Upstream Countries Research Articles

Impacts of Irrigation with Sewage Effluent on Physical and Chemical Parameters of Egyptian Soil آثار الری بمیاه الصرف الصحی على المعاییر الفیزیائیة والکیمیائیة للتربة المصریة

Egypt may soon suffer from water problems due to many factors, including the intransigence of upstream countries in addition to climate change and various pollution factors. Under these circumstances, many farmers are forced to use sewage water for irrigation, which may eventually lead to deterioration of soil and environmental quality. Therefore, the present investigation aims to study the influences of sewage water application for varied extended periods on some physical and chemical parameters of Abu-Rawash soil and to compare between the general properties of sewage effluent water and Nile water. In sewage effluent, Na+ was the dominant cation and EC, SAR, pH, and NH4+ values below the Permissible Maximum Level while nitrate content exceeds the safe level. The total N content in sewaged water was more than 13 folds that of Nile water. In sewage effluent irrigated soils, there are appreciable increases in clay fraction by 8.02 and 12.0 folds compared with the virgin soil. CaCO3 content of soil continuously irrigated with sewage water reduced as increasing period of application while there are an increasing in soil pH and EC. Only remarkably increase in ESP was occurred in the top soil layers of sewage irrigated soils. Bulk density and Hydraulic conductivity of sewaged soil decreases with increasing period of application and total porosity and available water capacity increased. The results reflect deficiency of nutritional status of uncultivated sandy soils in an arid zone, especially in N content.

Analysis for spatial-temporal matching pattern between water and land resources in Central Asia

AbstractCentral Asia, the pioneering place of the ‘Belt and Road’, is under the threat of prominent water issues. Based on the Gini coefficient model and the matching index, the amount of the total renewable water resources and the cultivated land area were introduced to evaluate the matching pattern between the water and land resources in Central Asia. The water problem of Kazakhstan, being the most prominent, shows low water resources per unit area with the highest reclamation rate. The matching degree for the upstream countries of the Aral Sea (Kyrgyzstan, Tajikistan) was better than those of the downstream countries (Turkmenistan, Uzbekistan, Kazakhstan). The Gini coefficient in Central Asia was 0.32, smaller than that of the global average value (0.59). The overall water available for use and the matching cultivated land resources was reasonable. Large differences exist in the matching degree in water distribution and utilization among Central Asian countries. The matching index of water and land resources in Central Asia was 1.25, similar to the matching degree estimated from the Gini coefficient model. Moreover, rational measures are suggested to alleviate the issue of water and land resources matching in Central Asia.

International Policies and Conventions on International Rivers and the Rights of Ethiopia to Construct Dam on Nile River: The Case of the Great Renaissance Dam of Ethiopia

Sustainable transboundary water resources managements are challenged by water governance problem. Equitable and reasonable use of water resources shared by co-basin countries requires reliable common agreements. International water laws such as UN Watercourses (1997), Helsinki Rules (1966) have provided vital legal instruments for effective management and negotiation over international water courses. However, Nile River use and development has challenged for last several decades due to discriminatory bilateral agreements made during colonial periods. The Cooperative Framework Agreement (CFA) provided to achieve equitable use of Nile River and promote regional socioeconomic development is important step advancing to stop unfair water allocation and claim in the region. The enduring claim over water share and use by Egypt and Sudan referring colonial era agreements are unacceptable because they denied legal and natural rights of the upstream countries as well as opposed international water law. With this respect, Ethiopia has natural and legal right to construct Great Ethiopian Renaissance Dam. The downstream countries (Egypt and Sudan) should ratify CFA and respect international water laws. Therefore, mutually acceptable cooperative commitment amongst the riparian states of the Nile basin is the only necessary condition for promoting sustainable use and development Nile River as well as achieving peace and security in the Nile river basin. Keywords: UN Watercourses, Helsinki Rules, Nile River basin, downstream countries, international water law principles DOI: 10.7176/IAGS/83-02 Publication date: June 30 th 2020

Simulation of the Potential Impacts of Projected Climate Change on Streamflow in the Vakhsh River Basin in Central Asia under CMIP5 RCP Scenarios

