Displays

Impacts of climate change on water resources will rise from the co‐occurrence of extreme hot and humid conditions. In this study, changes in the daytime and nighttime hot and humid conditions were analyzed in the Mississippi River Basin, USA covering large semi-arid regions. Results indicated that humid nights and days have increased over 1948-2017 in at least 93% of the basin. Concurrent hot and humid events were increased during both nights and days with more significant trends for nighttime events. A change-point analysis was completed and more significant upward trends were observed after the 1980s and 1990s for extreme temperature, humidity, and hot-humid events. Results suggested a higher risk of receiving extreme hot and humid conditions for the central and southern Mississippi River Basin. The findings can help improve water resources management and allocation in the semi-arid regions of the watershed where access to surface water resources is limited.

How to cite: Tavakol, A. and Rahmani, V.: Spatiotemporal analysis of extreme temperature and humidity in the Mississippi River Basin, USA, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21006, https://doi.org/10.5194/egusphere-egu2020-21006, 2020.

Groundwater abstraction has increased significantly around the world in the last three decades, placing a strain on the sustainability of domestic and agricultural use plus negatively impacting the role groundwater plays in water storage in the absence of surface water. While the proportionality of surface water use has decreased as a result, groundwater has expanded its share of freshwater use. Groundwater management challenges are particularly acute in semi-arid zones due to low replenishment rates. Multiple regulatory innovations are consequently emerging in different countries to regulate groundwater usage but comparative analyses of their effectiveness are limited. In addressing this gap, our paper therefore compares the regulatory performance of the Water Framework Directive (WFD) in Turkey with the Sustainable Groundwater Management Act (SGMA) in California, two semi-arid zones, as a basis for policy learning. Both legislative measures impose river basin planning to protect groundwater resources and should provide them with strong protection. In analysing the effectiveness of these measures, this paper firstly identifies the key regulatory requirements of each legislative framework regarding groundwater protection. Secondly, it compares the institutional arrangements for implementing them, using specific river basin case studies. Thirdly, it quantifies groundwater use trends in river basins to assess the effectiveness of the WFD and SGMA. Finally, it comparatively discusses outcomes to determine the factors influencing implementation effectiveness, in order to inform future regulatory design.

How to cite: Ak, M. Y., Benson, D., and Scott, K.: Analysing the effectiveness of groundwater regulation: a comparative study of Turkey and California, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20988, https://doi.org/10.5194/egusphere-egu2020-20988, 2020.

The region of Corridor Seco (Dry Corridor, including parts of Guatemala, Honduras and El Salvador) has been facing multiple food crises caused by extreme weather events, water scarcity and land degradation phenomena. In this situation, Rooftop Water Harvesting (RWH) systems can effectively enhance local livelihoods, especially in marginalized communities, by providing an additional water source for domestic use, livestock, and irrigation of small horticultural plots which are key for vegetable production and thus for vitaminic input in a well-balanced diet.

Dimensioning sufficient storage tanks for rainwater collection is key, since smallholder farmers’ capabilities are often hindered by low financial capacity as well as by limited land extension for reservoir building.

Efficiency of storage tanks and design criteria for water harvesting systems are investigated on the base of rainfall time series analysis, probabilistic risk assessment and Monte Carlo simulation (Ursino, 2016). The approach is tested on a series of (RWH) systems built in Guatemalan part of the Corredor Seco, Chiquimula department, with sustainable and appropriate building techniques, but with variable size due to the variability of each household. Factors affecting efficiency of storage tanks are discussed to inform future sustainable water management planning in the area.

Reference:

Ursino, N. Risk Analysis Approach to Rainwater Harvesting Systems. Water 2016, 8, 337. https://doi.org/10.3390/w8080337

How to cite: Bresci, E., Castelli, G., Ursino, N., Giacomin, A., and Preti, F.: Multi-method efficiency analysis of Rainwater Harvesting Systems in Corredor Seco region, Central America, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16844, https://doi.org/10.5194/egusphere-egu2020-16844, 2020.

