Basin Water Research Articles

Vertical water renewal and dissolved oxygen depletion in a semi-enclosed Sea

The limited water renewal in semi-enclosed seas may contribute to the oxygen deficiency and thereby may exacerbate the ecological degradation. Previous research has focused more on horizontal water renewal, while the role of vertical water renewal remains poorly documented despite its significance to the bottom oxygen supply. This study explores the vertical water renewal process in the Bohai Sea, a semi-enclosed sea prone to oxygen deficiency, by developing a water age model, incorporated into a developed Delft3D hydrodynamic model. Findings unveiled the key role of thermal stratification, tides, and winds on vertical water renewal. Results revealed significant spatial heterogeneity and seasonal variations in water age in the Bohai Sea. During summer, stratified from the upper water column, the deep basin water age can reach up to 30 days. Thermal stratification was crucial in regulating vertical water renewal, acting as a constraint and impediment. Spring tides and neap tides can positively and negatively influence vertical water renewal by strengthening and weakening thermal stratification, respectively. Wind forces intensified the vertical water exchange by changing the flow field structure. Additionally, higher bottom water age coincides with the oxygen-poor areas and deep-water regions. Based on this, we employed the product of the oxygen consumption rate and the bottom water age (oxygen consumption duration) to approximate oxygen depletion. This method was applied to successfully estimate vertical oxygen depletion in the Bohai Sea. The findings will serve environmental management and oxygen-poor attribution analysis.

Development of sustainable energy: Performance investigation of the combined utilisation of a seawater electrolyser and single slope solar desalination still

The primary objective of this work is to investigate experimentally the desalination performance of seawater, hydrogen, and oxygen gas generation through the use of two identical single-slope solar stills. Seawater collected from “Bay of Bengal” was used as the fluid and analysis was conducted at a constant water depth of 20 mm. The system was constructed using mild steel and stainless steel 316 L was used as electrodes. A set voltage and current of 12 V and 40 A was supplied to the electrodes through switched-mode power supply (SMPS). The study investigated the impact of solar radiation and induction of electrolysis system on the performance of solar stills. The results demonstrate a significant positive correlation between solar radiation and still temperature, with 877.1 W/m2 of maximum solar radiation intensity resulting in a still temperature of 53.9 °C. The temperature of the basin water increased by an average of 4.25% upon the addition of an electrolyser. It was noted that with the introduction of electrolyser there was increase in productivity by 48 % than the still without the electrolyser. When the solar radiation was at its peak the maximum amount of hydrogen and oxygen were produced which is 0.44 kg/L and 0.24 kg/L respectively. It was noted that when the system with electrolyser is operated at its peak there was increase in solar still and exergy efficiency by 30.5 % and 9.32 % than the system operated without electrolyser. The economic analysis revealed that the hybrid system which possessed electrolyser has very short pay back period of 1.5 days which is approximately 90 days less than the still without electrolyser. The study shows the use of hybrid system reduces the carbon emission significantly which contributes for its sustainable utilisation. The study highlights the interaction between solar radiation, electrolyser induction, and overall efficiency in the context of seawater desalination and shows the system's strong performance.

Heavy Metal Concentrations in Surface Water of the Lower Mekong River Basin (Vietnam)

Heavy Metal Concentrations in Surface Water of the Lower Mekong River Basin (Vietnam)

Study on the Application of Water Resource Management Based on GF-7 Stereo Mapping Satellite

Abstract. GF-7 satellite was successfully launched on 3 Nov 2019. The two-line stereo camera can effectively obtain 20 km-width panchromatic stereo images with resolution better than 0.8m and 3.2m-resolution multispectral images. Through the composite mapping mode of stereo camera and laser altimeter, the satellite realizes 1:10,000-scale stereo mapping. This article selected the Qiafuqihai Reservoir and its upstream of the Yili River Basin as the study area. Hydrological landforms and vegetation coverage were monitored and three-dimensional dynamic simulation software was developed to verify the potential application of GF-7 stereo mapping satellite data in supporting drainage basin water resource allocation and management in future scenarios. 3 meters DSM derived from GF-7 surveying and mapping satellite finely portrayed the characteristics of hydroponic landforms of small watersheds. The upstream of Qiafuqihai was divided into eleven small watersheds. The water density was 8.5 times more than which was produced from STRM 90m. The elevation of the water-level fluctuation zone of the Qiafuqihai Reservoir ranged from 970 to 998 meters with the water area changed from 28.3 to 57.6 square kilometres. The terrain in the northwest and northeast was flat, with the main vegetation types being natural grasslands (64.9%) and arid lands (5.03%). The three-dimensional dynamic visualization software was developed and demonstrated hydrology information, vegetation coverage information and dynamic changes in the landform of the basin in three-dimensional environment. GF-7, the stereo surveying and mapping satellite, could be perfectly able to support the application of water resources deployment and management in the future.

