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[Display omitted] Energy consumption from air cooling systems in summer, water scarcity in hot regions, and the functional reusability of waste paper are emerging environmental problems. Finding solutions to these problems simultaneously remains a significant challenge. Herein, a superhydrophobic passive cooling Cellulose-CaCO 3 film with hierarchical nano-sheets was fabricated to realize daytime radiative cooling with a temperature drop of 15–20 °C in summer and water harvesting with harvesting efficiency of 387 mg cm−2h−1 bd utilization of recycled waste paper. The superhydrophobic Cellulose-CaCO 3 film demonstrates its self-cleaning properties against inorganic and organic pollutants. Furthermore, the superhydrophobicity of the film was maintained after base/acid corrosions, dynamic water flushing, and thermal treatment at 100 °C for 7 h, exhibiting good durability of the superhydrophobicity. Moreover, the superhydrophobic Cellulose-CaCO 3 film is nonflammable after exposure to fire combustion for 1 min. In addition to waste paper, waste maize straws, and pasteboards were also collected to produce superhydrophobic passive cooling films. Results indicate that the above three cellulose-based raw materials can be well used to prepare durable superhydrophobic passive cooling materials. Environmental toxicology assessments confirm the safety of the material. This study not only provides a protocol for preparing superhydrophobic materials; but also demonstrates their potential for passive cooling and water harvesting. [ABSTRACT FROM AUTHOR]

The research presented in this paper introduces a novel environmental energy‐harvesting technology that harnesses electricity from the evaporation of water using porous structural materials. Specifically, a strategy employing paper‐based hydroelectric generators (p‐HEGs) is proposed to capture the energy produced during water evaporation and convert it into usable electricity. The p‐HEGs offer several advantages, including simplicity in fabrication, low cost, and reusability. To evaluate their effectiveness, the water evaporation‐induced electrical output performance of four different p‐HEGs are compared. Among the variants tested, the p‐HEG combining wood pulp and polyester fiber exhibits the best output performance. At room temperature, this particular p‐HEG generates a short‐circuit current and open‐circuit voltage of ≈0.4 µA and 0.3 V, respectively, thereby demonstrating excellent electrical stability. Furthermore, the electrical current and voltage generated by the p‐HEG through water evaporation are able to power an LED light, both individually and in series and parallel connections. This study delves into the potential of electricity harvesting from water evaporation and establishes it as a viable method for renewable energy applications. [ABSTRACT FROM AUTHOR]

Using sorbent materials to separate and concentrate ambient humidity is a promising option for atmospheric water harvesting in the face of impending worldwide freshwater scarcity. The method of cycled sorption and forced release can facilitate efficient condensation, but performance strongly depends on device-scale issues of heat and mass transfer. We examine the potential of using microwave radiation to liberate sorbed vapor, in proof-of-concept experiments with hygroscopic salt-infused paper towel as simple sorbents. We quantify performance as a function of tunable system parameters and ambient humidity. Our results demonstrate promising aspects: both rapid desorption and regeneration, owing to water-tuned dielectric heating and directing flow through fibrous sorbent, respectively; substantial efficiency of moisture separation toward very low (∼ 25 %) relative humidity; and robust repeatability over many cycles, due to the targeted energy input and retention of hygroscopic salt within the paper scaffold. [ABSTRACT FROM AUTHOR]

Small-scale landslides that occur at unexpected locations and seasons can cause severe losses of life and property. Unusually, the Shidang landslide occurred prior to the rainy season in Jinkouhe County, Sichuan Province, China, resulting in 19 deaths and missing persons. In this paper, landslide characteristics and causes are revealed through a field investigation, laboratory experiments, and numerical calculations. The results show that the Shidang landslide was a small-scale landslide with a total volume of approximately 19500 m3, originating from hollow colluvial deposits. The geomorphological hollow above the landslide provided topographic conditions for the collection of subsurface runoff. Groundwater flow was transported downward along dolomite and accumulated in the area above shale, with a low conductivity. Groundwater table rise combined with the decrease in the soil strength led to landslide occurrence. Improper siting of residential areas and insufficient vigilance against post-rainfall landslides caused this tragedy. Considering the post-disaster lessons, it is strongly recommended that in the future, more attention should be given to the investigation of landslides triggered by groundwater, especially in determining landslide hydrological system boundaries. In mountainous areas where the developable space is limited, areas with hollow landforms are potentially at risk of geohazards. This paper could provide a reference for the prevention and management of similar landslides and new insights for updating landslide investigation systems and residential housing plans. [ABSTRACT FROM AUTHOR]

With the increasing demand for freshwater resources, the sustainable and effective utilization of atmospheric water has become a critical issue. Herein, an efficient and stable monolithic water-adsorbent is designed via functionalizing glass fiber paper loaded with two-linker metal-organic frameworks (CGF-mixed-MOFs(Al)). Firstly, a chitosan (CTS) polyelectrolyte layer is constructed on glass fiber paper to improve the MOFs loading capacity (306.71%) through electrostatic interaction and hydrophilic interaction. Subsequently, a series of two-linker metal-organic frameworks (mixed-MOFs(Al)) composed of MIL-160(Al) and Al-fumarate are tailor-made on CGF surface through a situ synthesis self-assembly technology. The resultant mixed-MOFs(Al) monolith exhibits better water harvesting ability and faster adsorption kinetics at low humidity owing to possessing more active adsorption sites. Different from CGF-MIL-160(Al) and CGF-Al-fumarate, the water sorption of CGF-mixed-MOFs(Al) 5 at 30% RH, 25% RH and 20% RH reaches 0.37 g/g, 0.31 g/g and 0.25 g/g, respectively. The lab-scale atmospheric water harvesting device based on CGF-mixed-MOFs(Al) 5 confirms the feasibility of this work-tailored product as a potential water sorbent in low-humidity environments. The cyclability results (50 times) indicate that CGF-mixed-MOFs(Al) 5 maintains good water capture performance, integrity (no MOFs leakage) and crystallinity, which guarantees its working reliability and sustainable benefits. Therefore, our customized water adsorption system provides a simple, long-effective, economical and advanced strategy to capture more fresh water from atmosphere in arid climates. [Display omitted] • The construction of chitosan layer on glass fiber paper promotes high MOFs loading. • Two-linker MOFs involving MIL-160(Al) and Al-fumarate is in-stiu synthesized. • The water adsorption properties of two-linker MOFs can be adjusted by changing the ratio of organic ligands. • The monolithic adsorbent shows high water-harvesting capacity even at low humidity. [ABSTRACT FROM AUTHOR]

