Sufficient Water Supply Research Articles

Tree-like 3D GNP-rPN composite structure for solar-thermal evaporation and photocatalytic degradation of antibiotic wastewater

To realize high-yield and long-term purification of wastewater containing antibiotic ciprofloxacin hydrochloride (CIP) and seawater, a tree-like 3D GNP-rPN solar-driven water evaporation and photocatalysis evaporator is developed by preparing and assembling GO/NPDI/PVA (GNP) hydrogel (canopy) and rGO/PU/NPDI (rPN) foam (trunk). The “tree-like” evaporation and photocatalysis evaporator design in this work has the following three characteristics: First of all, graphene oxide (GO) and reduced graphene oxide (rGO) sheets broaden the light absorption range of the photocatalyst perylene imide nanowires (NPDI), which facilitates absorption of more sunlight; secondly, GO and rGO adsorb pollutants in water and provide them to NPDI for catalytic degradation under sunlight irradiation because of their huge specific surface area; thirdly, the excellent photothermal conversion ability of GO and rGO converts solar energy into heat energy, thus facilitating the catalytic degradation of CIP by NPDI. Thanks to the reduced enthalpy of water evaporation by GNP hydrogel, the sufficient top-down water supply, the superior photocatalytic performance of NPDI nanowires, and the efficient solar light absorption and solar-thermal energy conversion of the GO sheets and NPDI nanowires, the resultant GNP-rPN evaporation and photocatalysis system achieves an average water evaporation rate of 2.84 kg m−2 h−1 and a CIP degradation efficiency of 74.04 % within 1 h under 1-sun irradiation. The GNP-rPN system exhibits an optimal degradation efficiency of 74.04 % for a CIP solution with an initial concentration of 10 mg/L within 1 h of irradiation, reaching a degradation efficiency of 96.37 % after 4 h, demonstrating its effectiveness in purifying antibiotic-laden wastewater.

Discovery of a new volcanic soil material, "Akahoya," as an adsorbent for bacterial and viral pathogens and its application to environmental purification.

Akahoya is a volcanic soil rich in alumina, primarily deposited in Kyushu, Japan. We have found that Akahoya adsorbs bacteria in the water surrounding cattle grazing areas, suggesting a potential for environmental purification. This study investigated the spectrum of microorganisms adsorbed by Akahoya using a column filled with Akahoya through which a suspension of microorganisms was passed. Shirasu soil, another volcanic soil with a different chemical composition, was used as a control. Akahoya effectively adsorbed a diverse range of microorganisms including Escherichia coli, Campylobacter jejuni, Vibrio parahaemolyticus, Salmonella Enteritidis, Staphylococcus aureus, Clostridium perfringens, spores of Bacillus subtilis and Bacillus anthracis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), murine norovirus, and avian influenza virus (H3N2), whereas Shirasu soil did not adsorb any of the organisms examined. Moreover, bacteria naturally present in river water, such as aerobic bacteria, total coliforms, and Enterobacteriaceae as indicators of river contamination, as well as E. coli added artificially to sterilized river water, were reduced to below the detection limit (<1 CFU/mL) after being passed through Akahoya. Additionally, the number of viable E. coli continued to decrease after contact with Akahoya for 1 month, suggesting bactericidal effects. Notably, the adsorption of E. coli to Akahoya was influenced by the concentration of phosphate and the pH of the suspension due to the interaction between the surface phosphorylation of organisms and Al2O3, the major chemical component of Akahoya. The present results demonstrate the remarkable ability of Akahoya to remove phosphate and microbes, suggesting that Akahoya could be used for water purification processes.IMPORTANCEAlthough a safe and sufficient water supply is essential for the maintenance of hygienic conditions, a major challenge is to develop a comprehensive effective, sustainable, and cost-effective technological approach for the treatment and purification of contaminated water. In this study, we demonstrated that a novel volcanic soil, Akahoya, which has unlimited availability, is a highly effective adsorbent for a wide range of bacterial and viral pathogens, suggesting its potential as a sustainable resource for this purpose. It was suggested that the adsorption of microorganisms on Akahoya was mediated by phosphate groups present on the surface structures of microorganisms, which bind to the alumina component of Akahoya according to the phosphate concentration and pH of the liquid phase. The present findings highlight the exceptional ability of Akahoya to eliminate or reduce phosphate and microorganisms effectively in water purification processes, thus contributing to the development of efficient and sustainable solutions for addressing water pollution challenges.

