Water Scarcity Issues Research Articles

Improving the saline water evaporation rates using highly conductive carbonaceous materials under infrared light for improved freshwater production

Because of the growing population and scarcity of limited freshwater resources, one out of three people in the world do not have access to safe drinking water today; thus, there is an urgent need to address this global concern. Desalinating sea water using renewable energy concepts can be one of the most efficient freshwater solutions for water scarcity issues. We hypothesized that the freshwater scarcity problem could be addressed using effective desalination processes associated with renewable energy and highly porous materials. The primary objective of this study is to investigate the capability of enhancing the saline water evaporation rates using thermally and electrically conductive carbonaceous materials. This study used commercially available carbon felt, woven carbon fiber fabrics, and carbon fiber reinforced composites (60% carbon fiber) to evaporate the saline water with different percentages of salt concentrations. Tap water (or 0 wt% water), 1.5 wt% saline water, and 3.0 wt% saline water sources were prepared and used in the saline water desalination process under simulated solar infrared (IR) light with a power of 250 W. The test results exhibited that the carbon felt water evaporation rate was about 5.37 kg m−2 h−1 with a water temperature of 97.9 °C for 3.0 wt% saline water, which is 32% greater than the base cases and considerably higher than other selected carbonaceous materials. Here, 3.0 wt% saline water represents the average salt concentration of the earth's ocean water, and the high surface area carbon felt seems an effective solar-driven water evaporator for this water. This research provides the potential to deliberate highly durable carbon materials for future freshwater production.

Ultralight electrospun fiber foam with tunable lamellar macropores for efficient interfacial evaporation

Solar-driven interfacial evaporation is regarded as one of the most promising technologies to address the critical issue of global water scarcity. However, a great deal of energy is lost via conduction during the interfacial evaporation process. Herein, a self-floating Janus evaporator containing micron-sized isolated bubbles that can enhance heat localization is designed. The evaporator is synthesized by gas foaming polyacrylonitrile (PAN) nanofibers and subsequently depositing polypyrrole (PPy). The hydrophilic PAN nanofiber layer on the bottom of the evaporator with abundant macropores can continuously pump water upward through the capillary force. The hydrophobic PAN@PPy composite nanofiber layer on the top possesses a broadband solar absorption property, converting solar irradiation to heat efficiently. The low thermal conductivity of the isolated micron-sized bubbles enhances the thermal insulation of the obtained PAN foam@PPy Janus evaporator, while the stretching and expanding of the nanofibers induced by the bubbles contribute to its increased mechanical stability. This work offers a simple route to fabricate evaporators that can continuously produce drinking water from brine under sunlight, and provides a fresh idea to enhance the thermal insulation and mechanical properties of the conventional electrospinning-based fiber scaffold.

Future upstream water consumption and its impact on downstream water availability in the transboundary Indus Basin

Abstract. The densely populated plains of the lower Indus Basin largely depend on water resources originating in the mountains of the transboundary upper Indus Basin. Recent studies have improved our understanding of this upstream–downstream linkage and the impact of climate change. However, water use in the mountainous part of the Indus and its hydropolitical implications have been largely ignored. This study quantifies the comparative impact of upper Indus water usage, through space and time, on downstream water availability under future climate change and socio-economic development. Future water consumption and relative pressure on water resources will vary greatly across seasons and between the various sub-basins of the upper Indus. During the dry season, the share of surface water required within the upper Indus is high and increasing, and in some transboundary sub-basins future water requirements exceed availability during the critical winter months. In turn this drives spatiotemporal hotspots to emerge in the lower Indus where seasonal water availability is reduced by over 25 % compared to natural conditions. This will play an important, but previously unaccounted for, compounding role in the steep decline of per capita seasonal water availability in the lower Indus in the future, alongside downstream population growth. Increasing consumption in the upper Indus may thus locally lead to water scarcity issues, and increasingly be a driver of downstream water stress during the dry season. Our quantified perspective on the evolving upstream–downstream linkages in the transboundary Indus Basin highlights that long-term shared water management here must account for rapid socio-economic change in the upper Indus and anticipate increasing competition between upstream and downstream riparian states.

