Water Self-sufficiency Research Articles

Integrated Exploitation of Rainwater and Groundwater: A Strategy for Water Self-Sufficiency in Ca Mau Province of the Mekong Delta

Groundwater sources have been exploited excessively for numerous purposes worldwide, leading to increasingly severe depletion. However, the replenishment of groundwater sources has not usually been a focus in economically and socially underdeveloped countries and regions. In coastal provinces of the Vietnamese Mekong Delta (VMD), rural areas are facing difficulties in accessing fresh water due to shortages from the water supply plant and excessive use of groundwater, highlighting an urgent need for sustainable development solutions. Our study first conducted interviews with 200 households in Ca Mau Province of the VMD to identify the current situation and the challenges and obstacles of rainwater harvesting and to find sustainable and proactive solutions. We then analyzed daily rainfall data from 10 meteorological stations to construct four scenarios of the water balance method: (i) potential rainwater harvesting based on existing roof area; (ii) optimal scale of storage tank and catchments for different levels of water usage; (iii) tank scale utilizing rainwater entirely during the rainy season and basic needs during the dry season; and (iv) integrated water supply between rain and groundwater. The results showed that using rainwater entirely for domestic water supply requires large storage tank capacities, making these scenarios difficult to achieve in the near future. Our research introduces a novel integrated water supply approach to storing rain and groundwater that has demonstrated high effectiveness and sustainability. With existing tank capacities (0.8 m3 per person), rainwater could only meet over 48% (14 m3 per year) of the water demand while requiring 14.8 m3 of additional groundwater extraction. With a tank capacity of 2.4 m3 per person, ensuring rainwater harvesting meets basic demand, harvested rainwater could satisfy 64% of the demand, with artificial groundwater supplementation exceeding 1.79 times the required extraction, while excess rainwater discharge into the environment would be minimal. Our research results not only provide potential solutions for rainwater and groundwater collection to supplement sustainable domestic water sources for Ca Mau but also serve as an example for similar regions globally.

Locating Hydrologically Unsustainable Areas for Supporting Ecological Restoration in China's Drylands

AbstractChina has undertaken extensive ecological restoration (ER) projects since the late 1970s in drylands, dominating the greening of drylands. The greening, especially ER‐induced, can affect regional water availability and even cause hydrological unsustainability (i.e., lead to a negative shift in ecosystem water supply and demand balances). However, there is still limited research on accurately identifying the hydrologically unsustainable greening areas (GA) in China's drylands. Here, we developed an ecosystem water supply‐demand indicator, namely, the water self‐sufficiency (WSS), defined as the ratio of water availability to precipitation. Using remote sensing and multisource synthesis data sets combined with trend analysis and time series detection, we conducted a spatially explicit assessment of the hydrological sustainability risk of greening in China's drylands in the context of ER projects over the period 1987–2015. The results showed that 17.15% (6.36 × 104 km2) of the GA faced a negative shift in the WSS (indicating hydrological unsustainability), mainly in Inner Mongolia, Shanxi, and Xinjiang provinces, driven by evapotranspiration. Moreover, 29.34% (1.09 × 105 km2) of the GA, whose area is roughly double that of hydrologically unsustainable GA, exhibited a potential water shortage with a significant WSS decline (−0.014 yr−1), concentrated in Inner Mongolia, Shaanxi, and Gansu provinces. The reliability of our findings was demonstrated through previous studies at the local scale and an analysis of soil moisture changes. Our findings offer precise grid‐scale identification of the hydrologically unsustainable GA, providing more specific spatial guidance for ER implementation and adaptation in China's drylands.