Watering ponds are the main source of drinking water supply for livestock in the rangelands of the SW Iberian Peninsula. Most of these ponds consist of small earth dams which collect surface runoff from intermittent streams, with pond sizes rarely exceeding 1 ha. Understanding the hydrological functioning of this type of infrastructures is crucial for an efficient water management in extensive livestock farms, especially in semi-arid areas, where water resources are often scarce.

In this line, we have analysed the temporal patterns of water availability in a sample of representative livestock watering ponds in the SW Iberian Peninsula, being the objectives (1) to determine the influence of temporal rainfall variability on water availability in the ponds; (2) to examine the influence of factors such as pond size and catchment area on the effectiveness of the ponds, understood as their capacity to keep water during dry periods; and (3) to suggest minimum values for those factors, which can serve as a guide for the design of watering ponds in comparable rangeland areas. The applied methodology was primarily based on the analysis of aerial photographs and rainfall data available from public sources, requiring only few field measurements, and could therefore be used in areas with data scarcity.

High correlation coefficients were obtained between the water availability observed in the ponds and the antecedent rainfall at several time scales, evidencing the principal role of precipitation in the hydrological dynamics of these infrastructures in the study area. The accumulation periods (AP) of antecedent rainfall that best explained the hydrological response of the ponds depended largely on pond size. In those ponds whose maximum flooded area (A_max) was less than 2000 m², water availability in the ponds was greatly influenced by AP between 2 and 5 months, while for the ponds larger than 2000 m², the best correlations were obtained for AP greater than 6 months. These results highlight the key role of the size of the ponds in their effectiveness. Thus, since the dry season usually lasts in the study area for 3-4 months, the large ponds (A_max > 2000 m²) could remain operational throughout the summer, if it rains enough during the wet season and if their watersheds are large enough to allow a sufficiently high pond water level to be reached at the end of the wet season. In relation to the latter, the analyses carried out led us to suggest, for the study area, a minimum value of the catchment-area/pond-capacity ratio around 100 m^-1.

Moreover, the analysis of the water availability observed in the ponds under drought conditions (i.e., with an antecedent rainfall substantially lower than normal for the corresponding time of year) revealed a high vulnerability to droughts in most of the ponds, which limits their use as the sole source of water supply in many farms.

How to cite: Marín-Comitre, U., Schnabel, S., and Pulido-Fernández, M.: Hydrological characterization of livestock watering ponds in semi-arid rangelands of the southwestern Iberian Peninsula, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4973, https://doi.org/10.5194/egusphere-egu2020-4973, 2020.

Water resources management involves allocation of ‘enough’ water, a limited resource, to users and stakeholders from multiple sectors such as agriculture, energy, ecosystems, and water supply. The integrated water resources management (IWRM) framework has been applied for such water resources allocation optimizations in river basins and watersheds with general constraints such as less water may result in operational inefficiency or in drought, and more water may result in risks such as flooding or infrastructure damage.

What seems to receive less attention in such IWRM applications is the role of moral considerations and the importance of distributive justice. 
Different allocation principles could be formulated, stemming from different moral principles and different views on distributive justice discussed 
in the literature:  

-  Utilitarianism: water resources should be allocated based maximizing happiness and well-being for the majority; 
-  Egalitarian: water resources should be allocated such that inequalities are reduced to the largest extent possible; 
-  Pareto: only the vital few should be considered when allocating water resources. 
-  Sufficientarianism: irrespective of inequalities, water should be allocated so that each user/stakeholder gets ‘enough’; 
- Prioritarinism: irrespective of inequalities, water should be allocated so that each the worse-off users/stakeholders get priority in allocating water resources; 

Operationalizing such moral principles in IWRM applications is important for an equitable and sustainable allocation of limited water resources, particularly in arid and semi-arid regions, and in the face of growing societal challenges such as from population growth and climate change.

In this study, we examine the role of moral principles in water resources allocation/optimization efforts. Using case studies in the Como Lake (Italy), Seine River (France) and the Merguellil basin (Tunisia), we demonstrate that operationalizing moral principles in IWRM is critical beyond aspects of efficiency in water resources allocation and/or optimization.

