Surface Water Accumulation Research Articles

A Study on the Water Management Knowledge of Traditional Villages from the Perspective of Stormwater Resilience—A Case Study of Changqi Ancient Village in Guangdong, China

With the advancement of resilience concepts, enhancing resilience capacity has become an effective approach to addressing rainwater and flooding issues. Most rural planning and construction efforts adopt urban planning models from economically developed regions, often leading to surface hardening, which subsequently causes drainage difficulties and severe surface water accumulation during the rainy season. In contrast, traditional Lingnan villages, exemplified by Guangdong’s Changqi Ancient Village, continue to function normally in flood-prone areas, suggesting that their water management knowledge merits investigation. Previous research on rainwater management in traditional Chinese villages has predominantly been qualitative, lacking scientific data support. This study employs an eco-social resilience perspective, combining field surveys and interviews with villagers, and utilizes the SWMM (Storm Water Management Model) software to conduct both qualitative and quantitative analyses of Changqi Ancient Village. The findings reveal the following: (1) The SWMM effectively quantifies rainwater and flood management in traditional villages. (2) From an ecological resilience perspective, the village’s geographical location is crucial. The topography, along with a rainwater regulation system comprising rivers, ponds, ditches, and permeable pavements, significantly influences the village’s drainage performance. (3) From a social resilience perspective, community participation is vital to the long-term stable development of traditional villages. This includes post-disaster collective fundraising by villagers for the restoration of rainwater and flood management facilities, the formulation of village regulations, and the construction and restoration of spiritual sites. (4) From an eco-social resilience perspective, the eco-social resilience system exhibits adaptive cyclical characteristics, where the geographical environment and the local economy significantly shape the ecological spatial patterns of Changqi, while positive interaction between nature and human society ensures the system’s dynamic equilibrium.

Space-time analysis, severity of the wilt disease in escabeche pepper (Capsicum baccatum var. Pendulum) and identification of the causal agent (Phytophthora capsici L.) under subtropical climate conditions in Peru

Phytophthora capsici is an aggressive pathogen in escabeche pepper on the Peruvian coast. Root rot has a strong correlation with humidity and environment. Disease behavior was evaluated epidemiologically using spatiotemporal variables. Severity was evaluated according to the advance of the secondary symptom according to grades 1 to 5. Then, coordinates of each plant were established by photogrammetric survey of a field with 1705 escabeche pepper plants. For temporal analysis, severity was adjusted to an exponential model (R2 = 0.909) and incidence to a Gompertz model (R2 = 0.921) that detected an initial delay of the disease due to temperature. For the spatial analysis, the Global Moran Index (Ii) showed a high spatial dependence of the disease reaching a peak of 0.4 and 0.7 for severity and incidence, respectively. Also, heat maps related to the Local Ii were generated from which an initial source of infestation was determined where the furrow irrigation started in random infestations. Then, the infestation spots were settled in areas of surface water accumulation. Also, rhizosphere samples were collected per plant by degree of severity on V8 or CMA whit PARB and PDA-A selective medium. As a result, significant differences were obtained between grade 1, grade 2, 3, 4 and grade 5. In addition, the effect on yield was significant for plants with grade 4 and 5 with respect to fruit weight (22.3 and 18.5g/fruit) and weight per plant (509.5 and 371.8g/plant), respectively.

Deformation-Adapted Spatial Domain Filtering Algorithm for UAV Mining Subsidence Monitoring