Local neighborhood affects stem rehydration under drought: evidence from mixtures of European beech with two different conifers.

Mixed-species forests are, for multiple reasons, promising options for forest management in Central Europe. However, the extent to which interspecific competition affects tree hydrological processes is not clear. High-resolution dendrometers capture sub-daily variations in stem diameter; they can simultaneously monitor stem growth (irreversible changes in diameter) and water status (reversible changes) of individual trees. Using the information on water status, we aimed to assess potential effects of tree species mixture, expressed as local neighborhood identity, on night-time rehydration and water stress. We deployed 112 sensors in pure and mixed forest stands of European beech, Norway spruce, and Douglas fir on four sites in north-western Germany, measuring stem diameter in 10-minute intervals for a period of four years (2019-2022). In a mixture distribution model, we used environmental variables, namely soil matric potential, atmospheric vapor pressure deficit, temperature, precipitation, and neighborhood identity to explain night-time rehydration, measured as the daily minimum tree water deficit (TWDmin). TWDmin was used as a daily indicator of water stress and the daily occurrence of sufficient water supply, allowing for stem growth (potential growth). We found that species and neighborhood identity affected night-time rehydration, but the impacts varied depending on soil water availability. While there was no effect at high water availability, increasing drought revealed species-specific patterns. Beech improved night-time rehydration in mixture with Douglas fir, but not in mixture with spruce. Douglas fir however, only improved rehydration at a smaller share of beech in the neighborhood, while beech dominance tended to reverse this effect. Spruce was adversely affected when mixed with beech. At species level and under dry conditions, we found that night-time rehydration was reduced in all species, but beech had a greater capacity to rehydrate under high to moderate soil water availability than the conifers, even under high atmospheric water demand. Our study gives new insights into neighborhood effects on tree water status and highlights the importance of species-specific characteristics for tree-water relations in mixed-species forests. It shows that drought stress of European beech can be reduced by admixing Douglas fir, which may point towards a strategy to adapt beech stands to climate change.

Dual-functional paper-like evaporator for boosting interfacial evaporation synchronized with organic pollutant degradation

Solar-driven interfacial evaporation is a sustainable method to produce freshwater, but volatile organic compounds (VOCs) inevitable accumulate in the condensed water, causing secondary pollution. Herein, paper-like photothermal evaporators were constructed by fixing zeolitic diazoate frameworks-8 derived N-doped carbon with different morphologies on the interwoven cellulose nanofibrils (CNFs) membranes for simultaneous steam generation and organic pollutant degradation. The results showed that the evaporator incorporated porous N-doped carbon with rhombic dodecahedron (NC-RD) into CNFs membranes not only increases the roughness to achieve broad spectrum solar absorption, but also capable of ensuring continuous evaporation of water, and maintaining a sufficient water supply. The NC-RD/CNFs membranes exhibit the high evaporation rate of 1.46 kg·m−2·h−1 under one sun. Meanwhile, N-doped carbon enable photothermal-synergistic peroxymonosulfate (PMS) activation to promote the generation of abundant 1O2 and O2∙– for degradation of methylene blue, tetracycline and phenol. Furthermore, the solar-vapor conversion efficiency and the evaporation rate are stable in a simulated seawater environment with 15 wt% NaCl solution. Importantly, an outdoor NC-RD/CNFs-based device was constructed, which realizes a high evaporation rate of 0.659 kg∙m−2∙h−1 under natural light irradiation for 10 h. The present study highlights that the NC-RD/CNFs membranes successfully coupled interfacial evaporation with PMS based-advanced oxidation processes to provide a subtlety strategy to solve the problem of VOCs accumulation in the evaporation process.