Janus membranes with unidirectional liquid transport property have tremendous applications in fields of functional fabrics, water harvesting, smart wound dressings and so on. Paper shows distinct advantages to other materials, such as hydrophilicity, low-cost, flexible and so on. However, there is still less attention on how to construct a Janus paper with unidirectional liquid transport capacity and its functional applications. Here, a multi-pores Janus paper with asymmetric wetting properties is developed through consecutive laser microdrilling, hydrophobic modification and air-plasma treatment. As a result, the prepared Janus paper can allow the water to transport from the hydrophobic side to the hydrophilic side, while it blocks the water to flow in the reverse direction. Meanwhile, it can also achieve antigravity unidirectional water transport. In addition, the mechanism for unidirectional liquid transport is investigated. Finally, as a proof-of-concept, the Janus paper is utilized for applications of information encryption/decryption. [Display omitted] • Multi-pores Janus paper is successfully reported in this manuscript through simple fabrication method. • The Janus paper can unidirectional transport water from the hydrophobic side to its hydrophilic side. • It can also achieve antigravity unidirectional water transport. • The multi-pores Janus paper is utilized for applications of information encryption/decryption. [ABSTRACT FROM AUTHOR]

Sunken green space is one of the urban rainwater collection facilities, which belongs to Low Impact Development (LID) techniques. It plays a key role in the construction of sponge city, and the amount of runoff collection is usually affected by the area of the sunken green space, the infiltration rate of the soil, and the annual runoff collection rate. To determine the minimum soil infiltration rate of sunken green space considering the annual runoff collection ratio of sponge cities, this paper selects a residential district in Hefei city, China, as the case study. Based on 45 years of precipitation data, the designed rainfall corresponding to annual runoff collection ratios of 75%, 80% and 85% is 21.3 mm, 23.4 mm and 27.5 mm, respectively. The characteristics of rainfall infiltration in sunken green space are analyzed by using the water balance model and runoff yield and conflux model. The results reveal that the soil infiltration rate is 1.16×10−4 cm/s~3.88×10−3 cm/s when the sunken depth is 0.1 m~0.3 m and that the ratio of green space area is 5%~25%. The runoff collection of the reconstructed sunken green space is 2.87 times and 1.98 times that of the nonsunken green space and the nonreconstructed sunken green space, respectively. That is to say, under the comprehensive performance of the sunken depth, sunken green space area, the steady soil infiltration rater of the reconstructed sunken green space cannot be less than the value obtained in this paper. Otherwise, the requirements of annual total runoff reduction ratio of the sponge city cannot be met. Therefore, this study provides references for realizing the ratio of annual runoff collection and sponge city construction in similar urban areas. It can also be applied to optimal selection of sunken green space in some sponge city projects. [ABSTRACT FROM AUTHOR]

As arid lands expand across the globe, scholars increasingly turn to the archaeological record for examples of sustainable farming in extreme environments. The arid north coast of Peru was the setting of early and intensive irrigation-based farming; it is also periodically impacted by sudden, heavy rainfall related to the El Niño Southern Oscillation (ENSO) phenomenon. While the sociopolitical effects, technologies, and engineering expertise of these irrigation systems have been thoroughly examined and theorized, little is known about how farmers managed periods of water stress. The aim of this study is to test whether arid zone farming was supported by hybrid, intermittent flood and perennial water source systems in the prehispanic past. An arroyo in the Chicama Valley was selected for preliminary data collection, and these data are presented here: (1) drone photography of the arroyo capturing the aftermath of a recent (2023) rain event; and (2) potassium (K) soil test kit results from samples collected near suspected prehispanic check dam features in the same area. The paper combines these data with comparative examples from the literature to suggest that the prehispanic features functioned as water-harvesting infrastructure. The paper concludes that sustainable, arid zone farming can be supported by hybrid, intermittent flood and perennial water source systems. [ABSTRACT FROM AUTHOR]

In this paper we examine whether there are significant gender differences in the adoption of climate‐smart agricultural (CSA) practices in sub‐Saharan Africa. Using individual‐level data from four sites in Kenya, Uganda and Senegal, our empirical analysis provides robust evidence that men have a higher likelihood of adopting high‐return CSA practices including modern chemical fertiliser, improved high‐yielding varieties and drought/pest tolerant livestock practices. In contrast, women tend to have a higher likelihood of adopting low‐risk and low‐return traditional CSA practices such as water harvesting, crop covering, rangeland management and pest management. Our subsample analysis shows significant heterogeneity in the gender gap across countries. The results of the decomposition of the observed gender gap show that personal values and norms, access to weather and production information and farm characteristics are important factors that explain the gender differential in the likelihood of CSA adoption. Our findings imply that equalising access to key resources such as plots of land, information and decision making power will be crucial to close the gender gap in the adoption of CSA practices. This is particularly important given the differential impacts of climate change between men and women in sub‐Saharan Africa. [ABSTRACT FROM AUTHOR]

In urban areas facing water stress, rainwater harvesting is essential. This paper proposes a passive rainwater harvesting system as a viable alternative for ensuring a clean water supply. The study introduces an innovative and original design for rainwater harvest. The presentation of the system is performed by analysis of efficiency and reliability of the system analytically. The optimal storage volume is determined through a 22-year precipitation data analysis using the mass balance method, ensuring high efficiency. Payback periods for various consumptions and tank sizes are calculated, showing shorter periods compared to active systems since the proposed system does not use electrical energy. The results demonstrate that 350 m3 of storage volume can assure 99% efficiency when potable water consumption is 0.01 m3/person/day. The payback period of the system was calculated to be between 5 and 10 years. The proposed system can be considered as an appropriate rainwater harvest alternative for existing buildings. [ABSTRACT FROM AUTHOR]