Feeding the Urban Leviathan

Mexico City, a crowded and sprawling metropolis of 22 million residents, is not only one of the world’s most populated urban settlements but also one of the most vulnerable. Overburdened by a centuries-long series of compounding crises, Mexico City has always lived on the verge of an imminent and irreversible collapse. Water scarcity, floods, earthquakes, pollution, violence, traffic, overpopulation, and health issues have all taken their toll on a city that has, nonetheless and against all odds, managed to survive. When the first wave of COVID-19 hit in early 2020, Mexico City faced a hitherto overlooked threat: food insecurity. One of the communities hardest hit by the pandemic was the central wholesale market, Central de Abasto, which controls 80 percent of the food bought, sold, and consumed throughout the Metropolitan Area of the Valley of Mexico. This article takes a close look at the political, economic, and ideological causes and effects of Mexico City’s over-centralized model of food supply and distribution and how it has added to its state of permanent crisis.

A Covalent Organic Framework/Graphene Dual-Region Hydrogel for Enhanced Solar-Driven Water Generation.

Solar-driven water generation is a sustainable water treatment technology, helping to relieve global water scarcity issues. However, this technology faces great challenges due to the high energy consumption of water evaporation yielding low evaporation rates. Here, a covalent organic framework (COF)/graphene dual-region hydrogel, containing hydrophilic and hydrophobic regions in one material, is developed through a facile in situ growth strategy. The hydrophilic COF is covering parts of the hydrophobic graphene regions. Through accurate control of both wetting regions, the hybrid hydrogel shows effective light-harvesting, tunable wettability, optimized water content, and lowered energy demand for water vaporization. Acting as solar absorber, the dual-region hydrogel exhibits a steam generation rate as high as 3.69 kg m-2 h-1 under 1 sun irradiation (1 kW m-2), which competes well with other state-of-the-art materials. Furthermore, this hydrogel evaporator can be used to produce drinkable water from seawater and sewage, demonstrating the potential for water treatment.

Diversity and determinants of traditional water conservation technologies in the Eastern Cape Province, South Africa

Water scarcity remains a major threat to most rural areas in Africa due to heavy reliance on rainfed agriculture. This prompts the need to document and understand the determinants of traditional knowledge of water conservation practices. Our aim here is to document and identify the determinants of people’s knowledge of traditional knowledge of water conservation in the South Africa’s Eastern Cape province. A mixed research method was used. Purposive approach was used to collect data, i.e., elderly people were targeted during the face-to-face pre-COVID-19 pandemic interviews on the basis that traditional knowledge increases with age. However, people of different age groups were also included in the study especially when we employed only online questionnaire during the pandemic. We used questionnaire to collect all the data, and 93 people responded in total to our questions. We documented 10 traditional water conservation technologies. We identified rainfall variation, water quality issues, and increased water demand as the major challenges linked to these technologies, while easy access and the amount of water harvested are reported as benefits of these technologies. We found that traditional knowledge is not influenced by age (β = −0.006 ± 0.01, P = 0.64) or gender (β = −0.16 ± 0.25, P = 0.64) but rather correlates positively with geographic location, irrespective of the starting point of the distance measurement (distance from Port Elizabeth city: β = 0.002 ± 0.0008, P = 0.004; distance from Ngqushwa village: β = 0.0024 ± 0.0009, P = 0.008). Counterintuitively, formally educated people tend to have more traditional knowledge, but this is likely linked to the modern technologies (online survey and social media platforms) used to collect data during the COVID-19 pandemic. We suggest that traditional knowledge that has sustained life for centuries in rural communities must be integrated into water resource management to address water scarcity issues in rural Africa.Supplementary informationThe online version contains supplementary material available at 10.1007/s10661-022-09848-2.

Flexible CuO-rGO/ PANI thermal absorber with high broadband photoresponse and salt resistance for efficient desalination of oil-contaminated seawater

