Water Infiltration Research Articles

Mapping the intrinsic potential of water infiltration in urban subsurface: feedback from France

In a context of increasing urbanization, with strong soil sealing, and with an increase in extreme weather events, the management of rainwater in urban areas is becoming a major issue. In order to improve water resource management and to prevent urban floods, more and more cities are considering or already implementing water infiltration systems. Infiltration of water is not possible anywhere due to natural and/or anthropic reasons. In this frame, the intrinsic infiltration capacity of the subsurface is one key natural parameter. Global maps are needed to build territorial strategies. In France, a lot of studies are available but a national methodological framework for mapping this index does not exist. In this paper, we analyse various studies carried out in France for such mapping and compare the methods with examples in other countries. Most of the French studies combine a Multi-Criteria Analysis (MCA) and a Geographic Information System (GIS) spatial analysis. The criteria include geological, hydrogeological and geomorphological parameters. The PHOEBUS method developed on Rennes Metropolis seems the most relevant and replicable one to provide a common framework at French scale. It takes into account 7 criteria, including rock/soil permeability, topographic slope and thickness of the unsaturated zone. The obtained maps may be used as such, modified by integrating sealed surfaces or crossed with other criteria linked to the urban environment (e.g. sealed surfaces, soil pollution, heat islands). They provide a decision support tool for urban planning. In particular, they are useful to improve rainwater management, but also in the elaboration of desealing or renaturation strategies. It seems essential to act in concertation with local stakeholders to identify their needs and the specificities of the territory.

Diagenesis Variation in Different Distributary Channels of Shallow Water Lacustrine Delta Deposits and Implication for High-Quality Reservoir Prediction: A Case Study in the Chang 8 Member in Caijiamiao Area, Sw Ordos Basin, China

Tight oil reservoirs are considered important exploration targets in lacustrine basins. High-quality reservoir prediction is difficult as the reservoirs have complex distributions of depositional facies and diagenesis processes. Previous research has found that the diagenesis process of tight oil sandstones varies greatly in different depositional facies. However, diagenesis variation in different depositional facies is still poorly studied, especially in distributary channels of shallow water delta deposits in lacustrine basins. Based on the description of core samples, the observation of rock slices, the interpretation of well logging data, and the analysis of porosity and permeability data, the differences in the lithofacies types, diagenesis processes, and pore structures of different distributary channels have been clarified. Ultimately, a model of diagenesis and reservoir heterogeneity distribution in the shallow-water delta of Chang 8 Member of the Yanchang Formation in the Caijiamiao area of the Ordos Basin has been established. This research indicates that the main distributary channels in the study area are dominated by massive bedding sandstone lithofacies, while the secondary distributary channels are primarily characterized by cross-bedding sandstone lithofacies. There are significant differences in the compaction, dissolution, and cementation of authigenic chlorite and carbonate among different parts of the distributary channels. Plastic mineral components, such as clay and mica, are abundant in sheet sands, and are more influenced by mechanical and chemical compaction. Influenced by the infiltration of meteoric water and hydrocarbon generation, dissolution pores are relatively well-developed in the underwater distributary channel reservoirs. A large amount of carbonate cementation, such as calcite and siderite, is found within the sandstone at the interface between sand and mud. The occurrence of authigenic chlorite exhibits a clear sedimentary microfacies zonation, but there is little difference in the kaolinite and siliceous cementation among different microfacies reservoirs. Finally, a model of diagenetic differences and reservoir quality distribution within dense sand bodies has been established. This model suggests that high-quality reservoirs are primarily developed in the middle of distributary channels, providing a theoretical basis for the further fine exploration and development of oil and gas in the study area.

