Phytoplankton are considered to be one of the most sensitive indicators of the ecological status of lakes. Nowadays, it is essential to recognize the prospects of the molecular approach (eDNA metabarcoding) in phytoplankton community assessments and combine them with the existing traditional microscopy-based morphological approach before its standardization. In this study, the aim was to characterize the phytoplankton community of a natural karstic lake by combining and comparing the morphological and molecular approach to check the applicability of eDNA metabarcoding as a biomonitoring tool. A total of 51 phytoplankton taxa were found using the morphological approach, whilst the molecular approach discovered 97 ASVs that corresponded to the algal community. The comparability of both approaches in describing phytoplankton communities is evident in the designation of centric diatoms, dinoflagellates and cryptophytes as descriptive taxa. Furthermore, both approaches proved reliable in detecting functional groups (Lo, C, X2, X3) with similar ecological demands. Moreover, the results have shown that euphotic zone samples can be reliably exchanged by composite samples to provide an accurate characterization of phytoplankton communities in the euphotic zone. It was confirmed that eDNA metabarcoding is an applicable tool for biodiversity monitoring of a natural karst lake and should be used as a feasible supplement to traditional microscopy in the phytoplankton community assessments, with regards to the drawbacks of each method. Full article

In 2020, Yellow River runoff was more than twice as much as past years, and the proportion of strong winds was also higher than that in past years, which will inevitably lead to a change in salinity plume distribution in the Yellow River Estuary and Laizhou Bay. Based on FVCOM numerical modelling, this paper presents the spatial salinity distribution and dispersion of the Yellow River Estuary and Laizhou Bay during the wet and dry seasons in 2020. We used data from six tidal and current stations and two salinity stations to verify the model, and the results showed that the model can simulate the local hydrodynamic and salinity distribution well. The influence of river discharge and wind speed on salinity diffusion was then investigated. The simulation results showed that under the action of residual currents, fresh water from the Yellow River spread to Laizhou Bay, and the low salinity area of Laizhou Bay was mainly distributed in the northwest. The envelope area of 27 psu isohaline can account for about one-quarter of Laizhou Bay in the wet season, while the low-salinity area was only concentrated near the estuary of Yellow River in the dry season. River discharge mainly affects the diffusion area and depth of fresh water, and wind can change the diffusion structure and direction. In the wet season, with the increase in wind speed, the surface area of the plume decreased gradually, and the direction of the fresh water plume changed counterclockwise from south to north. During the dry season, the plume spread to the northwest along the nearshore. The increase in wind speed in the early stage increased the surface plume area, and the plume area decreased above a wind speed of 10 m/s due to the change in the turbulence structure. The model developed and the results from this study provide valuable information for establishing robust water resource regulations for the Yellow River. This is particularly important to ensure that the areas with low salinity in the Yellow River Estuary will not decrease and affect the reproduction of fish species. Full article

Drought stress is an inevitable factor that disturbs the production of plants by altering morphological, physiological, biochemical, and molecular functions. Breeding for drought tolerance requires a complete understanding of the molecular factors controlling stress-responsive pathways. The plant responds to drought stress by adopting four mechanisms: avoidance, escape, tolerance, and recovery. Traditional plant-breeding tools have been employed to increase tolerance in cotton, but the complexity of drought tolerance has limited the use of these breeding methods. The plant adopts several key strategies against drought stress, such as activating the signaling network and activating molecular factors. Cotton breeders have been engaged in elucidating the molecular mechanisms of drought tolerance in cotton using significant molecular tools such as quantitative trait loci (QTL) mapping, transcription factor (TFs) analysis, transcriptome analysis, genome-wide association studies (GWAS), genetic engineering, and CRISPR/Cas9. Breeders have studied the functional description of genes and the interacting pathways accountable for controlling drought tolerance in cotton. Hundreds of genes/QTL have been identified, and many have been cloned for drought tolerance in cotton; however, a complete understanding of these traits still needs more study. This review presents a detailed overview of molecular tools, their application for improving drought tolerance in cotton, and their prospects. This review will help future researchers to conduct further studies to develop drought-tolerant cotton genotypes that can thrive under conditions of water scarcity. Full article