Solar Steam Generation (SSG) is a promising and efficient technology to limit the global water scarcity issue. Nevertheless, it is challenging to utilize versatile photothermal absorbers with salt-resistance and anti-oil-fouling capability through a facile, scalable, and cost-effective fabrication technique. This work demonstrated the combination of cheap semiconductor material with a porous ionic polymer (PIP), emeraldine salt (ES) form of polyaniline (PANI), as salt-resistant and oil-repellent evaporator, which was synthesized through a facile and cost-effective one-step method. PANI enhanced the photoresponse of the CuO-rGO and its honeycomb-like structure increased the photothermal conversion due to the multi-scattering of the incident light. The CuO-rGO/PANI achieved an evaporation rate of 2.02 kg m−2 h−1 and a solar-to-steam efficiency of 94.2% under 1 sun illumination. Furthermore, the composite presented high in-water (138.5°) and in-air (135.2°) oil contact angles with simultaneously high-water affinity (<8°) which proved the hydrophilicity and oleophobicity of this membrane. CuO-rGO/PANI can work effectively in high-concentration brine with no activity loss, due to the “Donnan exclusion” effect generated from cationic quinonoid and benzenoid structure of ES-PANI against cations from saline solution, which exhibit superb durable evaporation performance over 10 cycles.

Membrane technology for sustainable water resources management: Challenges and future projections

Although water is essential for human survival and has always been critical to the social and economic growth of the world, it is unfortunately distributed irregularly worldwide and is threatened by countless source of pollution. Addressing the issue of water resources sustainability is extremely crucial for societies in order to maintain safety as well as social, ecological and economic progress. The issue of water scarcity has pushed the world to develop adequate technologies and approaches for sustainable water resources management. In addition, to seawater and brackish water, industrial and municipal wastewater are also considered to be important available resources that need to be taken into consideration to increase sustainability and at the same time to meet SDGs. Indeed, as the population grows, agricultural, domestic and industrial activities produce large amounts of wastewaters that can be treated and reused in variety of purposes considering circular economy philosophy. Nowadays, wastewaters are treated in order to be reused for industrial, agricultural and other domestic purposes. In this context, membrane technology is a preferred choice for treatment of water from different wastewater streams for reuse in a more sustainable way, taking into account the philosophy of circular economy and the targets set from UN. This review discusses the links between the concept of sustainability and the treatment of water resources, including wastewaters with membrane technology. It provides a tangible framework for presenting the relevant challenges and future prospects but also the benefits that will come. The practical results of the research serve as reference point for stakeholders, policy makers dealing with sustainable water development strategies considering SDGs and circular economy.

Sustainable Water Allocation in Umarkhed Taluka through Optimization of Reservoir Operation in the Wardha Sub-Basin, India

Climate change is causing shifts in seasonal weather patterns and variation in seasonal time scales in India. Factors including uneven distribution of water, faulty agricultural practices and water policies, low prices of farm products, and debt are leading farmers to commit suicide in Umarkhed Taluka of the Yavatmal District. This study aimed to develop a sustainable solution to water scarcity in the surrounding watershed by introducing optimization modeling in reservoir operation. Past studies have conducted different hydrologic analyses to address the water scarcity issue in this region. However, none of the studies incorporated optimization in their models. This study developed an integrated hydrologic and optimization model that can predict the daily reservoir releases for climate change scenarios from 2020 to 2069 based upon Representative Concentration Pathway (RCP-4.5 and RCP-8.5) climate change scenarios from 2020 to 2069. The integrated simulations were able to deliver around 19% more water than the historical discharge at the most downstream station of the Wardha Watershed. The simulated approaches store less water than the actual unoptimized scenario and deliver water when there is a need at the downstream locations. Finally, because the downstream locations of the Wardha Watershed receive more water, a localized storage system can be developed and a transfer method can be utilized to deliver sufficient water to the Umarkhed Taluka.

Future of Water/Wastewater Treatment and Management by Industry 4.0 Integrated Nanocomposite Manufacturing

Innovative technologies enable businesses to stay competitive in marketplace while also increasing profits in manufacturing of nanocomposites for water treatment. Aforementioned driving factors resulted in adoption of a number of innovative technologies, and no other trend has had a greater impact in recent years than Industry 4.0. Industry 4.0 is a comprehensive term that encompasses data management, manufacturing competitiveness, manufacturing processes, and efficiency. The term “Industry 4.0” refers to a group of key enabler technologies, such as cyber physical models, Internet of Things (IoT), artificial intelligence (AI), and big data analytics, including embedded devices which are all significant components to the mechanized and digitized industrial environments. AI approaches have been used for water treatment processes as well as desalination in recent years for optimizing the process along with providing realistic answers to water scarcity and water pollution‐related issues. AI applications have been used to predict and minimize water treatment process operational costs by lowering costs and optimizing chemical utilization. Several AI models are successful and accurate in predicting effectiveness of various adsorbents used in the removal process of a variety of contaminants from water. To identify the current level of research and future development prospects of smart manufacturing, this study uses a comprehensive literature review technique for manufacturing sustainability of nanocomposite fabrication for water treatment applications. The model provided will help to create a baseline for AI and hybrid models in the water treatment and wastewater management sectors, allowing for the increased performance and innovative growth. It will serve to provide the framework and give guidance for researchers interested in creating superior nanocomposites for waste and fresh water treatment and management using Industry 4.0. This study looks at a variety of AI approaches as well as how they may be used in water treatment, with an emphasis on pollutant adsorption. This assessment also identified certain obstacles and research gaps in the field of AI applications in water treatment processes.