The novelty of the paper is the analysis of the possibilities of reducing the operating costs of a mine water pumping station in an abandoned coal mine. To meet the energy needs of the pumping station and reduce the carbon footprint, "green" energy from a photovoltaic farm was used. Surplus green energy generated during peak production is stored in the form of green hydrogen from the water electrolysis process. Rainwater and process water are still underutilized sources for increasing water resources and reducing water stress in the European Union. The article presents the possibilities of using these waters, after purification, in the production of green hydrogen by electrolysis. The article also presents three variants that ensure the energy self-sufficiency of the proposed concepts of operation of the pumping station. [ABSTRACT FROM AUTHOR]

This document is an editorial from the International Journal of Water Resources Development, discussing the importance of water resource management in agriculture for achieving food and water security in Asia. It highlights the role of agriculture in water usage and the challenges posed by climate change and increased demand. The editorial presents research papers on topics such as the impact of climate change on food security, the effects of weather variables on crop yields, the benefits of irrigation mechanization, and groundwater governance. It concludes by emphasizing the need for integrated measures, technological development, provision of irrigation facilities, and improved water governance for sustainable water management in agriculture. Additionally, the document includes a list of contact information for individuals affiliated with institutions such as the Asian Development Bank Institute and the University of Glasgow's School of Social & Environmental Sustainability. [Extracted from the article]

To examine the driver of groundwater depletion, this paper estimates a dynamic panel regression model using district-level secondary data from 1995 to 2017. Results show that the number of rainwater-harvesting structures, annual average rainfall, forest cover and net sown area improve groundwater levels. Tube well irrigation and rice cultivation can adversely affect groundwater levels. The positive relationship between surface water and improved groundwater level is consistent in all the estimated models. Hence, efficient use and management of surface and groundwater are crucial for the long-term sustainability of water resources. [ABSTRACT FROM AUTHOR]

As the increasing scarcity of fossil fuels and the ever‐present need to address environmental concerns are faced, the development of efficient and sustainable energy harvesting techniques gains more and more significance. The liquid–solid triboelectric nanogenerator (TENG) has emerged as a promising solution for harvesting mechanical energy in water. Although the liquid–solid contact electrification technique is studied by numerous researchers, there is still a need to enhance energy harvesting efficiency in liquid–solid TENG. This comprehensive review discusses recent advances in kinetic energy harvesting from water, focusing on the solid–solid and liquid–solid interaction mechanisms when using TENGs as an energy conversion medium. The review summarizes the recent developments in structure design and material improvements, as well as hybridization with other generators as methods of enhancing the output performance of TENG. Besides discussing advancements of TENG, the potential impact and future challenges of liquid–solid TENG are highlighted. This paper provides insight into the current state of knowledge and the future directions of research in the field of liquid–solid TENG energy harvesting. [ABSTRACT FROM AUTHOR]

The impact of global climate change on water resources is a pressing concern, particularly in arid and semi-arid regions, where water shortages are becoming increasingly severe. Rainwater harvesting (RWH) offers a promising solution to address these challenges. However, the process of selecting suitable RWH sites is complex. This paper introduces a comprehensive methodology that leverages various technologies and data sources to identify suitable RWH locations in the northern region of Iraq, considering both historical and future scenarios. The study employs remote sensing and geographic information systems to collect and process geospatial data, which are essential for the site selection process. AHP is utilized as a decision-making tool to assess and rank potential RWH locations based on multiple criteria, helping to prioritize the most suitable sites. The WLC approach is used to combine and weigh various factors, enabling a systematic evaluation of site suitability. To account for the uncertainty associated with future climate conditions, a stochastic weather generator is employed to simulate historical and future precipitation data for period (1980–2022) and (2031–2100). This ensures that the assessment considers changing climate patterns. Historical precipitation values ranged from 270 to 490 mm, while future projections indicate a decrease, with values varying from 255 to 390 mm. This suggests a potential reduction in available water resources due to climate change. The runoff for historical rainfall values ranged from 190 mm (poor) to 490 mm (very good). In the future projections, runoff values vary from 180 mm (very poor) to 390 mm (good). This analysis highlights the potential impact of reduced precipitation on water availability. There is a strong correlation between rainfall and runoff, with values of 95% for historical data and 98.83% for future projections. This indicates that changes in precipitation directly affect water runoff. The study incorporates several criteria in the model, including soil texture, historical and future rainfall data, land use/cover, slope, and drainage density. These criteria were selected based on the nature of the study region and dataset availability. The suitability zones are classified into four categories for both historical potential and future projections of RWH zones: very high suitability, covering approximately 8.2%. High suitability, encompassing around 22.6%. Moderate suitability, constituting about 37.4%. Low suitability, accounting for 31.8% of the study region. For the potential zones of RWH in the future projection, the distribution is as follows: very high suitability, approximately 6.1%. High suitability, around 18.3%. Moderate suitability, roughly 31.2%. Low suitability, making up about 44.4% of the study region. The research's findings have significant implications for sustainable water resource management in the northern region of Iraq. As climate change exacerbates water scarcity, identifying suitable RWH locations becomes crucial for ensuring water availability. This methodology, incorporating advanced technology and data sources, provides a valuable tool for addressing these challenges and enhancing the future of water management to face of climate change. However, more investigations and studies need to be conducted in near future in the study region. [ABSTRACT FROM AUTHOR]

Energy, as an indispensable part of human life, has been a hot topic of research among scholars. The water kinetic energy generated by ocean currents, as a kind of clean energy, has high utilization rate, high power generation potential, and a broad prospect of powering microelectronic devices. As a result, the water kinetic piezoelectric energy harvester (WKPEH) has made significant progress in powering ocean sensors by harvesting ocean currents. This paper provides a comprehensive review of technologies that have been used in recent years to harvest energy from marine fluids using WKPEH. Detailed study of the energy harvesting mechanism of WKPEH. WKPEH can use the flutter-induced vibrations, vortex-induced vibrations, and wake oscillation principles to harvest water kinetic energy. The structural characteristics and output performance of each mechanism are also discussed and compared, and finally, a prospect on WKPEH is given. [ABSTRACT FROM AUTHOR]