The most critical issue that was the main research interest is its groundwater quality which is vital for public health concerns. Groundwater is a significant worldwide water supply for diverse communities, especially in dryland regions. Groundwater quality assessment in desert systems is largely hindered by the lack of hydrological data and the remote location of desert Oases. This study provides a preliminary understanding of the influences of climate, land usage, and population growth on the groundwater quality in El-Farafra Oasis in the Western Desert in Egypt from 2000 to now. Therefore, the study’s main objective was to determine the extent of change in temporal water quality and the factors causing it. The present study integrates chemical analyses and geospatial modeling better to assess groundwater quality in the study area. A chemical analysis of thirty-one groundwater samples from wells representing each study area was carried out during three time periods (2000, 2010, and 2022). Several chemical properties of groundwater samples gathered from wells in the research area were analyzed. Furthermore, the groundwater quality trend from 2000 to the present was identified using three approaches: Wilcox and Schoeller Diagram in Aq.QA software, interpolation in the ArcGIS software, and Ground Water Quality Index (GWQI). Moreover, the influence of changing land usage on groundwater quality was studied, and it was found that the increase in agriculture and urbanization areas is linked to groundwater quality degradation. The findings revealed that the barren area in 2000, 2010, and 2022 was 371.7, 362.0, and 343.2 km², respectively, which indicates a substantial decrease of 6.2% within this research timeframe. In contrast, agriculture and human-made structures have expanded by 1.8%. Also, population growth has led to an increase in water consumption as the population has grown at a rate of 7.52% annually from 2000 to 2020. As the climatic condition increases from 2000 to 2022, these changes could extend to the water quality in shallow aquifers with increasing evaporation. Based on the water quality spatial model, it is found that, despite a declining tendency in the rate of precipitation and an expansion in agricultural areas and population growth, the water quality was still appropriate for human and farming consumption in large areas of the study area. The presented approach is applicable to the assessment of groundwater in desert regions in the Middle East area. Full article

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Many issues with water quality and water ecology are caused by the Xinghai Lake’s enormous catchment, significant evaporation rates, and one additional water supply. To quantitatively study Xinghai Lake’s water displacement characteristics, a two-dimensional hydrodynamic-tracer coupling model based on MIKE21 was developed. The findings indicate that: (1) Xinghai Lake’s water replacement cycle exhibits spatial heterogeneity, with a general characteristic of fast water renewal in the southern lake area and slow renewal in the northern lake area, and the gradient change of the water replacement cycle from south to north is influenced by a variety of factors, including the lake’s flow field, flow, topography, and wind field. (2) The throughput flow has an impact on the majority of the waters in Xinghai Lake. When there is a high water flow, the lake region has a high flow velocity, rapid water transport, and a large capacity for water exchange; when there is a low water flow, the lake area has a slow flow velocity, poor water flow, and a lengthy water exchange period. (3) The flow field of Xinghai Lake is complicated, the flow velocity is low, and it is a lake system where quick water exchange and slow water exchange coexist. This flow field is influenced by the interplay of wind-generated flow and throughput flow. (4) To speed up the water body’s rejuvenation, the Xinghai Lake wetland needs more inlets and exits to introduce new water sources. Full article

The lower Athabasca River (Canada) has experienced notable declines in streamflow and increasing oil sands development since the 1970s. This study investigates the potential impacts of climate change on navigability using both observed historical and projected future flows derived via hydrological simulations driven by an ensemble of statistically downscaled general circulation model climate data. Our use of proposed indices that form the Aboriginal Navigation Index (ANI) and a new index based on percentage over threshold (POT) occurrences yielded novel insights into anticipated changes to the flow regime. Comparisons of near (2041–2070) and far (2071–2100) future periods with the historical baseline (1981–2010) yielded results that project significant reductions in the 500 m³ s⁻¹ POT during the fall navigability period spanning weeks 34 to 43, as well as reductions in the integrated ANI_Fall. These results indicate that challenging navigational conditions may become more frequent in the second half of the 21st century, not only during this fall period but also earlier into the summer, due to a shift in the flow regime, with potentially severe impacts on the users of the river channels. Our assessment approach is transferable to other regional study areas and should be considered in water management and environmental flow frameworks. Full article

