With the continuous increase in the amount of mulch film, “white pollution” caused by plastic fragments (PF) has seriously affected agricultural production progress and poses a great threat to the safety and health of the agricultural environment. In the present study, PFs collected from 20 mulched agricultural farmlands in Sichuan Province were investigated. The PFs were separated and screened following the density flotation method. Optical microscopy was used to assess the fragments’ distribution, abundance, color, size, and morphology, and Raman spectroscopy was used to identify the types. In addition, through the analysis of a questionnaire survey, a random forest (RF) model was conducted to assess the effects of environmental factors on the amount of PF. The results showed that the abundance of PFs was the highest in Lade Town, Zigong City, reaching 1158.33 ± 52.04 particles kg⁻¹. Meanwhile, PFs were less abundant in Foyin Town, Luzhou City, with 50.00 ± 25.00 particles kg⁻¹; the morphology features of PF in the cultivated soil were mainly transparent (60.06%) and flaky-like (83.41%), with sizes < 5 mm (63.61%). In total, 75% of the representative PFs were PE PFs, while PVC PFs were 25%. The RF model indicated that there were significant effects due to the total mulch film amount, annual precipitation, and planting pattern on the number of derived residues (PF). This study provides data indicating the urgent need to prevent and control plastic pollution in mulch farming, specifically in the soils of Sichuan Province. Full article

The Itacaiúnas River basin, an important watershed for the mining sector in Brazil, has had 51% of its native forest area deforested in the last forty years. It is in the arc of deforestation of the Amazon. It has protected areas essential to local biodiversity maintenance, in addition to owning ore reserves. Here, we present the first study to assess the mean annual, seasonal, and spatialized hydrological processes, providing results on a detailed scale in the basin, including mining sites. We used five future projections of mean monthly temperature and daily precipitation as input to the MGB hydrological model to simulate how hydrological processes, such as evapotranspiration, water availability, and high flows, may change in the next 30 years. The future decrease in precipitation (−8%) and increase in temperature (10%) may strengthen the monsoon seasonal cycle and lengthen the dry month for evapotranspiration. Furthermore, some parts of the basin expect an increase in the high flows (8.1%) and a decrease in water availability (−93.6%). These results provide subsidies to develop adaptation strategies to ensure the viability of mining operations and safeguard the surrounding environment and communities. Full article

Since the beginning of the 1980s, several regions in the northern Sahara of Algeria have been confronting the rising groundwater. Among all these regions, Oued Souf Valley represented one of the most acute affected by this phenomenon. Due to the natural topography and the insufficient/weakness of water management and miscoordination between different sectors that are represented by intensive exploitation of deep groundwater reservoirs which returns to the shallow aquifer, absence of sewage and drainage network, leakage from drinking water supply system, the groundwater has raised to the surface or near to the surface, affecting the traditional cultural environment and urban areas and degrading all socio-economic aspects of the Oued Souf habitants. To preserve the Oued Souf environment, a vertical drainage system has been constructed. Consequently, in this research, an evaluation of the vertical drainage system performance and its impact on groundwater level stabilization has been performed by mapping the water table of the phreatic groundwater level using geostatistical modeling using ordinary kriging (OK) interpolation method, which has been applied to analyze the spatial and temporal structure of groundwater level fluctuation. Meanwhile, hierarchical cluster analysis (HCA) was applied for grouping the wells based on the groundwater fluctuations for 2008, 2009, 2014, 2016, 2018, and 2021. However, the vertical drainage system reflected a significant decline of groundwater from 2009 to 2018 due to the important drained volumes through it but another rising phenomenon might be threatening the region in the near future and this is what was indicated in the 2021 groundwater level data. Cluster analysis has generated four groups based on their fluctuation means that are increasing from the first group to the fourth group ascendingly. The first cluster grouped the drains that have a shallow depth (average mean of 5.91 mbgl) and declined over the clusters. The clusters are spatially combined with significant separation of the fourth cluster which represents the deepest group (12.89 mbgl). Based on this research, several factors are influencing the stability of the phreatic groundwater level and even the performance of the drainage system, the most important of which is the overexploitation from deep groundwater reservoirs such as complex terminal and continental intercalary (in drinking and irrigation) and even the illegal use of the phreatic groundwater with important quantities for irrigation and illegal industries. Full article