Slide-shaped cotton-based photocatalytic solar evaporator with dual mutually strengthening functions for simultaneous desalination and dynamic fast dye removal

High-salt dyeing wastewater would do harm to both the environment and people's health. Herein, a photocatalytic solar evaporator with bifunctions of photothermal evaporation and photocatalysis was prepared by loading MnO2 and TiO2 on the cotton fabric, aiming at simultaneous pure water derivation and dye degradation. The evaporator was positioned in a slide-shaped configuration that uses downward capillary force and gravity-assisted water transportation for a sufficient water supply, avoiding salt accumulation during photothermal evaporation and realizing a fast dynamic dye removal via photocatalysis. Interestingly, the loaded TiO2 enhances the photothermal activity of the loaded MnO2 by increasing light absorption. While MnO2 also enhances the photocatalytic activity of TiO2 by charge transfer and heat generation. It was exciting to find that the solution streaming down dynamically through the slide-shaped evaporator into the downstream container was completely colorless, which was in sharp contrast with the blue dye solution at the upstream. Under one sunlight, the evaporator showed a evaporation rate of 1.65 kg m−2 h−1, a photothermal conversion efficiency of 96.65 % and a methylene blue removal efficiency of >95 % during the 8-day evaporation. This study realizes the synergistic effect of photothermal evaporation and photocatalysis, providing a novel strategy for the treatment of high-salt dyeing wastewaters.

Water fluxes and energy partitioning over a Larix principis-rupprechtii plantation forest in a dryland mountain ecosystem, Northwest China

Plantations make up a sizable component of forest ecosystems in China's drylands and play an important role controlling the energy balance and water cycle. However, there is limited knowledge regarding the exchange of water and energy in dryland plantations, particularly those located within the intricate and unique environments of dryland mountain regions. The focus of this study was the investigation of a Larix principis−rupprechtii plantation within a dryland mountain ecosystem located in Northwest China. The eddy covariance method was employed to calculate the water and energy fluxes, while the thermal dissipation probe (TDP) method was utilized to measure forest overstory transpiration (T) from 2018 to 2021. The links between energy allocation and various components in water flux were investigated, as well as the variable dynamics of water and energy flux and their relationship with environmental conditions. The findings demonstrated that the annual mean cumulative evapotranspiration (ET) was about 510 mm, accounting for over 82.8 % of the precipitation, which was mainly from soil evaporation and understory transpiration, rather than overstory transpiration (T). The average value of T/ET was 0.25 for the growing season, and surface conductance (Gs) was always higher than canopy conductance (Gc) on both daily and monthly scales. The evaporative fraction (EF) and Priestley-Taylor model coefficient (α) in the growing season were significantly higher than those in the non-growing season, and α>1 from June to September, indicating that the ecosystem in the study area had sufficient water supply. Furthermore, during the growing season, the ratio of latent heat flux (LE) to net radiation (Rn) was larger than that in the non-growing season, while the proportion of sensible heat flux (H) was opposite, and soil heat flux (G) accounted for the smallest proportion of net radiation. This study provides valuable insights into the energy fluxes and water fluxes within the ecosystem of dryland mountain plantations, and it serves as a guide for choosing afforestation tree species in the future.

Exploring environmental factors that influence the distribution of poplar trees

AbstractPoplar is an invasive alien plant (IAP) that encroaches on fragile landscapes in South Africa, but the environmental factors that contribute to its spread are not well understood. To address this gap, we conducted a study using generalised linear models (GLM) to identify the most significant local environmental factors that drive poplar establishment and dispersion in Golden Gate Highlands National Park (GGHNP). We then ranked these variables according to their contribution to poplar occurrence using a random forests regression approach. Our GLM analysis revealed that soil properties such as soil organic carbon, sand and silt, topographical variables such as aspect and slope, normalised difference moisture index (NDMI) and poplar distance from rivers are significant factors affecting poplar survival. After ranking the variables, we found that the three most important factors influencing poplar occurrence were aspect, slope and poplar distance to rivers, followed by the sand, silt, NDMI, and soil organic carbon. Our results are consistent with previous studies, indicating that topographical variables and the availability of sufficient water supply are the primary drivers of the spread of IAPs. This study provides useful insights in managing and monitoring poplars in delicate landscapes.