Underground coal mining induces surface subsidence, leading to disasters such as damage to buildings and infrastructure, landslides, and surface water accumulation. Preventing and controlling disasters in subsidence areas and reutilizing land depend on understanding subsidence regularity and obtaining surface subsidence monitoring data. These data are crucial for the reutilization of regional land resources and disaster prevention and control. Subsidence hazards are also a key constraint to mine development. Recently, with the rapid advancement of UAV technology, the use of UAV photogrammetry for surface subsidence monitoring has become a significant trend in this field. The periodic imagery data quickly acquired by UAV are used to construct DEM through point cloud filtering. Then, surface subsidence information is obtained by differencing DEM from different periods. However, due to the accuracy limitations inherent in UAV photogrammetry, the subsidence data obtained through this method are characterized by errors, making it challenging to achieve high-precision ground surface subsidence monitoring. Therefore, this paper proposes a spatial domain filtering algorithm for UAV photogrammetry combined with surface deformation caused by coal mining based on the surface subsidence induced by coal mining and combined with the characteristics of the surface change. This algorithm significantly reduces random error in the differential DEM, achieving high-precision ground subsidence monitoring using UAV. Simulation and field test results show that the surface subsidence elevation errors obtained in the simulation tests are reduced by more than 50% compared to conventional methods. In field tests, this method reduced surface subsidence elevation errors by 39%. The monitoring error for surface subsidence was as low as 8 mm compared to leveling survey data. This method offers a new technical pathway for high-precision surface subsidence monitoring in mining areas using UAV photogrammetry.

Extraction of vegetation disturbance range using aboveground biomass estimated from Sentinel-2 imagery in coal mining areas with high groundwater table.

Coal mining in regions characterized by high groundwater table markedly predisposes to surface subsidence and water accumulation, thereby engendering substantial harm to surface vegetation, soil, and hydrological resources. Developing effective methods to extract surface disturbance information aids in quantitatively assessing the comprehensive impacts of coal mining on land, ecology, and society. Due to the shortcomings of traditional indicators in reflecting mining disturbance, vegetation aboveground biomass (AGB) is introduced as the primary indicator for extracting the mining disturbance range. Taking the Huaibei Coal Base as an example, Sentinel-2 MSI imagery is firstly used to calculate spectral factors and vegetation indices. Multiple machine learning algorithms are coupled to perform remote sensing estimation and spatial inversion of vegetation AGB based on measured samples of vegetation AGB. Secondly, an Orientation Distance-AGB (OD-AGB) curve is constructed outward from the center of subsidence water areas (SWA), with the Boltzmann function used for curve fitting. According to the location of the inflection point of the curve, the boundary points of vegetation disturbance are identified, and then the disturbance range is divided. The results show that (1) the TV-SVM model, utilizing total variables and support vector machine, achieves the highest estimation accuracy, with σMAE and σRMSE values of 208.47g/m2 and 290.19g/m2, respectively, for the validation set. (2) Thirty-six effective disturbance areas, totaling 29.89 km2, are identified; the Boltzmann function provides a good fit for the OD-AGB curve, with an R2 exceeding 0.8 for typical disturbance areas. (3) Analysis of general statistical laws indicates that disturbance distance conforms to the general characteristics of normal distribution, exhibiting boundedness and directional heterogeneity. The research is expected to provide scientific guidance for hierarchical zoning management, land reclamation, and ecological restoration in coal mining areas with high groundwater table.

APPLICATION OF PERMEABLE ASPHALT PAVEMENT CONSTRUCTION IN TRAFFIC AREAS

Lithuania’s total road network consists of more than 84000 km of roads, of which more than 21000 km are national roads. Roads of national importance are managed by the Lithuanian Road Administration. The remaining roads are classified as local roads managed by local governments. Road installation and maintenance often lead to the problem of surface water drainage and accumulation on the road surface. The aim of this study is to identify and propose the most appropriate permeable asphalt pavement construction to solve this problem, taking into account the purpose of the application and the class of pavement structure. The scope of the study identifies three recommended permeable asphalt pavement designs for the installation of DK 0.1-DK 1 pavement structures in ancillary streets, parking and recreation areas where light vehicle traffic with occasional heavy vehicle traffic. It has also been found that in areas of high traffic intensity, it is appropriate to use an alternative to permeable pavements – a permeable pavement design for the shoulder, where the roadway structure is impermeable to water and the shoulders are permeable to water (a permeable pavement structure is installed). The recommended permeable asphalt pavement structures, when properly selected, reduce the risk of flooding on the roadway.