How to cite: Yalew, S. G., Kwakkel, J., and Doorn, N.: Distributive Justice in Water Resources Allocation and Management, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7274, https://doi.org/10.5194/egusphere-egu2020-7274, 2020.

Crops are facing greater drought stress and are being relocated to more arid regions as the climate changes. Ranking high-yield crops according to their efficient and sustainable use of water resources under drought stress is critical for selecting suitable crops to relieve the stress on food security and water resources in dryland agricultural regions. A global meta-analysis was conducted by incorporating 907 experimental observations from 96 research studies to assess the water-use efficiency (WUE) of 40 crop species under drought stress conditions across various environments. The results showed that compared with well-watered conditions, drought stress decreased crop WUE significantly by an average of 2.8%, but the effects varied among crop species. Most (93.6%) of the variance in crop WUE could be explained by four factors and drought intensity was the most important factor (32.9%), followed by climate type (23.5%), soil texture (20.2%), and crop type (17.1%). Perennial, liana, fiber, and fruit crops displayed the largest increases in WUE under drought stress. Moreover, crops grown in semi-arid regions with medium-textured soil and a drought intensity of < 20% showed the best WUE performance relative to crops grown in other environments. The specific ranks of crops according to their WUE in response to drought across different environments were given. This study highlights factors affecting the WUE of crops in response to drought and provides high-yield crop candidates that can adapt to drought in drylands. The dataset has been made freely available and could be updated with more crop species in the future.

How to cite: Yu, L., Zhao, X., and Gao, X.: Water-use efficiency of crops under drought: A global meta-analysis, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2845, https://doi.org/10.5194/egusphere-egu2020-2845, 2020.

It is of great practical significance to analyze water resources load carry and clarify the bearing capacity of water resources in the Yellow River basin for the ecological protection and economic and social development with high quality of the Yellow River. The Entropy model and EFAST weight algorithm is coupled and employed to assess the water-resources bearing capacity in the Yellow River basin based on the double index of water quantity and quality. The results show that there are 78 groundwater overdraft areas existing, the total area and ultra-picks quantity of which is 2.26×10⁴ km² and 14×10⁸ m³, respectively. Massive cones of depression are developing like Yinchuan and Dawukou in Ningxia province; Fengdong, Xinghua, Lvqiao and Weibin in Shaanxi province; Songgu, Taiyuan and Yuncheng in Shanxi province; Wuzhi, Wenxian and Mengxian in Henan province. Moreover, 47 of 70 assessed prefecture cities are in the state of overload or severe overload, in which, there are 24 severe-overload prefecture cities and the proportion is 34.3%, and the number of overload prefecture cities is 23 accounting for 32.9%. The overload and severe-overload regions concentrate in Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi and Henan provinces at the upper and middle Yellow River. In conclusion, the current water supply has exceeded its water-resources bearing capacity in the Yellow River basin. Strengthening water saving, the construction of main-stream controlled reservoirs and water diversion are the effective ways to relieve the overload state.

How to cite: Yang, L.: Assessment for water resources bearing capacity based on Entropy model and EFAST weight algorithm in the Yellow River basin, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3021, https://doi.org/10.5194/egusphere-egu2020-3021, 2020.

Blue water (surface and ground water) and green water (water stored in unsaturated soil layer and canopy evapotranspiration from rainfall) are the two sources of water generated from precipitation and communicating vessels that define the limits of water resources for both human activities and ecosystems. However, the blue and green water evapotranspiration in irrigated fields and their contribution to blue and green water flows have not been identified in studies conducted on blue and green water resources. In addition, information on intra-annual variations in blue and green water footprints (WFs) is limited. In particular, there is a lack of information on water consumption obtained from hydrological model-based blue and green water assessments at the basin scales. In this study, the Yellow River Basin (YRB) over 2010-2018 was considered as the study case, and the inter- and intra-annual variations in blue and green water resources, WFs and water scarcities were quantified at sub-basin levels. Water resources and WFs were simulated using the Soil and Water Assessment Tool (SWAT) model. The results revealed that the annual average blue and green water resources of the YRB were 119.33 × 10⁹ m³ yr^-1 and 296.94 × 10⁹ m³ yr^-1, respectively, over the study period. The total amount of green water flow was larger than the total amount of blue water flow each year. The blue and green WFs of the crops in the middle reach were significantly larger than those of the crops in the upper and lower reaches. The annual blue and green water scarcity levels under the consideration of the overall YRB were low. However, several areas in the middle reaches were subject to both blue and green water scarcities at least modest level for a minimum of three months a year. The northern region of the YRB was subject to significant and severe blue water scarcity throughout each year.

