Estimating willingness to pay for desalinated seawater: the case of Djerba Island, Tunisia

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

Non-conventional water resources and opportunities for water augmentation to achieve food security in water scarce countries

In the 21st century water scarcity is almost universal -something that is unfortunately either not recognised by or is concealed from the majority of the people.The world's population is growing steadily, the standard of living and the associated demand for water are both increasing, freshwater sources are becoming increasingly polluted and the climate is changing due to the enhanced greenhouse effect.As a result, the volumes of fresh water that have traditionally been available to many centres of industry, food production (irrigation) and urban population have been declining for some time.The quantity of naturally occurring, good quality fresh water available to each person throughout the world is decreasing daily.The motive underlying the preparation of this monograph is an attempt to discuss all forms of water scarcity and to provide suggestions and guidelines for: (1) anticipating and preparing for water scarcity; (2) the way thinking about traditional practices in communities has to change, particularly among community leaders and politicians, to manage situations where water is becoming increasingly scarce; and(3) possible practical remedies for locations where water scarcity is already acute.Thanks are due to UNESCO for authorizing the use of material that the authors produced in the context of the 6th International Hydrologic Program in the preparation of this book.We sincerely acknowledge the help provided by Ms. P.

According to FAO, water scarcity is now affecting all five continents and is expected to intensify in the coming years as the water demands of the growing population increase and the impacts of climate variability become more pronounced. The existing unevenness of water resource availability and insufficient investment in relevant infrastructure have forced the water sector to recognize the importance of nonconventional water resources (NWR) in planning for a sustainable water future. The purpose of this review is to highlight the available and potentially available NWR and to discuss the future application of these water sources.

Water scarcity is becoming a global challenge to attempts to narrow the water demand–supply gap. To overcome this problem, it is sensible to consider alternative technologies that can exploit non-conventional water resources. The choice of such technologies should be, however, carefully analyzed, because any choice might be unfeasible from an economic point of view. In this work, a methodology to select the most appropriate non-conventional water resource, out of municipal wastewater and seawater, was proposed. Specifically, we attempted to determine which alternative provides cheaper water supply and production costs for domestic uses, depending on the wastewater treatment system used and the water plant capacity. The production of water under three scenarios was analyzed: (i) a city that has a conventional wastewater treatment plant (WWTP); (ii) a city that uses primary treatment and submarine outfalls to treat municipal wastewater; (iii) seawater desalination. The proposed methodology was tested in Chilean cities that are located in areas where water is a scarce resource. The results showed that the reuse of municipal wastewater represents a cost-competitive alternative to seawater desalination, mainly when municipal wastewater is treated in a conventional WWTP and when water flow demand is higher than 1500 m3/d. In contrast, seawater desalination becomes more profitable than wastewater reuse when the treatment of municipal wastewater is based on the use of submarine outfalls. This study provides a useful economic tool for promoting municipal wastewater reuse as a non-conventional water source for supplying water to cities that suffer from water scarcity in Chile and in similar areas of the world.

Climate change, unsustainable water use by the tourism sector, and short-term-based decisions by policymakers create additional stress on limited water resources in arid and semi-arid tourism destinations. Non-conventional water resources are playing an important role in making additional water available for these destinations, and the use of desalination plants has gradually increased. However, they can create additional externalities on the environment that can compromise the sustainability of the tourist destination. The decisions of key stakeholders and cooperation among them hold vital importance for the sustainability of tourism and the availability of water resources. Mykonos Island (Greece) is a globally recognized tourist destination in the Eastern Mediterranean Sea. The island has suffered significant water-scarcity problems in recent years, in particular during the peak tourist season, and desalination plants are being built to reduce stress on the water supply. The first objective of this work was to analyze the perceptions of hospitality stakeholders regarding water shortages and climate change in Mykonos. A second objective was to assess whether the same hospitality stakeholders feel that desalination plants are the solution to water scarcity in island-tourism destinations such as Mykonos. The results show that (i) hospitality stakeholders have significant awareness regarding water-scarcity problems and the impacts of climate change on tourism activity, (ii) they do not view desalination plants as the only solution to water scarcity, and (iii) they perceive a significant lack of coordination among actors who participate in the decision-making process. These results provide clues regarding the importance of awareness, coordination, and cooperation of each actor involved in the decision-making process and can be of interest to policymakers and public authorities in tourism destinations facing water-scarcity problems.