With the increasing prominence of extreme climate events and the construction and development of scenic areas, strengthening the management of rainwater resources in scenic areas has become an urgent need to enhance the capability to resist rain-induced flooding disasters and utilize rainwater resources for building safe, ecological, and sustainable scenic areas. In this paper, the Yesanpo scenic area was taken as the research object. Based on topographic and hydrometeorological data, the soil conservation service (SCS) model and ArcGIS spatial analysis tools were used to simulate the inundation areas resulting from an extreme daily rainfall event that 100-year return period within the research region, and comprehensively analyze the inundation areas. Drawing inspiration from the concept of resilience in ecology, this study proposed the construction of rainwater resource management strategies at three levels of ecological resilience, facility resilience, and social resilience. These strategies aimed to facilitate the transformation of stormwater from disaster to resource, thereby enhancing the systemic resilience of the Yesanpo scenic area against floods and water scarcity issues. At the same time, these strategies promoted the construction of resource-saving and environmentally friendly scenic spots, committed to treat rainwater as a valuable resource, and achieved the goal of rainwater recycling, providing a new perspective for promoting the sustainable development of scenic spots. [ABSTRACT FROM AUTHOR]

In Algeria, at the present time, there are no rainwater harvesting systems (RWHS) registered with the public authorities as an alternative to the public water supply. This is explained by numerous factors, the most important being inhabitants' acceptance. The aim of this article is to investigate the current level of acceptance of an RWHS as a viable method for backing up the public water supply system. Our hypothesis is that inhabitants' acceptance can be improved by the increasing awareness of the benefits of an RWHS. For the purposes of this study, an RWHS located in northern Algeria was designed, and its benefits were measured and discussed with the direct participation of residents living in the building. The first benefit was the potential potable water saving (PPWS) and the second was the benefit-cost ratio (BCR). The PPWS was estimated at 51 m3/year. The BCR was estimated at 7% (15% with local council funding). This paper shows that, in the case of an existing building, inhabitant acceptance of an RWHS depends on three factors: (1) the amount of rainwater delivered by the RWHS; (2) the cost of building and managing it; and (3) the extent of the modifications made to the building. [ABSTRACT FROM AUTHOR]

Water is one of the most contended resources on the planet. The need and the un-ubiquitous nature of the resource is a reality faced by the Bally-Jagachha block in Howrah, West Bengal. Here, the available water sources are tube-well and piped water, both having Water Quality Indices of more than 300 and 200, respectively. This indicates that drinking water is unpalatable, making people vulnerable to diseases. Additionally, as is evident through the Water Poverty map, inaccessibility is an expensive, debilitating problem, as people have to travel twice in 4-7 min to and from the water source to collect it and then again spend more to filter the same. The Ridit scores thus state that people are overcome by water woes in supply, availability, consumption, quality, demand, etc., but yet have no alternatives like rainwater harvesting (RWH), despite people's acceptance to it. Thus this paper attempts to collate all the problems regarding water and suggest ways by which the Gram Panchayats here can safely implement RWH and resolve the situation for the future. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENG) have shown great potential in harvesting energy from water. For the TENG that harvests water energy, surface hydrophobicity is crucial for its performance. In this paper, we prepare a hydrophobic composite film of Polyvinylidene Fluoride/Polydimethylsiloxane/Polytetrafluoroethylene (PVDF/PDMS/PTFE) and an electrode of Polyaniline/Carbon nanotubes/Silver nanowires (PANI/CNTs/AgNWs) by electrospinning technology and a doping method, respectively, which are served as the friction layer and top electrode of TENG. The contact angle of the hydrophobic film and electrode both reach over 120°, which makes the separation process between water and the interface complete and promotes the output of TENG. The open-circuit voltage (Voc) and short-circuit current (Isc) can reach 150 V and 60 μA approximately. In addition, the composite electrode can be applied in the preparation of complex electrode shapes. Furthermore, the different reactions of TENG to different liquids indicate that it may contribute to liquid-type sensing systems. This work presents an efficient approach to fabricating hydrophobic films and electrodes, laying a foundation for the development of TENG for harvesting water energy. [ABSTRACT FROM AUTHOR]

Collecting water from the air could alleviate freshwater shortages in arid regions such as remote and inland areas. However, it is challenging to prepare adsorption materials that have high adsorption and desorption performance using straightforward synthesis routes for water harvesting applications. In this paper, a polydopamine (PDA)@Sodium polyacrylamide carboxymethyl cellulose (PAM-CMCNa)-calcium chloride (CaCl2) composite aerogel (PDCA) with a vertical channel was prepared by salt template method and photopolymerization for atmospheric water collection (AWH). The designed vertical channel promotes the rapid transport of water molecules from the atmosphere to the interior of the hydrogel through capillary action. During this process, the hydrogel further expands to prevent the leakage of the internal salt solution, which effectively improves the water vapor adsorption and desorption by hydrogel. Experimental results showed that the hydrogel can absorb 2.78 g/g of water at 90% relative humidity (RH), where 56.3% of the captured water can be desorbed within 60 min of exposure under 1.0 sun light intensity. After 10 adsorption-desorption cycles, the PDCA still possesses excellent water sorption performance. The indoor water collection test showed that the water collection performance reached 2.143 kg/kg day at 90% RH and 25°C adsorption for 12 h and desorption for 6 h. The proposed method for the preparation of PDCA composites can achieve high water harvesting performance over a wide humidity range to enable solar-driven clean water production in remote areas. [ABSTRACT FROM AUTHOR]

During the development of the urban water system from 1.0 to 3.0, the impervious surface area gradually increased, hindering the natural infiltration and self-purification process of urban rainwater, resulting in serious urban water pollution, urban waterlogging in the rainy season, and groundwater problems. Since water will seep into the ground, serious water pollution will cause damage to the ground. Therefore, in dealing with urban rainwater problems, we want to use the sponge's ability to absorb and store water to build our cities into sponge cities. In this paper, we have constructed a sponge city planning and information system development based on geographic information fuzzy processing. We use differentiated fuzzy processing methods to eliminate classified information to achieve a perfect combination with nearby images and use ordinary fuzzy processing methods to solve the problem of nonconfidential information. This paper discusses the impact of natural topography on the planning and construction of sponge cities, including whether natural topography will affect rainwater, whether it will affect the distribution of different strata, and whether it will affect the utilization of groundwater resources. The basic functions of this platform are provided by a series of functions of GIS, and multiple modules are developed according to management requirements. The initial state of street view data is a lot of fisheye lens photos and corresponding point location information, which are displayed online after data preprocessing, detection information, editing information, and blurring processing. [ABSTRACT FROM AUTHOR]