Millions of people in Uzbekistan, Turkmenistan, Tajikistan, and Kyrgyzstan are dependent on the freshwater supply of the Vakhsh River system. Sustainable management of the water resources of the Vakhsh River Basin (VRB) requires comprehensive assessment regarding future climate change and its implications for streamflow. In this study, we assessed the potential impacts of projected climate change scenarios on the streamflow in the VRB for two future periods (2022–2060 and 2061–2099). The probable changes in the regional climate system were assessed using the outputs of five global climate models (GCMs) under two representative concentration pathways (RCPs), RCP4.5 and RCP8.5. The probable streamflow was simulated using a semi-distributed hydrological model, namely the Soil and Water Assessment Tool (SWAT). Evidence of a significant increase in the annual average temperature by the end of the 21st century was found, ranging from 2.25 to 4.40 °C under RCP4.5 and from 4.40 to 6.60 °C under RCP8.5. The results of three GCMs indicated a decreasing tendency of annual average precipitation (from −1.7% to −16.0% under RCP4.5 and from −3.4% to −29.8% under RCP8.5). Under RCP8.5, two GCMs indicated an increase (from 2.3% to 5.3%) in the average annual precipitation by the end of 2099. The simulated results of the hydrological model reported an increasing tendency of average annual streamflow, from 17.5% to 52.3% under both RCPs, by the end of 2099. A shift in the peak flow month was also found, i.e., from July to June, under both RCPs. It is expected that in the future, median and high flows might increase, whereas low flow might decrease by the end of 2099. It is concluded that the future seasonal streamflow in the VRB are highly uncertain due to the probable alterations in temperature and precipitation. The findings of the present study could be useful for understanding the future hydrological behavior of the Vakhsh River, for the planning of sustainable regional irrigation systems in the downstream countries, i.e., Uzbekistan and Turkmenistan, and for the construction of hydropower plants in the upstream countries.

Hindcast and forecast of daily inundation extents using satellite SAR and altimetry data with rotated empirical orthogonal function analysis: Case study in Tonle Sap Lake Floodplain

The Tonle Sap Lake (TSL) is the largest natural freshwater lake in Southeast Asia and is called the “heart of the lower Mekong” due to its high aquatic biodiversity and is considered as one of the most productive freshwater ecosystems of the world. Its floodplain eco-system, which is strongly tied to seasonal flood pulse, is extremely important for food security, trade and economy of Cambodia, supporting the livelihoods of about 1.7 million people. On the other hand, flood can also be extremely devastating in the region along the TSL. In recent years, studies have pointed out that rapid growing number of water infrastructures as well as future climate changes may alter the hydrological cycle of the Mekong River Basin (MRB) and are expected to influence the flood pulse of the TSL and surrounding TSL floodplain. Therefore, it is timely to understand historical inundation extent and predict its likely future state. In this study, we proposed a Rotated Empirical Orthogonal Function (REOF) analysis-based daily inundation extent estimation framework, integrating multi-temporal stack of Sentinel-1A Synthetic Aperture Radar (SAR) imagery and Jason-series satellite altimetry data. The framework can generate daily, cloud-free and gap-free inundation extents for any given time depending on the altimetry data provided. A long-term El Niño and Southern Oscillation (ENSO) index-based daily TSL level forecasting method with months of lead time was also proposed to fulfill the framework's forecasting capacity. In this study, the framework was adopted in the TSL floodplain area for hindcast (2003 to 2015) and forecast (January to July 2019) of daily inundation extents. Estimated inundation extents were cross-compared with MODIS-derived and Sentinel-1-derived inundation maps, resulting in up to higher than 90% of Critical Success Index (CSI). The proposed framework has (1) innovative capacity of estimation of future daily areal inundation extents and is (2) a fully remote sensing-based framework which can empower local authorities tasked with water resource management decisions without relying on upstream countries. The framework has potential to be implemented in other major river basins or wetlands (e.g., Amazon River Basin, and Congo River Basin). The implementation on SAR imagery from other satellites with different bands of electromagnetic wave is also possible but requires more investigation.