The implementation of natural parks in cities is a current and controversial theme. Therefore, in Lake Buritis, which is a leisure area for the population of the city of Goiatuba, Goiás, Brazil, the quality of the water was analyzed, carrying out quantitative tests of the water samples at six different points between the source and the outlet of the lake that flows into the stream, Chico À Toa. Physical–chemical tests (turbidity, pH, alkalinity, electrical conductivity, color, nitrate and hardness parameters), microbiological tests for species identification, analysis of the antimicrobial susceptibility profile, metals analysis and Allium cepa test, were performed. The total coliforms number in water samples was higher than the maximum value established by Brazilian legislation, demonstrating high fecal contamination during the spring in samples from an artesian well. The bacterial diversity found was large and there were many pathogenic bacteria. The A. cepa test demonstrated a cytotoxic potential for water from the source and outlet of Buritis Lake. Statistical tests were applied to verify existing correlations between parameters. Among the analyzed data, the highest correlation was between the color and turbidity parameters and the grouping between the metals (lead, iron, cadmium and magnesium). Full article

Many rivers in semiarid areas have ecological degradation and flood control problems that need to be addressed urgently. In order to maintain river health and to promote the sustainable development of cities near these rivers, a comprehensive river regulation project must be carried out. In this study, first, the factors influencing river health are discussed, and the principles and main restrictions involved in comprehensive regulations are studied. The scientific regulation mode is proposed, and new financing channels for water conservancy construction are also suggested. Second, a river reach adjacent to a city in the middle part of the Luanhe River in North China is used as a case study. The health status of the river is analyzed, and a comprehensive river regulation plan combined with urban development is put forward on this basis. The plan includes embankment construction, river regulations, multilevel rubber dam storage, ecological restoration, and artificial lake and riverside landscape construction. The influence of the engineering treatment on the river flood discharge capacity is examined, and the treatment effect is verified by a hydraulic scale model. After implementation of the comprehensive river regulations, the flood control safety of the city and river ecological environment are found to be significantly improved, with the hidden danger of dust storms eliminated. The treatment project incurs environmental, social, and economic benefits and preliminarily achieves the coordination and mutual promotion of river regulation and urban development. Full article

In phosphate buffer, the degradation of ATZ by ozone/(O₃/H₂O₂) under various circumstance was explored and the degradation mechanism and dynamics were probed. The findings revealed that when maintaining the reaction temperature at 25 °C, the H₂O₂ concentration and the O₃ concentration were 20 mol/L and 20 mol/L, respectively. Moreover, the degradation rate of 5 mol/L ATZ under the influence of O₃/H₂O₂ was 92.59% in phosphate buffer at pH7. The mechanism analysis showed that HO• and O₃ underwent co-oxidized degradation and that the HO• and O₃ oxidation degradation ratios were close to 1:1 under acidic conditions. Furthermore, HO• oxidative degradation dominated the ATZ degradation process. The kinetics analysis showed that the ATZ kinetics of O₃/H₂O₂ degradation were more compatible with quasi-second-order reaction kinetics under different temperatures, pH values, and H₂O₂ concentrations. Full article

First, this paper presents a thorough review of water quality data using a rainwater tank, categorizing the data as with and without sedimentation. Data are presented showing minimum, maximum, and mean values for the different parameters. The data measured from several sources reveal that water collected from the tank is much better than the water directly collected from the roof. In addition, to analyse the phenomena through a mathematical model, a hypothetical 5 kL rainwater tank with a 200 m² roof was modelled with the MUSIC model. The simulations were compared with the measured water quality data from a rainwater tank in Melbourne. In general, we found that MUSIC’s simulations on the mean daily concentrations of total suspended solids (TSS) and total phosphorus (TP) are slight underestimations compared to the measured data from Melbourne. Further MUSIC simulations reveal that significant reductions in the daily maximum concentrations of TSS, TP, and total nitrogen (TN) are expected through a rainwater tank. Full article