Global Water Scarcity Assessment Incorporating Green Water in Crop Production

AbstractOver the past decades, water scarcity has become prevalent in many regions of the world. Previous water scarcity assessments largely considered “blue water” (surface and groundwater) and overlooked “green water” (soil moisture), despite its key role in supporting crop production. Moreover, the long‐term evolution of water scarcity remains unclear. Here, we propose an agricultural water scarcity index (WSIAW) that explicitly combines green and blue water. The WSIAW measures the degree to which both green and blue water availabilities can satisfy the agricultural water requirement. The WSIAW can directly indicate water scarcity in both rainfed and irrigated areas, which cannot be captured by the blue water scarcity index alone. Using the WSIAW, we assessed the evolution of water scarcity across regions of the world during 1971–2010 at a spatial resolution of 0.5 arc degree. We found that 22% of the 228 river basins with a WSIAW of &gt;1 presented a much broader geographical coverage compared with estimates of water scarcity based on blue water only (8% of total basins). The WSIAW also exhibited a clear trend of increasing severity over the study period, particularly in major agricultural regions. Expanding cropland and increasing/competing water withdrawals by other sectors were the main reasons for the intensification of water scarcity, which was pronounced in some Asian and African river basins. The proposed WSIAW can be applied to different regions with various scales and is important for addressing global water scarcity issues.

UTILIZATION OF AGRICULTURAL WATER AND ECONOMIC GROWTH

South Asia region has the largest agricultural land area and has the largest irrigated system for agriculture – abstracts groundwater for irrigation purposes. The world is facing water scarcity issues and South Asia is also facing the water-stressed due to high population growth. This study tried to examine the impact of water utilization in the agriculture sector and examined the agriculture sector impact on economic growth in South Asian countries. Water utilization means growth in the agriculture sector and it may cause an increase in economic growth. The study used data from South Asian countries (Pakistan, India, Bangladesh, Afghanistan, Sri Lanka, Nepal, Bhutan and Maldives) from 2001 to 2018. Data has been observed through graphical representation to understand the relationship of variables of interest. The results of the research showed that the utilization of water in analyzed countries is one of the reasons for the development of agriculture. Moreover, the development of agriculture may, among other factors, positively affect economic growth. In all the South Asian countries, utilization of water is not efficient some countries utilized the maximum amount of water and get more agricultural growth. Some countries utilized the minimum amount of water and got less agriculture growth. Pakistan, India and Sri Lanka utilized a large amount of water and got more agricultural growth. Afghanistan, Nepal and Bangladesh utilized less amount of water and got less agriculture growth. So, this is not an efficient way of getting agricultural output. Due to old techniques of agriculture production in South Asia, it causes the wastage of water. The developed countries use less input and get more outputs because of this modern era of technology. Also, results revealed that agriculture growth has a positive impact on economic growth for all these countries such as Pakistan, India, Sri Lanka, Afghanistan, Nepal and Bangladesh. It means South Asian countries are agricultural base countries.

Air dan Dampak Kelangkaannya bagi Perekonomian Masyarakat Urban: Studi Pustaka Pulau Jawa

The purpose of this study is to determine and analyze the effect of water resources on the economy of urban communities in Java and to answer the issue of clean water scarcity in 2040. The results of this study indicate that the issue of water scarcity in Java in 2040 is caused by climate change. population growth, land-use change, and water pollution. The suggestion in accordance with this is that all stakeholders are expected to be aware of and continue to monitor the availability of clean water by providing education and socialization at various professional and educational levels in order to obtain more sustainable use of water.

