“Futurology” has been classified as one of the Social Sciences disciplines and focused on the future of people. Now, holistic “Futures studies” are expanding to include environmental trends, S&T, and technological advancement. HS is devoted to researching water signals and their future impacts. Many new research techniques and instruments are being could be utilized in Foresight discipline. Promising examples included Big Data Analysis, Bibliometrics, Semantic Analysis, Data mining, Text mining, Technology mining, Scientometrics, and visualization (displays of the large data). Among the most significant are computer science, social science computing (SSC), computational social science (CSS), artificial intelligence (AI), business intelligence, natural language processing, machine learning, cloud computing, and application programming interfaces (APIs). Computationally, Big data sets could be analyzed to reveal trends, and patterns, relating to human consumption, behavior, production, and interactions. As an example, A future orientation index is proposed to assess the correlation between a country’s Gross domestic product (GDP) and the tendency of seeking information about the future among Internet users33.
Water vision
Water Vision is a process that facilitates societies, civilizations, and countries in achieving SDGs and could be considered the backbone of an integrated water strategic framework for action. The Water vision should be a result of a huge amount of knowledge, extensive experience, long-term practice, Water wisdom, and foresight skills. Arabsphere’s Water Vision for 2050 is tailored to lead to a sustainable water future, mitigate the disastrous threats, enhance coordination, cope with the future growth constraints, reduce poverty, motivate innovative water solutions, optimize value for all consumers, and stimulate social well-being and life decent. The Water Vision is devoted to the Arabsphere, water-scarce countries, countries, societies, and civilizations facing serious water challenges. From an economic perspective, Water resources could be used as a final product for vital activities such as Water, sanitation, and hygiene (WASH), or as raw and input material for cooking, irrigation, agriculture, and many industries.
The world is far from achieving SDG 634. Based on the country data extracted from34, the 2021 status and trend of SDG 6 in the Arabsphere have been shown in Tables 8 and 9, respectively. In fact, these data show a clear picture of the existing water status which is mandatory for foreseeing Arabsphere’s Water Vision. The latest data depend on collection cycles. The trend signifies a ( +) positive, ( =) no change, and (−) negative changes with regard to a specific global target. In both Tables 8 and 9, columns I, II, III, IV, V, VI, VII, VIII, IX, X, XI, and XII represent drinking water, sanitation, hygiene, domestic wastewater, industrial wastewater, water quality, water stress, integrated water management, ecosystems, transboundary water cooperation, international water cooperation, and water participation, respectively. For both Tables 8 and 9, the following Legend could be applied.
Water drivers of future changes
Significant drivers in Arabsphere are water vision, sustainable and climate-resistant water management, irrigation, agriculture and food (plant, animal, hunger, food, and agricultural reclamation projects), herbicide, chemical contaminants, pesticides, veterinary drug residues, infectious diseases in fish and animals, food traceability, food authenticity, anti-biotic residues, illegal and unregulated fishing, eradication of fish species, taking areas out of food production, irrigation, water quality challenges, bioinformatics, sustainable food production, food safety, food security, aquaculture products, sustainable fishing and marine resources, responsible fisheries, water policies, water use, water pollution, water reuse, drought tolerance, flood control, rainwater storage, water control methods, innovative hydraulic structures, protection of deltas, river widening, water systems, water shortages, disaster mitigation, sustainable systems, systems innovations, sustainable society, salinization, animal, plant, weed, invasive alien species, risk maps and flood risk management plans, reforestation, weather control and modification, biofuels, clean water and sanitation, water scarcity, water bill, drinking, hygiene, hand washing, used water, automatization, diagnostic technologies, integrated surveillance, innovative sensors, remote control, lab testing, risk assessment, nanomaterials, nanotechnologies, non-conventional water resources and good health.
Circular water
Circularity (Circular economy) principle could be applied to improve water management. Used water could be the pathway to SWF and environmental sustainability. Water Circularity in the perspective of CE is the most significant emerging research topic. Water could be a main pathway to CE. Water and used water utilities can lead the pathways to SDGs, in particular SDG6 (concerning sustainable water) and SDG12 (concerning circular economy)35. Circular-Economy could strength sustainable water resource and recovery36. Combined sewer approach could improve combined sewer quality and mitigate water pollution and flooding problems, especially in crowded urban areas. Combined sewer system components are grey [flush tanks (FTs)], green [constructed wetland] and blue [receiving water body (RWB)] infrastructures37. Interpenetrating hydrophilic (hydratable polymeric) polymer networks have been utilized to purify water by solar energy (solar vapor generation). A durable and stable hydrogel solar evaporator could extract water from complex contaminants including heavy metal, detergents and salts components38.