Impacts of extreme precipitation on water conservation in Beijiang River Basin, China

Water conservation, which has been regarded as one of the most crucial ecosystem service functions of river basins, is a key factor for sustainable development, that has garnered widespread attention in the context of climate change. However, little attention has been paid to daily water conservation and its response to extreme precipitation events. In this study, we selected the Beijiang River Basin (BJRB) as the study area, which is an important ecological barrier for the Guangdong-Hong Kong-Macau Greater Bay Area (GBA), based on the distributed hydrological model WEP-L (Water and Energy transfer Processes in Large River basin) and water balance equation, the spatiotemporal characteristics of extreme precipitation and four daily water conservation indicators (maximum 1 day, maximum 3 day, maximum 5 day, maximum 7 day water conservation) in the BJRB from 1965 to 2009 were analysed, and the responses of these indicators to extreme precipitation were investigated. The results reveal that (1) the amount (RX1day, RX3day, RX5day, RX7day, R95p, and R99p), intensity (SDII), and frequency (R50mm) of extreme precipitation increased in the BJRB during 1965–2009, with SDII undergoing a significant increase. (2) The four water conservation indicators were positive, indicating that the watershed reduced peak flow during the extreme precipitation period by accumulating precipitation. The rate of increase of the four water conservation indicators were lower than that of extreme precipitation indices, there will be more extreme precipitation converted into surface runoff, thereby increasing the risk of flooding. The four indicators increased in the southern and northern regions of the BJRB, while decreased in the central region during 1965–2009. (3) The four indicators were generally positively correlated with most of the extreme precipitation indices in the northern BJRB, especially RX1day, RX3day, RX5day, RX7day, R99p, and R50mm. The results provide a scientific reference for water conservation adaptation to extreme precipitation variations, protection of the ecological environment, and the prevention and reduction of disasters in the region.

Response of evapotranspiration to the 2022 unprecedented extreme drought in the Yangtze River Basin

AbstractThe response of evapotranspiration (ET) to drought is essential for understanding water availability under drought conditions, which has received increasing scientific attention but remains highly uncertain. An unprecedented extreme drought sweeping the whole Yangtze River Basin during the summer and autumn of 2022 provides a novel opportunity to explore the ET response to drought within large river basins. Here, we apply multiple ET products to investigate the spatiotemporal variation of ET during the 2022 extreme drought and analyse the response of ET to drought in the Yangtze River Basin. The results show that this drought, characterized by widespread substantial precipitation deficit and high level of atmospheric evaporative demand (AED), leads to evident abnormal ET. Over the whole basin, ET exhibits a notable increase in the initial 2 months of this drought, which can significantly reduce water availability. However, despite continued high AED, the increase in ET fails to remain in the following months due to limited moisture supply. This suggests that ET response to drought varies as drought progresses. Among other drought events from 2003 to 2022, the response of ET is similar to that in the 2022 extreme drought. Specifically, for most sub‐basins, ET typically shows positive anomalies in the early stage of drought, followed by negative anomalies in the late stage. Generally, our findings improve the understanding of the dynamic response of ET to drought at the basin scale, which is crucial for basin water security.

Physico-chemical characterisation of irrigation basin waters and inventory study of their algal communities.

To cope with the water shortage in Sous Massa region of Morocco, agricultural producers in the region have resorted to different types of water supply basins, known as "irrigation basins" but the phenomenon of eutrophication has hindered the continuity of agricultural productivity by altering the quality of the water used for irrigation on the one hand, and causing economic damage to agricultural producers due to the clogging of the water pumping network on the other. We began by characterising the physico-chemical quality of the water to determine the causes of its high nutrient content, then we determined the taxonomy of the algal species in the irrigation basins to which we had access. A qualitative study of the water in the irrigation basins in order to better explain the inventory obtained from the taxonomic identification of the algal biomass collected, which proved the existence of new species, not previously identified, characterising the freshwaters of the Moroccan region, is under the scope of this work. The species studied belong mainly to the following groups: green algae (11 genera of Chlorophyta and 7 genera of Charophyta), blue algae (7 genera of Cyanobacteria), brown algae (7 genera of Diatoms), and one genus of Euglenophyta.