Evaluation of Skid Resistance and Comfort of Pedestrian Pavement with Asphalt-Based Wood Chip

This paper conducts an in-depth study and evaluation of pedestrian paths, with a particular focus on the anti-slip performance and walking comfort of wooden chip pedestrian walkways. Through controlled experiments, a comparative analysis was performed between wooden chip pedestrian walkways and ordinary paved brick walkways. The experimental results indicate that under dry conditions, the anti-slip performance of various road surfaces is good. However, in wet environments, the anti-slip performance of paved brick roads deteriorates significantly. In contrast, wooden chip pedestrian walkways, especially those mixed with asphalt and wood chips, exhibit excellent anti-slip properties and comfort. Additionally, the study reveals that the comfort of wooden chip pedestrian walkways is significantly better than that of paved brick walkways, and the comfort of asphalt materials is slightly better than emulsified asphalt. It is worth mentioning that fine wood chips provide less comfort than coarse wood chips. Although reducing the thickness can enhance comfort, considering the service life of the road, a thickness of 4–6 cm is most suitable. Finally, asphalt and wooden chip mixtures with coarse wood chips possess good water permeability, making them suitable for permeable drainage pavement designs, effectively reducing road surface water accumulation.

Simulation and Management Impact Evaluation of Debris Flow in Dashiling Gully Based on FLO-2D Modeling

Dashiling Gully, located in Miyun District, Beijing, exhibits a high susceptibility to debris flow due to its unique geological and topographical characteristics. The area is characterized by well-developed rock joints and fissures, intense weathering, a steep gradient, and a constricted gully morphology. These factors contribute to the accumulation of surface water and loose sediment, significantly increasing the risk of debris flow events. Following a comprehensive field geological investigation of Dashiling Gully, key parameters for simulation were obtained, including fluid weight, volume concentration, and rainfall. The formation and development conditions of potential mudslides were analyzed, and numerical simulations were conducted using FLO-2D software (version 2009) to assess scenarios with rainfall probabilities of 1 in 30, 50, and 100 years. The simulations accurately reconstructed the movement velocity, deposition depth, and other critical movement characteristics of mudslides under each rainfall scenario. Using ArcGIS, pre- and post-treatment hazard zoning maps were generated for Dashiling Gully. Furthermore, the efficacy of implementing a retaining wall as a mitigation measure was evaluated through additional numerical simulations. The results indicated that mudslide velocities ranged from 0 to 3 m/s, with deposition depths primarily between 0 and 3 m. The maximum recorded velocity reached 3.5 m/s, corresponding to a peak deposition depth of 4.31 m. Following the implementation of the retaining wall, the maximum deposition depth significantly decreased to 1.9 m, and high-risk zones were eliminated, demonstrating the intervention’s effectiveness. This study provides a rigorous evaluation of mudslide movement characteristics and the impact of mitigation measures within Dashiling Gully. The findings offer valuable insights and serve as a reference for forecasting and mitigating similar mudslide events triggered by heavy rainfall in gully mudslides.

Susceptibility to Flooding and Urban Flooding in Small Municipalities: Hydrogeomorphological, Land Use and Land Cover Aspects in a Multi-Criterion Analysis

Objective: To investigate areas susceptible to flooding and inundation, testing the hypothesis that the accumulation of surface water does not depend exclusively on fluvial flood pulses. Theoretical Framework: Anthropogenic actions have played a significant role in modifying natural physiography, especially through urbanization and occupation of environmentally sensitive areas. These interventions have a direct impact on the dynamics of natural processes, highlighting the need to understand local hydrogeomorphology in order to ensure efficient territorial planning. Methodology: The research comprised a multi-criteria analysis involving hydrological, geomorphological, land use and occupation data associated with precipitation data for a small municipality. This municipality has urban development in the area of influence of a main river in its catchment area. Results and Discussion: Around 52% of the municipality is urbanized with 95% on slopes ranging from 0 to 23º, upstream of a cumulative flow of 18,000. Rainfall is 1366 mm/year and tends to decrease, although there has been a 62% increase in flooding in recent years. Around 75% of the urbanized area is vulnerable to pluvial flooding, while the rest is subject to both pluvial flooding and fluvial flood pulses. Research Implications: Insights into how the results can influence urban planning practices, extending to the fields of hydrogeomorphology and land use and occupation management. Originality/Value: The methodology is simple and accessible to small municipalities and urban planning entrepreneurs. Its relevance is evidenced by the fact that it improves urban planning, minimizing socio-economic and environmental costs.

