Water Scarcity Issues Research Articles

Assessing the impact of groundwater abstractions on aquifer depletion in the Cauvery Delta, India

Many of the world’s deltas are highly productive areas for agriculture as well as important places of socio-economic development but are currently under stress. This study assesses the impacts of stresses on groundwater pumping, changing cropping patterns, and saltwater intrusion on groundwater resources in the Cauvery Delta in Tamil Nadu, India. A transient groundwater flow model of the delta was constructed for this assessment. The historical changes in groundwater resources in response to decreasing irrigation canal flows and increasing groundwater abstractions were assessed for the past 30 years. Furthermore, the model was used to formulate and analyze future sustainable groundwater development scenarios. Farmers’ narratives about a drying delta, as they experience water scarcity and quality issues most closely, were ascertained in the research. Farmers have abandoned many shallow wells in their fields. The model simulation shows groundwater levels are decreasing and aquifer storage depleting. Furthermore, salinization has increased, with continuous declining groundwater levels in the deep aquifer from 1990 to 2019. A more robust hydro-chemical assessment and further modeling of seawater intrusion are needed to better assess the sources and distribution of groundwater salinity. The pathway for future sustainability requires enhancing groundwater recharge in the shallow aquifer and controlling groundwater abstraction in the deep aquifers.

3D porous N-doped lignosulfonate/graphene oxide aerogel for efficient solar steam generation and desalination

Solar-driven interfacial evaporation has been considered one of the most promising approaches to tackle the issue of water scarcity. The salt resistance and water transport capacity of solar evaporation materials are essential to evaluate desalination performance. Herein, a 3D-porous N-doped lignosulfonate/graphene oxide (GO) aerogel (NLGA) was facilely prepared by a one-step hydrothermal method. By introducing ethylenediamine (EDA) as a nitrogen source, the wettability and water transport capacity of the aerogel were enhanced; by introducing lignosulfonate (LS), its porous structure was regulated, and its light absorption capability was significantly improved. The obtained aerogel exhibited an outstanding evaporation rate (1.57 kg m−2 h−1) and efficiency (95.2 %) under 1 sun illumination, which is significantly better than some reported foam-based solar evaporators. In addition, NLGA maintained a stable evaporation rate over long-term cyclic evaporation without visible salt accumulation on the surface. The good salt rejection performance is due to the rich-pore structure and superhydrophilicity of NGLA, which provides sufficient water supply to dissolve the salts during water evaporation. NLGA has enormous potential as a solar evaporator based on its excellent performance in solar vapor generation.

Development of the crop coefficient for vertically trained cucumber vines grown in soilless media under naturally ventilated greenhouse conditions

AbstractIn the wake of climate change and water scarcity issues, protected cultivation combined with precise irrigation management allows effective water resource utilization. This research was intended to find the actual crop evapotranspiration (ETc) of vertically trained cucumber vines in a soilless medium and develop crop coefficients (Kc) under greenhouse conditions. Experiments were performed in three micro‐lysimeters (volume 0.015 m3) placed inside a naturally ventilated greenhouse from April to June 2018 (season I) and September to December 2019 (season II) with a planting density of 0.32 m2/plant. The FAO‐56 Penman–Monteith equation was used to calculate reference evapotranspiration (ETo), and lysimeters were used to calculate the actual ETc. The average actual ETc of cucumber vines in season II (147.81 mm) was almost half of the ETc in season I (275.24 mm). The higher ETc in season I was due to a higher ETo of 493 mm during season I compared to 150 mm in season II inside the greenhouse. Kc values for season I were 0.3, 0.74, 1.11 and 0.68 compared to 0.3, 0.77, 1.38 and 0.79 in season II during the initial development, mid and end stages of cucumber vines, respectively, under greenhouse conditions.