Improved water supply infrastructure to reduce acute diarrhoeal diseases and cholera in Uvira, Democratic Republic of the Congo: Results and lessons learned from a pragmatic trial.

Safely managed drinking water is critical to prevent diarrhoeal diseases, including cholera, but evidence on the effectiveness of piped water supply in reducing these diseases in low-income and complex emergency settings remains scarce. We conducted a trial of water supply infrastructure improvements in Uvira (DRC). Our primary objective was to estimate the relationship between a composite index of water service quality and the monthly number of suspected cholera cases admitted to treatment facilities and, as a secondary analysis, the number of cases confirmed by rapid diagnostic tests. Other exposures included the quantity of supplied water and service continuity. We used Poisson generalised linear models with generalised estimating equations to estimate incidence rate ratios. Associations between suspected cholera incidence and water service quality (RR 0·86, 95% CI 0·73-1·01), quantity (RR 0·80, 95% CI 0·62-1·02) and continuity (RR 0·81, 95% CI 0·77-0·86) were estimated. The magnitudes of the associations were similar between confirmed cholera incidence and water service quality (RR 0·84, 95% CI 0·73-0·97), quantity (RR 0·76, 95% CI 0·61-0·94) and continuity (RR 0·75, 95% CI 0·69-0·81). These results suggest that an additional 5 L/user/day or 1.2 hour per day of water production could reduce confirmed cholera by 24% (95% CI 6-39%) and 25% (95% CI 19-31%), respectively. Ensuring a sufficient and continuous piped water supply may substantially reduce the burden of endemic cholera and diarrhoeal diseases but evaluating this rigorously is challenging. Pragmatic strategies are needed for public health research on complex interventions in protracted emergency settings. The trial is registered in ClinicalTrials.gov ID NCT02928341. https://classic.clinicaltrials.gov/ct2/show/NCT02928341.

Особенности формирования высокопродуктивного посева нового гибрида подсолнечника Фогор

Influence of seed sowing rates (40, 60 as control and 80 thousand seeds/ha) on productivity of sunflower hybrid Fogor was studied on leached black soils of the Western Ciscaucasia (Korenovsk district, Kranodar region) in 2022–2023. It is established the highest seed (3.62 t/hа) and oil (1.46 t/hа) yields are reached at the seed-sowing rate of 80 thousand seeds/ha under sufficient moisture supply. Under weather conditions of 2022–2023, the less prevalence of bacteriosis (by 2 and 13%) and rust (by 6 and 8%, respectively) in the crops were observed. In 2023, population of fungal micoflore in rhizosphere was high enough (5.5 × 104 CFU/g), at the control level (5.7 × 104 CFU/g), the most was presented by saprophyte fungi from genera Penicillium (55.3% of the total fungi amount) and Aspergillus (25.4%). But the share of pathogenic fungi was less significantly: Fusarium spp. – 4.5%, Rizopus spp. – 0.8%. Consequently, the highly productive crops of the new sunflower hybrid Fogor is formed under sufficient water supply at the seed-sowing rate of 80 thousand seeds/ha.

Study on multidimensional frost heave characteristics and thermal-hydro-mechanical predictive model

The multi-dimensional estimation of frost heave deformation is crucial for predicting soil deformation and the pressure generated during the freezing process. This study offers a comprehensive review and analysis of frost heave characteristics in the heat flow direction and the transverse direction to it. Based on the frost heave test results, an innovative method for calculating the anisotropic parameter has been introduced. This method includes only two parameters: one reflects the more pronounced characteristic of frost heave in the direction of heat flow, and the other represents the sensitivity of anisotropic parameters to constraint stress. Through comparative analysis with experimental results, this method can effectively express the evolution of the anisotropic frost heave with changes of the confining stress in different directions. Then, a combined thermal-hydraulic-mechanical coupling model is established, offering a way of applying the improved model. The coupling model can predict significant frost heave under conditions of sufficient water supply and effectively captures the frost heave characteristics under various temperature and stress boundary conditions. This research contributes significantly to predicting frost heave deformation in low-temperature natural gas pipelines and calculating the frozen soil pressure exerted on the pipelines.