Increasing water irrigation demand combined with water scarcity and deterioration of the water quality in the Lower Jordan Valley (hereafter referred to as LJV) - Palestine, has led to a serious challenge in managing current and future water demands. This problem is not restricted to Palestine but to the region in general. Providing feasible solution strategies for water management has demonstrated to be a complex task. Mismanagement of water resources aggravates the problem. Therefore, integrated water resources management promises applicable and creative solutions for the future in terms of water strategies. The main goals of this study are to develop these strategies end based on regional agricultural strategies development. The Case Study Area (Hereafter referred to as CSA), Auja area, is located in the LJV., CSA has suffered from water scarcity and water quality deterioration, This was manifested in decreasing irrigated lands from 10,000 donums in 2010 to only about 4,000 donums in 2013and change in crop patterns in the area. Moreover high chloride concentration in shallow aquifer - with 2000μs/cm² in some wells - has caused increased deterioration in water quality. Therefore, the study investigated creative alternatives based on integrated available water resources management and the exploration of non-conventional resources in the area. The study assumed many strategies of agricultural and water resources development, which jointly constitute strategies of firstly, agriculture development and secondly, water strategies. Both strategies should act as the core of the problem as well as its solution. Accordingly, integrated water resources management (hereafter referred to as IWRM) focused on managing aquifer recharge (MAR) and using brackish water in irrigation. This idea is the base for the assumption of this research. MAR and brackish water eventually are top priority scenarios for meeting water requirements in the future. Decision-makers are urged to take these scenarios into consideration to achieve sustainable development plans in the Palestinian territories. Irrigated lands in the CSA cover 3,800 donums vis-à-vis 30,000 irrigable donums. Main water resources come from Auja Springs and shallow aquifer wells. Available irrigation water does not exceed 3.5 Mm3/a. CSA is served by field survey including soil, water, land, and agriculture cover use. CSA is composed of three Agricultural land zones: zone 1, zone 2 and zone 3. These zones reflect the current cultivated area as well as lands expansion scenarios for an additional 8,500 donums of new irrigated lands with plantations of date palm trees, intensive green house agriculture and grapes. The scenario is based on soil profile analysis of root zone and soil hydrochemistry analysis. Water Management Strategies towards Sustainable Agricultural Development XVI These three land zones represent three agricultural development strategies based on water budget analysis and are jointly linked with the three assumed water strategies. The three water strategies (WSs) are: 1- WS I which is the Do-Nothing approach which reflects large water quantities deficit; 2-The WS II is based on MAR scenario, the Mathematical model of transient GMS-Modflow It is considered as a tool for water management in the CSA. It supplies 2 million cubic meters of surplus water by direct injection into the shallow aquifer wells, in addition to infiltrated flood surface run-off from Wadi Auja. 3-The WS III, is based on 100% of IWRM using all non-conventional water resources, varying from brackish water desalination and treated effluent to importing water from outside the CSA and the use of Current Untapped Water Resources (CUWR). This strategy will change the current crop pattern taking into consideration the water budget. It could offer additional 12 million cubic meters (Mm3) for the extra irrigated expanded land scenario. Evaluating the best management scenarios regarding performance and impact assets based on Driving-Pressure-State-Impact-Response (DPSIR) frame work, would give several decision variables (DVs) as a prelude to form decision criteria analysis and analytical hierarchy procedure (AHP) used for scaling and weighing different decision variables (DVs) This would produce the best management scenario by mixing brackish and fresh water and completely change the crop pattern in the CSA. The change would accrue through planting date palms. In this context, MAR scenario comes as intermediate priority by evaluation results, although it would need further investigation in the future.