A Study of the Cereal Benches Based System for Protection of Soil in Algerian Oued Mellegue Tebessa Dry Lands

The study was intended to mitigate the destructive after-effects of erosion, where runoff water erodes the arable layers through the increased transport of soil particles. The study was conducted in Ain Zerga across 40 plots, covering an area of 405 hectares, during 2023 and 2024, with a focus on the dimensional evaluation of cereal beds. The evaluation mainly focused (a) on the durability of the structure, including the measurement of settlement, which indicates distribution and strength of resistance to climatic hazards, and (b) proportional sustainability and the interbank aspects. The height of benches, at 0.481± 0.086 m, and the length of 82.583 ± 24.203 m were influenced by height differences and the intensity of water flows. The retention of runoff water was influenced by the slope toward the natural spillway. Furthermore, the destructive intensity of the runoff, amplified by the sharp increase in altitude, was confirmed by statistically significant differences in the length, height, and number of cracks between the study sites (p-value = 0.000). The number of cracks per breach at the Gastel site (4.25 units) and Kef Mebdoua (3.917 units) was higher compared to Ain Zerga, Berket Frass, Ouled Mebarek, and Zlassde, where the number ranged from 0.750 to 1.583 units. The statistical significance in the number of cracks (p<0.001) signified that variation in cracks between the locations was due to the topographic steep slopes on site. The non-significant difference in width suggests that the observed differences could be due to the phenomenon of compaction following the annual infiltration of water on the ridges of cereal bench, plus the act of trampling constantly exercised by sheep and cattle herds when passing to the paths. This work proposed in this article is an attempt to structure a chain of impact analysis of risks and vulnerability of intensity via the sustainability of cereal bench carried out in the Tebessa region.

Assessment of Pollution of the Waters in the South Kuril Fishing Zone of Russia by Radioactive Waters from the Fukushima-1 NPP Based on Lagrangian Modeling

The study investigates the potential hazard arising from the actions taken by the Japanese government regarding the discharge of technical radioactive water from the Fukushima-1 nuclear power plant storage facilities. The contamination of the South Kuril Fishing Zone (SKFZ), which is one of the most promising fishing areas for the Russian Federation, with radioactive particles, is considered. Based on the modeling of passive markers simulating radioactive contamination, the study analyzes the pathways and mechanisms of pollution transfer into the SKFZ. The research is conducted using altimetric data on geostrophic currents for the period from August 24, 2022, to August 24, 2023. The pollution transfer into the SKFZ is determined by a set of conditions related to the current development regime of the First Kuril Meander and the local vortex system with varying characteristics, both near the discharge site and at the SKFZ border. A seasonal dependence of the speed and quantity of polluted water infiltration toward the Russian Federation’s shores is established. The possibility of rapid pollution advection into the SKFZ within 13 days has been discovered. This speed is due to the entrainment of contamination by the Kuril Meander and its further transport by the mesoscale vortex system to the SKFZ border. The study reveals periodicity in the influx of pollution into the SKFZ. Graphs depicting the distribution of the quantity of “dirty” markers over their release times and the arrival of polluted water at the SKFZ border have been created.

Delineation of fresh groundwater potentiality zones in saline coastal aquifers, Southwest Bangladesh using remote sensing and GIS approaches.

Bay of Bengal in southern Bangladesh is a major source of water from coastal aquifers, but prone to contamination by seawater intrusion,making climate-vulnerable populations and economies unfit for potable, agricultural water, adopting crops, etc. The study area located in Khulna district lies in the southwestern coast of the country is among the most vulnerable due to its salinity issues. Therefore, this study identified fresh groundwater potential zones in the southwestern coastal zones of the country suited for community usage helping coastal peoples meet their demands. This study focused on twelve thematic layers employing remote sensing and GIS with analytical hierarchy process. Here, groundwater salinity is 84% brackish to saline over 70% of the region [electric conductivity: 295-16,295 micro-Siemens/cm]. However, groundwater chloride in 88% signifies a slightly to medium salty zone. The annual average rainfall reduced surface water infiltration in 75% of the area with little to very slightly soil salinity. The fresh groundwater resource zone has classified based on its potentiality as: very high (0.52%)-for drinking, agricultural irrigation, or industrial work; high (25%)-marginal salinity suitable for agricultural or industrial uses; low (11%)-low salinity, but usable for high salt tolerant crops in irrigation; and very low (64%)-very high groundwater salinity, and not suitable for human consumption and community uses. Finally, this study will help develop sustainable groundwater resources in the coastal region and a fresh groundwater supply plan in saline-prone areas.

