Shortage Of Water Resources Research Articles

The Problem of Water Scarcity in Central Asia: the Factor of Afghanistan

The article deals with the problem of water scarcity in the countries of Central Asia. Despite their efforts, the lack of water availability continues to persist. This increases tension in the inter-state relations in the region, as in recent years the countries increasingly face a shortage of water. Recently, Afghanistan has begun to influence the distribution of water resources in the region. Its actions are aimed at increasing abstraction of water resources from transboundary rivers of Central Asia. At the same time, Afghanistan has a right to act in this way. However, given the increasing shortage of water resources, Afghanistan’s policy may lead to new conflicts and exacerbation of relations with the Central Asian states.

Spatial Correlation between Water Resources and Rural Settlements in the Yanhe Watershed Based on Bivariate Spatial Autocorrelation Methods

The production–living–ecological functions of rural settlements are closely tied to water resources, which are the primary influencing factors of the spatial characteristics of rural settlements. However, the specific relationship between water resources and the spatial characteristics of rural settlements remains unclear. Understanding the interrelationship between the two can better safeguard the ecological pattern of the basin and optimize the living environment of settlements. This study utilized multi-source data to calculate the water yield, water demand, and ecological surplus or deficit of water resources in the Yanhe watershed. We quantified the spatial characteristics of rural settlements and employed bivariate spatial autocorrelation methods to analyze the spatial correlation between water resources and the spatial distribution, scale, and boundary form of rural settlements in the Yanhe watershed. The results show the following: ➀ Seven sub-basins in the upper reaches exhibit a severe ecological deficit in water resources, with insufficient water resources to support the demands of regional socio-economic development. The middle and lower reaches have achieved a balance between water supply and demand. ➁ Rural settlements are most densely distributed in the middle reaches, with the smallest area scale, exhibiting a transitional spatial characteristic towards the upstream and downstream ends. ➂ The Moran’s I values of spatial aggregation and morphological index of rural settlements with respect to the ecological surplus or deficit of water resources are 0.36 and 0.50, respectively, indicating a strong positive correlation. The Moran’s I value of the area scale with respect to the ecological surplus or deficit of water resources is −0.60, indicating a significant negative correlation. This research has important practical significance for guiding the spatial layout of rural settlements in the Yanhe watershed and promoting their sustainable development.

Application of water resource economic management model in agricultural structure adjustment

Abstract Taking the watershed of Nanchang city as an example, through extensive investigations, the socio-economic status, water environment status, and development status of the agricultural industry in the watershed of Nanchang city were evaluated, and the coupling relationship between industrial structure and water environment was analyzed. The dynamic simulation of agricultural industrial structure adjustment in the Nanchang city basin under the constraints of the water environment was carried out to provide scientific decision-making on water resource shortage and other issues in the Nanchang city basin and to effectively solve the problem of water resource shortage. The research results showed that under the constraints of Scheme 2, the growth rate of agricultural output was in a relatively good development process, which was 8.56% in the short term, 6.65% in the medium term, and 10.33% in the long term. It is necessary to conduct research on the agricultural industrial structure in Nanchang city, which is also conducive to the protection of the water environment.

Urbanization and the Emerging Water Crisis: Identifying Water Scarcity and Environmental Risk with Multiple Applications in Urban Agglomerations in Western China

Urbanization and climate change have combined to exacerbate water shortages in cities worldwide. While rapid urbanization is faced with the risk of water resource shortage, there are few studies on the impact of water resource shortage and the ecological environment in mega-regions. Taking the three major urban agglomerations in Western China as an example, the spatial–temporal agglomeration pattern and driving force for the risk of water shortage are analyzed. First, a new comprehensive index system for environmental risks of water resources has been established, which can be used to assess spatial changes in water resource shortage risks. Secondly, the relationship between water resource shortage and the urban agglomeration effect is discussed in regards to water resource vulnerability, exposure, and recoverability. The results showed: (1) From 2000 to 2018, the risk of total water shortage in 12 provinces (cities) in Western China decreased from 3.42 to 2.59; the risk of total water shortage in the Guanzhong Plain urban agglomeration dropped the fastest, with an average annual decline rate of 10.57%. (2) Water resource shortage in different cities of the three major urban agglomerations is out of sync in time and space; the risk level of water shortage is high in the north and low in the south. (3) Geological environmental change is an important influencing factor of water resource shortage; the negative impact of industrial water use on the risk of water shortage is the largest, with a contribution of 24.9%. In addition, this paper also puts forward policy suggestions to alleviate the risks of water shortage in the urbanization process in the western region. This research can provide a scientific basis for the sustainable development of urban water resources.