A Nature-Inspired Green–Blue Solution: Incorporating a Fog Harvesting Technique into Urban Green Wall Design

This research aims to explore the use of vegetation and nets to collect water from fog on facades to meet the needs of buildings’ functional requirements, particularly outdoor thermal comfort, water demands, and encouraging sustainability by suggesting a new architectural green–blue wall system. The system is posited to be applicable within an urban context, given its minimal spatial requirements and adaptability to existing structures. However, similar challenges to those encountered by green walls are anticipated, wherein the provision of sustainable benefits is offset by the demands of maintenance and associated additional costs. For this reason, this paper is mainly divided into two parts: in the first part, green facades are explained, referring to their effect on urban environment, including thermal comfort, pollution absorption, noise pollution, and well-being, as well as types of plants to apply on green walls; the second part focuses on the fog collector as an irrigation system for green walls, analyzing its components, structure, and fabric, to identify its development margins in the construction industry. Fog harvesting initiatives predominantly focus on rural regions to cater to agricultural demands; however, limiting fog harvesting to agricultural settings is considered insufficient, as it represents a crucial solution for addressing water challenges in specific urban environments. Nevertheless, it is worth investigating the fog collector’s potential for integrating water supply in urban environments as well. The study focuses on exploring the environmental benefits of fog harvesting and green walls, particularly through their combined implementation. The proposed review is significant for guiding the integration of a device into green facades, ensuring water self-sufficiency while concurrently addressing air purification, noise reduction, and thermal comfort for pedestrians and urban inhabitants. Nevertheless, it is worth investigating the fog collector’s potential for integrating water supply in urban environments as well. The proposed review is, therefore, useful for integrating a device represented by the fog harvesting system, also identified in the text as the blue system, into the design of green facades, identified in the text as the green system, integrating the blue element in the design of the green wall to make them water self-sufficient and at the same time purifying the air, reducing noise pollution, or giving thermal comfort to pedestrians and inhabitants of the urban context.

Development of an integrated membrane condenser system with LNG cold energy for water recovery from humid flue gases in power plants

This paper investigates a detailed thermodynamic analysis of a modular-type membrane condenser system where a cooler or condenser is connected in series upstream of the membrane condenser module. A coolant circulates inside the cooler/condenser to cool down the industrial flue gas up to saturation conditions. The analysis covers water recovery rate and energy requirement for different combinations of flue gas humidity, flow rate, and temperature. Additionally, a case study is included which considers a practical industrial exhaust flue gas where the constituents of the flue gas with volumetric ratio and the feed parameters are referred from the literature. The case study investigated the utilization of cold energy obtained by LNG regasification facility as a cooling power source for the water vapor recovery process. A detailed heat transfer analysis based on the heat exchanger model is performed to determine the required mass flow rate of cooling water and natural gas. It is concluded that, the water self-sufficiency of a power plant can be achieved if the mass flow rate of the −50 °C natural gas which is entering the membrane condenser is kept around 0.3 kg s−1 for every 1 kg s−1 flow rate of the 168 °C flue gas.

The potential of local food, energy, and water production systems on urban rooftops considering consumption patterns and urban morphology

The external resource dependency of urban areas results in the externalization of environmental and socioeconomic impacts. Implementing food, energy and water production systems on urban rooftops (roof mosaics) can potentially help cities become more self-sufficient but depends on the city's urban morphology. We studied the supply potential and impacts of four roof mosaic scenarios for different urban forms in Cerdanyola, a 58 thousand-inhabitant town in the metropolitan area of Barcelona. We combined spatial analysis of potential rooftops, metabolism analysis, and social and environmental impacts. The municipality has an average rooftop/household potential of 31 m2 on which to implement any of the mosaic scenarios, with the highest potential in the single-family housing typology. The highest level of vegetable self-sufficiency was found in housing estates (32%), and the lowest in originary fabrics (28%). Regarding electricity and water self-sufficiency, the highest self-sufficiency level was found in the single-family housing typology (51% and 14%, respectively) and the lowest in housing estates (26% and 8%, respectively). Regarding impacts, the implementation of the electricity and rainwater harvesting systems depicts the most positive indicators in single-family housing areas. However, for housing estates and originary fabrics typologies, the best performance is shown to be in the implementation of rooftop farming systems.