Application of GIS to monitor the impact of urbanization on surface water quality in Kim Dong district, Hung Yen province, Vietnam

Rapid urbanization profoundly affects surface water quality in lower-income countries, often extending pressure on resources beyond urban areas. This study assesses the impact of urbanization on surface water quality in Kim Dong district, highlighting its broader implications for the Red River Delta. The demands of urban systems significantly strain natural resources, notably water, impacting both human consumption and environmental sustainability. With a focus on less developed regions where water infrastructure may be limited, ensuring sufficient water supply as these areas grow presents a complex challenge. The economic and population growth in Kim Dong district has heightened water demand in recent years. Despite ample water sources, Kim Dong district is facing surface water pollution, leading to shortages for domestic, agricultural, and industrial use. This study aims to evaluate surface water quality using the Water Quality Index (WQI) and examine urbanization’s impact, employing GIS to map pollution loads across communes. Results of the study reveal significant water quality deterioration, notably in areas with high population density and industrial concentration, causing severe pollutant loads in rivers. Hierarchical Cluster Analysis (HCA) and Discriminant Analysis (DA) was utilized to classify communes into three distinct clusters based on pollutant loads, emphasizing Luong Bang town and adjacent communes as high-load areas. The study demonstrates a strong positive correlation between population density and pollutant loads, indicating the profound impact of urbanization on water quality. Our research calls for strict monitoring of discharge sources, especially from industries and residential areas, emphasizing compliance with environmental regulations. It recommends regular drainage system maintenance, comprehensive environmental assessments for future development plans, and consistent efforts to mitigate urbanization’s adverse effects on surface water in Kim Dong district. These measures aim to sustainably manage water resources and safeguard environmental integrity amidst rapid urbanization.

Water Use Strategies and Shoot and Root Traits of High-Yielding Winter Wheat Cultivars under Different Water Supply Conditions

Drought is the most important factor limiting winter wheat yield in the North China Plain (NCP). Choosing high-yielding cultivars is an important measure to minimize the negative effects of drought stress. Field studies were conducted with 10 cultivars in the 2020–2022 seasons under three irrigation treatments (I0, without irrigation; I1, irrigated at jointing stage; I2, irrigated at jointing and anthesis stages) in the NCP to examine the water use strategies and root and shoot traits of high-yielding cultivars under different water supply conditions. The results showed that yield variation among cultivars was 21.2–24.6%, 23.7–25.9% and 11.6–15.3% for the I0, I1 and I2 treatments, respectively. Under water deficit conditions (I0 and I1), high-yielding cultivars reduced water use during vegetative stages and increased soil water use during reproductive stages, especially water use from deeper soil layers. Those cultivars with higher root length density (RLD) in deep soil layers exhibited higher water uptake. Each additional millimeter of water used after anthesis from the 100–200 cm soil layers increased grain yield by 23.6–29.6 kg/ha and 16.4–28.5 kg/ha under I0 and I1, respectively. This water use strategy enhanced dry matter accumulation after anthesis, decreased canopy temperature (CT) and increased relative leaf water contents (RLWC), which ultimately improved grain yield. For winter wheat grown under I2, cultivars that decreased water use after anthesis had higher water productivity (WP). Root length (RL), root weight (RW) and root:shoot ratio were each negatively correlated with grain yield, while above-ground biomass was positively correlated with grain yield. Therefore, higher dry matter accumulation and smaller root systems are two important traits of high-yielding cultivars under sufficient water supply conditions (I2) in the NCP.