Plasmon-Mediated Solar Steam Generation over Au@Cu7S4 Yolk@Shell Nanocrystals

In recent years, solar steam generation has attracted extensive attention because it can address the shortage of water resources. Traditional techniques enabling solar steam generation are based on heating water under concentrated solar irradiation, suffering from low solar to heat conversion efficiency. By exploiting the heat localization effect from photothermal materials, the efficiency of solar steam generation can be significantly improved. Similarly, electromagnetic field confinement induced by plasmonic materials has also proven efficient for promoting solar steam generation. In this study, Au@Cu7S4 yolk@shell nanocrystals were prepared and employed as plasmonic mediums for superior solar steam generation. Here, Au was a typical plasmonic metal showing a plasmon resonance peak around 550 nm. Cu7S4, on the other hand, represented a self-doped plasmonic semiconductor capable of absorbing photons beyond 1000 nm. The combination of Au and Cu7S4 in Au@Cu7S4 nanocrystals allowed a broadband light absorption across the visible and near infrared regions. The superior solar steam generation over Au@Cu7S4 was attributed to the broadband light absorption and the enhanced solar to heat conversion efficiency rendered by the combined plasmonic effects of Au and Cu7S4.

Spatiotemporal analysis and predicting rainfall trends in a tropical monsoon-dominated country using MAKESENS and machine learning techniques

Spatiotemporal rainfall trend analysis as an indicator of climatic change provides critical information for improved water resource planning. However, the spatiotemporal changing behavior of rainfall is much less understood in a tropical monsoon-dominated country like Bangladesh. To this end, this research aims to analyze spatiotemporal variations in rainfall for the period 1980–2020 over Bangladesh at seasonal and monthly scales using MAKESENS, the Pettitt test, and innovative trend analysis. Multilayer Perception (MLP) neural network was used to predict the next 8 years' rainfall changes nationally in Bangladesh. To investigate the spatial pattern of rainfall trends, the inverse distance weighting model was adopted within the ArcGIS environment. Results show that mean annual rainfall is 2432.6 mm, of which 57.6% was recorded from July to August. The Mann–Kendall trend test reveals that 77% of stations are declining, and 23% have a rising trend in the monthly rainfall. More than 80% of stations face a declining trend from November to March and August. There is a declining trend for seasonal rainfall at 82% of stations during the pre-monsoon, 75% during the monsoon, and 100% during the post-monsoon. A significant decline trend was identified in the north-center during the pre-monsoon, the northern part during the monsoon, and the southern and northwestern portions during the post-monsoon season. Predicted rainfall by MLP till 2030 suggests that there will be little rain from November to February, and the maximum fluctuating rainfall will occur in 2025 and 2027–2029. The ECMWF ERA5 reanalysis data findings suggested that changing rainfall patterns in Bangladesh may have been driven by rising or reducing convective precipitation rates, low cloud cover, and inadequate vertically integrated moisture divergence. Given the shortage of water resources and the anticipated rise in water demand, the study's findings have some implications for managing water resources in Bangladesh.