Emergency water supply decision-making of transboundary river basin considering government–public perceived satisfaction

The emergency supply of transboundary water resources is a prominent problem affecting the social and economic development of basin countries. However, current water supply decisions on transboundary water resources may ignore the psychological perception of multi-stakeholders, and the evolution of emergencies increases the uncertainty of decision making. Both factors would lead to the low acceptance of water-related decisions. Utility satisfaction, perceived losses, and quantity satisfaction were selected in this paper to identify the perceived satisfaction of upstream governments, downstream governments, and the public, respectively, over multiple decision-making stages. A modeling framework combining prospect theory and the multi-stage multi-objective programming methodology was then developed to measure the perceived satisfaction of different stakeholders in a watershed under emergency. A two-stage NSGA-II and TOPSIS based approach was adopted to find the optimal compromise solution to solve the model. The framework was applied in the Lancang–Mekong River basin to provide suggestions to decision makers. Upstream decision makers must choose a moderate proportional fairness degree when making emergency decisions to maximize the perceived satisfaction of all stakeholders. Meanwhile, the perceived loss of downstream countries with low water demand should be considered first in the formulation of emergency water supply plans. Furthermore, although water supply from upstream countries can improve perceived water quantity satisfaction of downstream publics, additional actions must still be taken to change the traditional concepts of the public.

Response of the interaction between surface water and groundwater to climate change and proposed megastructure

Arid and semi-arid regions present special challenges for water management. Streamflow variation in the upstream countries of the international river basins (River Nile basin), due climate changes or anthropogenic activities such as the ongoing construction of the Grand Ethiopian Renaissance Dam (GERD) is making management of water resources in the downstream countries (Egypt) difficult especially with increasing water demands. Groundwater (GW) and surface water (SW) are two interconnected components of one single resource, impacts on of these components will inevitably affect either the quantity or quality of one another, and that is the situation in the study area. Accordingly, not just SW availability will be affected, but also GW. A three-dimensional transient GW model is used to investigate the impacts of expected decreasing in SW supply due to natural (climate change) or artificial (GRED) changes and increasing GW extraction due to increasing population and agricultural development. This model helps to understand the interaction between the River Nile and the main SW canals and the Quaternary aquifer and to study the recharge possibilities of the aquifer as well as prediction of the aquifer behavior under different stresses in Minia Governorate, Egypt. Three scenarios with eleven probabilities were proposed for the prediction simulations and GW budget, levels and flow exchanges between SW and GW were also calculated on year 2050. The first scenario evaluates the impact of decreasing SW levels by 0.5, 1, and 1.5 m due to climate change or the (GRED), the second scenario studies the effect of increasing GW extraction by 25% and 50% from the extraction rate in the current situation due to agricultural development and increasing demand of GW in different uses. The third scenario examines the potential impact of climate change or the (GRED) and pumping scenarios on GW budget and levels in the Quaternary aquifer where it studies the effect of increasing GW extraction by 25% and 50% with decreasing SW levels by 0.5, 1 and 1.5 m on the aquifer. The maximum change in GW budget and levels was found in the third scenario in the case of increasing GW extraction by 50% and decreasing SW levels by 1.5 m in which ΔS of the aquifer will decrease to −712821.9 m3/day and GW levels will decrease to range from 23.31 to 43.07 m, respectively.

A fuzzy cooperative game theoretic approach for multinational water resource spatiotemporal allocation

Water resource allocation in multinational river basins has been a major concern for all riparian countries. From the perspective of cooperative and sustainable water resource development, considering the spatiotemporal characteristics of the water demand, namely, the priority of water use due to the geographic location of each riparian country, the seasonality of water demand, and the differences in the net utility of water utilization, this paper constructs a fuzzy coalition game model for multinational water resource allocation and provides the optimal allocation strategy using the example of the Lancang-Mekong River. The study indicates that considering the geographic locations and the differences in the water utility of each country compared with the initial allocation strategy based on agricultural water demand, the cooperative strategy increases the allocated water resources in high-utility countries (expect countries near the estuary) and the overall water utility in the entire basin. Then, considering the seasonality of the water resource reallocation, the fuzzy coalition among riparian countries further increases the net water utility of each country and achieves the optimal allocation. As the preconditions for the establishment of cooperative relationships, upstream countries need to transfer partial water rights to downstream countries in certain seasons. The basic idea that is presented in this paper, the fuzzy coalition model of water resource allocation with spaciotemporal constraints, can be applied to the water allocation of other multinational rivers.