This paper tries to breakdown 12 years of research on storm water harvesting systems that can aid in flood mitigation by methodically evaluating the existing literature and identifying relevant research gaps. Bibliometric co-citation meta-analysis is used to understand decentralized storm water harvesting methods that can aid in flood management. 165 articles from multiple disciplines in scopus database are used in this study to identify literature pertaining to flood mitigation techniques using storm water harvesting methods. Further these articles where analyzed for their scientific productivity, relevance and collaboration. Also the VOS viewer software and Bibliometrix R Package software were employed for visualization. The results of this study revealed that most of such studies focus on urban context. Thus, the study offers academics and practitioners a pertinent multidisciplinary platform for research on urban water security and encourages the growth of further knowledge on this subject. [ABSTRACT FROM AUTHOR]

Water crisis issues are common in rural and urban areas, which can be tackled honestly by planning and managing existing water resources. The site suitability map is the principal footstep of planning practice for a region's sustainable surface and groundwater resource development. The paper aims to delineate and suggest suitable sites for water harvesting for sustainable water resource development by taking the lower Kulsi watershed as a study area. Analytical Hierarchical Process (AHP) and Geographical Information System (GIS) techniques are used in the multi-criteria decision-making process to identify a suitability map of water harvesting structures like percolation tanks, check dams, and surface farm ponds on the basin of the specific key factor of each design. About one hundred ninety-six sites are detected from the most suitable category of suitability based on particular criteria and suggestions for sustainable water conservation in the study area. [ABSTRACT FROM AUTHOR]

Hydrophilic–hydrophobic hybrid wettability structures, inspired by desert beetles, have been widely designed to enhance the dewdrops' migration under subcooled or/and high-humidity environment. However, it is still a challenge to regulate the graded distribution of the hydrophilic micro-regions for condensation applications. In this paper, we design a simple spray method to prepare the superamphiphilic–superamphiphobic hybrid wettability coatings by controlling the mass ratio (MR) of superamphiphobic SiO2 nano-powder and superamphiphilic gypsum micro-powder. We compare the macroscopical wettability, condensation heat transfer efficiency, frosting delayed time and water harvesting rate to demonstrate the unique advantage of hybrid wettability structures. The results show that the condensation heat transfer efficiency, frosting delayed time and water harvesting rate can be respectively promoted to about 131.50% (MR = 1 : 0. 5) , 134.74% (MR = 1 : 0. 5) and 135.62% (MR = 1 : 1) , although their macroscopical wettability will gradually reduce with the MR increase. This work will provide substantial insights into the fabrication of efficient superhydrophilic–superhydrophobic hybrid wettability surfaces for condensation heat transfer, anti-frosting and water harvesting applications. The hybrid wettability coatings have been designed by spraying superamphiphobic SiO2 nano-powder and superamphiphilic gypsum micro-powder with different mass ratio (MR). The condensation heat transfer efficiency, frosting delayed time and water harvesting rate can promote to about 131.50% (MR = 1:0.5), 134.74% (MR = 1:0.5) and 135.62% (MR = 1:1), respectively, although their macroscopical wettability will gradually reduce with the increase in MR. This paper provides substantial insights into the fabrication of efficient superhydrophilic–superhydrophobic hybrid wettability surfaces for condensation heat transfer, anti-frosting and water harvesting applications. [ABSTRACT FROM AUTHOR]

Electricity is the basic and essential need for every single person and guarantees the development of society, industry, and the economy. The limited conventional fossil fuel meets the challenge of the sharply increasing demand, while may lead to severe pollution. Emerging green energy harvesting systems can convert ambient kinetic, thermal, and solar energy to electricity effectivity. In this review paper, the authors provide an overview of the new and emerging methods, droplet‐based electricity generators, that convert energy from the ubiquitously existing water droplets. The authors begin with a brief introduction of the working principle for droplet‐based power generators. Existing configurations of the droplet‐based power generator are also summarized, including 1) single electrode, 2) transistor‐based, and 3) direct current generator. Then, a detailed discussion of the design and operation factors that may impact the energy harvesting efficiency of droplet‐based power generators is provided. Hybrid energy harvester that integrates droplet‐based power generators with other triboelectric, pyroelectric, and photovoltaic‐based devices are summarized. Finally, challenges and perspectives regarding the future development of droplet‐based power generators are described. The reviews demonstrate a highly efficient method for energy harvesting from water droplets to meet the vital needs of the energy crisis. [ABSTRACT FROM AUTHOR]

In water-scarce regions where fog is abundant, the population can rely on this resource to obtain fresh water. The potential to harvest fog is confirmed by Large Fog Collector projects worldwide, which are reviewed. Mostly maintenance issues due to environmental and complex social factors compromise the sustainability of such projects. The researchers endeavour to resolve these issues by developing enhanced materials, while others use biomimetic design, hence creating innovative collectors. The objective of this paper is to survey and review the state of the art and develop a framework of different types of innovative fog collectors, including conceptual, experimental and operational aspects. [ABSTRACT FROM AUTHOR]

Water supply has been a chronic challenge in Istanbul since its foundation. Authorities have sought alternative methods since the Roman and Byzantine periods. Cisterns, channels and wells surveyed in urban heritage sites in Istanbul provide evidence of rainwater harvesting (RWH) as a working solution in the past. However, RWH systems have only been utilized in contemporary plans and policies very recently, particularly since the climate change crisis entered the political agenda in Turkey. Taking this as a point of departure, this paper investigates the challenges of widespread implementation of RWH systems in Istanbul through a participatory inquiry with water management actors. Challenges and needs are explored through a set of in-depth interviews and participatory workshops with representatives from water management institutions. The findings reveal that current challenges are related to planning and development, legislation and governance, financing, society, infrastructure, installation and operation of systems. The potential solution is the establishment of a governance mechanism that enables collective action among relevant actors. [ABSTRACT FROM AUTHOR]