Pollution by total suspended solids and its relationship with the liquid-solid flow of the lower basin of Usumacinta River in Tabasco, Mexico

Rivers are natural environments that collect water from basins and transport it in laminar flow to the sea. Gradual changes occur due to the erosion of the walls and the bottom of rivers and the deposition of solids that the current carries. In the Usumacinta River basin, there is a sinusoidal correlation between liquid and solid flow. The term solid flow refers to the amount of sediment in motion, gaining its name from the product between liquid flow and the concentration of suspended solids. 21 simple samples of surface water were taken from June to December 2017, in the municipalities of Tenosique, Emiliano Zapata and Jonuta, in the state of Tabasco, Mexico. The concentrations of total suspended solids exceed the maximum permissible limits of the NOM-001-SEMARNAT-1996 (Mexico), for urban public use. Moreover, according to CE-CCA-001/89 (Ecological Water Quality Criteria in Mexico), the surface water of the lower basin of the Usumacinta River is classified as polluted.

Successive bootstrapping deep learning approach and airborne EM-borehole data fusion to understand salt water in the Mississippi River Valley Alluvial Aquifer

Increasing demands from agriculture and urbanization have decreased groundwater level and increased salinity worldwide. Better aquifer characterization and soil salinity mapping are important for proactive groundwater management. Airborne electromagnetic (AEM) is a powerful tool for aquifer characterization and salinity delineation. However, AEM needs to be interpreted with caution before being used for groundwater quality analysis. This study introduces a framework that utilizes the AEM data for both lithologic modeling and salinity delineation. A resistivity-to-lithology (R2L) model is developed to interpret AEM resistivity to lithology based a depth-dependent multi-resistivity thresholds. Then, a cokriging method is used to integrate AEM data from two different EM systems to predict resistivity at the aquifer. Finally, a resistivity-to-chloride concentration (R2C) model utilizes the resistivity model to estimate chloride concentrations at sand facies. A deep learning artificial neural network (DL-ANN) model is introduced with a successive bootstrapping approach to estimate total dissolved solids first and then use it together with resistivity data to estimate chloride concentration. The methodology was applied to delineating salinity plumes in the Mississippi River Valley alluvial aquifer (MRVA). This study found that the salinity distribution in MRVA is highly correlated with the Jurassic salt basin, salt domes, faulting, seismicity, and river water quality. The result indicates salinity upconing due to excessive pumping.

Quantification of water, soil and nutrient losses in the Farinha river basin, Carolina - MA, in the Cerrado biome

Natural resources, such as soil and water, play a crucial role in sustaining life on Earth. When used appropriately, these resources can mitigate environmental impacts. However, inadequate soil management practices can result in negative effects, such as the intensification of erosion processes and significant losses of soil, water and nutrients essential for plant growth. Thus, considering that the Farinha River basin - MA is located in the Cerrado biome and has a large part of its area occupied by highly erodible soils, the aim was to quantify water, soil and nutrient losses using a rainfall simulator. The experimental design adopted was entirely randomised (DIC), in a bifactorial scheme with 5 replications. Factor 1 considered two types of soil management systems (Anthropised Area and Non-Anthropised Area), while factor 2 involved three simulated rainfall intensities (80mm.h-¹, 110mm.h-¹ and 130mm.h-¹). The response variables assessed were losses of water, soil and nutrients and organic matter.The averages were subjected to analysis of variance and, if significant, the Tukey test was applied at 5% probability using Past 4.03 software. The results indicated significant losses of soil, water and nutrients associated with both the soil management system and the rainfall intensities, as well as making it possible to quantify the nutrients lost in runoff water on site. The conclusion is that the combination of inadequate soil management practices and intense rainfall can exacerbate erosion processes and the leaching of macro and micronutrients, resulting in an increasing need to incorporate fertilisers and correctives into agroforestry activities. Furthermore, it is important to emphasise that water erosion also contributes to an increase in soil and nutrient loss, which can lead to adverse environmental impacts, such as contamination of water resources and degradation of soil quality.