Effects of Long-Term Fenced Enclosure on Soil Physicochemical Properties and Infiltration Ability in Grasslands of Yunwu Mountain, China

Fenced enclosures, a proven strategy for restoring degraded grassland, have been widely implemented. However, recent climate trends of warming and drying, accompanied by increased extreme rainfall, have heightened soil erosion risks. It is crucial to assess the long-term effectiveness of fenced enclosures on grassland restoration and their impact on soil physicochemical properties and water infiltration capacity. This study investigated the effects of enclosure duration on soil organic matter, aggregate composition and stability, and infiltration capacity in Yunwu Mountain Grassland Nature Reserve, comparing grasslands with enclosure durations of 2, 14, 30, and 39 years. Results showed that grasslands enclosed for 14, 30, and 39 years had infiltration rates increased by 20.66%, 152.03%, and 61.19%, respectively, compared to those enclosed for only 2 years. After 30 years of enclosure, soil quality reached its optimum, with the highest root biomass, soil organic matter, aggregate stability, and a notably superior infiltration rate. The findings suggest that long-term fenced enclosures facilitate grassland vegetation restoration and enhance soil infiltration capacity, with the most significant improvement observed at the 30-year enclosure milestone, followed by a gradual decline in this effect.

Multi-Technique Approach for the Sustainable Characterisation and the Digital Documentation of Painted Surfaces in the Hypogeum Environment of the Priscilla Catacombs in Rome

The purpose of this paper is to identify an efficient, sustainable, and “green” approach to address the challenges of the preservation of hypogeum heritage, focusing on the problem of moisture, a recurring cause of degradation in porous materials, especially in catacombs. Conventional and novel technologies have been used to address this issue with a completely non-destructive approach. The article provides a multidisciplinary investigation making use of advanced technologies and analysis to quantify the extent and distribution of water infiltration in masonry before damage starts to be visible or irreversibly causes damage. Four different technologies, namely Portable Nuclear Magnetic Resonance (NMR), Audio Frequency–Acoustic Imaging (AF–AI), Laser-Induced Fluorescence (LIF), Infrared Thermography (IRT), and 3D Laser Scanning (RGB-ITR), were applied in the Priscilla catacombs in Rome (Italy). These imaging techniques allow the characterisation of the deterioration of painted surfaces within the delicate environment of the Greek chapel in the Priscilla catacombs. The resulting high-detailed 3D coloured model allowed for easily referencing the data collected by the other techniques aimed also at the study of the potential presence of salt efflorescence and/or microorganisms. The results supply an efficient and sustainable tool aimed at cultural heritage conservation but also at the creation of digital documentation obtained with green methodologies for a wider sharing, ensuring its preservation for future generations.

Hail hazard modeling with uncertainty analysis and roof damage estimation of residential buildings in North America

This research presents a statistical approach for hail risk modeling that incorporates the uncertainties of hail model prediction to provide insight into assessing the roof damage of a residential house in hail events. By quantifying the inherent uncertainties in evaluating hailstorm characteristics, this study extends the current existing hail models. The hail data are sourced from the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) in the U.S. In the modeling process, the largest hail diameter reported in the CoCoRaHS database serves as a primary input variable to estimate the number of observations for the largest hail diameter, hailstorm duration, and hit rate. The assessment of hail risk in this study focuses on the probability of hail damage and resultant repair costs for five types of roofs in North America (unrated roof and impact-resistant roofs with UL 2218 rating classes 1 to 4). The probability of hail damage is calculated as the failure probability by integrating all individual hailstone hits having variable diameters during a hailstorm with fragility curves, which estimate the probability that hailstones will fracture asphalt shingles (allowing water infiltration) or that they dislodge enough granules to cause visible damage requiring replacement for aesthetic reasons. The results reveal that an impact-resistant roof (impact-resistant rating classes 1 to 4) is associated with lower hail risks, with 60 % to 98 % reduction on average compared to unrated roofs. This study provides a comprehensive uncertainty modeling approach for hail hazard and risk, enabling better-informed decision-making and risk management strategies.