The circular economy could enhance sustainable water management and mitigate water scarcity and nutrients shortage. Drinking water resource recovery using thermal process, chemical precipitation and reverse osmosis has been successfully examined in a pilot plant39. Water Circularity approach has been proposed considering economic and ecosystems and their interdependencies40. Used water could be a sustainable water source, nutrients, and energy resources41. The used water as an economic resource could support water utilities which operating sustainable water supply and sustainable sanitation systems. The World Bank initiative of concerning resource recovery devoted to transfer used water to resource has been highlighted42.
Water color
Many species of water exist. Precipitation is the main freshwater source on the Earth. Pure freshwater is colorless. The color of water is a good detector for biological, chemical and physical characteristics. Impurities, suspended, particulate and dissolved materials result in discoloration. The color of water can used to diagnose the water quality status.
In case of drinking water, blue, red, green, black colors can be related to specific physical, biological and chemical drivers. Diagnosing water quality based on color spectrum analysis can make solving water problems, especially industrial used water, is a simple and straightforward process.
From irrigation perspective, green water is the precipitation consumed by non-irrigated agriculture, whereas blue water is the precipitation consumed by irrigated agriculture. Green water represents the quantity of freshwater available directly for the ecosphere (biosphere). Blue water is the quantity of freshwater available in surface water (rivers, canals, channels, etc.) and groundwater aquifers. Both “green water” and “blue water” be considered as a productive rainfall.
From domestic used water perspective, grey water is the quantity of domestic used water used at home, except urinals, bidets and toilets. Yellow water represents human urine. Brown water represents human feces without human urine. Black water represents all toilet used water, i.e. yellow water (human urine) in addition to brown water (human feces).
From industrial used water perspective, there is a spectrum of color patterns. In some conditions, all rainbow colors, Variable-colored and iridescent may be existed. The most common are white water (milky white, and whitish to greenish, blueish or brownish), green, yellow, orange, reddish-orange, red, violet, purple, yellowish to brownish, brown, dark brown, grey, and black water. The water general appearance may be quite different. Most common phenomena are Water swirls, filmy, plates, lumpy, cloudy, chalky, foamy, sudsy, scum, gelatinous, shades, dull sheen, dark, fluorescent, and rainbow sheen.
From non-conventional waters perspective, the main idea for defining the colors of domestic used water is to facilitate used water as a valuable water and economic resource. Used water as a resource may be separated into grey water, and black water (yellow water and brown water). Grey water may be reused to irrigate the gardens and green walls. Yellow water can be a source for plant nutrition as urine fertilizers. Brown water can be used to alleviate soil degradation, consequently, enhance irrigation environment.
Non-conventional waters
In dry regions, water future necessitates application of non-conventional waters which considered base of the circular economy43. Non-conventional waters include desalinated water, reclaimed used water, reuse of agricultural drainage, urban or industrial used waters, fog harvesting and cloud seeding. Emerging sustainable water technologies should be environmentally compatible, socially acceptable, economically feasible and technically promising. Innovative nature-inspired water technologies include atmospheric water harvesters, biomimetic membranes, and biosaline agriculture.
Harvest icebergs could be acquired by hauling the icebergs to a suitable site in the path as an ice, where the ice converted to water, then towing this freshwater to the Arabsphere. From foresight point of view, iceberg towing to Arabsphere from Arctic or Antarctica could be a feasible solution to alleviate water stress and provide freshwater in the Arabsphere. DEEPEST holistic framework could be applied to icebergs hauling scenarios.
Advances in many scientific disciplines, engineering branches, innovation fields and technologies lead to success, achievement and superiority. Engineering fields such as Ocean engineering, Offshore engineering, Mining, Mechatronics, Power, Thermal, Mechanical, Manufacturing, Industrial, Vehicle, Materials, Electronic, Structural, Transport, Information, Safety, Reliability, Systems engineering, Supply chain engineering, Quantum engineering, applied engineering, project engineering, and Engineering management are promising in this vision. Technological advances in fields such as artificial intelligence, computer modelling and simulation, computer-aided design, automation, robotics, artificial satellites, control systems, and super powerful rig towing tug can make a difference. Financial institution, insurance companies, and investment banks could support scenarios of icebergs hauling and offer palatable economic risk-free mechanism. Greenhouse gas and carbon footprint should be mitigated to allowable international standards.
Atmospheric water harvesting (AWH)
One of the most promising Emerging Water Technologies is Atmospheric Water Harvesting (AWH). Recently, many scholars have made significant contributions in this optimistic field. AWH is emerging technology to mitigate the global water scarcity. AWH is constructed to extract water. Arid Air Water Harvesting by using composite sorbent made of hygroscopic salt and Metal–Organic Frameworks is an emerging water technology44. AWH using Metal organic frameworks as adsorbents is a promising device in the light of temperature and pressure responses, and working capacity45. Atmospheric water could be harvested from air by nano sorbent. Multiple water harvesting cycles could be achieved for effective applications by nano-carbon shell46. Hydrogels are emerging materials for atmospheric water harvesting. Water could be absorbed and evaporated within hydrogels. Hydrogels have tailor-made physiochemical characteristics.47. Atmospheric water could be harvested by nano biopolymer hygroscopic aerogel have high-capacity water storage using lyophilization (freeze-drying/cryodesiccation) process in dry, cool, and nature sunlight severe environmental outdoor conditions48.