The use of integrated anaerobic-aerobic bioreactor (IAAB) to treat the Palm Oil Mill Effluent (POME) showed promising results, which successfully overcome the limitation of a large space that is needed in the conventional method. The understanding of synergism between anaerobic digestion and aerobic process is required to achieve maximum biogas production and COD removal. Hence, this work presents the use of artificial neural network (ANN) to predict the COD removal (%), purity of methane (%), and methane yield (LCH₄/gCOD_removed) of anaerobic digestion and COD removal (%), biochemical oxygen demand (BOD) removal (%), and total suspended solid (TSS) removal (%) of aerobic process in a pre-commercialized IAAB located at Negeri Sembilan, Malaysia. MATLAB R2019b was used to develop the two ANN models. Bayesian regularization backpropagation (BR) showed the best performance among the 12 training algorithms. The trained ANN models showed high accuracy (R2 > 0.997) and demonstrated good alignment with the industrial data obtained from the pre-commercialized IAAB over a 6-month period. The developed ANN model is subsequently used to create the optimal operating conditions which maximize the output parameters. The COD removal (%) was improved by 33.9% (from 68.7% to 92%), while the methane yield was improved by 13.4% (from 0.23 LCH₄/gCOD_removed to 0.26 LCH₄/gCOD_removed). Sensitivity analysis shows that COD inlet is the most influential input parameters that affect the methane yield, anaerobic COD, BOD and TSS removals, while for aerobic process, COD removal is most affected by mixed liquor suspended solids (MLSS). The trained ANN model can be utilized as a decision support system (DSS) for operators to predict the behavior of the IAAB system and solve the problems of instability and inconsistent biogas production in the anaerobic digestion process. This is of utmost importance for the successful commercialization of this IAAB technology. Additional input parameters such as the mixing time, reaction time, nutrients (ammonium nitrogen and total phosphorus) and concentration of microorganisms could be considered for the improvement of the ANN model. Full article

Kazakhstan, a former Soviet republic that is now independent, lies near the center of arid Eurasia. Its sparse hydrographic network includes a small number of large rivers, lakes, and reservoirs, many ponds and smaller streams, as well as littoral zones bordering the Caspian Sea and the Aral Sea. A diverse fisheries sector, initially based on wild fish capture and later including aquaculture, developed in these waters during the Soviet era, when animal agriculture was unable to meet the protein needs of Soviet citizens. The sector, which was originally centered on the Volga–Caspian basin, was tightly managed by Moscow and benefitted from coordinated investments in research, infrastructure, and human resources, as well as policies to increase the consumption of fish products. Independence in 1991 administered a political and economic shock that disrupted these relationships. Kazakhstan’s wild fish harvests plummeted by more than two-thirds, and aquaculture collapsed to just 3% of its previous level. Per capita consumption of fish products also declined, as did processing capacity. Favorable recent policies to define fishing rights, incentivize investments, prevent illegal fishing, and make stocking more effective have helped to reverse these trends and stabilize the sector. Continued recovery will require additional steps to manage water resources sustainably, prioritize the use of water for fish habitats, and minimize the effects of climate change. This comprehensive assessment of Kazakhstan’s fisheries sector over the past century provides the basis to understand how long-term dynamic interactions of the environment with the political economy influence fisheries in Eurasia’s largest country. Full article