Artificial Groundwater Replenishment in the Republic of Kalmykia: The Sources, Problems, and Perspectives

The Republic of Kalmykia is located in the northwestern part of the Caspian Region and belongs to arid regions. The issue of water resources availability is extremely relevant here. Groundwater plays an important role in this aspect as a main and often the only source of drinking water supply. However, its use is limited because of its low natural quality. An approach to an increase in the operational groundwater reserves is its artificial replenishment. The Russian Research Institute for Integrated Use and Protection of Water Resources in 2020–2021 studied the possibility of replenishing water resources of subsurface water bodies in the Republic of Kalmykia by the accumulation of surface water. The results of the studies suggested a conclusion that the artificial replenishment of groundwater in the territory of the Republic of Kalmykia is inexpedient, because even in years with the surface runoff volume with 50% exceedance probability, the volume of surface runoff will be not enough for freshening groundwater within a year to the standard level (TDS ≤1.0 g/dm3). The formation of a permanent freshwater lens (the presence of which is of particular importance in dry years) in an aquifer within the system including infiltration basin and water well is impossible because its full drawdown will take place every year.

Protected areas for surface water accumulation from a hydrogeologist’s the point of view – the effect of possible realization of surface water accumulation on hydrogeological conditions

Protected areas for surface water accumulation from a hydrogeologist’s the point of view – the effect of possible realization of surface water accumulation on hydrogeological conditions

Determinants of exposure to Aedes mosquitoes: A comprehensive geospatial analysis in peri-urban Cambodia

Aedes mosquitoes are some of the most important and globally expansive vectors of disease. Public health efforts are largely focused on prevention of human-vector contact. A range of entomological indices are used to measure risk of disease, though with conflicting results (i.e. larval or adult abundance does not always predict risk of disease). There is a growing interest in the development and use of biomarkers for exposure to mosquito saliva, including for Aedes spp, as a proxy for disease risk. In this study, we conduct a comprehensive geostatistical analysis of exposure to Aedes mosquito bites among a pediatric cohort in a peri‑urban setting endemic to dengue, Zika, and chikungunya viruses. We use demographic, household, and environmental variables (the flooding index (NFI), land type, and proximity to a river) in a Bayesian geostatistical model to predict areas of exposure to Aedes aegypti bites. We found that hotspots of exposure to Ae. aegypti salivary gland extract (SGE) were relatively small (< 500 m and sometimes < 250 m) and stable across the two-year study period. Age was negatively associated with antibody responses to Ae. aegypti SGE. Those living in agricultural settings had lower antibody responses than those living in urban settings, whereas those living near recent surface water accumulation were more likely to have higher antibody responses. Finally, we incorporated measures of larval and adult density in our geostatistical models and found that they did not show associations with antibody responses to Ae. aegypti SGE after controlling for other covariates in the model. Our results indicate that targeted house- or neighborhood-focused interventions may be appropriate for vector control in this setting. Further, demographic and environmental factors more capably predicted exposure to Ae. aegypti mosquitoes than commonly used entomological indices.

Behavior and welfare impacts of water provision via misting in commercial Pekin ducks.