Urban Water Management Using Water Self-sufficiency

Water demand is increasing because of population increases and industry developments as well as demands for improved living standards. Existing water treatment and supply systems cover large areas and have a centralized system; consequently, development of new water resources requires a construction of pipe infrastructure over long distances. The variability of water quantity, as climate changes, is hampering efforts to secure water resources and decide facility capacity. Therefore, a new urban water management system to address these problems is required. This study suggests such a system as well as a new index, i.e., the water self-sufficiency ratio (WSSR) for evaluating the system. WSSR is calculated by dividing the total self-provided water quantity with the total water use in a city. The current WSSR for Suwon City is 11 %, but there are plans to achieve 50 %. This would be accomplished by using rainwater (26.8 million ton/year), encouraging water conservation (31.3 million ton/year), building tunnel-type rainwater-retention facilities (2.5 million ton/year) and reusing treated sewage (1.72 million ton/year). In addition, financial incentives are expected through such as reduction of floor area proportion, tax reduction and governmental subsidies. The WSSR is expected to be useful in evaluating urban water self-reliance as well as in quantitativly establishing a sustainable water management system.

Virtual water transfers in Africa: Assessing topical condition of water scarcity, water savings, and policy implications

Africa is facing an increasing challenge with respect to water scarcity (WS), which is driven by climate change, population growth, and socioeconomic growth combined with inadequate water resources management. In particular, there is significant concern of virtual water (VW) trade, which plays the key role in water resource management and food security sustainability. Using bilateral trade data, this study consistently evaluated the change and balanced trade of major grains, the VW flows, WS status, water dependency (WD), water self-sufficiency (WSS), and water savings/losses within5 African sub-regions and their partners from 2000 to 2020. The ratio of water use to water availability was used to estimate the WS. The WD was quantified by the ratio of the net VW import to the regional water appropriation and the regional water savings/losses were also quantified by multiplying the inter-regional trade by the virtual water content of the imported/exported grains. The overall average trade deficit of African regions was found to increase to −1364.22 × 106 tons and Africa imported 41,359.07 Bm3 of VW from grain products. Green water contributed 79.33% of the total VWI. The WS values for East African countries were >100, indicating overexploitation. Besides, the overall WD in Africa was 465.5% for the studied period. The trade of main grains between Africa and the rest of the planet corresponded to a global water loss of 2820.7 Bm3·yr−1. However, the inter-continental cereal VW trade pattern and high trend will continue in the future. In view of the rising tension of WS, some African countries need to revise international crop trade and water resources conservation policies to promote a more balanced ecosystem. This study exemplifies that decision makers would consider VW flows and water savings/losses for enhancing water use efficiency and fair trading, thus increasing food production in Africa.

Rural Experiments with the Management of Basic Resources. Key Characteristics of European Ecovillages Aiming at Partial Self-Sufficiency in Water, Food and Energy

Abstract The goal of this paper is to provide a preliminary analysis of European ecovillages considered as rural grassroots experiments with the sustainable management of the Water-Energy-Food Nexus. The article presents empirical data on the management of basic resources in 60 European ecovillages collected with an online survey in 2020. The results show that a vast majority of ecovillages pursue some self-sufficiency in food, water or energy, and that 50% of them seek some self-sufficiency in all three of these resources. However, ecovillages do not try to be completely self-sufficient but rather aim at achieving feasible levels of self-sufficiency complemented with local and regional cooperation. While the role of ecovillages in driving conventional rural growth is limited, they can help in guiding sustainability transitions by illustrating opportunities and difficulties of reducing resource consumption of settlement units without reducing personal and communal well-being.