How to cite: Xie, P., Zhuo, L., and Wu, P.: Spatial-temporal variations in green and blue water resources, water footprints and water scarcities in a large river basin：a case for the Yellow River Basin, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3217, https://doi.org/10.5194/egusphere-egu2020-3217, 2020.

Recharge estimation in arid and semi-arid areas is complicated. As for the country where the potable water for both the people and livestock is supplied from shallow unconfined aquifer due to the lack of existing ground water, the recharge estimation is crucial to water source management. However, since the deficiency of available data, such estimation has not been completed in the Gobi desert of Mongolia. Water-bearing rock units of the Undai river basin consist of Upper Quaternary alluvial-proluvial sands, gravels and pebbles. In this paper, direct recharge was estimated using chloride mass balance (CMB) and rainfall infiltration breakthrough (RIB) model in shallow unconfined aquifer, Undai watershed area Southern Mongolia.  As a result of groundwater recharge estimation survey conducted in 2018, the annual mean recharge of the groundwater along the Undai dry riverbed is calculated to be 13.7mm/year according to RIB model based on the water level fluctuation, which makes up 6.3% of total precipitation and 21.7mm/year according to CMB (chloride mass balance), which comprises 10% of the total annual precipitation. The largest recharge estimates were determined using the daily basis RIB method and the smallest estimates were determined using the chloride-mass-balance method.

How to cite: Danzan, A., Nemer, B., Altangadas, E., and Purevsuren, U.: Groundwater recharge estimation in Undai watershed area, southern Mongolia , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4500, https://doi.org/10.5194/egusphere-egu2020-4500, 2020.

Since the Gravity Recovery and Climate Experiment (GRACE) launch in 2002, a global dataset of Earth’s total water storage (TWS) measures is available, providing additional and useful information for global and regional hydrologic models. In this study we demonstrate how this data can be easily integrated with a simple two-parameter regional water balance model also at the small scale (i.e. area < 50’000 km²). In particular, we show how the inclusion of additional information reduces the predictive uncertainty of the hydrologic model. As test case, the island of Sardinia (Italy) located in the Mediterranean Sea, with an area of about 24000 Km², is chosen. The water balance model simulates at monthly scale surface and subsurface runoff, actual evapotranspiration fluxes, and terrestrial (surface and ground) water storage of the island during the period 2002–2017. The results show that GRACE data constitutes a reliable dataset for the hydrologic modeling also at the small scale and their integration into the proposed regional water balance model reduces the uncertainties in reconstructing long-term variations of the TWS.

How to cite: Perra, E., Urru, S., Deidda, R., and Viola, F.: The more hydrologic info the less uncertainties in monthly runoff prediction: The case study of a semi-arid Mediterranean island, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5834, https://doi.org/10.5194/egusphere-egu2020-5834, 2020.

Determination of "Double Control" Management Threshold Value for Groundwater Based on GMS -- A Case Study of Changchun City, Jilin Province

Linlin Qi¹, Xiaoying Zhang¹, Zhenxue Dai¹, Sida Jia ¹, Funing Ma ¹

（1. College of Construction Engineering, Jilin university, Changchun 130021, China）