Prediction of soil texture using remote sensing data. A systematic review

Soil particle size fractions play a critical role in determining soil health attributes, including soil aeration, water infiltration and retention capacity, nutrients, and organic matter dynamics. Traditional soil mapping methods rely predominantly on ground-based surveys and laboratory analysis which are reported to be time-consuming and expensive. To address these challenges, there has been a global shift towards digital soil mapping (DSM) techniques that utilize remote sensing data. This review, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline, aims to provide a comprehensive synthesis of the current state of soil texture prediction using remote sensing data. In particular, the review extract and synthesizes the satellite images used, identify the derived environmental covariates and their relative importance, and assesses the prediction models/algorithms used in the prediction of soil texture. Synthesis and analysis of 70 articles show that clay content is the most predicted of the three soil particle fractions accounting for 37% of the reviewed studies predominantly from topsoil layer (74.29%). Sentinel 2 and Landsat 8 are reported as the most frequently used satellite images. Among the covariates derived from these images, NDVI (80.4%) and SAVI (60.8%) are by far the most derived band ratios (indices). Red (37.3%), NIR (35.3%), Green (33.3%), Blue (33.3%), and SW2 (29.4%) bands were the five most incorporated as covariates for soil texture prediction amongst individual satellite bands. Regarding the DSM algorithms, Random Forest (RF) appeared in most reviewed articles followed by Support Vector Machines (SVM), and Quantile Regression Forest (QRF). The comparative model performance analysis showed that RF and Artificial neural network (ANN) had a good trade-off across validation metrics indicating their best performance in the prediction of both clay, sand, and silt. The RF performance showed a decreasing trend with increasing depth interval for clay and sand prediction and inconsistent for silt prediction.

World-class amethyst-agate geodes from Los Catalanes, Northern Uruguay: genetic implications from fluid inclusions and stable isotopes

AbstractThe amethyst and agate geodes from the Los Catalanes Gemmological District in Uruguay represent one of the main deposits of its kind worldwide. The geometry of the deposit is horizontal, with an irregular distribution of amethyst geodes within the upper level of the basalt lava flows and shows strong variations in their abundance, as well as quality, geometry, and shape. Reliable exploration guides are scarce, and the limited knowledge of the geological parameters controlling its occurrence makes exploration unpredictable, leading to inaccurate reserve estimation. Based on cutting-edge methods including nucleation-assisted microthermometry of one-phase fluid inclusions and determination of triple oxygen isotope in silicates and carbonates, as well as analysis of geode-hosted water and groundwater, we estimate the crystallisation temperatures in the range between 15 and 60 °C. These low temperatures point to amethyst crystallisation after the emplacement of the complete basalt pile. The mineralising fluid shows isotopic signatures consistent with meteoric water and very low salinities from pure water up to rarely over 3 wt% NaCl-eq., likely sourced from the groundwater hosted in the aquifers in the basaltic sequence and underlying units. Based on the insights provided by the new data, we propose the combination of open- and closed-system crystallisation inside pre-existing cavities due to the episodic infiltration of meteoric water in a rather stable geological context.

Optimizing Irrigation Systems for Water Efficiency and Groundwater Sustainability in the Coastal Nile Delta

This study investigates the replacement of traditional surface irrigation methods with modern irrigation systems (MIS) including horizontal sprinkler, central pivot, surface drip, and subsurface drip aimed at improving water efficiency in the Nile Delta, Egypt. The primary objectives were to determine the optimal agricultural area for implementing MIS and to assess the effects of these systems on groundwater quantity and quality in the region. To achieve this, the LINDO software was employed to optimize land allocation for each irrigation method. At the same time, the SEAWAT code was utilized to simulate saltwater intrusion (SWI) in the Nile Delta aquifer. The transition from traditional surface irrigation to MIS resulted in significant water savings, reaching 2.15 × 10^9 m³. However, groundwater modeling indicated a decrease in groundwater levels, leading to an 8 % increase in aquifer salinity due to reduced infiltration of recharge water. These findings underscore the urgent need to revise outdated irrigation practices and enhance water management strategies in the Nile Delta to mitigate salinity issues in coastal aquifers. This research's outcomes are crucial for decision-makers and stakeholders in selecting appropriate irrigation methods, particularly in arid and semi-arid regions, to ensure sustainable water use and agricultural productivity.