Towards Water and Energy Self-Sufficiency: a Closed-Loop, Solar-Driven, Low-Tech Laundry Pilot Facility (LaundReCycle) for the Reuse of Laundry Wastewater

In the scope of this study, a pilot facility for the recycling of laundry effluent was developed and tested. With the aim to enable nearly complete energy and water self-sufficiency, the system is powered by a photovoltaic plant with second-life batteries, treats the wastewater within the unit and constantly reuses the treated wastewater for washing in a closed cycle. The technology for wastewater treatment is based on a low-tech approach consisting of a physical/mechanical pre-treatment and biological treatment in trickling filter columns. The treatment process is operated in batch mode for a capacity of five washing cycles per day. During five weeks of operation water quality, energy consumption and production, water losses and washing performance were monitored. The system recovered 69% of the used water for the washing machine while treating the wastewater to the necessary water quality levels. The average COD removal rate per cycle was 92%. Energy analysis was based on modelled data of the monitored energy consumption. With the current set-up, an internal consumption rate of 80% and self-sufficiency of 30% were modelled. Future developments aim at increasing water and energy self-sufficiency and optimizing the water treatment efficiency.

Beyond mains water: a survey of households that are self-sufficient for water in regional Australia

ABSTRACT There is little recognition in policy of existing adaptive capacities and experiments with alternate water systems in the Global North. Households that are self-sufficient for water present a space in which alternative relationships between water, comfort and convenience manifest. This article presents insights from a survey completed by 209 households that are self-sufficient for water in the Eurobodalla Shire, in regional New South Wales, Australia. The survey sought to understand practices, experiences, and perceptions of people who take responsibility for managing the capture, storage, consumption, and disposal of water at home. We found that most respondents rely on household-collected rainwater for all domestic purposes. Most drink rainwater, and many drink rainwater untreated. Respondents identified challenges of self-sufficiency, including running out of water, and infrastructure maintenance and failure. Notwithstanding these challenges, most respondents indicated that they enjoy living in a water self-sufficient home and would do so again in future. Most respondents moved to their non-mains water home for reasons other than being in control of water; adapting to water self-sufficiency was therefore a necessity rather than a choice. The results of this survey are significant as the water sector looks to diversify sources of domestic water to better adapt to uncertain futures.

Spatio-temporal trends of hydrological components: the case of the Tafna basin (northwestern Algeria)

Abstract Climate change is expected to increase in the future in the Mediterranean region, including Algeria. The Tafna basin, vulnerable to drought, is one of the most important catchments ensuring water self-sufficiency in northwestern Algeria. The objective of this study is to estimate the evolution of hydrological components of the Tafna basin, throughout 2020–2099, compared to the period 1981–2000. The SWAT model (Soil and Water Assessment Tool), calibrated and validated on the Tafna basin with good Nash at the outlet 0.82, is applied to analyze the spatial and temporal evolution of hydrological components over the basin throughout 2020–2099. The application is produced using a precipitation and temperature minimum/maximum of an ensemble of climate model outputs obtained from a combination of eight global climate models and two regional climate models of the Coordinated Regional Climate Downscaling Experiment project. The results of this study show that the decrease of precipitation in January, on average −25%, ranged between −5% and −44% in the future period. This diminution affects all of the water components and fluxes of a watershed, namely, in descending order of impact: the river discharge causing a decrease −36%, the soil water available −31%, the evapotranspiration −30%, and the lateral flow −29%.

From self-sufficient provision of water and energy to regenerative urban development and sustainability: exploring the potentials in Mashhad City, Iran

Increased resource demand due to rapid urbanization has made cities like Mashhad highly dependent on their surroundings for resource supply and waste disposal, and has negatively impacted their local-regional hinterlands. To reduce the metabolic footprint of cities and create an environmentally restorative relationship between cities and their supporting ecosystems, a transition toward local alternative and renewable sources is essential. This paper explores potentials for water and energy self-sufficient provision in Mashhad using the Urban Harvesting method to practically illustrate how cities could seek opportunities to meet their needs within their boundaries before relying on external supplies. Results showed that solar photovoltaic and biogas could provide 4495.2 and 472.6 GWh/yr electricity, altogether enabling Mashhad to offset 100% of its consumption. Water cascading and recycling have the potential to meet 72% of the demand, and replace around 125 mcm/yr of imported water. Similarly, water self-sufficiency would increase by 5%–8% (8.6–14.7 mcm/yr) when collecting rainwater from rooftops.