Simulation of Hydrological Processes in the Jing River Basin Based on the WEP Model

Inappropriate vegetation reconstruction in the Loess Plateau region has led to a significant increase in regional evapotranspiration and water consumption, further aggravating the shortage of soil water resources in the Loess Plateau region. The Jing River basin is a typical area for vegetation reconstruction in the Loess Plateau region. A thorough understanding of changes in hydrological processes in the Jing River basin is of significant scientific importance for efficient utilization of soil water resources and sustainable vegetation restoration in the region. In this study, the physically based Water and Energy Transfer Processes (WEP) distributed hydrological model was used to simulate key hydrological processes in the Jing River Basin during different periods before and after the implementation of cropland conversion to forest and grassland from 1980 to 2019. The results showed that after the implementation of cropland conversion to forest and grassland from 2000 to 2019, the average runoff volume in the Jing River Basin decreased by 20.91%. The most significant decrease in average runoff occurred in the central and northern parts of the basin, with a maximum reduction of 48.6%. The decrease in runoff in flood season is more obvious. The peak discharge decreased by 24.91%, and the most significant decrease occurred in the northern and central parts of the basin, ranging from 10.3% to 50.2%. The spatial distribution pattern of average soil moisture in the 0–0.8 m soil layer showed more moisture in the south and less in the north, with the minimum value occurring in certain areas in the eastern part of the basin. Overall, the implementation of cropland conversion to forest and grassland led to a certain degree of decrease in soil moisture in the basin. After the implementation of cropland conversion to forest and grassland, reference evapotranspiration fluctuated only in specific areas of the basin with no significant overall change.

Regional water demand forecasting based on shared socio-economic pathways in the Zhanghe River Basin

Abstract Based on the framework of shared socio-economic pathways, this study predicts future population and economic conditions of the Zhanghe River Basin and combines with the water quota to predict future water demand. First, the localization parameter system is constructed. Furthermore, the water demand is calculated. The results show that (1) under regional competitive pathway, the population is the largest, while under uneven pathway, the population is the smallest. The largest economic forecast is obtained under fossil fuel development pathway, while the smallest economic forecast is obtained under regional competitive pathway. (2) The results for domestic and economic water use in the basin show that the annual water demand shows an increasing trend. Fossil fuel development pathway is the scenario with the highest socio-economic water demand, while regional competitive pathway is the scenario with the least. (3) The Zhanghe River Basin faces a high risk of water resource shortage in the future. Even under the situation of minimum socio-economic water demand, the total water demand is difficult to meet fully. The forecasting framework established in this paper has high application value and can provide a reference for water demand forecasting and prospective water demand management in river basins.

High-efficiency and low-carbon inactivation of UV resistant bacteria in reclaimed water by flow-through electrode system (FES)

With the increasingly serious shortage of water resources globally, it has been paid more attention on how to secure the biosafety of reclaimed water and other non-traditional water sources. However, the 3 most applied disinfection technics, which are chlorine, ultraviolet (UV), and ozone disinfection, all have their disadvantages of selecting undesired bacteria and low energy utilization efficiency. Electrode disinfection is a promising solution, but the current electrode disinfection process still needs to be optimized in terms of the use conditions of the configuration reactivation. In this paper, we built a flow electrode system (FES). To evaluate the disinfection techniques more precisely, we isolated ultraviolet-resistant bacteria (URB) bacteria from the water of the full-scale water plant and tested the disinfection performance of FES and UV. The inactivation rate, reactivation potential, and energy consumption were analyzed. FES could inactivate 99.99 % of the URB and cause irreversible damage to the residual bacteria. FES could make all bacteria strains apoptosis in the subsequent 24 h of storage after alternating pulse current (APC) treatment, 3 V, within 27.7 s. Besides, the energy consumption of FES is about 2 orders lower than that of UV disinfection under the same inactivation rate. In summary, APC-FES is an efficient and low-carbon alternative for future water disinfection, which could achieve the ideal disinfection effect of a high inactivation rate, no reactivation, and low energy consumption.