Magnetized Saline Water Drip Irrigation Alters Soil Water-Salt Infiltration and Redistribution Characteristics

Magnetization constitutes an efficacious physical treatment technique applicable to saline water. The new spiral flow magnetizer, in conjunction with the cyclic magnetization process, has the effect of maximizing effective magnetization time and thereby achieving the optimal magnetization results. Based on this, saline water (0.27, 3, 6, and 10 g L−1) was treated with different levels of magnetization (0, 0.2, 0.4 and 0.6 T), and the effects of magnetized saline water (MSW) drip irrigation on loamy-sand soil moisture, soluble salt infiltration, and redistribution characteristics were studied through a vertical soil column simulation experiment. The results showed that the wetting front migration in MSW drip irrigation experiments exhibited minimal variation during soil water infiltration, and a notable change during redistribution with the experimental duration of 0.27 and 3g L−1 saline water treatments being significantly different (p < 0.05). Treating saline water with different mineralization levels with magnetization demonstrated water retention (0.27 g L−1 excluded) and salt drainage characteristics; calculated soil water storage increased by 1.58–14.19% and salt storage decreased by 0.22–7.66%. The optimal magnetization intensity for low-mineralization (0.27 and 3 g L−1) saline water was 0.2 T and for high-mineralization (6 and 10 g L−1) it was 0.6 T. The adsorption and exchange of cations (19.58–32.12%) by the optimum MSW treatments was greater than that of anions (9.46–14.15%); specifically, the relative exchange capacity of Ca2+ and Mg2+ in cations was more than K+ and Na+, while HCO3− and SO42− in anions was more than Cl−. This study provides theoretical and technical support for the irrigation of farmland with poor-quality water, as well as for the development of magnetized water irrigation technology.

Soil amendments and water management to improve attenuation and recovery of wastewater originated nutrients through a vegetation filter

Vegetation filters (VFs) are on-site wastewater (WW) treatments that can be considered as a nature-based solution (NbS). They are green infrastructures that provide several environmental benefits such as non-potable water reuse, contamination reduction, biomass production, landscaping improvements and CO2 fixation, among others. However, nutrient leaching, especially nitrate, partially exists. To overcome this limitation, operational parameters related to the irrigation water management and soil amendments were tested in a real system receiving WW from an office building operated along 4 years.The attenuation of N is improved (up to 83%) in the vadose zone by boosting biodegradation. Lower hydraulic loads and more frequent irrigation events using drippers and the incorporation of woodchips as a layer above the topsoil promote denitrification processes. Changes in organic carbon characteristics also confirm that biodegradation is enhanced.P attenuation is a result of abiotic processes, mainly driven by chemical equilibriums between the liquid and the sorbed and/or precipitated phase and, when uncontrolled changes in the WW quality occurs, removal efficiency is negatively affected. However, only 10% of the samples collected at 45 cm depth present concentrations above 2 mg/L. The woodchips application does not seem to ameliorate P removal regardless of the application method.The implemented measures allow higher soil water content, infiltration and groundwater recharge and prevents aquifer contamination.