Per- and polyfluoroalkyl substances (PFAS) are omnipresent synthetic chemicals. Due to their industrial importance and widespread use as a key component in various applications and a variety of products, these compounds can be found today in high concentrations (>1 μg/L) in surface and groundwater but also spread throughout the ecosystem, where they represent a serious threat to most living organisms. The removal or degradation of PFAS contaminants from water and soil is becoming a legal obligation in a growing number of countries around the globe. This, however, demands novel techniques for the degradation of PFAS since conventional water treatment techniques are either insufficient or extremely expensive due to the persistent nature of these compounds caused by their extraordinary chemical stability. The goal of this work was therefore to investigate the practical potential of the application-oriented use of atmospheric non-thermal plasma as a powerful advanced oxidation method for the purification of water contaminated with PFAS compounds. Special attention was devoted to the development of the concept that can be scaled up to the capacity level of approximately 100–200 m³ of water per hour, contaminated with PFAS and other contaminants including organic and inorganic material generally present in soil, and surface or groundwater. Our major research interest was to define the minimum required treatment time for optimal purification results, as well as to understand the influence of the initial concentration of PFAS in water and the potential presence of co-contaminants often present in situ on the efficiency of the degradation process. A chemical analysis of the treated samples demonstrated the ability of the atmospheric plasma to reduce more than 50% of the initial PFAS amount in the water samples in less than 300 s of treatment time. PFOA, however, showed more rigidity towards degradation, where a double treatment time was needed to reach similar degradation levels. The obtained results showed that the initial concentration level does not play a major role in the process. However, the PFAS degradation profiles for all tested concentrations show a strongly nonlinear behavior with time, characterized by the fast decrease of the process efficiency in the case of longer treatment times. For prolonged treatment times, a constant increase in the samples’ conductivity was measured, which might be the limiting factor for the degradation rate in the case of prolonged treatment times. Full article

More frequent and more intense heat waves and greater drought stress will occur in the future climate environment. Short-term extreme heat and drought stress often occur simultaneously after winter wheat anthesis, which has become the major constraint threatening future wheat yield. In this study, short-term heat, drought and their combination stress were applied to wheat plants after anthesis, and all wheat plants were restored to the outdoor normal temperature and full watering after stress treatment. The aim of the current study was to evaluate the role of nitrogen (N) in modulating the effects of post-anthesis short-term heat, drought and their combination stress on photosynthesis, N metabolism-related enzymes, the accumulation of N and protein and growth, as well as on the yield and water (WUE) and N use efficiency (NUE) of wheat after stress treatment. The results showed that compared with low N application (N1), medium application (N2) enhanced the activities of nitrate reductase (NR) and glutamine synthase (GS) in grains under post-anthesis heat and drought stress alone, which provided a basis for the accumulation of N and protein in grains at the later stage of growth. Under post-anthesis individual stresses, N2 or high application (N3) increased the leaf photosynthetic rate (A_n), PSII photochemical efficiency and instantaneous WUE compared with N1, whereas these parameters were usually significantly improved by N1 application under post-anthesis combined stress. The positive effect of increased A_n by N application on growth was well represented in a higher green leaf area, aboveground dry mass and plant height, and the variation in A_n can be explained more accurately by the N content per unit leaf area. Short-term heat, drought and combined stress after anthesis resulted in a pronounced decrease in yield by reducing grain number per spike and thousand kernel weight. The reduction in NUE under combined stress was higher than that under individual heat and drought stress. Compared with N1, N2 or N3 application significantly prevented the decrease in yield and NUE caused by post-anthesis heat and drought stress alone. However, N1 application was conducive to improving the productivity, WUE and NUE of wheat when exposed to post-anthesis combined stress. The current data indicated that under short-term individual heat and drought stress after anthesis, appropriately increasing N application effectively improved the growth and physiological activity of wheat compared with N1, alleviating the reduction in yield, WUE and NUE. However, under combined stress conditions, reducing N application (N1) may be a suitable strategy to compensate for the decrease in yield, WUE and NUE. Full article

This study assessed the performance of two well-known gridded meteorological datasets, CFSR (Climate Forecast System Reanalysis) and CMADS (China Meteorological Assimilation Driving Datasets), and three satellite-based precipitation datasets, TRMM (Tropical Rainfall Measuring Mission), CMORPH (Climate Prediction Center morphing technique), and CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data), in driving the SWAT (Soil and Water Assessment Tool) model for streamflow simulation in the Fengle watershed in the middle–lower Yangtze Plain, China. Eighteen model scenarios were generated by forcing the SWAT model with different combinations of three meteorological datasets and six precipitation datasets. Our results showed that (1) the three satellite-based precipitation datasets (i.e., TRMM, CMORPH, and CHIRPS) generally provided more accurate precipitation estimates than CFSR and CMADS. CFSR and CMADS agreed fairly well with the gauged measurements in maximum temperature, minimum temperature, and relative humidity, but large discrepancies existed for the solar radiation and wind speed. (2) The impact of precipitation data on simulated streamflow was much larger than that of other meteorological variables. Satisfactory simulations were achieved using the CMORPH precipitation data for daily streamflow simulation and the TRMM and CHIRPS precipitation data for monthly streamflow simulation. This suggests that different precipitation datasets can be used for optimal simulations at different temporal scales. Full article