Novel concept for water scarcity quantification considering nonconventional and virtual water resources in arid countries: Application in Gulf Cooperation Council countries

Many countries in the MENA region (Middle East and North Africa) are facing water scarcity, which poses a great challenge to agricultural production. Furthermore, water scarcity is projected to increase due to climate change, particularly in arid and semi-arid regions. The integration of solar power and water desalination systems in greenhouses to overcome water shortages is one of the preferred technologies in crop-growing areas. Crop growth control is done through sufficient management of environmental climatic variables as well as the quantity and quality of water and applied fertilisers with irrigation. Numerous crops such as cucumbers, tomatoes, peppers, lettuces, strawberries, flowers, and herbs can be grown under greenhouse conditions using desalinated water. This paper displays the state of the art in (i) solar-driven saltwater desalination to irrigate crops, (ii) the feasibility of water desalination for agriculture in the MENA region, (iii) the economics and environmental impacts of the desalination process, (iv) the quality of desalinated water compared with other non-conventional water resources and (v) recommendations for the future in the MENA region.

In an era of increasing contest for limited water resources, the wise joint management of conventional and non-conventional water resources must be considered. Water scarcity is aggravated in coastal zones which are often characterized by high population densities and intense economic activities making heavy seasonal water demands. In this context, the use of non-conventional water increases the availability of water supplies. Non-conventional water resources of lower quality could be directed to meet additional needs. As a consequence, significantly more potable water would be available to meet human demand for safe water. Non-conventional water resources are described: waste water reclamation and reuse, and its potential application for increasing groundwater resources, as well as several practical applications.

Water consumption continues to grow globally, and it is estimated that more than 160% of the total global water volume will be needed to satisfy the water requirements in ten years. In this context, non-conventional water resources are being considered to overcome water scarcity and reduce water conflicts between regions and sectors. A bibliometric analysis and literature review of 81 papers published between 2000 and 2020 focused on south-east Spain were conducted. The aim was to examine and re-think the benefits and concerns, and the inter-connections, of using reclaimed and desalinated water for agricultural and urban-tourist uses to address water scarcity and climate change impacts. Results highlight that: (1) water use, cost, quality, management, and perception are the main topics debated by both reclaimed and desalinated water users; (2) water governance schemes could be improved by including local stakeholders and water users in decision-making; and (3) rainwater is not recognized as a complementary option to increase water supply in semi-arid regions. Furthermore, the strengths–weaknesses–opportunities–threats (SWOT) analysis identifies complementary concerns such as acceptability and investment in reclaimed water, regulation (cost recovery principle), and environmental impacts of desalinated water.

Non-conventional water resources research in semi-arid countries of the Middle East

Sustainability assessment approaches based on water-energy Nexus: Fictions and nonfictions about non-conventional water resources

Water is the most essential substance for human being and living organisms. Water scarcity in Africa is mainly economic due to the poor management of water resources. The Nile River is the major source of water for different applications, i.e., drinking, industries and agriculture in Egypt; therefore, the development of water resources is inferior, especially under the excessive growth of population. Furthermore, agricultural activities in Egypt consume more than 80% of the available quantity of The Nile water; hence, potential scarcity in water is expected to occur in Egypt; especially, there is a critical argument due to the buildup of the Grand Ethiopian Renaissance Dam (GERD). It is worth mentioning that using the classical irrigation system lead to lose vast amounts of available water. Therefore, attention should be paid to overcome the drought problems of one-third of agricultural soils due to the GERD, which might lead to change in the demographical map in Egypt. Also, efforts should be established to urge the Egyptian farmers to shift their surface irrigation system, which is the common irrigation technology to more advanced technologies, i.e., drip or sprinkler irrigation systems. However, to ensure the success of advanced irrigation systems, the quality of water resources should be taken into consideration. Despite nonconventional water resources are not adequate to compensate for the potential reduction of The Nile water; however, there is an actual need to develop these resources in Egypt.

Contingent valuation analysis of willingness to pay for beach erosion control through the stabiplage technique: A study in Djerba (Tunisia)