Ducks will access water to maintain feather condition and exhibit natural water-related behaviors such as wet preening. Providing water to ducks commercially is challenging as it may reduce litter and air quality leading to higher duck mortality or illness. This research aimed to measure the behavioral and welfare impacts of water provision via a misting system for commercial Pekin grower ducks in Victoria, Australia. Seven grower flocks were observed (four misted and three nonmisted in open-sided sheds) during May and November 2021. From 26 until 33 d of age, treatment ducks were provided 1 h of misting with shed curtains closed in both treatment and control sheds. At the start and end of the misting application period, external health and welfare measures were taken directly on the ducks via transect walks throughout each shed and catch-and-inspect observations on a sample of 150 ducks from each shed. Video recordings were also made of the misted and nonmisted ducks for 3 h representing time periods prior to, during, and after the 1-h misting across all sheds for all 8 d of the treatment period. Observations were made of all behavior that ducks exhibited at 10-min scan sample intervals across four cameras per shed, totaling 4,198 scans across the seven sheds. General linear mixed models showed the misting application predominantly had impacts on the patterns of behavioral change across the treatment time periods between the misted and nonmisted ducks rather than increasing or decreasing the overall expression of specific behaviors (interaction terms all P ≤ 0.003). The misted ducks increased drinking, tail wagging, and walking, and reduced preening, rooting litter, sitting, and stretching during misting relative to what they showed prior. The nonmisted ducks showed less sitting and more panting during misting relative to prior. Pearson's Chi-square tests showed some differences between the treatment groups in feather cleanliness on the back and wings (both P < 0.0001), likely resulting from pre-existing differences between sheds in blood from pin feathers. Most welfare indicators showed no positive or negative effect of the misting treatment. These results indicate overhead misting does affect duck behavior to some degree without compromising their welfare, but further research with larger water droplet sizes resulting in greater accumulation of surface water or extended durations of misting may lead to greater effects.

Spatial assessment of accelerated surface runoff and water accumulation potential areas using AHP and data-driven GIS-based approach: the case of Ilorin metropolis, Nigeria

This study assesses and maps accelerated surface runoff and water accumulation hazards in the Ilorin metropolis (Nigeria), using topographic and climatic variables that control accelerated surface runoff and water accumulation. Regarding the accelerated runoff, profile curvature, tangential curvature, drainage density, slope length (L-S) factor, convergence index, catchment shape, land use, and rainfall data were utilized. For the water accumulation process, surface slope, topographic wetness index, drainage density, convergence index, elevation, and altitude above channel were considered together with rainfall and land use. In each case, criteria weights were computed using Multi-Criteria Decision Analysis (MCDA) technique and subsequently integrated into the GIS environment to generate the accelerated surface runoff and inundation hazard maps applying weighted overlay operation. The final map showed that about 35.07 km2 (8%) and approximately 56.55 km2 (14%) of the study area are identified as very high- and highly prone to accelerated surface runoff, respectively. Correspondingly, around 79.89 km2 (18%) and 122.02 km2 (∼28%) belong to the very high and high-water accumulation potential areas, respectively. In summary, it is estimated that about 36% of the water accumulation potential area falls in the densely populated urbanized zones, compared to the accelerated runoff potential detected in undeveloped areas. This implies that there is a higher risk of flooding in the study area than accelerated runoff. However, since the runoff effect occurred mostly in agricultural areas, there is a need for a detailed investigation of this on crop production. Although this study applied a very simple approach, it yielded a high accuracy map (87.5%) which provides useful information for decision-makers to stimulate effective land use planning, alleviate flood occurrence, and reduce soil degradation.

Efficient monolithic MnOx catalyst prepared by heat treatment for ozone decomposition.

The effects of calcined temperature on the properties and ozone decomposition activity of manganese oxide catalysts were investigated under high-humidity, low ozone conditions. An outstanding manganese-based catalyst (MnOx (260 ℃)) was prepared, which could decompose above 90% (RH = 0%) and 70% (RH = 90%) ozone after 6h using. Specific characterization showed MnOx (260 ℃) had excellent properties. XRD results showed MnOx (260 ℃) was mainly Mn3O4 and partially MnO2. TEM indicated MnOx (260 ℃) exposed highly active crystal family plan MnO2 (110), and the lattice fringes of MnO2 (110) and Mn3O4 (103) overlapped. In situ DRIFT showed hydroxyl groups adsorbed on MnOx (260 ℃) were removed, which is beneficial to inhibiting the inactivation caused by surface water accumulation. O2-TPD results proven MnOx (260 ℃) had good oxygen migration ability. XPS results manifested that MnOx (260 ℃) had the most adsorbed oxygen. In short, when the calcination temperature is appropriate, MnOx (260 ℃) has coexisted multiple phases, exposed high active crystal family plan and removed surface hydroxyl, which is conducive to the exposure of oxygen vacancies and the inhibition of deactivation.