Indirect estimation of deep percolation using soil water balance equation and NASA Land Simulation Model (LIS) for more sustainable water management

Accurate estimation for groundwater recharge is required for more sustainable management to water resources. On-farm level, deep percolation is one of the water loss sources that researchers and agronomists work hard to minimize. However, on a large scale or district level, it is considered as a valuable source for recharging the aquifer. Indirect estimation to deep percolation would be an economic effective mean, especially for large scale studies. The presented research study aims at checking the capability of Land Information System (LIS) model in estimating deep percolation by soil-water balance equation. The model was validated using precipitation data extracted from meteorological stations randomly selected and distributed along the Nile basin. Multi-thematic map layers including all soil water balance model parameters i.e. deep percolation and change in soil moisture content were developed to the year 2013 at a scale of 10 km2. The relationship between measured rainfall values and estimated ones by LIS has a coefficient of determination (R2) of 0.88. The obtained results revealed a good capacity of LIS model in estimating deep percolation on a large scale from its direct simulation to the soil-water balance parameters. It was found that deep percolation rates were generally higher in the Nile River's downstream than in upstream especially in Egypt, Sudan, and parts of Uganda. This is in contrary to the behavior of precipitation rates and both surface and sub-surface runoff. They were higher in upstream countries than in downstream ones. The highest deep percolation rate (19.63 mm day-1) was observed in Ethiopia and parts of Sudan during May 2013. It was found that low elevated lands with loose texture tend to have higher rates of deep percolation than elevated rocky lands. The current research results could be of great benefit for sustainable water management in Egypt. However, further study should be conducted in different agro-ecological zones in Egypt for more precise model calibration and validation. This may require access to a large amount of field data and long-term meteorological data to run the model.

Human and Natural Impacts on the Water Resources in the Syr Darya River Basin, Central Asia

Water resources are increasingly under stress in Central Asia because downstream countries are highly dependent on upstream countries. Water is essential for irrigation and is becoming scarcer due to climate change and human activities. Based on 20 hydrological stations, this study firstly analyzed the annual and seasonal spatial–temporal changes of the river discharges, precipitation, and temperature in the Syr Darya River Basin and then the possible relationships between these factors were detected. Finally, the potential reasons for the river discharge variations have been discussed. The results show that the river discharges in the upper stream of the basin had significantly risen from 1930 to 2006, mainly due to the increase in temperature (approximately 0.3 °C per decade), which accelerated the melting of glaciers, while it decreased in the middle and lower regions due to the rising irrigation. In the middle of the basin, the expansion of the construction land (128.83 km2/year) and agricultural land (66.68 km2/year) from 1992 to 2015 has significantly augmented the water consumption. The operations of reservoirs and irrigation canals significantly intercepted the river discharge from the upper streams, causing a sharp decline in the river discharges in the middle and lower reaches of the Syr Darya River in 1973. The outcomes obtained from this study allowed us to understand the changes in the river discharges and provided essential information for effective water resource management in the Syr Darya River Basin.

Assessment of Upstream Human Intervention Coupled with Climate Change Impact for a Transboundary River Flow Regime: Nile River Basin

The aim of this article is to determine how human interventions in upstream countries coupled with drought events are affecting the flow regime of downstream countries using the Nile River basin for illustrative purposes. This has been addressed by assessing climate change in the study area through analyses of precipitation data obtained from the Global Precipitation Climatology Centre (GPCC) and detecting if there is a trend, and subsequently calculating drought events in the main basins impacting on the downstream flow. Then river discharge data were analysed using different hydraulic indices at key stations in the downstream country and measuring the alterations occurring in the flow. The degree of alteration is a function of the number of civil engineering projects being in operation and classified by time windows; pre-alteration is between 1900 and 1925, while the alteration period is between 1933 and 2012. The alteration period was classified into three periods based on the degree of alteration. The findings revealed that there are changes in the river flow regime caused by both changes in the rainfall pattern in addition to the regulation in the upstream countries. There is a direct relationship between the interventions in the upstream countries and changes in the flow regime especially when coupled with drought events. By increasing the water usage upstream, there is an increase in the alteration of the flow downstream. The years between 2000 and 2012 were linked to the highest alterations between the modified years.