CO2 emissions of drained coastal peatlands in the Netherlands and potential emission reduction by water infiltration systems

CO₂ emissions of drained coastal peatlands in the Netherlands and potential emission reduction by water infiltration systems

Petroleum induces soil water repellency and impedes the infiltration and evaporation processes in sandy soil

Contamination with petroleum could alter the soil hydrological processes and degrade soil and vegetation. Reclamation of petroleum contaminated soil is limited by the absence of scientific data regarding contaminated soil hydrological properties. In this study, we determined the effects of petroleum contamination on the hydrological properties of sandy soil with different contamination levels (0 g kg−1, 5 g kg−1, 10 g kg−1, 20 g kg−1, and 40 g kg−1), through the Water Drop Penetration Time (WDPT) test, infiltration and evaporation experiment in soil columns. The results showed that petroleum contamination increased the water repellency of sandy soil (hydrophilic) to slightly hydrophobic (5 g kg−1), strongly hydrophobic (10 g kg−1), extremely hydrophobic (20 g kg−1, 40 g kg−1). With the increased water repellency, the average infiltration rate decreased from 5.65 mm min−1 to 2.88, 1.17, 0.24, 0.13 mm min−1, and the accumulated evaporation decreased from 59.62 mm to 55.26, 53.91, 45.03, 37.76 mm. Our study indicated that petroleum contamination reduced the soil infiltrability and evaporation in sandy soil, and the increased water repellency was the main reason for these changes. However, more researches were still deserved to explore the effects of hydrological properties on soil water, rainfall-runoff, and pollutant migration in petroleum contaminated soil, especially in the future of global warming and intensified hydrological cycles. Our findings provide the scientific data for understanding the hydrological properties to remove pollution and restore vegetation successfully in petroleum contaminated soil.

Analytical study of water infiltration and contaminant transport in barrier systems

An analytical model was developed to assess the service time of the barrier system consisting of a two-layer cover system and a cut-off wall. The recursive method is used to evaluate the influence of the variable head loss boundary condition caused by the water infiltration. The impact of the types of cover systems and cut-off walls on the barrier system performance is assessed. The results show that cover system types are more likely to influence the long-time performance of barrier systems. Contaminant concentrations with H1* = 0.5 m and H2* = 0.3 m when t = 40 and 100 years are 1.17 and 1.42 times larger than those with H1* = H2* = 0.5 m, respectively. The decrease in hydraulic conductivity of cut-off wall and the increase in the thicknesses and retardation factors of it can also significantly improve the performance of barrier systems. Among all of the parameters, the cut-off wall thickness poses the most significant influence on the contaminant cumulative concentrations, followed by the retardation factor of the cut-off wall, the thickness and hydraulic conductivity of the lower cover layer, the hydraulic conductivity of the cut-off wall, and the thickness and hydraulic conductivity of the upper cover layer. Additionally, the proposed solution is used for the barrier system design of a mine legacy site. The minimum design thicknesses of the cut-off walls for three different cover system types and service times are obtained.

A Multi-Scale Analysis of the Extreme Precipitation in Southern Brazil in April/May 2024

Since 2020, southern Brazil’s Rio Grande do Sul (RS) State has been affected by extreme precipitation episodes caused by different atmospheric systems. However, the most extreme was registered between the end of April and the beginning of May 2024. This extreme precipitation caused floods in most parts of the state, affecting 2,398,255 people and leading to 183 deaths and 27 missing persons. Due to the severity of this episode, we need to understand its drivers. In this context, the main objective of this study is a multi-scale analysis of the extreme precipitation between 26 April and 5 May, i.e., an analysis of the large-scale patterns of the atmosphere, a description of the synoptic environment, and an analysis of the mesoscale viewpoint (cloud-top features and lightning). Data from different sources (reanalysis, satellite, radar, and pluviometers) were used in this study, and different methods were applied. The National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN) registered accumulated rainfall above 400 mm between 26 April and 5 May using 27 pluviometers located in the central-northern part of RS. The monthly volumes reached 667 mm and 803 mm, respectively, for April and May 2024, against a climatological average of 151 mm and 137 mm for these months. The maximum precipitation recorded was 300 mm in a single day on 30 April 2024. From a large-scale point of view, an anomalous heat source in the western Indian Ocean triggered a Rossby wave that contributed to a barotropic anticyclonic anomalous circulation over mid-southeastern Brazil. While the precipitant systems were inhibited over this region (the synoptic view), the anomalous stronger subtropical jet southward of the anticyclonic circulation caused uplift over RS State and, consequently, conditions leading to mesoscale convective system (MCS) development. In addition, the low-level jet east of the Andes transported warm and moist air to southern Brazil, which also interacted with two cold fronts that reached RS during the 10-day period, helping to establish the precipitation. Severe deep MCSs (with a cloud-top temperature lower than −80 °C) were responsible for a high lightning rate (above 10 flashes km−2 in 10 days) and accumulated precipitation (above 600 mm in 10 days), as observed by satellite measurements. This high volume of rainfall caused an increase in soil moisture, which exceeded a volume fraction of 0.55, making water infiltration into the soil difficult and, consequently, favoring flood occurrence.