We analysed a 24 cm long sediment sequence (past ~200 years) from an alpine lake (Tatra Mts., Slovakia) for chironomids, cladocerans, and diatoms to reconstruct the effects of a historically documented fish introduction. Our results indicate that fish introduction predated the age of the sequence, and thus, we did not cover the lake’s fishless period. The individual proxies coincide in showing two main lake development stages. The first stage lasted until ~1950 CE and was interpreted as the stage when brown trout and alpine bullhead co-occurred. The extremely low concentration of cladocerans, the dominance of small-bodied chydorids, and the low share of daphnids, together with the low proportion/absence of large-bodied tanypod chironomids, suggest a strong effect of both species. The beginning of the next stage is probably related to the ban on fish manipulations and grazing in the catchment. A significant increase in the total abundance of cladocerans and of daphnids may indicate the extirpation of trout. The steep increase in thermally plastic chironomid taxa since the end of the 20th century indicates climate warming. Generally, while cladocerans primarily indicate fish manipulations, chironomids and diatoms mainly reflect other local and global environmental stressors. Full article

River flooding has been triggering significant damage to lives and infrastructure and is a major worry all around the globe. To lessen these losses, proper planning and management methods need to be deployed. The purpose of this research is to fill a knowledge gap on the effects of reservoirs operation of the Idukki and Idamalyar to Periyar River Basin massive flooding. The proposed methodology is implemented on the Periyar River Basin located in Kerala, India, where severe flooding occurred during monsoon season in the year 2018. In this study, modelling technique has been used in two-step: (1) development of 1D physically based, distributed-parameter model (Soil and Water Assessment Tool, SWAT) to compute the stream flow and estimate the stream discharge at different outlet points; and (2) hybrid model is developed by linking SWAT with a well-known 2D hydrodynamic model (International River Interface Cooperative, iRIC) to display flood scenarios and to identify the flood-prone areas. The ArcSWAT user interface employed in the ArcGIS software was utilized to delineate the river basin. The SWAT model was calibrated and validated on daily and monthly basis at two gauge discharge stations, i.e., Neeleeswaram and Kalady. The statistical coefficients result obtained from SWAT model was in good agreement with the measured values for calibration and validation. The hybrid model simulation results compared with observed flood depth and remote sensing data demonstrated good capability of the model. Agreeable performances of computed results were observed in both flow fields and flood propagations. The result was compared with 2018 flood to check model accuracy and found to be satisfactory. The proposed framework can be utilized as an effective tool for efficient planning and management of natural disasters, such as flash floods. Full article

The pursuit of low-cost, high-efficiency co-catalysts that are free of noble metals has become an area of considerable interest in the field of photocatalysis over the past few years. In this work, a series of cobalt phosphide (CoP 0.125–1.00 wt.%)-promoted bismuth vanadate (BiVO₄) photocatalysts was synthesized and physicochemical characterized by means of X-Ray diffraction, nitrogen isotherm absorption diffuse-reflectance spectroscopy, and high-resolution transmission electron microscopy. The efficiency of the as prepared photocatalytic materials was investigated for sulfamethoxazole (SMX) destruction in ultrapure water under simulated solar light irradiation. Results showed that the deposition of small amounts (0.50 wt.%) of CoP on BiVO₄ enhances SMX degradation. Moreover, SMX removal increased by increasing 0.50 CoP/BiVO₄ loading (up to 1 g/L) and decreasing SMX loading (1000–250 μg/L). Further tests were carried out in real and synthetic matrices, such as wastewater secondary effluent and bottled water, revealing the existence of hindering effects on SMX removal. The efficiency of 0.50 CoP/BiVO₄ photocatalyst was further investigated in a pilot plant configuration where the examined system was able to remove >99% of 300 μg/L SMX in deionized water utilizing 80 kJ/L of solar irradiation. Full article