Groundwater is an essential controlling factor for economic and social development, human survival and good ecological environment. Many areas use groundwater as a regular source of water. However, with the development of economy and society, water pollution problems keep emerging, water resources crisis is increasingly serious, especially in the northern water resources shortage areas, so groundwater management is particularly important. It is no longer possible to objectively reflect the groundwater safety situation in a certain area by controlling the amount of groundwater mining or the groundwater level. Therefore, it is necessary to construct the groundwater “dual-control” management mode. However, the foundation of “dual-control” management is to establish the mathematical relationship between the groundwater control level and the amount of groundwater mining. Taking Changchun city in Jilin province as an example, the study area was divided into different management zones, and the threshold value about the groundwater level and the amount of groundwater mining were determined by analytical method. Then using GMS software to establish a model of groundwater resources in the study area. After identification authentication model to simulate the groundwater resources and the relationship between the groundwater table, ultimately determine the threshold value of groundwater level and water quantity under dual control management in this area. It can be used as the most intuitive data of groundwater dual control management and control. With the groundwater protection as the starting point and the sustainable utilization of resources as the goal, it will be the focus of future research in China to establish the groundwater management mode of "water level" and "water quantity", in order to make the groundwater management more flexible, controllable and scientific.

How to cite: Qi, L., Zhang, X., Dai, Z., Jia, S., and Ma, F.: Determination of "Double Control" Management Threshold Value for Groundwater Based on GMS -- A Case Study of Changchun City, Jilin Province, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7072, https://doi.org/10.5194/egusphere-egu2020-7072, 2020.

The Municipality of Fasano (Puglia, Italy), i.e. owning one of 32 managed aquifer recharge (MAR) sites in operation in the Puglia region, has pioneered the reuse of tertiary-treated municipal effluent for both soil irrigations and the containment of seawater intrusion via groundwater recharge by ditches.

In this work, quantitative microbial risk assessment (QMRA) methodologies have been applied to assess the degree of safety associated with such integrated practices by assessing the risks for public health resulting from the exposure to the reclaimed water. Escherichia coli (E.coli) dose-response model was used in this work since the pathogenic E.coli is reported to potentially occur in reclaimed water obtained from treated municipal effluents. The target count of pathogens ingested during swimming or inoculated by contaminated (uncooked) vegetables and fruits, was determined from the Monte Carlo Markov Chain (MCMC) Bayesian procedure applied to the results obtained from a monitoring campaign carried out in 2019. An optimization routine was applied in order to determine the most probable target pathogen count by minimizing the number of water samplings. The monitoring positions along the coast were defined by means of mathematical modeling, which highlighted the preferential pathways followed by pathogens when released into the fractured aquifer at a recharge operation flow rate of 10-30 L/s.

QMRA results indicated a negligible risk impact (12% probability of 0.4 infections per year) for soil irrigation practices and no impact on the seawater quality as a result of the additional treatment barrier provided by the so-called "soil-aquifer treatment" during the pathogen transport through the fractures of groundwater.

How to cite: Masciopinto, C., Vurro, M., Lorusso, N., Santoro, D., and Haas, C. N.: Application of QMRA to MAR operations for safe agricultural reuse and marine recreational impacts in coastal areas, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7208, https://doi.org/10.5194/egusphere-egu2020-7208, 2020.

Due to a reduce cost, availability of many favorable locations, easy access due to proximity, the number of small reservoirs has increased, especially in arid and semi-arid regions. The cumulative impact of reservoirs in a catchment is considered as the modifications induced by the reservoir network taken as a whole. The impact may exert on the flow regimes and sediment, nutrient and contaminant transfer, and thereby modify the ecological behaviour of the aquatic environment, the continuity of rivers and the habitats of organisms living in them. The cumulative impact is not necessarily the sum of individual and local modifications, because reservoirs may be inter-dependent. This is the case for instance in cascading reservoirs along a stream course. The cumulative impact is not straightforward to estimate, even solely considering hydrological impact, in part due to the difficulty to collect data on the functioning of those reservoirs. However, there are evidences that the cumulative impacts are not negligible.

This work is dedicated to a review of the studies dealing with the cumulative impact of small reservoirs on hydrology, focusing on the methodology as well as on the way the impacts are reported. It is shown that similar densities of small reservoirs can lead to different impacts on the quantitative water resource in different regions. This is probably due to the hydro-climatic conditions, and makes it difficult to define simple indicators to provide a first guess of the cumulative impact. The impacts vary also on time, with a more intense reduction of the river discharge during the dry years than during the wet years. This is certainly an important point to take into account in a context of climate change.