Effects of Planting and Nitrogen Application Patterns on Alfalfa Yield, Quality, Water–Nitrogen Use Efficiency, and Economic Benefits in the Yellow River Irrigation Region of Gansu Province, China

Appropriate planting and nitrogen application patterns to support high-quality production of cultivated forage in light of issues of water scarcity, extensive field husbandry, and low productivity in cultivated grassland planting areas were investigated in this study. Using Medicago sativa L. (alfalfa) as the research object, this study analyzed the effects of planting patterns (conventional flat planting (FP) and ridge culture with film mulching (RM)) and nitrogen level (N0: 0 kg·ha−1, N1: 80 kg·ha−1, N2: 160 kg·ha−1, N3: 240 kg·ha−1) on the growth, yield, quality (crude protein content (CP), acid detergent fiber content (ADF), neutral detergent fiber content (NDF), and relative feeding value (RFV)), the water–nitrogen use efficiency, and economic benefits (EB) of alfalfa in the year of establishment. Results demonstrated that (1) RM might greatly increase the growth of alfalfa when compared to FP. The plant height, stem diameter, and leaf:stem ratio of alfalfa all increased under the same planting patterns before decreasing as the nitrogen application rate (NAR) increased. (2) Appropriate NAR combined with RM could improve the yield and quality of alfalfa. Compared with other treatments, the yield, CP, and RFV under RMN2 treatment increased by 5.9~84.9%, 4.9~28.6%, and 19.6~49.3%, respectively, and the ADF and NDF decreased by 14.0~27.6% and 13.0~26.1%, respectively. (3) Under the same nitrogen level, RM showed better performance than FP in terms of water use efficiency (WUE), irrigation water use efficiency (IWUE), precipitation use efficiency (PUE), partial factor productivity of nitrogen (PFPN), agronomic nitrogen use efficiency (ANUE), and EB of alfalfa. Under the same planting pattern, PFPN decreased as the NAR increased, while WUE, IWUE, PUE, ANUE, and EB first increased and then decreased as the NAR increased and reached a maximum value under the N2 condition. In conclusion, the RM planting pattern combined with a nitrogen level of 160 kg·ha−1 can significantly promote alfalfa growth as well as the yield, quality, water–nitrogen use efficiency, and EB of alfalfa, making it a suitable planting management mode for alfalfa production in the Yellow River irrigation region in Gansu Province, China and areas with similar climate.

Discourses on the history of the irrigation of Bukhara oasis

The following article discusses the hard work of the peasants of the Bukhara Oasis, the issues of crop irrigation and water scarcity, the causes and factors of the lack of water in the Bukhara Oasis, especially the efforts done to eliminate water scarcity as the result of the diminishing of the water resources of the Zarafshan River year by year, which provides water to Bukhara during the occupation of the Russian Empire, to reduce water year by year.

Blue Water Scarcity Assessment in Banas River Basin using Water Footprint Approach

In order to increase water availability, improve water quality, and ensure long-term sustainability, river basin-scale planning and management of water resources is crucial. Using the blue water scarcity index and the water footprint concept, this study assesses blue water scarcity in the Banas river basin from 2008 to 2020. Banas basin experiences considerable scarcity, with the value of the average annual blue water scarcity index being 140.9% which can be characterized as moderate. Banas river basin typically experiences significant blue water scarcity for three months of the year (November, December and January). Compared to these months, it is low for three months (August, September, and October), moderate for four (April, May, June, and July), and significant for two months of the year (February and March). Farmers in the basin should adopt improved water management practices to ensure sustainability and address water scarcity issues. This study can provide a framework for policy to solve some policy and water management related issues in the basin. It can also help with more effective water resource allocation and utilization.

Review on MBR Technologies for Emerging Pollutant Removal from Wastewater and Their Associated Antifouling Strategies

It was necessary to reclaim water from wastewater to tackle water scarcity issues. However, it was difficult to treat waste-water for resue purpose through conventinal treatment technologies due to the wastewater contains various emerging contaminants. Membrane bioreactors (MBRs) were promising techniques to reclaim wastewater, which hybrid activity sludge and membrane technol- ogies. Although it was a challenge to eliminate the emerging contaminants efficiently through conventional MBRs due to specific chem- ical structures of these chemicals, more and more novel hybrid MBRs were applied to the removal of emerging contaminants. The evo- lution of MBR systems for treating emerging pollutants was summarized in this review. In addition, the process of biofouling on mem- branes and the development of relevant antifouling technologies were investigated. Besides, the perspectives of MBR systems on the ap- plication of emerging pollutant treatment were provided, which would help support the research and development of technologies in the field of water reclaiming in the future.