Optimal allocation of urban and rural water supply in coastal water shortage cities: The case of Yingkou City

AbstractCoastal cities play a significant role in regional economic development and national water resource supply. However, the shortage of water resources in coastal cities has become a bottleneck for sustainable economic, social and ecological development. As a typical coastal city in Liaoning province, China, Yingkou has a relatively developed economy, but faces increasingly serious water shortages. Taking Yingkou as a case study, this study analysed the current situation of urban and rural water supply and conducted a rational estimation of the water supply and demand based on the time series method in the short‐term (2025) and long‐term (2035). Then, the allocation of urban and rural water supply was carried out on the principle of priority use of surface water, sufficient use of diverted water, expanding use of unconventional water and limited use of underground water. To achieve the optimal scheme, the method of ‘allocation‐feedback‐regulation‐reallocation’ was adopted to coordinate the water sources and consumption in different districts and sectors. Overall, the results clarified the red line of water consumption in 2025 and 2035 and defined water consumption and water sources in different sectors and districts. Finally, the water supply and demand balance in Yingkou and its subdistricts was achieved with surplus water rates of 6% and 7% in 2025 and 2035, respectively. Based on these results, suggestions for the sustainable development and utilization of water resources in Yingkou and coastal cities were proposed.

Runoff Simulation and Climate Change Analysis in Hulan River Basin Based on SWAT Model

The shortage of water resources is a long-standing constraint on the development of the Chinese economy and society. In this paper, the climate change occurring in Hulan River Basin is analyzed using the data collected at Wangkui Meteorological Station from 1960 to 2020. The overall temperature in the basin shows an upward trend, with a cumulative increase of 1.6 °C, as does the precipitation, which reaches 566.2 mm. In contrast, there is a downward trend shown by wind speed, with a cumulative decrease of 1.313 m/s. GIS remote sensing technology is applied to build a SWAT distributed hydrological model for the purpose of conducting runoff simulation in Hulan River Basin, and SWAT-CUP software is used to correct and analyze the simulation results. The parameters of snow melt are set to improve the accuracy of the model. The runoff data collected from Lanxi Hydrological Station from 2008 to 2020 are used to verify the model. The results show that the efficiency coefficient (NES) and correlation coefficient (R2) are 0.75 and 0.84, respectively, in the validation period from 2010 to 2013, while they are 0.77 and 0.93, respectively, in the correction period from 2014 to 2016, meeting the criteria of model evaluation. It can be seen from results noted above that SWAT is applicable in Hulan River Basin, providing a certain reference for the management of hydrological and water resources available in this region and for the construction of a distributed hydrological model of rivers in those high-latitude cold regions.

Assessment of water quality using multivariate statistics and geographical information systems (GIS) of Wadi Aldabab, Taiz, Yemen

The shortage of water resources in Yemen has an implication on the availability and supply of safe water in the country. This study assessed the water quality in Wadi Al-Dabab, Taiz, Yemen. Water samples were collected from the springs and different types of wells (tube, manual) with depths ranging from 9 to 500 m. Multivariate statistical analysis was performed on 15 water quality parameters (WQP) from 15 locations to investigate the significant WQP and the possibility of data reduction. The water quality index (WQI) approach was used to assess its suitability for drinking purposes. Four principal components were identified to be significant, which explained 86.2% of the overall variance while four varifactors (VF) explained 80% of the data variance. The findings showed the possibility of data reduction by 20%, which could assist in water quality monitoring at a reduced cost. The WQI map shows that the water quality is good in a limited area and poor to very poor in most of the study area. The findings are likely to assist in identifying the important WQP for the protection of the drinking water sources while the less important WQP can be excluded, which might reduce the cost of water quality monitoring. The proposed approach is likely to be a cost-effective approach for the economically weak and water-stressed countries, which can contribute positively for the sustainable water resource management in Yemen and other water-stressed regions.