Physico-Chemical and Isotopic (&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;O, &amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;H and &amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;H) Characterization of the Upper Dallol Maouri Watershed (Niger)

Dallol Maouri is one of the fossil valleys on the left bank of the Niger River. Its watershed drains water from valleys in the Tahoua and Dosso regions of Niger. The watercourse is not continuous and has areas of surface water accumulation (ponds) and areas of spreading and infiltration. The surface water potential in this area is limited, with most of the ponds having a temporary to the semi-permanent regime. Groundwater resources are, therefore, the main sources of withdrawal for human food, agriculture, and livestock. Climate change through the variation in rainfall, the often-anarchic multiplication of catchment works (wells and boreholes) and agricultural activities can have impacts on the qualitative and quantitative evolution of surface and groundwater. The objective of this study is to characterize the surface and underground water of the upper dallol Maouri through the physicochemical parameters of the water and the use of the isotopes of the water molecule (18O, 2H and 3H). A total of 53 water samples were analyzed at the laboratory of the Regional Directorate of Hydraulics and Sanitation of Tillabéri (Niger) for chemical parameters and 73 samples were analyzed at the Radio Analysis and Environment Laboratory (LRAE) of the National School of Engineers of Sfax (ENIS) of Tunis for isotopy. The water of the ponds is characterized by three types of facies: calcium bicarbonate, calcium and magnesium bicarbonate, and calcium nitrate chloride. The groundwater is 75% of the chloride-nitrate-calcium facies and the CT3/CT2 groundwater is calcium and magnesium bicarbonate. The results of the stable isotopes made it possible to highlight the presence of four distinct water groups: ponds characterized by highly evaporated water, the sheets of Continental Terminal 1 and 2 (CT1 and CT2) with an isotopic cachet of old water, the water table consisting of a two-layer system in the southwestern part of the area. The water is not very mineralized (40 μS to 600 μS) and is slightly acidic (pH = 6.4). The analysis of the radioactive isotope (3H) content of the water from the water table has made it possible to identify the areas of recharge of the water table. These results also highlight: the presence of an upward drainage zone, and the contribution of lowland ponds to the recharge of alluvial aquifers ranging from 24% to 84%. No structure in this zone reaches the Continental Intercalaire and the Continental Hamadien, the depth of which is estimated at an average of 600 m. The relationship between the 18O and 3H contents of groundwater water shows two types of water with tritium contents higher than 2 TU for alluvial aquifers and tritium contents lower than 2 TU for groundwater (CT3). The analysis of the radioactive isotope (3H) contents of the groundwater has made it possible to identify recent recharges at the level of the alluvial aquifers and in the outcrop zone of CT3. There is no hydraulic continuity between the plateau ponds and groundwater.

Multi-dimensional dynamic simulation of rainstorm waterlogging in urban communities

One major threat to cities at present is the increasing rainstorm waterlogging hazards due to climate change and accelerated urbanization. This paper explores the mechanism of rainstorm waterlogging and enables the fine simulation of surface water propagation over complex urban terrain. A novel community-scale waterlogging modeling scheme is presented by loosely coupling a one-dimensional sewer model with a two-dimensional overland model under an open-source framework. The coupled model was applied to Waigaoqiao Free Trade Zone located in Pudong New Area of Shanghai. To quantify the influence of rainfall intensity and drainage conditions on the waterlogging, 12 scenarios were constructed by combining four rainfall return periods (3, 5, 10, and 20 a) and three startup water depths (1.5, 2.0, and 2.5 m) of pump stations. The multi-scenario simulation results show that the waterlogging risk increases from north to south in the study area, and that risk zones with water depth above 0.3 m are mostly concentrated in the southwest and southeast corners of the site. The longer the rainfall return period, the larger the submerged area, and the spatial distribution of surface water accumulation is affected by local topography and drainage system. In addition, reducing the startup water depth of pump stations has an obvious effect on inhibiting the severity of water accumulation. The results provide insights into overland flow across an urban area with densely populated buildings and help to reduce the risk of rainstorm-induced waterlogging disasters.