Energy resources and the risk of conflict in shared river basins

This study examines the effect of energy resources on the chances for militarized conflict, water related conflict and cooperation events, and cooperative river treaties between pairs of states on shared international river basins. We examine trade-offs that riparian states can make between energy resources such as oil or natural gas and fresh water resources. Integrating upstream and downstream states’ geographical position in a river basin with energy resource information, we examine four related scenarios of states sharing rivers: (1) Joint energy where both upstream and downstream countries have energy resources, (2) Downstream energy where only the downstream state has energy resources, (3) Upstream energy where only an upstream country has energy resources, and (4) No energy. Theoretically, we argue that Downstream energy dyads are most likely to find cooperative solutions to conflicts over shared river resources because downstream states can offer oil and natural gas side payments to upstream states in exchange for greater water supplies. Empirical analyses of dyadic data in shared river basin dyads from 1945 to 2001 provide strong support for the theory. Riparian cooperation through river treaties and diplomacy is best achieved in Downstream energy dyads, where the downstream states have energy resources that can be traded for water resources with upstream states. Militarized conflict and water related conflict events are most likely in Joint energy dyads. Case illustrations from the Aral Sea and Ganges river basins are used to demonstrate the theoretical arguments.

River Basin Management Plans as a tool for sustainable transboundary river basins' management.

Data availability and the existence of exchange mechanisms are considered crucial issues for the management of water bodies shared among riparian countries. Moreover, common legislative and technical frameworks are assets that foster the management of transboundary waters in an integrated and sustainable manner. The River Basin Management Plans of the European Union's Water Framework Directive implementation process not only incorporate a cooperative framework, but also include open access internet-based databases that can enhance cooperation and shed light on water-related conflicts among countries that share transboundary waters. The proposed methodological approach in this research is applied in four transboundary river basins, where Greece is the downstream country, and the upstream countries are not all member states of the European Union. The areas of dispute were found in the 2nd Water Convention Report. For each particular case study, data and information from the respective River Basin Management Plans were used to investigate the actual situation. The results demonstrated that significant conflict situations in the past, which involved both water quality and water quantity issues, could be resolved using continuous and reliable datasets included in the management plans. The use of freely available data sources renders the findings of this work useful for the sustainable management of shared waters.

Applying Interconnected Game Theory to Analyze Transboundary Waters: A Case Study of the Kura–Araks Basin

The Kura–Araks Basin is facing problems with insufficient water availability for all needs and poor water quality, which results in high rates of waterborne diseases. The riparians of the basin struggle with management of water resources within their national borders, as well as internationally, across the basin. With international rivers, interdependency among countries is created, where the upstream country can impact the quantity and quality of water downstream. This study focuses on the upstream–downstream relationship with the Kura River between Azerbaijan and Georgia. The analysis uses a game theoretical framework, which incorporates several issues in the negotiation space. Specifically, water quantity and water quality are analyzed separately and combined into an aggregated isolated game. The analysis compares the aggregated isolated game, where the outcome of each game is negotiated separately, with an interconnected game, where the two games are jointly negotiated. Using realistic parameters, results show that due to the repeated nature of some of the payoffs, cooperation is unlikely to be achievable in each game independently, since at least one country has an incentive to deviate. In contrast, the interconnected game can achieve full cooperation and increase the welfare of both countries.

Változások kora az árvízvédelemben

In the ever-changing conditions of the Hungarian water management, due to the increasing extremes that can be derived from climate change, a new direction must be taken in water damage prevention activities. Hungary is heavily exposed to the upstream countries in respect of water management. The structural and non-structural flood prevention measures in the upstream countries directly affect the Hungarian water management. Apart from the presentation of the changes, I would also like to suggest a solution to the problem in this article.

Optimal Operation of the Eastern Nile System Using Genetic Algorithm, and Benefits Distribution of Water Resources Development

The Eastern Nile Basin is facing a number of transboundary issues, including water resources development, and the associated impacts. The Nile Basin, particularly the Eastern Nile Sub-basin, is considered as one of a few international river systems of potential conflicts between riparian countries. The Eastern Nile is characterized by the high dependency of downstream countries on river water generated in upstream countries, with limited or no contribution to the runoff itself. The aim of this paper is to analyze optimal scenarios for water resources management in the Eastern Nile with regard to hydropower generation and irrigation development. A hydro-economic optimization model based on Genetic Algorithm has been used to determine the maximum benefits for two scenarios: (i) non-cooperative management of hydraulic infrastructure by the riparian countries (status quo), and (ii) cooperative water resources management among the riparian countries. The hydro-economic model is developed using a Genetic Algorithm and deterministic optimization approach covering all hydraulic infrastructures in the Eastern Nile, existing and planned, including the Grand Ethiopian Renaissance Dam (GERD). The results show that cooperative management yields an increase in hydro-energy returns for all countries compared to the status quo, with a very high increase in Ethiopian’s returns, as expected. Non-cooperative system management would negatively impact the hydro-energy of Egypt compared to the cooperative management (reduced by 11%), without a significant increase of hydro-energy for Ethiopia. For Sudan, the results show that hydropower generation benefits from the presence of GERD, in both management scenarios. Non-cooperative management of the system, along with the internal trade-off between irrigation and hydropower facilities, would negatively impact irrigation supply in Sudan. The findings support the argument of positive impact of GERD development on the three Eastern Nile riparian countries, Ethiopia, Sudan and Egypt, provided that the three countries agree to manage the system cooperatively.