Comparison of process-based and statistical approaches for simulation and projections of rainfed crop yields

Accurate and comprehensive modelling aimed at investigating the impact of climate change on rainfed crop yields is of great importance due to the interconnected issues of water scarcity and food security. Because the process-based and statistical approaches to simulating crop yields are different in nature, a comparison between them is needed. This study investigates the accuracy of crop yield simulations in the historical period as well as future projections using two modelling approaches: 1) a process-based approach employing the Soil and Water Assessment Tool+ (SWAT+) model, and 2) a statistical approach employing a data-driven model, Feed Forward Back Propagation Neural Network (FFBPNN) over a medium-sized catchment in north-western Poland. The application of two potential evapotranspiration methods (Penman-Monteith and Hargreaves) in SWAT+ permitted calibration (2004–2011) and validation (2012–2019) of runoff and yields of winter wheat and spring barley. Different combinations of climatic parameters with a drought index based on Joint Deficit Index were applied to simulate and project rainfed crop yields (winter wheat, barley, potato, rye, rapeseed, sugar beets, cereals, maize for grain, maize for green forage, pulses) with FFBPNN. The results reveal that adding the new drought index helped increase the FFBPNN performance. This approach showed that future yields of the studied crops would slightly increase under RCP8.5 by 2060. Winter wheat and spring barley projections from SWAT+ showed very small changes using both the Penman-Monteith and Hargreaves method. Policy-wise, the results should be of interest to climate change adaptation practitioners and food security experts. Future studies should aim at more thorough investigation of the role of the downscaling technique and extreme events, as well as the effect of elevated CO2 on future crop yields.

An assessment methodology for drought severity and vulnerability using precipitation-based indices for the arid, semi-arid and humid districts of Tamil Nadu, India

Abstract As the short- and long-term impacts of climate change are becoming more visible at smaller regional scales, frequent occurrence (absence) of erratic precipitation as well as water scarcity issues can be identified as reliable indicators for predicting meteorological droughts. A supervised declaration of meteorological drought based on available precipitation data requires an understanding of reliability and consistency of drought indices for appropriate severity classification. An attempt has been made in this study to critically evaluate the performance of six popular drought indices namely, Standardized Precipitation Index (SPI), China Z Index (CZI), Modified China Z Index (MCZI), Deciles Index (DI), Rainfall Anomaly Index (RAI), and Z-Score Index (ZSI) for four districts in Tamil Nadu falling under arid (Karur), semi-arid (Cuddalore), dry sub-humid (Kanyakumari) and moist sub-humid (Coimbatore) conditions based on 120 years of precipitation records. Results showed that the SPI and CZI provided similar quantification of drought events (about 18% of the total months) irrespective of their climatic considerations while ZSI and RAI resulted in overestimation of drought severity (about 30–47%). Based on the classification strategy adopted for the selected indices, a framework for drought vulnerability assessment is proposed in conjunction with the estimated drought severity classifications.

Micro-macro-capillaries fabric-based evaporator for eliminating salt accumulation and highly efficient solar steam generation

Solar steam generation is considered to be a perspective technology to address water scarcity issues globally. However, its further application is limited by the complicated preparation strategy, poor salt rejection, and durability. In this study, a novel solar steam generation system based on a three-dimensional (3D) hierarchical flax fabric (HFF) is fabricated by carbonizing and coating with polypyrrole (PPy) on the fibers surface. The HFF fabric fabricated by an ordinary loom has a 3D hierarchical structure composed of float layer (FL), basket weave layer (BWL) and plain weave layer (PWL) by an ordinary loom. The hydrophilic carbonized hierarchical flax fabric modified by PPy (CHFF-PPy) shows highly efficient water supply by the continuous water transport channels for water transportation. The formed double-scale capillary water on the surface of CHFF-PPy is composed of micro-capillary water in the yarns for high interfacial water evaporation and macro-capillary water between the yarns for salt-rejection. Therefore, these functions cooperatively to endow the CHFF-PPy with all-in-one function including superior solar-driven water evaporation (1.4 kg m−2 h−1, 91.5 % efficiency for saline), efficient solar desalination, and long-term salt-rejecting property without any post-cleaning treatment. The design principle of the 3D fabric structures is provided for extending the application of salt rejection and the investigation of structure-design-induced double-scale capillaries control in the solar desalination field.