Major cities located in the Colorado River Basin (CRB) rely on incentive‐based policies to address water use and supply reliability challenges, through programs provided by cities themselves, by state and federal agencies, and by NGOs. This review examines water use trends across cities, the phenomena of declining per capita use, and finds that most large cities have adopted municipal rate structures designed to incentivize lower use. A number of urban areas provide incentives to use gray water and effluent for outdoor use and to harvest rainwater. Incentive‐based programs to protect watershed health have become a water supply strategy implemented through programs and partnerships across the CRB. The paper concludes by reviewing the ways that incentive‐based urban water policies are being evaluated, and by providing guidelines for designing and evaluating programs to reduce urban use and protect watersheds that provide urban supplies. [ABSTRACT FROM AUTHOR]

The main potential benefits of rainwater harvesting, namely water saving and storm water management, are easily evaluable at a building scale when well-known behavioral models are used. However, the evaluation is often more complex at an urban scale, due to a lack of building characteristics and demographic data. In the present paper, we propose a method, which is based on the representative building concept that can be used to quantify the potential benefits of rainwater harvesting at different scales, that is, from the building scale to the district and city scales. Particular attention has been paid to the sizing of the system so that it can be used for different rainwater collection purposes. The method has been applied to the city of Turin (Italy) considering different scenarios: 1) domestic use (e.g., toilet flushing and the washing machine), where buildings are independent of each other, and 2) two public uses (the irrigation of public green areas and street washing), for which we have hypothesized that the rainwater collection takes place at a district scale. The non-potable water saving for domestic use varies across the city from 29% to 62%, according to the characteristics of the buildings, while the reduction of the flow peak conveyed to the sewerage system, during extreme storms, is quite constant (in the 57–67% range). Irrigation and street washing require a lower amount of water, thus about 80% of water can be saved, but the retention efficiency is low, and a slight reduction in the flow peaks can be expected. The aim of the methodology presented in this work is to provide a suitable decision-making tool for policy makers and urban planners to evaluate the capability and efficiency of rainwater harvesting systems for buildings, districts, and cities. [ABSTRACT FROM AUTHOR]

• The newly proposed design for AWGs boosts water production and cuts energy use. • This AWG system offers fresh water production even in arid climates (25% humidity) • The AWG system is optimized using AI for maximum efficiency under harsh conditions. • Developed correlations allow researchers to assess AWG viability in various regions. • The system offers a promising water solution with a low levelized cost in arid areas. Providing potable water poses a severe and chronic challenge for the human race. Conventional desalination systems are only feasible in large-scale production, requiring significant energy and a source of feeding water. Atmospheric water harvesting is a decentralized water production method that uses air humidity as a renewable water source. This technique holds promise for providing water even in hard-to-reach regions with no source of liquid water. However, the feasibility of this method declines in arid or semi-arid climates. In this paper, a novel absorption-based atmospheric water generator is proposed to improve the feasibility and cost-effectiveness of this technique to make it a viable method for producing fresh water, even in arid regions. The system is modeled using EES software to explore the effects of seven adjustable parameters on its performance. Subsequently, the modeled system is transferred into MATLAB through the utilization of artificial neural networks. A tri-objective optimization is then carried out using the genetic algorithm approach. The optimized system can produce 14016 m 3 / y e a r of fresh water, with a levelized cost of approximately 33.72 $ / m 3 , operating under hot and arid weather conditions (27 ° C and 25 % RH). The data acquired from the system's performance parameters is leveraged to derive correlations that are used to determine the system's performance based on the input weather data. These correlations allow for the assessment of system feasibility across various regions and serve as a valuable shortcut in modeling similar systems for future research. [ABSTRACT FROM AUTHOR]

Photovoltaic power generation technology has gained significant attention from researchers due to its advantages of simple structure, environmental friendliness, and high sustainability. However, the photon-to-electron conversion efficiency (PCE) of photovoltaic (PV) panels is limited by the residual heat produced during the solar absorption process. Thus, an effective heat management is vital for the long-term stable and efficient photovoltaic system. In this paper, a novel dual-function device was proposed to realize effective cooling of PV panels and harvest freshwater from the air simultaneously. Through the utilization of evaporative cooling with hygroscopic hydrogel, the photovoltaic cooling-water generator (PVC-WG) device achieves up to 8 °C reduction in the operating temperature of PV panels along with a freshwater generation rate of 122.32 g m−2 h−1 in the laboratory at solar intensity of 1 kW m−2. At night, the hygroscopic hydrogel automatically absorbed moisture from the air to achieve self-regeneration, confirming its excellent reusability. Even in real outdoor environments, a maximum cooling effect of 9.2 °C and a stable freshwater generation of 98.08 g m−2 day−1 could be achieved. The system not only accomplishes thermal management for PV panels but also attains additional freshwater generation, which enhances the efficiency of harnessing the entire spectrum of solar energy. • A dual-function device was proposed to cool PV panel and produce freshwater. • A cooling effect of 8 °C and a water yield of 122.32 g m−2 h−1 could be obtained. • The hygroscopic hydrogel has good stability and recycling characteristics. • Effective photovoltaic cooling and freshwater generation could be achieved outdoors. [ABSTRACT FROM AUTHOR]

A high-performance low-humidity sensor and moisture-enabled electric generator are prepared through a mesoporous silica-mediated polymerizable deep eutectic solvent platform. The strong hydrophilicity and high ionic conductivity of ionogels are the main reasons for realizing dual-function devices. This work provides a novel approach for the combination of humidity detection and utilization. [Display omitted] • Mesoporous silica/polymerizable deep eutectic solvent functionalized ionogels were prepared by UV light stimulation. • Mesoporous silica containing abundant hydroxyl groups can regulate the intermolecular forces in polymer networks. • Low-humidity sensing and moisture-enabled electric generation can be realized simultaneously through functionalized ionogels. Although technologies related to humidity detection and utilization, such as humidity sensors, atmospheric water harvesting, energy collection, and moisture-enabled electrical generation technologies, have been widely reported, there is still an urgent need for effective monitoring and utilization of humidity in low-humidity places. An ideal low-humidity sensor requires a high response, fast response time and low humidity hysteresis. Soft ion power supplies inspired by electric eels convert the chemical potential energy of ion gradients into electrical energy by utilizing humidity, but their production is challenging. This paper reports a new strategy for developing functionalized ionogels based on mesoporous silica and a polymerizable deep eutectic solvent (SiO 2 @PDES). Due to their strong hydrophilicity, high ionic conductivity, excellent adhesion, flexibility and mechanical strength, SiO 2 @PDES ionogels can not only detect low humidity but also generate electric power through a reasonably designed device structure. In the 5–30% RH range, the response of the SiO 2 @PDES humidity sensor reaches 1600%, with negligible humidity hysteresis (0.8% RH). As a biomimetic soft ion power supply, SiO 2 @PDES ionogels generate a high open-circuit voltage of ∼600 mV at 33% RH, which expands the environmental adaptability of moisture-enabled electrical generation equipment. In addition, the excellent moisture-enabled electrical generation performance endows portable wearable power supplies with high potential for applications such as charging capacitors and lighting LEDs. [ABSTRACT FROM AUTHOR]