Habets, F., Molénat, J., Carluer, N., Douez, O. and Leenhardt,D, 2018, The cumulative impacts of small reservoirs on hydrology: A review, Science of The Total Environment, 643, 850-867, doi.org/10.1016/j.scitotenv.2018.06.188

How to cite: Habets, F., Molénat, J., Carluer, N., Douez, O., and Leenhardt, D.: Cumulative impact of small reservoirs : a review of estimations and methods, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10100, https://doi.org/10.5194/egusphere-egu2020-10100, 2020.

Precipitation measurement has always been of human interest. Its estimation can guide the decisions concerning flooding prevention and irrigation scheduling in semi-arid regions.

Nowadays, manufactures offer several types of rain gauges. Among them, the tipping-bucket rain gauges (TBRs) is the most frequently used worldwide to collect rainfall data. It structure is simple and the manufacturing cost is reasonable. Also, the operating mechanical mechanism saves energy and can be easily automated. Its manufacture began in the seventeenth century although the recent models have improved their original characteristics.

Likewise, these gauges have some disadvantages such us: measurement errors, that can be significant during heavy rainfall or light drizzle; losses from evaporation and wind effects; time of onset; sampling procedure and rain residue in the bucket. Therefore, calibration is often needed.

This study assesses the data from a set of 12 TBRs spread in the small mountain basin “Venero Claro”, Avila (Spain). This is highly monitored due to its capacity to generate torrential flows and flash floods.  The data comprised a time interval of 14 years; the oldest TBRs were installed in 2006. The objective was quantified the errors, especially those caused by high precipitation intensities, which are common in the area. Thus, calibration curves for data analysis were estimated by a dynamic laboratory calibration for two different TBRs’ models.

The results from the calibration data have been statistically analysed in order to determine the errors and their significance along time and topography. A significant underestimation was observed in TBRs, especially in those located at higher areas.

How to cite: Rodriguez-Sinobas, L., Segovia-Cardozo, D. A., Zubelzu, S., Estefania, E., and Díez-Herrero, A.: Assessment of the measuring errors in tipping rain gauge located on a small mountain basin, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11634, https://doi.org/10.5194/egusphere-egu2020-11634, 2020.

The ability to dynamically simulate the supply and demand of irrigated water in arid and semi-arid regions is needed to improve water resources management. To meet this challenge, this study developed an agriculture water resources allocation (WRA) module and coupled this module to an integrated surface water-groundwater model GSFLOW. The original GSFLOW, developed by USGS, is able to simulate the entire hydrological cycle. The improved GSFLOW with the WRA module allows the simulation, analysis and management of nearly all components of agriculture water use. It facilitates the analysis of agricultural water use when limited data is available for surface water diversion, groundwater pumpage, or canal information. It can be used to simulate and analyze historical and future conditions. The improved GSFLOW program was applied to the Heihe River Basin (HRB), which is the second largest inland river basin in China. The calibration and validation results of the program shows that the program is capable of simulating both hydrological cycle and actual agriculture water use with limited data. Then the model was used to analyze a set of agriculture water use scenarios, for example, limiting groundwater pumpage, adjusting water allocations between the middle stream and the lower stream. Based on these scenarios, it was found that the improved model could be used as a decision tool to provide better agriculture water resources management strategies. The improved model could be easily used in other basins.

How to cite: Tian, Y.: Improvement of agriculture water resources management in large arid river basin through an integrated hydrological modeling approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12341, https://doi.org/10.5194/egusphere-egu2020-12341, 2020.