System-wide approaches to mitigate environmental and health impacts of water contamination

Abstract There is an urgent need to address the challenges of inadequate safe water and proper sanitation in peri-urban communities in low-income countries. Agencies have tended to focus on a single aspect of the challenge for service delivery, which ultimately fails to capture the full scope of the problem. In this study, 63 household surveys and 15 key informant interviews regarding water and sanitation issues were conducted in a peri-urban area of Dar es Salaam, Tanzania. Results revealed that 87% of households experience water scarcity issues. More than 50% of the homes were surrounded by swampy areas with sewage and stagnant pools, with 40% reporting water source contamination due to seepage and overflowing of sewage collection systems. Key informants reported water scarcity and poor water quality due to poor sanitation practices and a compromised water supply network. We found that a highly integrated approach that invests in cultural, social, political, human, financial, and built community capitals is needed to address these challenges. Community self-efficacy and empowerment will be critical to accomplishing this and protecting public health.

Desiccation of a saline lake as a lock-in phenomenon: A socio-hydrological perspective

Understanding of how anthropogenic droughts occur in socio-hydrological systems is critical in studying resilience of these systems. This is especially relevant when a “lock-in” toward watershed desiccation occurs as an emergent outcome of coupling among social dynamics and surface and underground water processes. How the various processes collectively fit together to reinforce such a lock-in and what may be a critical or ignored feedback worsening the state of the socio-hydrological systems remains poorly understood. Here we tackle this gap by focusing on the case of Lake Urmia in Iran, a saline lake that faces the same fate as that of Aral Sea due to over-extraction of water sources that feed the lake. We develop an integrative, system-level understanding of how various anthropogenic, surface and underground environmental processes collectively generate the water scarcity and soil salinization issues in the study case. To this end, we investigate a paradoxical phenomenon wherein the increase of soil salinity has not noticeably affected the level of vegetation cover in Lake Urmia Basin. The outcome of our analysis may provide useful insights for informing policymakers how to cope with drought and water scarcity issues in many fragile saline lakes around the world that are currently under threat by overexploitation.

Application of Soil Water Assessment Tool (SWAT) Model in Analyzing Nitrogen Transport Inside the Narmada River Basin

The Narmada River is one of the largest rivers in Western India encompassing a watershed area of 92,672 km2. It is one of the most important rivers for water needs of the state of Gujarat, Maharashtra, and Madhya Pradesh. The climate of the basin is humid and tropical but region surrounding this river watershed is predominantly dry and resembles semi-arid conditions. The population inside the states covering this watershed increased by an average of 23% from 1991 to 2011 causing multitude of water scarcity and water quality deterioration issues. These problems were caused by increase in sewage waste and untreated industrial discharge dumped into the river stream along with chemical fertilizers washing off from the farmlands flowing into the river. While there are several studies that model the watershed hydrology and water balance components, there has been no study that analyses the transport of nutrients inside the watershed. This study aims at using a semi-distributed hydrological model—Soil Water Assessment Tool (SWAT) to model the nitrogen (NO2 + NO3) transport and distribution inside the basin for 2001–2019. Nutrients and discharge data from Central Water Commission (CWC) of India were used to build this model along with other required input forcing obtained through remotely sensed datasets. We found that the subbasins near boundary of the Narmada watershed are experiencing significant increase in nitrogen concentrations at an estimated rate of 0.0001–0.002 mg/L/yr. The potential reason for such increase is high rate of conversion of forested land to agricultural land causing usage of fertilizers that are rich in nitrogen.

Energy and Water Related Parameters in Tomato and Cucumber Greenhouse Crops in Semiarid Mediterranean Regions. A Review, Part II: Irrigation and Fertigation

Increasing agricultural systems’ resource efficiency is the key action for producing adequate food quantities in semi-arid Mediterranean regions while coping with water scarcity, environmental constraints and economic issues. Optimisation of irrigation and fertigation practices imposes different approaches, considering plant-water-soil relationships based on prevailing greenhouse microclimatic conditions, ensuring optimal production per drop of water and unit of fertiliser. In the content of "precision agricultural farming systems", nutrient uptake modelling, phyto-sensing, smart and sustainable technologies must be applied for monitoring and evaluating water and nutrients crops supply. However, in many cases, the use of irrigation and fertigation recipes given in the literature may not be compatible in the Mediterranean, as they usually originated based on northern European climatic conditions. The objective of this work is an attempt to understand various aspects of irrigation and fertigation management in vegetable fruiting crops such as tomato and cucumber towards nutrients and water resource sustainability in Mediterranean greenhouses.