Investigation of Salt and Nitrogen Distribution under Belt Plastic Film Mulching in Surface- and Drip-Irrigated Maize Field in Hetao Irrigation District

Hetao Irrigation District (HID) is one of the main regions for maize and sunflower production in North China. However, water resource shortages and soil salinization greatly limit maize and sunflower production. The surface irrigation method is the main irrigation method in HID; however, now, the plastic mulching and drip irrigation area is increasing to reduce irrigation water and enhance crop yield. In this study, the soil water, salt, and nitrogen contents at the 0–100 cm soil layer under plastic mulching and non-mulching conditions with the surface irrigation—fertilizer broadcast practice and drip fertigation method were investigated at the maize elongation and maturation stages in the 2021 and 2022 seasons. The results show that the mulching practice and irrigation methods greatly influenced the soil salt and ionic nitrogen (NO3− and NH4+) distributions and, ultimately, the maize yield. Mulching reduced the soil salt content in the 0–20 cm soil layer by a mean of 35.7% under surface irrigation and by 18.6% under the drip irrigation condition. The NO3− content in the 0–20 cm soil layer with the drip fertigation system was approximately 8 times higher in mulching soil than that out of mulching. However under the surface irrigation condition, the NO3− content was 8–10 times lower under mulching than that out of mulching. The soil salt and NO3− contents were distributed uniformly at each soil layer deeper than a 40 cm depth, indicating minor effects of mulching. The soil NH4+ content decreased as the soil depth increased and distributed uniformly at each soil layer, indicating the insignificant influence of the mulching practice. As a result, the maize yield under the drip-mulching condition was approximately 11% (10.6~11.4%) higher than that under the surface-mulching condition in the two maize seasons. Given that surface irrigation is currently the primary irrigation method in the Hetao Irrigation District (HID), we have proposed three approaches aimed at enhancing maize production through the improvement of nitrogen levels in surface-mulching practices.

Effects of Bio-Organic Fertilizer on Soil Infiltration, Water Distribution, and Leaching Loss under Muddy Water Irrigation Conditions

This study analyzes the soil water infiltration characteristics under muddy water irrigation and bio-organic fertilizer conditions in the current context of muddy water irrigation rarely being used in agricultural production and in combination with the problems of water resource shortages and low soil fertility in arid and semi-arid regions. An indoor one-dimensional soil column infiltration device was used for studying the effects of four muddy water sediment concentration levels (ρ0: 0; ρ1: 4%; ρ2: 8%; ρ3: 12%) and four bio-organic fertilizer levels (FO0: 0; FO1: 2250 kg·hm−2; FO2: 4500 kg·hm−2; sFO3: 6750 kg·hm−2) on soil water infiltration, evaporation characteristics, and leaching loss. The results demonstrated that a higher muddy water sediment concentration and fertilization level resulted in a smaller wetting front distance and cumulative infiltration amount within the same time, but the infiltration reduction rate (η) gradually increased. The three infiltration models (Kostiakov, Philip, and Horton) were fitted, and it was discovered that all three had good fitting results (R2 > 0.8), with the Kostiakov model displaying the best fit and the Horton model exhibiting the worst fit. The cumulative evaporation amount and evaporation time in muddy water irrigation and fertilization conditions was consistent with the Black and Rose evaporation models (R2 > 0.9), the Black model was proved to be higher than the Rose model. In comparison to ρ0, muddy water irrigation increased conductivity and total dissolved solids (TDS) in the leaching solution, but it reduced cumulative evaporation, soil moisture content, the uniformity coefficient of soil water distribution, and leaching solution volume. Compared with FO0, the application of bio-organic fertilizer increased soil water content and reduced soil water evaporation while also reducing the leaching solution volume, conductivity, and TDS in the leaching solution. The results of this research can provide scientific reference for the efficient utilization of muddy water irrigation and the rational application of bio-organic fertilizer.