Under climate change conditions, arid and semi-arid regions need facing challenges of sustainable water resources management. Climate change in these regions is the accelerator of extreme events (droughts and flash floods) and the increase of water scarcity issues. Afghanistan is a landlocked country which is located in the south of Asia. Kabul River Basin (KRB) is the most populous region in the country. The total catchment area of KRB is about 108000 km². The elevation ranges between 260 and 7600 m a.s.l.. There are some major tributaries in the basin such as Kabul, Logar, Kunar, and Panjsher. The study area has a semi-arid climate. In the Central Kabul sub-basin (capital of the country) the groundwater is more prone to declination due to the rapid population increase of internal displacement people. The groundwater is significantly affected by anthropogenic alterations especially in the Central Kabul sub-basin areas of the river basin. Groundwater overexploitation, droughts, and rapid population increase are among common phenomena in the KRB which greatly affect the availability of water resources. The domestic water supply for the city of Kabul is entirely dependent on groundwater. The city with an average per capita water supply of 20 l/day is among the most water-stressed cities in the world. Artificial Recharge (AR) applications can be used to mitigate these phenomena. Due to the highest evapotranspiration rate, special attention indeed, has been paid to AR in water resource management in arid and semi-arid regions.  

In this study, a detailed literature review on the existent AR types suitable for arid and semi-arid region and Geographic Information System (GIS) techniques, are used to identify the most suitable AR areas in the KRB. The hydrological behaviour of AR is investigated and the design criteria are defined. Infiltration, evapotranspiration, retention capacity and other hydrological parameters connected with hydraulic risk, underground recharge, soil moisture, and run-off are particularly analysed. Some parameters including topography, geology, hydrography, climate variables, existing water infrastructures, and demography are used for the identification of potential AR areas in the KRB. The analysed parameters are classified, weighted, and thematic maps are developed in GIS environment.

The implementation of AR could bring great benefits to the basin especially as far as the groundwater resources enhancement for domestic water supply and irrigation is concerned. The groundwater of the KRB is about 70% and 60% vulnerable to droughts and floods respectively. The groundwater recharge rate of the basin is about 90 mm/year. The use of Karez, springs, and wells are responsible for the overexploitation of the groundwater in the KRB. Suitable AR types and suitability maps of the study area are developed. The developed map can be used as a tool for the future implementation of AR techniques in the KRB. KRB is a trans-boundary river basin in which a part of the river basin is located in Pakistan. In trans-boundary water resources management, some measures should be taken to prevent water-related dispute issues.

How to cite: Himat, A. and Caporali, E.: GIS-based techniques for identification of potential artificial recharge areas in Kabul River basin, Afghanistan, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20716, https://doi.org/10.5194/egusphere-egu2020-20716, 2020.

Transregional Ecosystem Service (ES) flows are ubiquitous and are receiving more attention in an increasingly metacoupled world. Water has typical flow properties and is a common flow medium of Water-related Ecosystem Services (WES), such as water supply, water conservation, etc. Ningxia is in a transition zone from semi-arid to arid areas of the Yellow River basin of China. Its role in the water transfer from the Qinghai-Tibet Plateau to the downstream city and agriculture is important in allocating the scarce water resources in (semi-)arid regions. This study described the water flow process to/from Ningxia and revealed the supply-demand balance of water in Ningxia and its adjacent basins. On the grid scale, the total dynamic residual water in Ningxia from 2000 to 2015 was 2.20×10¹² m³~6.26×10¹² m³. However, there was still a dynamic water demand gap of -72.25×10⁸ m³ ~ -59.08×10⁸ m³, which could only be supplemented by manual water intake. At the regional scale, Ningxia had two sides, which was both the beneficiary of the upper Xiaheyan basin, Qingshui River - Kushui River basin, Xiaheyan - Shizuishan basin, Hexi Inland River-Shiyang River basin, Hexi Inland Rive-Hexi desert basin and internal flow area, and the supplier of the downstream Shizuishan - Hekou town, Longmen to Sanmenxia subbasin. As the benefitting district, the total net inflow water supply service in the supply area from 2000 to 2015 was 135.86×10⁸ m³ ~ 294.22×10⁸ m³, among which the non-Ningxia region in the sub-basin above the Xiaheyan basin was the main source region of water supply service in Ningxia. As the supply area, the net outflow volume of water supply service in Ningxia from 2000 to 2015 was 72.83×10⁸ m³~200.46×10⁸ m³, mainly flowing to non-Ningxia regions from Shizuishan to Hekou town. Overall, the net volume of water supply service flowing into Ningxia from 2000 to 2015 ranged from 63.03×10⁸ m³ to 93.76×10⁸ m³. This study can enhance the understanding of trans-boundary telecoupling relationship of WES in Ningxia and contribute to form a foundation for interregional management and allocation of WES in (semi-)arid regions to promote equity in sustainable regional development.