English

The issue of water scarcity in many parts of the world, especially in arid and semi-arid regions, is a major dilemma. The amount of moisture for plants is not comparable to rain, but in arid areas, it is a huge contribution to plant water supply. In this research, the effect of using Peltier to improve soil condensation by performing several tests was studied in order to investigate the possibility of increasing soil capacity and reducing surface evaporation. Due to the Peltier cooling effect, with copper, iron and aluminium plates, results were evaluated in normal water, saline water and soil texture. The results showed that by using the copper plates in Peltier module, temperature dropped and it was 10% more than iron and aluminium one. It showed that there were significant differences in the results.   Key words: Aluminium, cold objects, copper, iron, moisture, refrigerants.

The perspective of a smart city by endorsing the nexus Bermuda triangle with the risk assessment of polluted water reuse in integrated water and food security management: the case of Semnan, Iran

AbstractLocated in a semi-arid and arid zone, Iran is suffering from growing challenges of water scarcity. In the paradigm of a circular economy, the reuse of treated wastewater in agriculture is currently regarded as a possible solution for alleviating the issues of water scarcity and pollution. Accordingly, this research aims to assess the use of polluted water in the integrated management of water resources in Semnan. The research used the Water Evaluation and Planning System (WEAP) software package to model and analyze the water sector. Also, the Bayesian network method was used to assess the risk of using polluted water and its effects on humans and plants. The research explored two general scenarios for the study site of Semnan. The first scenario assumes the increase in population, crops (food), and industries, and the second has the same assumptions plus an increase in agricultural efficiency (food production). Based on the results, the agricultural, urban, and industrial water demands are 37, 0.06, and 0.01 million m3 in the base year, respectively. The water demand in the next years will be higher due to population growth. Finally, it is safer to use the wastewater of both treatment plants of the region (Mehdishahr and Semnan) in the industry than in other sectors. Additionally, the wastewater of the Mehdishahr Sewage Treatment Plant is more reliable than that of the Semnan Sewage Treatment Plant.

Multifunctional hydrophilic MXene/Gelatin composite aerogel with vertically aligned channels for efficient sustainable solar water evaporation and Oil/Water separation

Solar-driven water evaporation has emerged as a sustainable approach for water purification and desalination, helping to relieve the long-standing water scarcity issues. However, achieving strong mechanical structure and superior light absorption simultaneously in an evaporator for various realistic conditions in marine environment remains challenging. Here, we prepared a hydrophilic and oleophobic Ti3C2Tx MXene/gelatin (M&G) composite aerogel with vertically aligned channels which are propitious to water transport, light absorption and vapor release for clean water generation. Simultaneously, the composite aerogel has excellent dry compression resistance and wet resilience due to the addition of gelatin, which are benefit to resist shear forces caused by water surface fluctuations. Acting as solar evaporator, M&G composite aerogel demonstrates high evaporation rate (1.7 kg m-2h−1, 1 sun) and preferable wastewater purification abilities. Furthermore, the hydrophilic and oleophobic properties of the composite aerogel is critical to extract water from oil/water mixture to adapt to the application of diverse water environments. Therefore, the designed composite aerogels show great potential for water treatment in a variety of water sources.

Coal fly ash derived adsorbent for enhancing waste water treatment

The contamination of pure water by various pollutants like dyes, heavy metals, and phenolic compounds is now a global issue. Millions of tons of fly ash are generated worldwide per year. Management and utilization of coal fly ash as industrial waste for wastewater treatment application attempted as a waste recycling technique to address the water scarcity issue. Characteristics and properties like shape, size, surface area, permeability, and composition make responsive adsorbents for the potential removal of azo, reactive, anionic, cationic dyes, and heavy metals from effluents. Some research articles summarized in this mini-review are based on coal fly ash (CFA) and their composites for better adsorptivity. Moreover, the main aim is to fabricate low-cost adsorbents with high removal efficiency.