Net Zero Urban Water from Concept to Applications: Integrating Natural, Built, and Social Systems for Responsive and Adaptive Solutions

Innovation in urban water systems is required to address drivers of change across natural, built, and social systems, including climate change, economic development, and aged infrastructure. Water systems are complex socio-technical systems that interact with biophysical systems to supply and reclaim water. We present a vision for enhancing urban water system resilience through a net zero urban water (NZUW) approach, which meets the needs of a given community with a locally available and sustainable water supply, without detriment to interconnected systems or long-term water supply. NZUW is an integrative approach with progressive targets assessed using a quantitative framework to expand adaptive and responsive solutions for urban water self-sufficiency. Decision makers can use NZUW to understand trade-offs between future interventions to urban water systems across spatial and temporal scales. We present the overall NZUW approach, drivers of change, applications, and research gaps.

Indicadores de la sostenibilidad urbana en Bilbao, País Vasco, España

Objetivo: contribuir al conocimiento de indicadores para la sostenibilidad urbana en Bilbao, País Vasco, España, ya que presentó particularidades en un territorio con autonomía administrativa, fiscal, de organización y gestión territorial única. Metodología: revisión de literatura del tema y de los documentos oficiales de Bilbao acerca de los indicadores que existen y con apoyo de datos estadísticos para conocer indicadores de sostenibilidad; además, se enriqueció con una entrevista a funcionaria del ayuntamiento y encuestas en el sitio que contribuyeron a estudiar los indicadores expuestos. Resultados: se explica la importancia del ingreso/PIB/ per cápita en Bilbao y en las tres capitales del territorio vasco, donde se expresa la pujanza y las diferencias entre sus tres principales ciudades, así como el comparativo con España y otros países de Europa. Se expresa, además, cuál es la problemática económica más importante en la ciudad, a través de encuestas dirigidas. Luego se analizó el efecto de la movilidad y el espacio en las personas en la Ciudad de Bilbao y los barrios seleccionados; en lo urbano tomó relevancia la ciudad y su condado, así como el territorio histórico de Bizkaia, donde está la mayor población de dicha región, y su decrecimiento poblacional de los últimos dos decenios; en lo ambiental, se considera la importancia de reducir el consumo de energía, de reducir el uso del vehículo particular, del uso de transporte alternativo y la tendencia de autosuficiencia hídrica, y la problemática de posible inundación por la ría en zonas cercanas. Limitaciones: conocer de mejor manera indicadores de que sean aplicables a ciudades medias, a partir de datos cuantitativos y cualitativos en la planificación urbana y ordenación del territorio, estrategias de participación ciudadana, impacto económico y social de mejora de servicios público. Conclusiones: los indicadores expresaron que la movilidad-desplazamiento y el espacio público son temas importantes para la sostenibilidad de una ciudad de un millón de habitantes, unido a la disponibilidad de recursos económicos, naturales y de la adecuada utilización de mejorar las energías renovables, pues las tareas y acciones que se realizan tienen impacto en el suelo urbano, y en la trasformación que experimentan ciudades como Bilbao, en el citado País Vasco, de España.

Ma’an – a new approach to the autonomous building

The paper describes the general principles of autonomous building operation. Derived from those, a building concept, which ensures energy and water self-sufficiency, has been presented. Another important benefit is the minimization of a carbon footprint – both during construction and operation. The proposed solutions are based on a system combining the technology of a cooling tower and a solar updraft tower enhanced with reverse osmosis technology and others. All of this has been achieved by creating an original architecture that matches its place of origin and functions.