A CMIP6 multi-model based analysis of potential climate change effects on watershed runoff using SWAT model: A case study of kunhar river basin, Pakistan

The hydrological regimes of watersheds might be drastically altered by climate change, a majority of Pakistan's watersheds are experiencing problems with water quality and quantity as a result precipitation changes and temperature, necessitating evaluation and alterations to management strategies. In this study, the regional water security in northern Pakistan is examined about anthropogenic climate change on runoff in the Kunhar River Basin (KRB), a typical river in northern Pakistan using Soil and Water Assessment tool (SWAT) and flow durarion curve (FDC). Nine general circulation models (GCMs) were successfully utilized following bias correction under two latest IPCC shared socioeconomic pathways (SSPs) emission scenarios. Correlation coefficients (R2), Nash-Sutcliffe efficiency coefficients (NSE), and the Percent Bias (PBIAS) are all above 0.75. The conclusions demonstrate that the SWAT model precisely simulates the runoff process in the KRB on monthly and daily timescales. For the two emission scenarios of SSP2-4.5 and SSP5-8.5, the mean annual precipitation is predicted to rise by 3.08 % and 5.86 %, respectively, compared to the 1980–2015 baseline. The forecasted rise in mean daily high temperatures is expected to range from 2.08 °C to 3.07 °C, while the anticipated increase in mean daily low temperatures is projected to fall within the range of 2.09 °C–3.39 °C, spanning the years 2020–2099. Under the two SSPs scenarios, annual runoff is estimated to increase by 5.47 % and 7.60 % due to climate change during the same period. Future socioeconomic growth will be supported by a sufficient water supply made possible by the rise in runoff. However, because of climate change, there is a greater possibility of flooding because of increases in both rainfall and runoff. As a result, flood control and development plans for KRB must consider the climate change's possible effects. There is a chance that the peak flow will move backwards relative to the baseline.

Optimization of the selection of suitable harvesting periods for medicinal plants: taking Dendrobium officinale as an example

BackgroundDendrobium officinale is a medicinal plant with high commercial value. The Dendrobium officinale market in Yunnan is affected by the standardization of medicinal material quality control and the increase in market demand, mainly due to the inappropriate harvest time, which puts it under increasing resource pressure. In this study, considering the high polysaccharide content of Dendrobium leaves and its contribution to today’s medical industry, (Fourier Transform Infrared Spectrometer) FTIR combined with chemometrics was used to combine the yields of both stem and leaf parts of Dendrobium officinale to identify the different harvesting periods and to predict the dry matter content for the selection of the optimal harvesting period.ResultsThe Three-dimensional correlation spectroscopy (3DCOS) images of Dendrobium stems to build a (Split-Attention Networks) ResNet model can identify different harvesting periods 100%, which is 90% faster than (Support Vector Machine) SVM, and provides a scientific basis for modeling a large number of samples. The (Partial Least Squares Regression) PLSR model based on MSC preprocessing can predict the dry matter content of Dendrobium stems with Factor = 7, RMSE = 0.47, R2 = 0.99, RPD = 8.79; the PLSR model based on SG preprocessing can predict the dry matter content of Dendrobium leaves with Factor = 9, RMSE = 0.2, R2 = 0.99, RPD = 9.55.ConclusionsThese results show that the ResNet model possesses a fast and accurate recognition ability, and at the same time can provide a scientific basis for the processing of a large number of sample data; the PLSR model with MSC and SG preprocessing can predict the dry matter content of Dendrobium stems and leaves, respectively; The suitable harvesting period for D. officinale is from November to April of the following year, with the best harvesting period being December. During this period, it is necessary to ensure sufficient water supply between 7:00 and 10:00 every day and to provide a certain degree of light blocking between 14:00 and 17:00.

A contactless 3D Janus evaporator with superhydrophobic core and superhydrophilic shell for efficient desalination and water purification

Solar interfacial evaporation is a low-cost strategy for desalination and water purification. However, for most evaporators, the coplanar configuration of light absorption and water evaporation results in a confined evaporation surface and salt deposition problems. Here, a contactless 3D Janus evaporator (Ag-NSP@BFP) with a core/shell structure is designed by wrapping Ag nanoparticles (Ag-NPs) decorated nickel sponge (Ag-NSP) using bamboo fiber paper (BFP). The superhydrophobic Ag-NSP core (absorber) achieves highly efficient light absorption and photothermal conversion. Meanwhile, the superhydrophilic BFP shell not only provides a larger evaporation area (side surfaces as evaporation surfaces) but also forms a 2D water channel to ensure sufficient water supply. Furthermore, polystyrene foam (EPS) isolates photothermal material from bulk water, minimizing heat transmission losses dramatically. The 3D Janus evaporator increases the evaporation area and harvests energy from the ambient environment, achieving an evaporation rate of up to 2.77 kg m−2h−1 and an energy conversion efficiency of 105.2%. Moreover, the Janus structure effectively inhibits salt accumulation on the photothermal surface and exhibits a good purification effect on wastewater containing dyes and heavy metal ions. Thus, combining a 3D evaporator with Janus structure to achieve efficient salt-resistant evaporation provides a new design idea for stable seawater desalination and wastewater purification.