Interpretations of integrated water cycle management (IWCM) differ across jurisdictions. This paper discusses 10 interpretations of the IWCM concept globally, in Australia and in jurisdictions similar to Australia. Five interpretations of many IWCM versions in Australia are reviewed. This strategic concept aims to address the internal challenges of managing water demand and supply, achieving appropriate disposal and/or wastewater recycling for re-use and distribution networks and providing services at an affordable rate, per changing community needs. The IWCM concept is also recognised as a resource planning tool to address external challenges, such as the uncertainties of climate change, the circular economy and resilience. All 10 IWCM concepts reviewed in this paper acknowledge governance and stakeholders to be of primary importance: governance to drive the conceptual interpretation and stakeholders to develop, drive, implement and promote IWCM as adept at addressing local challenges. The two global interpretations place primary importance on governance, stakeholder engagement and natural resource management, whereas the local interpretations place equally high importance on water critical infrastructure and water economy. Technology, which is changing at an unprecedented pace, is considered, but not as an immediate or primary challenge. These differences are mainly attributed to the organisations’ responsibilities and constraints, which drive IWCM concept design. Full article

A four-day glacier-melt flood (13–16 August 2013) caused abrupt geomorphic changes in the proglacial gravel-bed Scott River, which drains the small (10 km²) Scott Glacier catchment (SW Svalbard). This type of flood occurs on Svalbard increasingly during periods of abnormally warm or rainy weather in summer or early autumn, and the probability of occurrence grows in direct proportion to the increase in temperature and/or precipitation intensity. In the summer of 2013, during the measurement season, the highest daily precipitation (17 mm) occurred on 13 August. During the following four days, it constituted in total 47 mm, i.e., 50% of the precipitation total for the measurement period of 2013. The largest flood in 20 years was caused by high precipitation with a synchronous rise in temperature from about 1.0 to 8.6 °C. These values exceeded multi-year averages (32 mm and 5.0 °C, respectively) at an average discharge of 0.9 m³/s (melt season mean 1986–2011). These conditions caused a rapid and abrupt response of the river with the dominant (90%) glacier-fed. The increase in discharge to 4.6 m³/s, initiated by the glacial flood, mobilized significant amounts of sediment in the river bed and channel. Geomorphic changes within the alluvial fan as an area of 58,940 m², located at the mouth of the Scott River, were detected by multi-sites terrestrial laser scanning using a Leica Scan Station C10 and then estimated using Geomorphic Change Detection (GCD) software. The changes found involved 39% of the alluvial fan area (23,231 m²). The flood-induced total area of lowering (erosion) covered 26% of the alluvial fan (6035 m²), resulting in the removal of 1183 ± 121 m³ of sediment volume. During the final phase of the flood, two times more sediment (1919 ± 344 m³) was re-deposited within the alluvial fan surface, causing significant aggradation on 74% of its area (17,196 m²). These geomorphic changes resulted in an average lowering (erosion) of the alluvial fan surface of 0.2 m and an average rising (deposition) of 0.1 m. Full article