Basin integrity and temporal-spatial connectivity of the water ecological carrying capacity of the Yellow River

<p indent=0mm>The Yellow River Basin is an important ecological barrier and economic zone in China, and both its ecological conservation and sustainable high-quality development are directly related to the success or failure of the ecological civilization construction of China. Currently, the Yellow River Basin, which is short on water resources, has a fragile natural ecology, and lags in economic and social development, is a key and difficult area for the ecological security and economic and social development of China. This paper summarizes the remarkable achievements in comprehensive prevention and control of soil erosion, such as the implementation of a series of major ecological projects, in the Yellow River Basin since the founding of New China, especially in recent years. These major ecological projects were implemented based on the different characteristics of the upstream, midstream, and downstream regions of the Yellow River Basin. However, the ecological function of the Yellow River Basin has not been fundamentally resolved. This is due to three main reasons. The first is the extent and spatial imbalance in the control of water and soil erosion in the Yellow River Basin watershed. Ecosystem quality has degraded and water conservation has declined in the upper reaches of the Yellow River, soil erosion is serious in the middle reaches, and the ecological flow is low and some estuary wetlands have shrunk in the lower reaches. The second reason is the adverse effect of water and sediment regulation on delta and coastal systems. Vegetation coverage has declined at the source of the Yellow River; there is the desertification of grasslands and the area of secondary bare lands has increased. Some degraded black-soil beaches have undergone secondary degradation and associated disasters have also increased. The third reason includes water and sediment problems caused by large-scale coal mining, such as serious changes in topography and landforms. There is the acceleration of land desertification and water shortages, where the original landforms are destroyed and some vegetation disappears in the upper reaches; the ground collapses and serious soil erosion causes increased sediments to flow into the Yellow River in the middle reaches. Surface subsidence deformation, water accumulation, and secondary salinization lead to a decrease in land productivity in the lower reaches. It is proposed that the key to solving the current outstanding problems restricting ecological protection and high-quality sustainable development of the Yellow River Basin lies in the integrity of the water ecology of the basin, spatial-temporal connectivity and ecosystem health to realize the scientific allocation of water resources in ecology, industry/mining, life, agriculture, and water and sediment regulation in the context of climate warming. To realize this scientific objective, three tasks of research are urgently needed. First, the clarification of the theory and technology of the digital Yellow River information platform, and timely and accurate determination of the river’s status are critical to understand and scientifically develop and manage the Yellow River Basin. Second, water resource monitoring and cloud water resource development and utilization across the entire Yellow River Basin must be carried out, which will require full use of advanced technologies, such as artificial weather modification, rational development and utilization of cloud water resources, the construction of water resource monitoring and cloud water resource development and utilization as soon as possible, and promotion of the effective use of water resources. Finally, identification and prediction of major ecological disaster risks are essential, which requires the integration of space-air-ground stereo observation; big data and machine learning; fusion of 5G, artificial intelligence, the Internet of Things, and other technical methods to establish the intelligent perception and identification of precursors for major disasters; disaster scenario simulation and risk prediction; and disaster risk prevention and control technology systems to enhance risk identification and management capabilities in ecological protection and high-quality sustainable development.