Regional Climate Effects of Irrigation under Central Asia Warming by 2.0 °C

There has been a severe shortage of water resources in Central Asia and agriculture has been highly dependent on irrigation because of the scarce precipitation in the croplands. Central Asia is also experiencing climate warming in the context of global warming; however, few studies have focused on changes in the amount of irrigation in Central Asia under future climate warming and their regional climate effects. In this study, we adopted the Weather Research and Forecasting (WRF) model to design three types of experiments: historical experiments (Exp01); warming experiments using future driving fields (Exp02); and warming experiments that involved increasing the surface energy (Exp03). In each type of experiment, two experiments (considering and not considering irrigation) were carried out. We analyzed the regional climate effects of irrigation under the warming of Central Asia by 2.0 °C through determining the differences between the two types of warming experiments and the historical experiments. For surface variables (irrigation amount; sensible heat flux; latent heat flux; and surface air temperature), the changes (relative to Exp01) in Exp03 were thought to be reasonable. For precipitation, the changes (relative to Exp01) in Exp02 were thought to be reasonable. The main conclusions were as follows: in Central Asia, after warming by 2.0 °C, the irrigation amount increased by 10–20%; in the irrigated croplands of Central Asia, the irrigation-caused increases (decreases) in latent heat flux (sensible heat flux) further expanded; and then the irrigation-caused decreases in surface air temperature also became enhanced; during the irrigation period, the irrigation-caused increases in precipitation in the mid-latitude mountainous areas were reduced. This study also showed that, in the WRF model, the warming experiments caused by driving fields were not suitable to simulate the changes in irrigation amount affected by climate warming.

Evaluation of the economic efficiency of the membrane method for drinking water preparation

Membrane methods - reverse osmosis and nanofiltration - are attracting more and more attention in the context of providing the population with high-quality drinking water. Kazakhstan attaches high priority to this issue, realizing the growing scarcity of water resources.The purpose of the study is to analyze the economic efficiency of the use of the membrane method for the preparation of drinking water.Methodology. To achieve this goal, a methodology was used based on the evaluation of proposed technological solutions using net present value (NPV), yield index (IR) and internal rate of return (IRR).Originality / value of the research. The study focuses on the economic efficiency of the membrane method of drinking water treatment. Currently, providing the population with high-quality drinking water is one of the main priorities of many countries, including Kazakhstan, due to the growing shortage of water resources. This study proposes a methodology for evaluating the cost-effectiveness of membrane methods such as reverse osmosis and nanofiltration using indicators such as NPV, ID and GNI. This allows you to make informed decisions about the selection of the most profitable innovative projects in the field of drinking water treatment. The study is of significant value because it provides practical recommendations and guidance for decision-making in the field of drinking water treatment, contributing to the provision of high-quality drinking water to the population and optimization of economic costs in Kazakhstan.Findings. The paper considers a set of issues related to the economic assessment and selection of innovative projects for the preparation of drinking water by reverse osmosis and nanofiltration by calculating the net present value (NPV), the return index (IR) and the internal rate of return (IRR). The study calculated the return on investment using nanofiltration for stations with a capacity of 300.6 thousand m3/year. The authors found that, taking into account discounting, the payback period for projects according to the proposed method is 5 years.

Floodwater utilization potential assessment of China based on improved conceptual model and multi-reservoir basin assessment method

Floodwater resource utilization is an important way to alleviate the water resources shortage in China. The quantitative assessment of the floodwater utilization potential under the current engineering conditions is vital for implementation of floodwater resource utilization. However, the imperfect conceptual model of floodwater utilization potential, the limited availability of reservoir engineering data, and the lack of universal assessment method that directly considers the reservoirs regulation capacity pose a major challenge to assessment of floodwater utilization potential in China. This study improves the universality of the previous conceptual model of floodwater utilization potential by analyzing the differences and connections of floodwater resources potentials under different states of utilization. The floodwater utilization potential assessment method for river basin with multi-reservoir was also proposed based on our previous assessment method for single reservoir controlled basin. The assessment method was used to evaluate the floodwater utilization potential of the first- and second-level water resources regions in China based on the reanalyzed monthly runoff data (1902 ∼ 2014) and large and medium-sized reservoirs data (as of 2015). Results indicate that the annual average total floodwater utilization potential of China was calculated as 668.62 billion m3 under the current reservoir regulation capacity, accounting for 34.05% of the total floodwater water resources in China. The study demonstrated that the frequency curve of floodwater utilization potential can provide a better understanding of the states of floodwater utilization, and the assessment method. Strategies for long-term floodwater utilization and flood control planning in different regions of China were also provided to government in our study.