استخدامات مياه نهر الفرات بين الدول المتشاطئة وفقاً للقانون الدولي

The Euphrates River is one of the most important rivers in the Middle East. Its waters feed several countries, namely Turkey, Syria and Iraq. These countries depend mainly on the waters of this river to achieve human development. Euphrates is an international river in accordance with the international concept (an international watercourse) and has its own independent water basin and its independent water network separated from other basins. The upstream countries started to use and utilize its waters taking no consideration to the rights and interests of the downstream state, Iraq. The large number of projects established by Turkey and Syria led to the shortage of waters entering Iraq, as well as the deterioration of their quality and lack of validity for some purposes causing damages to Iraq, especially in the agricultural sector and other sectors. The works of the upstream countries on the Euphrates River are breaching the principles and rules of international law concerning international rivers, including the rule of equitable and reasonable usage and utility as well as the rule of non-harm and pollution control.

Water Use Efficiency in Rice Production: Implications for Climate Change Adaptation in the Vietnamese Mekong Delta

Water scarcity and competition in the Vietnamese Mekong Delta becomes a great matter of concern under the contexts of climate change and tributary dam construction in upstream countries. Moreover, water productivity or water use efficiency in rice production was quite low in the region due to free-rider problem. Therefore, the study was aimed at measuring water use efficiency at farm level and investigating the factors affecting water use efficiency. The study applied stochastic frontier analysis to estimate water use efficiency for 159 rice farmers in the upstream of the Vietnamese Mekong Delta. The study shows that the average water use efficiency was 18.81%, indicating that rice farmers did consume water very inefficiently. On the average, the rice farmers could reduce their water consumption about 81.19%, keeping their output level and other inputs constant. To improve water use efficiency, the study found that land accumulation or large-scaled production is essential.

Evaluation of multi-storage hydropower development in the upper Blue Nile River (Ethiopia): regional perspective

Study regionEastern Nile River Basin (Ethiopia, Sudan and Egypt). Study focusThis study aims to understand the future water development perspective in the Eastern Nile region by considering the current water use situation and proposed reservoirs in the upper Blue Nile (Abbay) River basin in Ethiopia using a simulation approach. The study was carried out by using a monthly time step and historical ensemble time series data as representative of possible near future scenarios. Series of existing and proposed cascaded water development projects in the upper Blue Nile were considered in the study. New hydrological insights for the regionThe results indicated an overall energy gain in the Eastern Nile region increases by 258%. The upstream country Ethiopia can generate as much as 38200 GWh/year of Energy while the energy production in Sudan increases by 39%. The cascaded developments integrated with existing water resources systems have a performance efficiency of above 92%. This study was an indicative analysis of the potential benefit of upstream Nile development without significantly affecting existing development in the Nile Basin. Further scientific analysis in this direction would help the Nile countries to reach a water use agreement.

Changes in discharge regimes of rivers in Croatia

This paper presents the results of the first comprehensive national analysis of changes in discharge regimes of rivers in Croatia. Seven types of discharge regimes have been defined for rivers in Croatia. We analyzed the changes in discharge regimes of all types, comparing the standard period from 1961 to 1990 with the most recent period from 1990 to 2009. We found evidence of a redistribution of discharge throughout the year, an increase in autumn and winter discharges (especially for rivers dominantly fed by snowmelt), and a decrease in summer discharge values. Furthermore, we detected a change in the month of the appearance of mean discharge maxima and minima. In most cases, the changes can be explained by changes in the regime of climate elements (temperature, precipitation, and evapotranspiration). The results are consistent with those from upstream countries; that is, Slovenia, Austria, and Bosnia and Herzegovina.