Site-scale Urban Water Mass Balance Assessment (SUWMBA) to quantify water performance of urban design-technology-environment configurations

Historically, little consideration has been given to water performance of urban developments such as “hydrological naturalness” or “local water self-sufficiency”. This has led to problems with increased stormwater runoff, flooding, and lack of local contributions to urban water security. Architectural design, water servicing technologies and environmental conditions are each known to influence water performance. However, most existing models have overlooked the integration of these factors. In this work, we asked ‘how the water performance of urban developments at site-scale can be quantified, with joint consideration of architectural design, water servicing technologies, and environmental context (i.e. climate and soil)’. Answering this question led to the development of a new method and tool called Site-scale Urban Water Mass Balance Assessment (SUWMBA). It uses a daily urban water mass balance to simulate design-technology-environment configurations. Key features include: (i) a three-dimensional boundary focussed on the “entity” of development (ii) a comprehensive water balance accounting for all urban water flows, (iii) methods that include key variables capturing the interactions of natural, built-environment and socio-technological systems on water performance. SUWMBA's capabilities were demonstrated through an evaluation of a residential infill development case study with alternative design-technology-environment configurations, combining three dwelling designs, seven water technologies and three environmental contexts. The evaluation showed how a configuration can be identified that strikes a balance between the conflicting objectives of achieving the desired dwelling densities whilst simultaneously improving water performance. For two climate zones, the optimal configuration increases the total number of residents by 300% while reducing the imported water per capita and stormwater discharge by 45% and 15%, respectively. We infer that SUWMBA could have strong potential to contribute to performance-based urban design and planning by enabling the water performance of dwelling designs to be quantified, and by facilitating the setting of locally-specific water performance objectives and targets.

Public health interventions for chronic diseases: cost–benefit modelizations for eradicating chronic kidney disease of multifactorial origin (CKDmfo/ CKDu) from tropical countries

BackgroundIn the mid-1970s, an unusual chronic kidney disease of multifactorial origin (CKDmfo), also known as CKD of unknown aetiology (CKDu), began to manifest in several economically poor, tropical, agricultural countries. This preventable, environmentally induced, occupational disease affects several peri-equatorial countries; it first manifested in Sri Lanka in the mid-1990s. The study goal was to estimate the costs of eradicating CKDmfo and the resulting cost savings, using CKDmfo in Sri Lanka as an example. This chronic disease model is applicable to CKDu and few other chronic diseases in other countries. MethodologyEight cost-effective, key interventions were identified that are essential to eradicate CKDmfo. A systematic assessment was performed on these interventions (including providing clean water, behavioural and lifestyle changes, alleviating malnutrition, reducing irresponsible and overuse of agrochemicals, and cost-effective treatment options), the cost of prevention, and the resultant cost savings. A cost–benefit analysis was based on the data collected during the past 20 years of work in Sri Lanka. FindingsThe yearly cost required to eradicate the disease was approximately one-tenth of the current annual operating and opportunity costs due to CKDmfo. Analysis indicates that implementation of a focussed chronic disease-prevention plan using essential multiple interventions, CKDmfo can be eradicated within 15 years. This includes provision of potable water; real-time disease surveillance program; public and professional education; prevention of environmental pollution; alleviation of poverty and associated malnutrition; sustainable self-sufficiency in food, clean water, energy, and security; diversification of economy and job opportunities; sustainable economic development; regionwide programs of effective screening, early diagnosis and intervention to reverse the disease progression at earliest possible; and effective treatment of CKDmfo. InterpretationThis analysis is based on multiple population-level, chronic disease-eradication strategies that include an interdisciplinary, geographic information system (GIS)-based, regionwide, long-term research and intervention program; economic diversification; and environmental, socioeconomic, and behavioural improvements. Such an approach will facilitate identification of root causes and key risk factors, enabling implementation of cost-effective longer-term interventions to eradicate chronic diseases, applicable to other countries as well.

Global socio-hydrology: An overview of virtual water use by the world economy from source of exploitation to sink of final consumption