Droughts are the most expensive climate disasters as they leave long-term and chronic impacts on the ecosystem, agriculture, and human society. The intensity, frequency, and duration of drought events have increased over the years and are expected to worsen in the future on a regional and planetary/global scale. Nature-based solutions (NBS) such as wetland and floodplain restorations, green infrastructures, rainwater harvesting, etc., are highlighted as effective solutions to cope with the future impacts of these events. While the role of NBS in coping with the impacts of other disasters, such as floods, has been extensively studied, there has been a lack of comprehensive review of NBS targeting drought. The following paper provides a unique critical state-of-the-art literature review of individual drought-related NBS around the world, in Europe, and particularly in Belgium, and assesses the critical differences between the NBS applied globally and in Flanders. An extensive literature review was conducted to systematically analyze NBS, listing the type, the location, the status of the implementation, and the possible recommendations proposed to optimize future NBS applications. Finally, a comparison is made between small- and large-scale applications of NBS. By analyzing all these aspects, especially the level of effectiveness and recommendations, insight was gained into the future potential of NBS and possible improvements. The research indicated a lack of scientific publications, especially in Belgium. Hence, grey literature was also included in the literature review. Only four papers included a quantitative assessment regarding the effectiveness of drought on a global level, all stating a positive impact on groundwater recharge. In contrast, at regional and country levels, the performance of NBS was not quantified. The number of large-scale implementations is low, where landscape- or watershed-scale holistic approaches to drought mitigation are still scarce. Some successfully implemented projects are only very local and have a long realization time, two aspects that limit achieving visible impact at a larger scale. Among the many NBS, wetlands are recognized as highly effective in coping with drought but are still degraded or lost despite their significant restoration potential. A common effectiveness evaluation framework shall be followed, which gives policymakers a clear view of the different NBS investment options. Furthermore, a more collaborative approach is recommended globally, including different stakeholder groups, with specific attention to the local communities. To conclude, future research should increase the evidence base and implementation of drought-mitigating NBS. • Drought-mitigating Nature-Based Solutions (NBS) are systematically reviewed. • Few NBS studies focus on drought compared to other hazards such as floods. • Most NBS implementations are located in Europe. • Effectiveness is not well quantified for implemented NBS. • For achieving considerable drought mitigation, large-scale NBS are needed. [ABSTRACT FROM AUTHOR]

Harvesting atmospheric water by solar regenerated desiccants is a promising water source that is energy-efficient, environmentally clean, and viable. However, the generated amounts of water are still insignificant. Therefore, more intensive fundamental research must be undertaken involving experiments and modeling. This paper describes several experiments, which were conducted to predict and improve the behavior of water absorption/desorption by the Calcium Chloride (CaCl2) desiccant, where the uncertainty did not exceed ±3.5%. The absorption effect in a deep container was studied experimentally and then amplified by pumping air into the solution. The latter measured water absorption/desorption by a thin solution layer under variable ambient conditions. Pumping air inside deep liquid desiccant containers increased the water absorption rate to 3.75% per hour, yet when using a thin layer of the solution, it was found to have increased to 6.5% per hour under the same conditions. The maximum amount of absorbed water and water vapor partial pressure relation was investigated, and the mean absolute error between the proposed formula and measured water content was 6.9%. An empirical formula, a one-dimensional mathematical model, was then developed by coupling three differential equations and compared to experimental data. The mean absolute error of the model was found to be 3.13% and 7.32% for absorption and desorption, respectively. Governing mathematical conservation equations were subsequently formulated. The mathematical and empirical models were combined and solved numerically. Findings obtained from the simulation were compared to experimental data. Additionally, several scenarios were modeled and tested for Jeddah, Saudi Arabia, under various conditions. [ABSTRACT FROM AUTHOR]

In recent years, the adverse effects of growing water scarcity on the lives and livelihoods of poor people have become a major policy concern in India. This paper reviews the effectiveness of macro-level policies for rainwater conservation and critically examines micro-level local community institutions for the sustainable management of traditional water bodies. Using Ostrom's design principles and qualitative data from three different multipurpose tanks, the study finds that management decisions at the local level have benefited few influential members of local communities and deprived a large number of poor households from resource uses, making the local institutions ineffective. [ABSTRACT FROM AUTHOR]

Water is a key factor for sustainable development which is in turn contributing to SDG 6 "Ensure access to water for all". Generally, in arid and semi-arid regions, water is becoming less in quantity. This is due to the increasing water demand for different uses and the consequences of climate change. This situation compiled the urgent need to implement a sustainable and non-conventional water resources, among which is rooftop rainwater harvesting (RRWH) which is being studied in this research. This paper aims to estimate potential volume of RRWH and to evaluate the possibility of adopting RRWH as a reliable water resource in trying to bridge the domestic water supply-demand (DWSD) gap in the West Bank. The methodology of this study mainly rely on the use of the geographic information system (GIS) together with MS Excel. RRWH volumes were estimated based on the available GIS shapefiles of rooftops and long-term areal annual average rainfall. According to Palestinian Water Authority (PWA) data for the year 2017, the DWSD gap in the West Bank is 32 million cubic meters (MCM). In the West Bank, and given the vulnerable water supply, RRWH was found to be a strategic option to bridge this gap. The results of this study show that the estimated RRWH volume potentially available from West Bank rooftops is 37 MCM. Moreover, the adoption of RRWH in areas with high to very high domestic rainwater harvesting suitability can collect up to 32 MCM. Implementation of RRWH in high domestic water poor areas yet highly suitable for rainwater harvesting amounted to 53% of total RRWH volume in the West Bank. This paper may help potential Stakeholders (e.g. PWA) to adopt RRWH as a sustainable water resource option to alleviate domestic water shortage in the West Bank. [ABSTRACT FROM AUTHOR]