Development and Application of Technical Key Performance Indicators (KPIs) for Smart Water Cities (SWCs) Global Standards and Certification Schemes

Smart water cities (SWCs) use advanced technologies for efficient management and preservation of the urban water cycle, strengthening sustainability and improving the quality of life of the residents. This research aims to develop measurement and evaluation tools for SWC key performance indicators (KPIs), focusing on innovative water technologies in establishing unified global standards and certification schemes. The KPIs are categorized based on the stage at which water is being measured, namely the urban water cycle, water disaster management and water supply and treatment. The objective is to assess cities’ use of technologies in providing sufficient water supply, monitoring water quality, strengthening disaster resilience and maintaining and preserving the urban water ecosystem. The assessment is composed of a variety of procedures performed in a quantitative and qualitative manner, the details of which are presented in this study. The developed SWC KPI measurements are used to evaluate the urban water management practices for Busan Eco Delta City, located in Busan, South Korea. Evaluation processes were presented and established, serving as the guideline basis for certification in analyzing future cities, providing integrated and comprehensive information on the status of their urban water system, gathering new techniques, and proposing solutions for smarter measures.

Where is the source? Water sources for non-resident students at the University of Kabianga, Kenya

The immense increase in residential developments around universities to provide private accommodation for the rapidly growing population of university students has constrained providing a safe, clean, and sufficient water supply. The Kenyan Constitution protects everyone`s fundamental right to access adequate water. However, the reality for non-resident students at the University of Kabianga (UoK) is far from their entitlements by the Kenyan Constitution. This project aims at establishing the sources of water available for non-resident students of the UoK. To achieve this, the study employed an exploratory approach that employed a descriptive survey. Its target population was the non-resident students (673 students) of the UoK, from whom a sample size of 250 students was selected. Simple random sampling was used in selecting the participants, while purposive random sampling was utilized to choose the study's private hostels (15 Hostels). The tools for data collection included questionnaires, key informant interviews, and an observation guide. The collected data was analyzed using SPSS to generate descriptive statistics. Findings obtained from the study revealed that most respondents (68%) relied on rainwater during the rainy season. However, most students (46%) relied on wells/boreholes, while 44% relied on private vendors during the dry season. In addition, majority of the respondents (61%), the available sources of water were not safe for drinking. In terms of challenged faced by the respondents in accessing water, time wastage while trying to access water was stated to be the main challenge (78%) as this highly affected their studies. Taken together, the study show that the water sources are unreliable, and this may not satisfy the demands of water in the area. The findings of this study will provide a basis for the provision of a sustainable water supply of adequate quality to non-resident students` hostels at the University of Kabianga and inform the stakeholders of appropriate measures that should be put in place to ensure adequate water supply to their tenants.

Rock and ice avalanche-generated catastrophic debris flow at Chamoli, 7 February 2021: New insights from the geomorphic perspective