How to cite: Xu, J., Xie, G., Xiao, Y., Liu, J., Qin, K., Wang, Y., and Zhang, C.: Spatial simulation of water supply service flow in Ningxia, China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20894, https://doi.org/10.5194/egusphere-egu2020-20894, 2020.

GIS-based modeling for selection of dam sites in the Kurdistan Region, Iraq

Arsalan Ahmed Othman¹*, Ahmed F. Al- Maamar², Diary Ali Mohammed Al-Manmi³, Ahmed K. Obaid^4’5 Veraldo Liesenberg⁶, Syed E. Hasan⁷, Ayad M. Fadhil Al-Quraishi⁸

¹   Iraq Geological Survey, Sulaymaniyah Office, Sulaymaniyah, Iraq; arsalan.aljaf@gmail.com

²   Iraq Geological Survey, Al-Andalus Square, Baghdad 10068, Iraq.

³   College of Science, Department of Geology, University of Sulaimani, Sulaymaniyah, Iraq.

⁴   Department of Geology, University of Baghdad, Al-Jadiryah, Baghdad, Iraq; ahmedobaid@uobaghdad.edu.iq.

⁵   Department of Earth Sciences, University of Durham, Durham, DH1 3LE, UK; a.k.obaid@durham.ac.uk.

⁶   Department of Forest Engineering, Santa Catarina State University (UDESC), Lages SC 88520-000, Brazil

⁷   Department of Earth & Environmental Sciences, University of Missouri, Kansas City, MO 64110-2499, U.S.A.

⁸   Environmental Engineering Department, college of Engineering, Knowledge University, Erbil, Iraq.

Abstract

Iraq is a country in the Middle East experienced serious drought events in the past two decades due to significant decline in the discharge of its two main rivers and severe decrease in annual precipitation. Water storage by building dams can minimize drought impacts and assure water supply. This work aims at identifying suitable sites to build new dams within the Al-Khabur River Basin (KhRB), using GIS and remote sensing methods. We evaluated 14 geological, environmental, topographical, hydrological, and socio-economic factors, derived from the Digital Elevation Model (DEM), Landsat 8, QuickBird, geological, and soil maps. The fuzzy analytic hierarchy process (AHP) and the weighted sum method (WSM) approaches were used to determine suitable dam sites and compared for accuracy. Based on the integrated use of GIS, remote sensing, and geology, 11 dam sites have been suggested for potential runoff harvesting. Three of the sites correspond to three of the 21 dams, which were preselected by Ministry of Agricultural and Water Resources (MAWR) within the KhRB. The accuracy of the suggested 11 dam sites was evaluated in both of the AHP and the WSM methods in relation to the location of 21 preselected dams. Three types of accuracies have been tested, which are: overall, suitable pixels by number, and suitable pixels by weight accuracies. Overall accuracies of the 11 dams ranged between 76.2 % and 91.8 %. Locations of the two most suitable dam sites are in the center of the study area. Comparative analyses of the two methods show that the AHP method is more precise than WSM. We argue that the use of QuickBird imageries to determine stream width for discharge estimation, when no in-situ data is available, is adequate and can be used for preliminary dam site selection.

The most suitable site for dams identified from this study have favorable geology, adequate reservoir storage capacity, and are close to population center. The study offers a valuable and relatively inexpensive tool to decision-makers for eliminating sites having severe limitations (less suitable sites) and focus on those with least limitation (more suitable sites) for selection of the final site for dam construction.

How to cite: Othman, A., Al- Maamar, A., Al-Manmi, D., Obaid, A., Liesenberg, V., Hasan, S., and Al-Quraishi, A.: GIS-based modeling for selection of dam sites in the Kurdistan Region, Iraq , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2057, https://doi.org/10.5194/egusphere-egu2020-2057, 2020.