Evaluation of surface water quality and carrying capacity as planned by 2030 in the Lai Giang River basin, Binh Dinh Province, Vietnam

The quality of surface water in the river basin under the influence of industrial development and urbanization is one of the issues that need attention in the management of water resources in Binh Dinh province. The study assessed water quality in the Lai Giang river basin gives an overview of the surface water quality situation and predicts future changes in wastewater reception through the 2030 planning scenario. The study corrected the NAM model flow at An Hoa hydrological station with R2 = 0.777 and BIAS = 5%. The results of adjustment of water level and flow in 2016 for R2 are 0.893 and 0.731, respectively. The test of water level and flow in 2017 for R2 is 0.882 and 0.582 respectively, along with the test result of water level in 2021 is 0.689. The calculation of the current carrying capacity in 2021 and the planning scenario in 2030 shows that there is still capability to receive, but consideration should be given to rational use of water resources.

Assessing the water potential and wastewater load capacity of the La Tinh River, Binh Dinh province by MIKE 11AD and Ecolab model combined with GIS method

The study used the NAM model of flow simulation with a time series of 14 years (2008 - 2021), statistical analysis method, and MIKE 11 AD water quality model, and Ecolab combined with GIS method to calculate wastewater reception capacity and load capacity of the basin. The model validation is highly reliable with a model efficiency factor of R2 of 0.777 and BIAS = 5%. The results of the application of the NAM model have determined the daily flow series of 14 years (2008 - 2021) and the average flow characteristics of many years of the La Tinh basin such as Qo flow is about 5.9; 6.0 m3/s, total amount of Wo = 292.1; 188.8 million m3 flow modulus Mo = 19.3 l/s-km2 flow class Yo = 611 mm and flow coefficient α= 0.3 for all sub-basins. The results of the study show that the capacity of receiving wastewater, the capacity of most river sections in the La Tinh basin is still received with five parameters at a relatively high level, the section of the Binh Tri river upstream alone has exceeded its capacity to receive. This is one of the very useful tools in integrated management and effective use management of river basin water resources.

Evaluation and valuation of tajan river basin ecosystem services

Rivers as a blue ecosystem have a lot of ecosystem services that awareness of the value of their services will protect them as much as possible and communities will benefit from their environmental services. In this study, Tajan river basin ecosystem services in the north of Iran was valuated. To valuate, the choice experiment method was used to estimate willingness to pay. Tajan river basin ecosystem services attributes including regulating, supporting, provisioning and cultural services and a price attribute at three levels were determined. Data from 239 resident households of Mazandaran province were used in 2017. The empirical analysis did by the conditional logit model and mixed logit model. Also, multi criteria decision making including techniques Entropy, TOPSIS and SAW used for evaluating the role and importance of the Tajan river basin ecosystem services. The findings indicated that residents were willing to pay for the conservation of Tajan river basin ecosystem services, 13.77 USD per year. It was for regulating, supporting, provisioning and cultural services of Tajan river basin, 2.62, 6.30, 2.50 and 2.35 USD per year to move away from the status quo to the improvement status respectively. Also, findings of weighting and prioritization of Tajan river basin ecosystem services with TOPSIS and SAW methods showed that supporting and provisioning services had the highest weight for the evaluation Tajan river basin ecosystem services. In other words, the residents prefer the services as the most important Tajan river basin ecosystem services. Results showed that willingness to pay can be introduced as a useful tool to investigated people's preference for conservation of river basin ecosystem services under various activities. Therefore, by determining the value of river ecosystem services, community will understand that river services are of great importance, and the application of its value in calculations related to comprehensive management of basin water resources will provide a suitable economic solution to increase user utility the river.