An Efficient Investigation and Machine Learning-Based Prediction of Decolorization of Wastewater by Using Zeolite Catalyst in Electro-Fenton Reaction

The shortage of water resources has caused extensive research to be conducted in this field to develop effective, rapid, and affordable wastewater treatment methods. For the treatment of wastewater, modern oxidation techniques are desirable due to their excellent performance and simplicity of implementation. In this project, wet impregnation and the hydrothermal technique were applied to synthesize a modified catalyst. Different analysis methods were used to determine its characteristics, including XRD, BET, FT-IR, NH3−TPD, and FE-SEM. The catalyst features a spherical shape, large surface area, high crystallinity, and uniform active phase dispersion. In order to eliminate the methylene blue dye as a modeling effluent, the catalyst’s performance was examined in a heterogeneous quasi-electro-Fenton (EF) reaction. The impact of various performance characteristics, such as catalyst concentration in the reaction medium, solution pH, and current intensity between the two electrodes, was elucidated. According to the results, the best operational circumstances included a pH level of 2, a catalyst concentration of 0.15 g/L, and a current of 150 mA, resulting in the greatest elimination efficiency of 101%. The catalyst’s performance was stable during three consecutive tests. A pseudo-first-order model for the elimination reaction’s kinetics was developed, which showed acceptable agreement with the experimental results. This study’s findings help clarify how well the heterogeneous zeolite catalyst functions in the pseudo-EF reaction. The results revealed the method’s potential to be implemented in wastewater treatment. An artificial neural network model is utilized to predict the removal percentage. The hyperparameter tuning is used to find the best model, and the model achieved an MAE of 1.26% and the R2 was 0.99.

Evolution Characteristics of Rainfall and Runoff in the Upper Reaches of Zhang River Basin

It is of great significance to study and analyze the surface water resources and their change trend in the groundwater overexploitation area of the North China Plain, which is of great significance to solve the shortage of water resources in the groundwater overexploitation area of the North China Plain, promote the exploitation of groundwater, and realize the sustainable development of water resources. This paper takes Minyou Irrigation District of Handan City, a typical overexploitation area in the North China Plain, as an example. Based on the measured rainfall and runoff data from 1957 to 2020, the Mann–Kendall trend test, cumulative anomaly method, double cumulative curve method, and Morlet wavelet transform were used to analyze and predict the trend of water resources in the irrigation area and the individual contribution of climate change and human activities to runoff change. The results show that the annual rainfall and annual runoff in the irrigation area have a significant downward trend and significant cyclical changes throughout the study period. In 1977, the annual runoff showed a sudden change, and the average contribution rates of climate change and human activities to its change were 40.55% and 59.46%, respectively. In the future (2020–2035), runoff will remain stable and rainfall will show an increasing trend. The research results can provide scientific reference for the development, utilization, and rational allocation of surface water resources in the groundwater overexploitation area of the North China Plain.

Wettability contrast on the surface of CuO nanostructures for highly efficient fog harvesting

Fog collection can provide a sustainable and efficient method for solving the shortage of water resources. In this article, CuO nanostructures were designed and synthesized on the Cu mesh by a one-step oxidation method and used to collect water from fog. Their morphology and surface wettability are characterized through scanning electron microscopy and dynamic contact angle measuring device, while the process of fog collection is investigated by a high-speed camera. The fog collection efficiency depends on the microstructure of the sample surface, which could be well controlled by adjusting the reaction temperature. Compared with CuO nanoneedles and CuO nanowire clusters, CuO nanosheets promote the rapid falling of liquid droplets, improving the fog harvesting efficiency, which can achieve 3168 mg/cm2 within 120 s. CuO nanosheets have ultra-low adhesion due to high roughness and high air restraint ability, accelerating the transport of water droplets and reducing the re-evaporation of water droplets.