Within mountainous landscapes neighboring glaciers, slope instabilities and consequent catastrophic mass flows are vital processes on Earth's surface, which have been of increasing interest for decades. These events commonly exhibit large volume, high velocity, and high mobility. Recently, a catastrophic debris flow occurred in India on 7 February 2021, which unfortunately claimed 70 lives and left 134 people missing. The failed mass comprises 80 % rock debris and 20 % glacier ice. Our remote sedimentological investigation of remnant deposition shows clear evidence of wet granular flow in upper Ronti Gad valley, which doesn't support the previous interpretation of immediate melting of the failed 20 % ice mass during the falling and impacting process. We further utilized the superelevation phenomenon to back-calculate the velocity downstream of the impact zone, and estimated the peak discharge, which is verified by field-documented data. Our results revealed an initial waning trend of rock and ice mass flow. As it entered the narrow valley of the lower Ronti Gad River, the extensive material erosion resulted in three-fold flow enlargement, which gave rise to a maximal peak discharge of up to 48–54 × 104 m3/s. The transition from granular flow to debris flow occurred in the 2-km-long channel downstream of the Ronti Gad-Rishigangga confluence. The sediment deposition of 4.8 × 104 m3 and the incorporation of stream water in this zone have dominated the rheologic transition. We inferred that the intense erosion of erodible sediment due to topographic constraint plays an essential role in maintaining the mobility of the flow. Therefore, the effect of glacier ice meltwater on high mobility may be overestimated. As long as the granular flow can access the stream water in major rivers, flow transformation can easily happen because of sufficient water supply in the channel. The valley morphology in the proglacial region is commonly featured by the shift from an upstream U-shaped valley carved by glacier erosion into a downstream fluvial-erosion-dominated V-shaped valley. This geomorphic setting of glaciated tributary favors the long-distance run-out of rock and ice avalanche.

Hyperspectral imaging reveals small-scale water gradients in apple leaves due to minimal cuticle perforation by Venturia inaequalis conidiophores.

Effects of Venturia inaequalis on water relations of apple leaves were studied under controlled conditions without limitation of water supply to elucidate their impact on the non-haustorial biotrophy of this pathogen. Leaf water relations, namely leaf water content and transpiration, were spatially resolved by hyperspectral imaging and thermography; non-imaging techniques-gravimetry, a pressure chamber, and porometry-were used for calibration and validation. Reduced stomatal transpiration 3-4 d after inoculation coincided with a transient increase of water potential. Perforation of the plant cuticle by protruding conidiophores subsequently increased cuticular transpiration even before visible symptoms occurred. With sufficient water supply, cuticular transpiration remained at elevated levels for several weeks. Infections did not affect the leaf water content before scab lesions became visible. Only hyperspectral imaging was suitable to demonstrate that a decreased leaf water content was strictly limited to sites of emerging conidiophores and that cuticle porosity increased with sporulation. Microscopy confirmed marginal cuticle injury; although perforated, it tightly surrounded the base of conidiophores throughout sporulation and restricted water loss. The role of sustained redirection of water flow to the pathogen's hyphae in the subcuticular space above epidermal cells, to facilitate the acquisition and uptake of nutrients by V. inaequalis, is discussed.

Design of a Novel Chaotic Horse Herd Optimizer and Application to MPPT for Optimal Performance of Stand-Alone Solar PV Water Pumping Systems

A significant part of agricultural farms in the Kingdom of Saudi Arabia (KSA) are in off-grid sites where there is a lack of sufficient water supply despite its availability from groundwater resources in several regions of the country. Since abundant agricultural production is mainly dependent on water, farmers are forced to pump water using diesel generators. This investigation deals with the increase in the effectiveness of a solar photovoltaic water pumping system (SPVWPS). It investigated, from a distinct perspective, the nonlinear behavior of photovoltaic modules that affects the induction motor-pump because of the repeated transitions between the current and the voltage. A new chaotic Horse Herd Optimization (CHHO)-based Maximum Power Point Tracking technique (MPPT) is proposed. This algorithm integrates the capabilities of chaotic search methods to solve the model with a boost converter to maximize power harvest while managing the nonlinear and unpredictable dynamical loads. The analytical modeling for the proposed SPVWPS components and the implemented control strategies of the optimal duty cycle of the DC–DC chopper duty cycle and the Direct Torque Control (DTC) of the Induction Motor (IM) has been conducted. Otherwise, the discussions and evaluations of the proposed model performance in guaranteeing the maximum water flow rate and the operation at MPP of the SPVWPS under partial shading conditions (PSC) and changing weather conditions have been carried out. A comparative study with competitive algorithms was conducted, and the proposed control system’s accuracy and its significant appropriateness to improve the tracking ability for SPVWPS application have been proven in steady and dynamic operating climates and PSC conditions.