Green and Blue Water Footprints of Major Crops in the Wami/Ruvu Basin, Tanzania: Implications for Water Scarcity and Sustainability

Accurate estimation of the blue and green water requirements of the various crops cultivated in a water basin is essential for planning specific plant/crop irrigation schedules. In this study, the crop water requirements of the major crops grown in the Wami/Ruvu basin were determined using the FAO-CROPWAT model based on meteorological parameters: monthly maximum and minimum temperature, wind speed, mean relative humidity, sunshine hours, rainfall data, and effective rainfall for 23 hydro-meteorological stations distributed in the study area. The studied crops are rice, maize, beans, tomatoes, and sugarcane. The crop reference evapotranspiration (ETo) and actual evapotranspiration (ETc) for each crop were determined using crop coefficients (Kc) of various growth stages of crops. The results indicated that the total annual reference evapotranspiration (ETo) was 1604 mm, whereas an average ETo per month was 134 mm. The highest total irrigation water requirements were recorded in sugarcane, followed by rice, while the lowest water requirements were observed in beans and tomatoes. The results presented in this study may facilitate plant-specific water irrigation implementation and maximize crop production while conserving the environment.

Post-mining related reactivation potential of faults hosted in tight reservoir rocks around flooded coal mines, eastern Ruhr Basin, Germany

The cessation of hard coal mining in the Ruhr Basin in 2018 marked the region's transition to the post-mining phase. Controlled mine water rebound induces changes in the subsurface stress conditions, as pore pressure increases locally. Presently, mine water rebound is observed in the eastern Ruhr Basin (water province “Haus Aden”) along with associated microseismicity. Furthermore, post-mining challenges might comprise the potential risk of fault reactivation, which is addressed in this study by conducting a fault slip assessment. Based on subsurface coal seam mapping data, a 3D structural model for the NE part of the “Haus Aden” water province has been constructed to serve as the basis for identifying the most vulnerable fault trends and types of the structural inventory. Slip tendency analysis, considering normal faulting conditions, revealed NW-SE to NNW-SSE trending normal faults to be most susceptible to reactivation. Probabilistic fault slip assessment, focused on NW-SE to NNW-SSE trending normal faults mapped within the “Heinrich-Robert” colliery, show no fault reactivation potential for a mine water rebound up to a level of 640 m below ground. Assuming hydrostatic conditions in the vicinity of the faults, friction coefficients are only partially exceeded for high differential stresses. In addition, a novel workflow is used to model the spatial variability of the frictional fault strength as input for a fault stability analysis, exemplified for a selected NNW-SSE trending normal fault. For considering hydrostatic pore pressure, results show that the fault consists mainly of stable, but also unstable, horizontally elongated patches. These findings question the conventional simplified approach of using a single constant friction coefficient for fault stability analysis.

Application of SWAT Model for Hydrological Simulation of Rapti River Basin

This study aimed at application of SWAT model for hydrological simulations of Rapti River Basin (RRB) water systems. The Rapti River originates from Nepal and then it comes in India. SWAT (Soil and Water Assessment Tool) model was used for hydrological simulation of the RRB surface and sub surface water systems. SWAT is a comprehensive, semi-distributed river basin model that requires a large number of input parameters, which complicates model parameterization and calibration. The RRB was discretised into 4 sub-basins and 630 hydrological response units (HRUs) and calibration and validation was carried out at Bagasoti using monthly flow data of 11 years, respectively. We first calibrated the model in SWAT-CUP which is a decision-making framework that incorporates a semi-automated approach (SUFI2) using manual calibration and incorporating sensitivity and uncertainty analysis. Parameter sensitivity analysis helps focus the calibration and uncertainty analysis and is used to provide statistics for goodness-of-fit. In this study Calibration has been done between simulated and observed discharge data (1974-1985) for 50 simulations with 6 parameters that is Curve number (CN2 = 0.945), Groundwater delay (GW_DELAY = 50), Baseflow alpha factor (ALPHA_BF = 0.58), Manning's "n" value for the main channel (CH_N2 = 0.15), Effective hydraulic conductivity in main channel alluvium (CH_K2 = 10.20) and Available water capacity of the soil layer (SOL_AWC = 0.28). The results were analysed and compared with the observational data. The model performance evaluation showed acceptable ranges of values (i.e., Nash Sutcliff was 0.75 and R2 was 0.71). After model calibration, in order to predict water balance, the model was validated by using the best parameter.