The Uncertain Future of New Mexico Chile

Chile is an essential component of New Mexico’s cuisine and is an economically important heritage crop. Despite its popularity, commercial New Mexico chile producers struggle to remain competitive in globalized markets. Geographical indication labels and branding, both based on claims of New Mexico’s unique terroir, are used to distinguish the product in the global marketplace and add value. Chile production, however, is increasingly also threatened by issues of water scarcity exacerbated by climate change. This article uses ethnographic data collected between 2014 and 2022 to examine strategies for securing a viable chile industry in a changing landscape of production. I discuss the benefits and drawbacks of fallowing, efficient irrigation systems, and the creation of new chile varieties to confront water scarcity and their potential effects on the quantity and quality of chile grown in the region. I show that both water scarcity and our adaptations to water scarcity, though necessary to confront water-scarce futures, could undermine claims of terroir that distinguish the product in the global marketplace.

The impact of interregional trade on both quantity- and quality-related water scarcity of Beijing-Tianjin-Hebei urban agglomeration in China

Exploring the impact of interregional trade on water resources from both quantity and quality perspectives is essential for sustainable water use in water-scarce metropolitan areas in emerging economies. This study used a multi-regional input-output model to uncover the trade-driven quantity and quality water stress through blue and grey water footprint of the Beijing-Tianjin-Hebei (BTH) region, one of the most water-scarce metropolitan in China. The results indicate that 35% of the blue water footprint and 54% of the grey water footprint in the BTH region can be attributed to local consumption. Moreover, interregional trade mitigates quantity water stress but intensifies quality water stress in the BTH region. The core cities, Beijing and Tianjin, shifted their quantity and quality of water stresses virtually to peripheral cities that located in Hebei province. We suggest that cities the water scare cities benefiting from inter-regional trade should gradually reduce their dependence on scarce water resources of other regions. Meanwhile, the cities whose water scarcity was intensified by interregional trade should improve water use efficiency to achieve sustainable water use. Our findings in China could provide references for other metropolitan areas facing similar quantity and quality water scarcity issues.

Adaptation of water resources management under climate change

The rapid growth of demand in agricultural production has created water scarcity issues worldwide. Simultaneously, climate change scenarios have projected that more frequent and severe droughts are likely to occur. Adaptive water resources management has been suggested as one strategy to better coordinate surface water and groundwater resources (i.e., conjunctive water use) to address droughts. In this study, we enhanced an aggregated water resource management tool that represents integrated agriculture, water, energy, and social systems. We applied this tool to the Yakima River Basin (YRB) in Washington State, USA. We selected four indicators of system resilience and sustainability to evaluate four adaptation methods associated with adoption behaviors in alleviating drought impacts on agriculture under RCP4.5 and RCP 8.5 climate change scenarios. We analyzed the characteristics of four adaptation methods, including greenhouses, crop planting time, irrigation technology, and managed aquifer recharge as well as alternating supply and demand dynamics to overcome drought impact. The results show that climate conditions with severe and consecutive droughts require more financial and natural resources to achieve well-implemented adaptation strategies. For long-term impact analysis, managed aquifer recharge appeared to be a cost-effective and easy-to-adopt option, whereas water entitlements are likely to get exhausted during multiple consecutive drought events. Greenhouses and water-efficient technologies are more effective in improving irrigation reliability under RCP 8.5 when widely adopted. However, implementing all adaptation methods together is the only way to alleviate most of the drought impacts projected in the future. The water resources management tool helps stakeholders and researchers gain insights in the roles of modern inventions in agricultural water cycle dynamics in the context of interactive multi-sector systems.

Highly Efficient and Salt-Rejecting Poly(vinyl alcohol) Hydrogels with Excellent Mechanical Strength for Solar Desalination.