A unique approach has been developed for explaining and forecasting the processes of flood and/or mudflow (debris) formation and their spread along riverbeds in mountainous areas, caused by flash increases in the water masses involved (considerably increasing in their expected level because of precipitation intensity) due to groundwater contributions. Three-dimensional crack-nets within the confines of unified rivershed basins in mountain massifs are a natural transportation system (as determined by some dynamic external stress factors) for groundwater, owing to hydrostatic/hydrodynamic pressure distribution, varied due to different reasons (e.g., earthquakes). This process reveals a wave nature characterized by signs of obvious self-organization, and can be described via the soliton model in nonlinear hydrodynamics on the surface propagation after a local exit of groundwater as the trigger type. This approach (and related concepts) might result in a more reliable forecasting and early warning system in case of natural water hazards/disasters, taking into account a groundwater-dominant role in some cases. Full article

In South Australia’s Eyre Peninsula, groundwater provides 85% of the region’s reticulated water supply. Fresh groundwater resides within shallow karstic limestone aquifers recharged by incident rainfall. Water levels are very responsive to short-term climate variability and are at risk of sustained decline due to long-term drying trends and the further rainfall declines indicated by projections of future climate, thereby increasing risk to water security and groundwater-dependent ecosystems. In 2009, a new adaptive resource management approach was enabled through legislative reform that better addresses climate variability, particularly where aquifer robustness is low. This allows the volume of water available for licensed allocations to be varied annually depending on the current condition of the aquifer resources. A three-tiered trigger level policy varies the rate at which water allocations are limited in proportion to monitored changes in groundwater storage. The three trigger thresholds are specified for each discrete groundwater resource, based on levels of risk. We now have more than five years of observations and practice of this approach to learn of its efficacy and consequences for water users, the water resources, and the environment. It has proved to be an effective way to deal with the uncertainties in how and when climate may change and how water management principles can effectively respond. Our case study provides an example of the importance of legislative reform to enable adaptive water resource management to effectively tackle the challenges of water planning in a drying climate. Full article

The Late Archaic Period (2600–1600 BC) site of Caral, located ~20 km inland from the Pacific Ocean coastline in the Supe Valley of the north central coast of Peru, is subject to CFD analysis to determine the effects of ENSO (El Niño Southern Oscillation) events (mainly, El Niño flooding and drought events) on its agricultural and marine resource base that threatened societal continuity. The first step is to examine relics of major flood events that produced coastal beach ridges composed of deposited flood slurries—the C14 dating of material within beach ridges determines the approximate dates of major flood events. Of interest is the interaction of flood slurry with oceanic currents that produce a linear beach ridge as these events are controlled by fluid mechanics principles. CFD analysis provides the basis for beach ridge geometric linear shape. Concurrent with beach ridge formation from major flood events are landscape changes that affect the agricultural field system and marine resource food supply base of Caral and its satellite sites- here a large beach ridge can block river drainage, raise the groundwater level and, together with aeolian sand transfer from exposed beach flats, convert previously productive agricultural lands into swamps and marshes. One major flood event in ~1600 BC rendered coastal agricultural zones ineffective due to landscape erosion/deposition events together with altering the marine resource base from flood deposition over shellfish gathering and sardine and anchovy netting areas, the net result being that prior agricultural areas shifted to limited-size, inner valley bottomland areas. Agriculture, then supplied by highland sierra amuna reservoir water, led to a high water table supplemented by Supe River water to support agriculture. Later ENSO floods conveyed thin saturated bottomland soils and slurries to coastal areas to further reduce the agricultural base of Supe Valley sites. With the reduction in the inner valley agricultural area from continued flood events, agriculture, on a limited basis, shifted to the plateau area upon which urban Caral and the satellite sites were located. The narrative that follows then provides the basis for the abandonment of Caral and its satellite Supe Valley sites due to the vulnerability of the limited food-supply base subject to major ENSO events. Full article