irrigation, the present study was conducted to evaluate the hydrochemical properties of irrigation groundwater in a typical agricultural region of Serbia. Groundwater was sampled at three monitoring locations in the Srem region in Republic of Serbia between 2011 and 2020. Examined parameters included electrical conductivity (EC), total dissolved salts (TDS), pH values, and the concentrations of cations (sodium (Na⁺), calcium (Ca²⁺), magnesium (Mg²⁺) and potassium (K⁺)) and anions (bicarbonate (HCO₃⁻), chloride (Cl⁻), sulfate (SO₄²⁻), and nitrate (NO₃⁻)). Further assessment was done using three classification systems; Nejgebauer’s, the US USSL, and the FAO classification. To obtain a more detailed assessment, additional indices were included, such as Soluble Sodium Percentage (SSP), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Permeability Index (PI), Kelly’s Ratio (KR), Magnesium Adsorption Ratio (MAR), and Total Hardness (TH). The PCA analysis detected that the concentration of K⁺, Ca²⁺, and Na⁺ in the irrigation water were lower in recent years, while the concentration of Cl⁻ was higher. The cluster analysis grouped the parameters into three clusters; I—electroconductivity, II—dry residue and HCO₃⁻, and III—other water parameters for all three monitoring localities. According to the applied classifications, the majority of underground water samples were suitable for irrigation. However, some samples fell out of the range of the first class, indicating the need for regular water quality monitoring. In light of climate changes that influence water deficiency, the urgent need for wise and sustainable water use implies the application of a comprehensive approach to irrigation water quality assessment, as shown in this study.

The Danube River plays significant role not only for preserving natural ecosystems. The aim of this paper is to examine the Middle Danube water quality in the part flowing through Serbia in section Bezdan -Banatska Palanka. Water quality data were examined for seven control points for period 2004-2018, for seven parameters: suspended solids (SS), dissolved oxygen (DO), electrical conductivity ( EC ), nitrates (NO ₃ ^– -N), total phosphorus (P _tot ), biochemical oxygen demand (BOD ₅ ) and chemical oxygen demand (COD). Data analyses included the application of ANOVA, linear regression analysis and Mann-Kendall trend test. The Mann-Kendall tests in most (32/49) cases, i.e. in 65 %, confirmed the non-existence of a significant trend. Significant downward trends were confirmed in 17 cases. Water quality improvement was confirmed at following control points: Bezdan for NO ₃ ^– -N, P _tot and BOD ₅ ; Bogojevo for NO ₃ ^– -N, P _tot , COD and BOD ₅ ; Novi Sad for P _tot , BOD ₅ and COD; Slankamen for BOD ₅ and COD; Smederevo for NO ₃ ^– -N and COD; Banatska Palanka for NO ₃ ^– -N. Slight deterioration of water quality was confirmed only in two cases, at the Zemun and Smederevo where DO was decreasing. Water quality for the examined period was stable and can be characterised as excellent and/or very good (class I or class II). Results emphasise fact that water quality trends monitoring reveals river sectors where the process of water quality degradation is ongoing. Timely detected critical river sectors can draw the attention of decision-makers, who can improve the existing legislation that would lead to water quality improvement.

The lowland area of the southeastern part of the Carpathian Basin is exposed to extreme hydrological conditions. The monitoring and analysis of the excess inland water are necessary in order to understand the scope and direction of the development of this type of flooding. When solving the problem of the drainage of an area and dimensioning drainage systems, one of the most important steps is to calculate the rate of runoff. Before calculating the rate of runoff, it is necessary to perform various analysis such as: hydrological, hydrogeological, pedological and land use analysis. The use of empirical formulas by different authors is one of the methods for determining the rate of runoff. These formulas can be of regional character, while some are applicable in different parts of the world. In this paper, the runoff coefficient and rate of runoff were calculated as indicators of the efficiency of the area drainage, employing the formulas by Nemet and Turazzo. The emphasis was put on the usage of modern tools and databases of soil characteristics while using a “traditional” method to determine rate of runoff. The obtained results demonstrate that the rate of runoff which reflects the current state of the drainage basin is very similar to the rate of runoff used for dimensioning of drainage system. The problem of retaining smaller amounts of water that remains even after the anticipated drainage deadlines can be solved with the regular maintenance of amelioration canals and additional ameliorative measures.

With the continuous trend of urbanization, increase in industrial capacities, and expansion of agricultural areas, there is also a rise in the amount of wastewater. One of the effective and economical solutions for wastewater treatment has proven to be Constructed Wetlands (CWs). Defining the locations where CWs can be built is not an easy task and there are several criteria that need to be considered. The Geographical Information Systems (GIS) and Multi-Criteria Decision Analysis—Analytic Hierarchy Process (AHP) are combined to select CW locations. AHP is one of the most commonly used methods in many environmental decision making problems, involving various conflicting criteria. In this case, conflicts arise between the evaluation of criteria that influence the selection of CW locations. The evaluation of selected criteria and sub-criteria resulted in a suitability map indicating that the first class represents 44%, the second class 37%, and the third class 16% of the total area. The fourth and fifth classes represent 3% of the total area. The criteria with the highest significance are land use, floodplains and distance of the location from populated places. This study has important implications for sustainable wastewater management in Serbia and provides guidelines for selecting locations for CWs.