Exogenous, Endogenous, and Peripheral Actors: A Situational Analysis of Stakeholder Inclusion within Transboundary Water Governance

Transboundary water governance involves collaborative decision-making across geopolitical boundaries to manage shared water resources sustainably. While this approach integrates public, private, and community efforts, little scrutiny has been directed toward the involvement of non-institutionally affiliated stakeholders. This study critically examines stakeholder participation in Upper Klamath Basin water governance by investigating how deficiencies in stakeholder inclusion impede transboundary water management processes by favoring institutionally affiliated actors. Findings reveal the differential influence of “endogenous” (directly involved), “exogenous” (indirectly involved), and “peripheral” (limited engagement and influence) actors. While endogenous and exogenous actors have formal or informal ties to institutions, peripheral actors lack institutional affiliation(s), making it difficult for them to participate in and ultimately influence water governance decision-making processes. Their limited access to financial, natural, and social capital further restricts their engagement with governance efforts. This imbalance underscores challenges to equity and inclusion in transboundary water governance processes. Addressing the exclusion of peripheral actors from transboundary water governance requires that governance institutions prioritize equity and inclusivity, fostering transparency, incentivizing inclusive practices, and comparing engagement processes to enhance effectiveness and equity in transboundary water management.

Суверенитет России на трансграничные реки

The article discusses issues of Russian sovereignty over transboundary rivers. It reveals that in accordance with the UN Charter and international treaties, states have full sovereignty over their natural resources. As to environmental protection against transboudary pollution and damage and also in relation to the use of shared natural resources, international law applies this principle in combination with the principle of limited sovereign rights. In conformity with the intergovernmental water basin agreements of Russia with the watershed countries the external involvement into the national decision-making process is carried out through mutual commitments and obligations to recover the environmental damage, conducting joint monitoring, notification about on-going and planned activities that have or may have negative impacts on a transboundary river, related water uses and facilities, division of a water flow, joint inspections and agreed exploitation of hydrotechnical objects. Application of the limited sovereign rights to shared water resources has an objective nature-based rationale – ecosystem integrity of a shared water body, that justifies and ensures its protection against degradation, equitable and reasonable utilization by coastal states.

Experimental investigation of a solar still system with a preheater and nanophase change materials

Solar desalination systems are crucial for generating fresh water, particularly in regions with water scarcity. They harness renewable solar energy, making them sustainable and cost-effective in remote areas. Solar desalination addresses water scarcity challenges with a sustainable, decentralized, and efficient approach. The objective of this study is to analyze the impact of varying depths of basin water on the overall productivity of distillate in a solar distillation system. The research specifically investigates three distinct scenarios, focusing on the concentration of freshwater at different depths. The investigation extends to the analysis of temporal variations in heat transfer loss for three different phase change materials (PCMs) namely paraffin wax + nano CuO, paraffin wax, and lauric acid. This study also examines the impact of varying depths of basin water on the overall productivity of distillate in three distinct scenarios. In all instances, it has been observed that the more concentrated form of freshwater can be found at a depth of 20 mm. The water basin temperature lowered by 44.78% for paraffin wax + nano CuO composite, in comparison to paraffin wax (45.31%) and lauric acid (47.37%) when the water depth was increased from 20 mm to 60 mm. The equations pertaining to energy conservation and heat transfer in the solar distillation system are presented. The investigation also encompassed the analysis of temporal variations in heat transfer loss for three unique PCMs. The study recorded an increase in the total distillate freshwater of 3480, 1248.5, and 2637 ml/m2/day for paraffin wax + nano CuO, lauric acid, and paraffin wax correspondingly. Lauric acid has exhibited a level of performance in terms of total distillate.

Hydrological study and assessment of water budget for Erbil basin, Kurdistan region, Iraq

<p>This research is conducted on Erbil basin, it is located in northern part of Iraq, the basin is composed of three main sub-basins which are: Northern part (Kapran), Central sub-basin and Southern part (Bashtepa) respectively. The total area of three sub-basins are approximately (3,200 km2). The main sources of aquifer recharge in the study area is depends on precipitation. The article estimated the percentage and amount of water budget elements for the selected basin. Therefore, the paper evaluates the obtained climate data form Erbil meteorological station for (25 years) to evaluate the water budget in the study area. The main objective to assess the Erbil basin water budget and determine amount of the each parameters related to the study area. Based on the results of this study data analysis the amount of the mean monthly temperature (18.94 C̊), and sun shine (8.18 hr/day), the average relative humidity is (47.82%), the evaporation percentage is (54%) of the precipitation. The study concluded that the amonut of the rainfall data is (394.65mm) and the percentage of precipitation over Erbil basin is (100%), the Recharge into groundwater is (24.23%), the Runoff and Evporation are (21.77%) and (54%) respectively.</p>