Interfacial solar steam generation (ISSG)-based solar desalination has recently emerged as a promising solution to tackle the global issue of fresh water scarcity. However, the energy-intensive process of conventional vapor generation techniques limits its practical applications. Hydrogels with three-dimensional (3D) structures have been reported to alleviate this energy demand, but their applications in sustainable solar desalination are hindered by their poor mechanical stability. Herein, we propose a 3D poly(vinyl alcohol) (PVA)-based hydrogel with excellent mechanical strength for effective solar desalination. The dual polymer network hydrogel (PVA-agar) incorporated with multi-walled carbon nanotubes (MWCNTs) achieved a noticeable evaporation rate of 3.1 kg m-2 h-1 under 1 sun irradiation, owing to its broadband light absorption, intrinsic water channels, and microporous structure that help reduce the latent heat of vaporization. More importantly, the application of kosmotropic ammonium sulfate ions was found to greatly improve the mechanical strength of the hydrogels using a facile Hofmeister-assisted soaking method. Finally, the PVA-agar-MWCNT hydrogel was able to desalinate seawater efficiently (2.5 kg m-2 h-1) with self-cleaning capability of salt crystals. The salinity level of the desalinated water was also comparable to drinking clean water. The present results would pave the way for fabricating mechanically strong, hydrophilic, and highly efficient hydrogels for effective and sustainable solar desalination.

Ultra-hydrophilic layered titanate nanosheet-based nanofiltration membrane with ultrafast water transport for low energy consumption desalination

Nanofiltration (NF) membranes have significant applications to solve global water scarcity issues. An ultra-hydrophilic inorganic NF membrane was fabricated using ultra-hydrophilic layered titanate H1.07Ti1.73O4·nH2O nanosheets (HTO-ns), which exhibits high selectivity for desalination and small molecule separations while maintained an ultrafast water transport at low operating pressure. This membrane would be a low-energy consumption NF membrane. To fabricate the HTO-ns membrane, a straightforward technique, namely, the self-adjusting membrane thickness process (SAMTP), was developed by the restacking process of negatively charged HTO-ns with cations on a porous polytetrafluoroethylene (PTFE) substrate. A large-scaled high-quality HTO-ns membrane can be fabricated on a PTFE substrate surface-modified with a silane coupling agent of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and Cu2+ adsorption. There are two kinds of nanochannels for water transport through the membrane, namely, interlayer nanochannels and nanosheet edges chink nanochannels. The excellent separation performances were contributed by the interlayer nanochannels and Donnan exclusion effect of the negatively charged HTO-ns. The SAMTP technique developed in this study could also be applied simply to fabricate other metal oxide nanosheet membranes, which would open a new avenue to the high-performance ultra-hydrophilic inorganic nanosheet-based membranes for low energy consumption separation processes.

Gypsum scale formation and inhibition kinetics with implications in membrane system

Water desalination using membrane technology is one of the main technologies to resolve water pollution and scarcity issues. In the membrane treatment process, mineral scale deposition and fouling is a severe challenge that can lead to filtration efficiency decrease, permeate quality compromise, and even membrane damage. Multiple methods have been developed to resolve this problem, such as scale inhibitor addition, product recovery ratio adjustment, periodic membrane surface flushing. The performance of these methods largely depends on the ability to accurately predict the kinetics of mineral scale deposition and fouling with or without inhibitors. Gypsum is one of the most common and troublesome inorganic mineral scales in membrane systems, however, no mechanistic model is available to accurately predict the induction time of gypsum crystallization and inhibition. In this study, a new gypsum crystallization and inhibition model based on the classical nucleation theory and a Langmuir type adsorption isotherm has been developed. Through this model, it is believed that gypsum nucleation may gradually transit from homogeneous to heterogeneous nucleation when the gypsum saturation index (SI) decreases. Such transition is represented by a gradual decrease of surface tension at smaller SI values. This model assumes that the adsorption of inhibitors onto the gypsum nucleus can increase the nucleus superficial surface tension and prolong the induction time. Using the new model, this study accurately predicted the gypsum crystallization induction times with or without nine commonly used scale inhibitors over wide ranges of temperature (25–90 °C), SI (0.04–0.96), and background NaCl concentration (0–6 mol/L). The fitted affinity constants between scale inhibitors and gypsum show a good correlation with those between the same inhibitors and barite, indicating a similar inhibition mechanism via adsorption. Furthermore, by incorporating this model with the two-phase mineral deposition model our group developed previously, this study accurately predicts the gypsum deposition time on the membrane material surfaces reported in the literature. We believe that the model developed in this study can not only accurately predict the gypsum crystallization induction time with or without scale inhibitors, elucidate the gypsum crystallization and inhibition mechanisms, but also optimize the mineral scale control in the membrane filtration system.