Regular water environment monitoring is crucial for minimizing contamination caused by waterborne viruses and reducing health risks. As the human adenovirus (HAdV) is linked to clinical episodes of gastroenteritis in children, the present investigation aimed to detect HAdVs in three wastewater treatment plants in Riyadh, Saudi Arabia (King Saud University (KSU-WWTP), Manfoha (MN-WWTP), and Embassy Quarter (EMB-WWTP)). The impact of seasonal variability and meteorological factors on the prevalence of HAdVs was also investigated. The HAdV hexon sequences of the isolated human adenoviruses were phylogenetically analyzed and revealed that the F species of HAdV, especially serotype 41, dominated. The highest prevalence of HAdV was detected in KSU-WWTP (83.3%), followed by MN-WWTP (75%), and EMB-WWTP (66.6%). Seasonal distribution insignificantly influenced the HAdV prevalence among sampling areas (p > 0.05). The highest prevalence of HAdVs (100%) was detected in late Summer and Autumn at temperatures (high: 34–43 °C, low: 18–32 °C) and moderate prevalence of 66.67% in Winter (particularly, in January and February) at lower temperature ranges (high: 26 °C, low: 10 °C–12 °C). The large variation of HAdV prevalence detected at different humidity ranges emphasized the significant impact of relative humidity on HAdV incidence in raw water of WWTPs (p = 0.009, R² = 0.419). In contrast, wind speed was detected to have insignificant influence on HAdV prevalence among different WWTPs (p > 0.05, R² = 0.03). The study provides important data for the incidence of HAdVs in wastewater treatments plants in Riyadh, Saudi Arabia, which enabled the successful management of health hazards of viral diseases transmitted via fecal-oral route. In addition, the non-significant influence of seasonal variability on HAdV prevalence highlights the potentiality of utilizing HAdVs as a potential fecal indicator of wastewater contamination. Full article

In the last few decades, the Mekong Delta coastlines have suffered serious erosion. Strong waves during the Northeast Monsoon are one of the main reasons for this. Many types of breakwaters with different structural components have been designed and built to mitigate coastline erosion. Vertical seawalls have been widely used, but they create reflection waves, which can generate water particle kinematics in front of the structure and increase the toe scour. In this study, an innovative block of inclined and porous breakwaters was studied by conducting laboratory-scale experiments. The experimental results show that inclined and porous breakwaters can considerably reduce wave energy due to transmission, reflection, and diffraction compared to inclined breakwaters. The porosity on the front and back sides of the structures has also been studied. Letting sediment-laden seawaters penetrate inside the sheltered zones, porous breakwaters promote accretion and facilitate the forestation of mangrove belts. Full article

Flow motion with complex patterns, such as vortex, stagnant flow, and seepage, put forward higher spatial resolution requirements for particle image velocimetry (PIV). With the development of deep learning technology in optical flow estimation, many attempts have been made to introduce deep learning-based optical flow (DLOF) into PIV. Compared with the traditional optical flow method, the DLOF method has the advantages of higher precision, faster calculation speed, and avoiding manual parameter adjustment. However, DLOF research is generally developed based on the basic characteristics of rigid body motion, and its key loss function part still generally uses the L1 (mean absolute error, MAE, L1) or L2 (mean square error, MSE, L2) loss functions, which lack consideration of fluid motion characteristics. Therefore, the current DLOF research has the problems of large angular error and serious curl-divergence loss in fluid motion estimation scenarios with smaller spatial scales than rigid bodies. Based on the prior knowledge of the traditional fluid motion characteristics, this study proposes a fluid loss function for describing the fluid motion characteristics, and combines this loss function with Flownet2. The compound loss (CL) function is combined with the displacement error, angular error, and div-curl smooth loss. The method combined with the loss function in this paper is called FlowNet2-CL-PIV. In order to verify that the compound loss function proposed in this study has a positive impact on the model training results, this paper uses the cosine similarity measure to demonstrate its effectiveness. In addition, the parameter selection of the compound loss function is analyzed and compared, and it is verified that the best training effect can be achieved by adjusting the parameter so that the order of magnitude of each part of the compound loss function is consistent. In order to test the calculation effect of the Flownet2-CL-PIV method proposed in this study, synthetic particle images are used for model training and performance analysis. Simulation results in various flow fields show that the root mean square error (RMSE) and average angular error (AAE) of Flownet2-CL-PIV reach 0.182 pixels and 1.7°, which are 10% and 54% higher than the original model, respectively. Full article