Systematic Triggering of Large Earthquakes by Karst Water Recharge: Statistical Evidence in Northeastern Italy

It is known that surface water accumulation by natural or anthropic causes like precipitation and reservoir impoundment can trigger earthquakes. The phenomenon is amplified and sped up in karst areas, where fracture systems can store large quantities of water and facilitate its percolation to seismogenic depths, increasing both elastic stress and pore pressure on pre-existent faults. The present work explored the possibility that this mechanism had systematically triggered major earthquakes in northeastern Italy, where seismicity is concentrated along the pre-Alpine thrust belt, characterized by the alignment of a series of karst massifs. The time occurrence of damaging and destructive earthquakes (moment magnitude Mw between 4.8 and 6.4) since 1901 was compared with the evolution of the Palmer Drought Severity Index (PDSI), an index of soil moisture that summarizes precipitation and, through temperature, water evaporation. Statistical analysis based on the bivariate Ripley’s K-function shows a significant time correlation between earthquakes and the peaks of PDSI since 1934, with the two strongest earthquakes (1936 Alpago-Cansiglio earthquake and 1976 Friuli earthquake, Mw 6.1 and 6.4, respectively) placed by the two PDSI maxima. The analysis was extended back in time to the last millennium, showing a time correlation between the occurrence of destructive earthquakes (Mw ≥ 6.2) and the peaks of ice extension in the European Alps, assumed as a proxy for groundwater accumulation in the study area. This evidence presented herein coupled with geological characteristics of the area and recent observations on large crustal deformations induced by heavy precipitation suggests that, if PDSI is a valid ground water indicator, karst water recharge may play a role in triggering major earthquakes in northeastern Italy, also relating their occurrence to the large scale climate changes affecting precipitation and evaporation.

Sorption of sulfadiazine and flow modeling in an alluvial deposit of a dry riverbed in the Brazilian semiarid

The Brazilian semiarid region is subjected to irregular rainfall, prolonged droughts, and high temperatures, hampering the surface water accumulation. The water access is restricted to the alluvium in the valleys, which are used for cattle and poultry livestock development. These activities trigger the excessive use of veterinary antibiotics. As a consequence, antibiotics reach sediment surfaces and promote deterioration of groundwater quality. This work aims to evaluate the sorption potential of Sulfadiazine (SDZ) and to understand the dynamics of water transfer and solute transport processes in a typical alluvial deposit of the Capibaribe River, in the Agreste of Pernambuco. The sedimentological characterization was performed by Miall's Code, defining four lithofacies (Scm, Scm,b, Gcm,o, Scm,o). Kinetics and isotherms experiments allowed the analyses of SDZ sorption. Kinetics sorption showed an equilibrium tendency after 40 h and was better described by a second-order model, while isotherm sorption data were better fitted by the Freundlich model. According to the particle size distribution curve, Scm had the highest number of fine particles and organic matter, affecting interaction of SDZ in sediments. Consequently, SDZ sorption was slightly higher in this lithofacies. However, overall, SDZ sorption was low, thereby offering a real risk of groundwater contamination. For further investigation the dynamics of water transfer and solute transport in a heterogeneous alluvial deposit were simulated with the HYDRUS-2D. The structural heterogeneity influenced the spatial distribution of water storage under unsaturated conditions and provided the emergence of preferential flows. The solute dynamic follow a similar behavior of the water flow, due to the low retention of SDZ in the soil. Considering a condition near to saturation, the contrast of hydraulic and transport properties influences simultaneously in the processes of water transfer and solute transport.

Groundwater microbial diversity and antibiotic resistance linked to human population density in Yucatan Peninsula, Mexico.

Microbial community composition in selected karst groundwater sites in the Yucatan Peninsula, Mexico, was assessed to determine the environmental variables influencing groundwater microbial diversity. The karst aquifer system is a groundwater-dependent ecosystem and is the world's second largest underwater karst cave system. The area's geology allows precipitation to infiltrate into the groundwater system and prevents accumulation of surface water; as such, groundwater is the only source of fresh water on the peninsula. The sampling locations consisted of three karst sinkholes that extend through the freshwater zone into the saline water, and an abandoned drinking water well of an ocean-side resort, during the dry and rainy seasons. The analysis showed that highly diverse microbial communities are present in the Yucatan groundwater, sustained by permanently warm temperatures and high nutrient input from human activity. Proximity to densely populated areas, such as tourist resorts, is the most important factor influencing both the diversity and presence of fecal bacteria and the antibiotic resistance profile.