Adsorption Water Harvesting systems could be effective by applying Advanced Metal–organic frameworks49. Atmospheric water could be harvested by water sorption process. Polymeric sorbent, which enhance performance and productivity, and free of metal and halide has been proposed50. The water harvester has been provided by non-toxic and bio-degradable desiccant51. Hygroscopic, Inorganic porous materials and Organic sorbents have successfully been used in atmospheric water harvesting. Sorbent-based water harvesting systems have significant design properties such as absorbency, stability, host materials, quantity, regeneration, relative humidity, maximum water harvesting, cost, safety, life cycle and technique52.
Recently, solar‐driven AWH has been emerged as an innovative discipline. Extraction of water vapor could be effective process to purify and produce freshwater when applying solar energy53. AWH is developed by inspiring the biological adaptability of some plant species that could absorb moisture using hygroscopic photothermal organogel powered by solar technique54. AWH is developed by desiccant-based, solar-driven model to reduce energy requirement55. AWH in arid regions is developed by Solar-Driven Dual-Stage Device utilizing advanced performing adsorbents to maximize water production and minimize heat losses56.
Humidity harvesting systems
Humidity Harvesting system utilizing a porous framework has been suggested. The system could purify moisture captured from contaminated air environment or atmospheric environment57. Advanced dehumidifiers could be effective devices for sustainable freshwater production, dehumidification and raising the thermal comfort. High humidity could be utilized as a freshwater resource to alleviate water scarcity.58. Humidity Harvesting systems depends on successful water adsorption. Emerging Water adsorbents involve porous organic polymers, metal–organic structures, hydrogen-bonded organic structures, covalent organic structures, bioinspired nanostructures, nano-porous water-absorbent gels, controlled morphologies nanomaterials, nanofibers, nanorods, and two-dimensional nanosheets materials. The physicochemical characteristics of merging Water adsorbents for water capture by dehumidification such as hydrophilicity, stability, binding enthalpy, surface areas, water uptake and tunable functionalities are extremely significant when designing such porous organic polymers materials59.
AW irrigation process using solar-powered for sustainable farming has been proposed. Super Moisture Absorbent Gels could harvest AW and irrigate the plants. Atmospheric water irrigation process causes the agriculture in drought and arid areas could overcome distant and/or remote water supplies60. AWH could be applied to enhance the performance of Green Roofs. Integrated green roof with fog harvesting (FH) and dew harvesting (DH) systems to enhance the performance of Green Roofs has been proposed61. AW in island regions could be harvested by air-cooled water device62.
Practical considerations are extremely important. The water source could be precipitation, fog, dew, or humidity. The innovative system could be manufactured, fabricated, installed, built, constructed or implemented in the site. Of course, the main concern is the WH capacity of technology, i.e. the total volume of water could be supplied per day. DEEPEST holistic framework could be applied to investigate challenges and sustainability aspects. Water sources, water treatment if any, community needs, target users, market price, design specifications, technical support, life cycle, safety, performance, spare parts, materials, energy requirement, hazards, quality systems and environmental conditions are significant elements.
Shared waters
The majority of the Arabsphere’s fresh water originates outside their political borders. Shared waters are serious to Arabsphere and must be cosidered as a tool for building cooperation and peace. Equitable allocation of WRs and exchange benefits through dialogue and negotiations are the key for active regional cooperation among countries in the Arabsphere and their neighbors. The Arabsphere needs to examine how to enhance cooperation and integration. The Arabsphere should develop innovative schemes for conflict resolution. Water balance should be explored at shared basins including both green and blue waters. Utilization of all waters including rivers, surface water, groundwater, blue-water, and green water, should be equitable and reasonable. IWRM, WUE and Water Nexuses should be monitored and supported.
Water’s horizons
The category of Water conservation techniques is the cheapest, easiest, and technologically simplest, so it is most suitable to be applied in the First Horizon. Comparably, the category of Circular Water techniques is more costly, harder, and technologically more complex, so it could be suitable to be applied in the Second Horizon. Similarly, the category of Emerging Water Technologies is the costliest, hardest, and most technologically complex, then it is hoped to be suitable to be applied in the Third Horizon. So, the decision-maker in the WRs discipline could emphasize technologies related to Water conservation in First Horizon (less than 5 years), technologies related to Circular Water in Second Horizon (within 5–10 years), and technologies related to Emerging Water Technology in Third Horizon (within 15–25 years). The items in the Emerging Water Technologies (EWTs) category are “Truly Innovative Ideas” which require positive and very complicated actions, the main idea is to harvest any drop of water.