Radiation grafting of vapour grown carbon nanofibers on cellulose acetate/halloysite nanotubes matrix membrane for MgSO4 rejection

Desalination method is regarded as a sustainable method to address the severe water scarcity issue from seawater or wastewater. For that purpose, several methods have been used amongst them, radaition can be employed for the modification and the advancement of material properties. Electron beam irradiation has tremendous applicability to modify structure of carbon nanofibers, in order to form suitable defects in the graphitic structure and production of reactive sites. In this work, a series of novel cellulose acetate (CA) membranes were prepared via blending with different concentration of halloysite nanotubes (HNTs) and irradiated grafted vapor grown carbon nanofibers (VGCNF) with the aim to remove MgSO4 from sea water. The morphology and topography of the VGCNF membranes were observed using SEM and AFM, respectively, which indicated the improved membrane structure, dispersity and surface roughness in the polymer matrix. The experimental data demonstrated that VGCNF grafted membranes have improved permeation flux (48 L/m2 h) and salt rejection (98% MgSO4) compared to the control membrane. More importantly, the thermal stability by TGA revealed that VGCNF4 showed enhanced stability compared to the control membrane. As a result, this study could provide great potential for the removal of salts from sea water.

Assessing Rainwater Harvesting Potential in Urban Areas: A Building Information Modelling (BIM) Approach

Water scarcity has become a major problem for many countries, resulting in declining water supply and creating a need to find alternative solutions. One potential solution is rainwater harvesting (RwH), which allows rainwater to be stored for human needs. This study develops an RwH assessment system through building information modeling (BIM). For this purpose, a hydrological study of Cfa-type climate cities is conducted with the example of Islamabad, Pakistan. The monthly rainfall data of three sites were assessed to determine the volume of the accumulated rainwater and its potential to meet human needs. The average number of people living in a house is taken as the household number. Household number or of the number of employees working at a small enterprise, roofing material, and rooftop area are used as the key parameters for pertinent assessment in the BIM. The data simulated by BIM highlight the RwH potential using five people per house as the occupancy and a 90 m2 rooftop area for residential buildings or small enterprises as parameters. The results show that the selected sites can collect as much as 8,190 L/yr of rainwater (48 L/person/day) to 103,300 L/yr of rainwater (56 L/person/day). This much water is enough to fulfill the daily demands of up to five people. Therefore, it is established that the study area has an RwH potential that is able to meet the expected demands. This study presents a baseline approach for RwH to address water scarcity issues for residential buildings and factories of the future.

Combined Impacts of Climate and Land Use Changes on Long-Term Streamflow in the Upper Halda Basin, Bangladesh

In Bangladesh, rapid population growth and associated land-use changes are escalating water scarcity issues, which will be further exacerbated under ongoing climate change. As such, predicting the consequences of climate and land-use change on freshwater supplies is critical for the sustainable management of water resources. In this study, a Soil and Water Assessment Tool (SWAT) associated with a Land Cover Model (LCM) were used to simulate long-term stream flows in the Halda Basin, Bangladesh, under baseline and future climate and land-use change scenarios. In addition, the separate and combined impacts of both types of change on long-term streamflow projections were assessed. Results indicate that by the 2060s, the maximum temperature of the Halda Basin may rise by 1.6 °C in comparison to the baseline 1986–2005 period, while minimum temperature will also increase, albeit at a lower rate than maximum temperature. Precipitation during the dry season is expected to increase, although it may decline in the monsoon period. Simulations show that these changes in climate are likely to increase future streamflow in the Halda catchment, with monthly streamflow influenced mainly by the variability in precipitation. The LCM projected decreases in grassland along with cultivated land at the expense of artificial areas. Combined, future climate and land-use changes are projected to increase annual streamflow, with climate change likely to be a greater driver of altered streamflow than land-use changes. Our results should guide environmental management authorities in more sustainable and strategic water resource planning under global climate change.