To reflect a key aspect of global socio-hydrology, this paper explores global virtual water use from source of exploitation to sink of final consumption via interregional trades within the world economy as reflected by world input-output database for 2014. An embodiment accounting model is developed, which takes full account of virtual water feedbacks related to primary inputs. Global total trade volume of virtual water is estimated to be in magnitude around 30% of the global direct freshwater withdrawal. Moreover, it is revealed that global virtual water transfer in intermediate trade is in magnitude around 1.4 times that in final trade. In intermediate trade of virtual water, China, Japan and the United Kingdom turn out to be the three leading net importers, while India, Russia and the United States are revealed as the leading net exporters. In final trade of virtual water, the United States, Japan and Russia are the major net importers, in contrast to China, India and Mexico as the leading net exporters. Trade connections and imbalances of major economies in terms of virtual water are quantified and analyzed. Two new indicators in terms of water self-sufficiency rate by source and that by sink are devised. It is found that around 40% of the use of China’s freshwater withdrawal finally sinks into foreign economies while only 20% of China’s virtual water use originates from other regions. With regard to Germany, Canada and France, they behave like active pumps driving vast virtual water inflows and outflows, demonstrating their high involvement in the global supply chain in terms of virtual water. With the increasingly frequent virtual water transfer within the world economy, nations and regions ought to assess their behaviors in intermediate and final trades of virtual water for sustainable use of freshwater resources.

Morphometric assessment and sub-watershed prioritization of Khari River basin in semi-arid region of Rajasthan, India

Watershed management is very crucial for arid and semi-arid regions dealing with limited availability of water resource. Morphometric assessment and prioritization studies provide basic criterion for effective local level watershed planning and natural resource management. The present study is an attempt to analyze morphometric characters of the Khari River basin and prioritize the sub-watersheds on the basis of ground water potentialities indicated by morphometric parameters using GIS approach. Khari River is semi-arid ephemeral; it is a tributary of Banas River, an important river of central Rajasthan (India). The basin has been subdivided in five sub-watersheds namely SW1 to SW5. Linear, areal, and relief parameters are calculated for Khari basin as well as for each sub-watershed. Morphometric parameters that are related to groundwater potentialities are ranked and compound factor values are calculated for each sub-watershed and priority is allotted based on these values. First priority is given to the least value of compound factor that indicate most deficit ground water condition. Overall results illustrate that Khari is a sixth-order stream and covers 6205 km2 area. Dendritic pattern is observed in Khari and in all the five sub-watersheds that indicate homogenous nature of underlain material and less structural control in the topography. Presence of low bifurcation ratio, low drainage density, and low drainage frequency values are favorable parameters of good permeability, infiltration in the basin, further gentle slope, coarse drainage texture, moderate to low relief, and elongated shape—all these parameters indicate good groundwater potentialities in major portions of the basin. Prioritization results show that the sub-watershed SW4 is at first priority with most deficit groundwater potential in comparison to other sub-watersheds and require water conservation measures. Sub-watershed SW4 has high values in linear parameters and low value in shape parameters that specify for poor groundwater potential, less permeability and high runoff, etc. Sub-watershed SW5 on contrary has indicated highest ground water potential in comparison to other sub-watersheds of the basin. The study provide local drainage morphometric information and preliminary prioritization for better water resource management in semi-arid region to achieve water self-sufficiency and sustainability at basin level.

National water, food, and trade modeling framework: The case of Egypt

This paper introduces a modeling framework for the analysis of real and virtual water flows at national scale. The framework has two components: (1) a national water model that simulates agricultural, industrial and municipal water uses, and available water and land resources; and (2) an international virtual water trade model that captures national virtual water exports and imports related to trade in crops and animal products. This National Water, Food & Trade (NWFT) modeling framework is applied to Egypt, a water-poor country and the world's largest importer of wheat. Egypt's food and water gaps and the country's food (virtual water) imports are estimated over a baseline period (1986–2013) and projected up to 2050 based on four scenarios. Egypt's food and water gaps are growing rapidly as a result of steep population growth and limited water resources. The NWFT modeling framework shows the nexus of the population dynamics, water uses for different sectors, and their compounding effects on Egypt's food gap and water self-sufficiency. The sensitivity analysis reveals that for solving Egypt's water and food problem non-water-based solutions like educational, health, and awareness programs aimed at lowering population growth will be an essential addition to the traditional water resources development solution. Both the national and the global models project similar trends of Egypt's food gap. The NWFT modeling framework can be easily adapted to other nations and regions.