Rainwater Harvesting (RWH), although an ancient technique of artificial recharge to groundwater and reuse of stored rainwater, has been improved with the developing technology. RWH systems have many benefits in rural as well as in urban areas of arid and semi-arid regions. Almost all metro cities of India are facing problems of water logging and flooding even after a short heavy rainfall. In metro cities RWH could be helpful for artificially recharging groundwater in depleted water level areas; reduction of flood risk in urban areas; assured source for an effective alternative water supply solution and use of harvested water during water scarcity period. Nevertheless, most of the studies in literature focused on the potential of RWH for buildings, institutional areas for reducing water consumption, whereas few examples were examined for their efficient use. Almost all big cities in India are planning metro rails which have huge potential for RWH with its elevated stations, viaduct (elevated corridor) and depot areas. This work aimed to investigate and realize the RWH potential especially for metro rails which are in the implementation stage for different cities in India. This paper also highlighted the legislations of RWH of different states where metro rails were implemented. It also emphasized on the root cause of inefficiency of the RWH system and how to increase the efficiency. [ABSTRACT FROM AUTHOR]

Three‐dimensional (3D) hierarchical structures have been explored for various applications owing to the synergistic effects of micro‐ and nanostructures. However, the development of spherical micro/nano hierarchical structures (S‐HSs), which can be used as energy/water harvesting systems and sensing devices, remains challenging owing to the trade‐off between structural complexity and fabrication difficulty. This paper presents a new strategy for facile, scalable S‐HS fabrication using a thermal expansion of microspheres and nanopatterned structures. When a specific temperature is applied to a composite film of microspheres and elastomers with nanopatterned surfaces, microspheres are expanded and 3D spherical microstructures are generated. Various nanopatterns and densities of spherical microstructures can thereby be quantitatively controlled. The fabricated S‐HSs have been used in renewable electrical energy harvesting and sustainable water management applications. Compared to a triboelectric nanogenerator (TENG) with bare film, the S‐HS‐based TENG exhibited 4.48 times higher triboelectric performance with high mechanical durability. Furthermore, an S‐HS is used as a water harvesting device to capture water in a fog environment. The water collection rate is dramatically enhanced by the increased surface area and locally concentrated vapor diffusion flux due to the spherical microstructures. [ABSTRACT FROM AUTHOR]

Typical spontaneous movement behaviors of condensate droplets include coalescence-induced jumping, gravity-driven sliding, and directional migration by wettability gradient. However, in the study of humid air condensation, it is uncommon to efficiently synergize two or three behaviors to enhance condensation capacity on a large surface. In this paper, droplet self-migration and gravity-driven sliding are successfully synergized by laser etching inverted trapezoidal superhydrophilic channels on the upper half of a 40 × 80 mm2 quasi-liquid surface. The dimension of droplets on the hydrophobic zone is effectively confined through rapid detachment of millimeter-scale droplets at the tip of the water-filled channels and subsequent frequent sweeping on the lower hydrophobic zone. Comparative analysis reveals that when the topline and baseline of the inverted trapezoidal superhydrophilic channel are set at 1.5 mm and 0.2 mm respectively, the surface exhibits the highest frequency of droplet formation in channels while utilizing coalescence-induced detachment of double droplets as its primary departure mode which achieves the most efficient detachment from the channel tips. Compared with a 1 mm vertical striped biphilic surface (directional-migration behavior only), this surface synergizes three movement behaviors of millimeter-scale droplets and demonstrates a remarkable increase in water harvesting rate by 33.0% in the best case. This experimental study not only provides a novel approach for the facile and large-scale fabrication of patterns on biphilic surfaces, but also offers different insight into synergizing various mobility behaviors of droplet at the millimeter-scale during humid air condensation. • Efficient synergism of multiple droplet behaviors is realized on biphilic surface. • Trapezoidal patterned surface achieves condensation enhancement in humid air. • Coalescence-induced sliding leads to effective departure of millimeter-scale droplets. • A facile way to fabricate an efficient biphilic surface with large area is introduced. [ABSTRACT FROM AUTHOR]

The study explored strategies and means of achieving wider acceptability and adoption of roof rainwater harvesting (RWH) systems in Ghana to improve water security and availability. The paper employed a qualitative approach in analyzing views expressed by a wide range of stakeholders participating in a workshop on the potential for up-scaling successful RWH technology. Dialogue and content analysis of the views on drivers and barriers to the uptake of RWH technology on a wider scale were synthesized to establish the sustainability of the technology. Some drivers identified included encouraging local fabrication industries to design and/or develop RWH installation components; using the cluster approach in the implementation of RWH technology to ensure cost-effectiveness and wider adoption of the system; and employing the media including television and radio to disseminate the socioeconomic and environmental benefits of the RWH system. Barriers to adoption of the RWH system identified included limited information, high cost of the system, limited institutional support and focus by developers as well as negative perceptions on sustainability and portability from the system. This paper demonstrates the significance of the RWH system as a tool for achieving water security in Ghana. We recommend that to promote wide adoption of the RWH system future studies should investigate the physical and chemical characteristics of harvested rainwater to establish a suitable and acceptable standard for obtained water. [ABSTRACT FROM AUTHOR]

Drainage of surface water from the pavement structure is an important parameter for preserving the designed period and safety during the operation of the pavement structure. The paper presents research on the relationship between the efficiency of drains depending on the cross slope. When the correct selection of transverse slopes and the collection of rain runoff from the catchment area of the road, the safety of the operating conditions itself increases. By changing the transverse slope, the parameters in terms of water runoff speed and drain efficiency also change. During the analysis, this paper also took into account the hydrological parameters for the site where the section in question is located. The analysis in this paper aims to show how the correct selection of cross slopes of pavement structures can be of key importance for the efficiency of the drain, and thus the efficient drainage of surface water from the pavement structure. [ABSTRACT FROM AUTHOR]