Tracing pesticide dynamics: High resolution offers new insights to karst groundwater quality

Generally, karst aquifers and springs are highly susceptible to contamination due to the high permeability and, therefore, groundwater flow velocities. The often thin soil cover, accompanied by dolines, can lead to fast infiltration of precipitation water loaded with mobilized contaminants such as pesticides and their transformation products. To date, continuous, temporally highly resolved in-situ monitoring to decipher concentration dynamics for a broad range of pesticides is missing. Therefore, a transportable HPLC-HRMS/MS system (MS2field) was positioned at two karst study sites in the Swiss Jura. Water samples were collected and analyzed for pesticides and their transformation products in-situ every 20 min for 6 weeks in 2021 and 8 weeks in 2022. During the spraying season in 2021, six rain events at site 1 and three at site 2 in 2022 were captured. Concurrently, the water quality parameters electrical conductivity, pH, nitrate, turbidity, and water level, were monitored continuously at high temporal resolution. Further, bacterial cell counts were monitored via online flow cytometry.In 2021, several pesticides and pesticide transformation products were detected in peak concentrations after rain events, of which metamitron showed the highest concentration of up to 1000 ng/L. In one rain event, the Swiss federal and EU drinking water limit of 100 ng/L was exceeded for up to 38 h. Compared with highly frequent MS2field samples collected every 20 min, 42-hours composite samples severely underestimated peak concentrations for all compounds, especially for labile ones. Therefore, it was demonstrated that exceedences of the regulatory limit would have been missed if just composite sampling would have been conducted. Peak concentrations of pesticides coincided with peaks in nitrate concentration and bacterial cell counts following rain events. The correlation analysis showed strong correlations between the three analyzed contaminants (pesticides, nitrate and bacteria), and the proxy parameters electrical conductivity, and pH. The investigation of a second spring revealed similar dynamics indicating that these can be expected in other karst aquifers as well.

Contribution of root and soil properties on soil infiltration capacity of gramineous and leguminous forages during root decomposition

Soil properties are generally altered during root decomposition, which impacts soil water infiltration. Gramineous and leguminous plants present distinct root properties, but it remains unclear whether the root or soil properties are primarily responsible for the soil infiltration capability during root decomposition. To identifythe differences in the contributions of root and soil properties to soil infiltration capability between these two species during root decomposition, a potted plant in situ decomposition experiment was conducted using Bothriochloa. ischaemum (Gramineae) and Lespedeza. davurica (Leguminosae) during three root decomposition times (the 90th, 270th and 450th day). The results revealed that all the root properties (root length, root volume, average root diameter and root biomass) gradually decreased during root decomposition, especially the root length (RL) and root volume (RV) of L. davurica in 0–40 cm soil layer, with reductions of 55.35% and 58.73% at the 450th day compared with the 90th day. The reverse was true for the soil porosity and mean weight diameter of the soil aggregates. Compared to B. ischaemum, L. davurica presented relatively high initial infiltration rate (IIR), steady infiltration rate (SIR), and average infiltration rate (AIR) values at three root decomposition times. A great increase in the soil infiltration rate was observed for both species at the late decomposition stage (450th day), especially for L. davurica, with increases of 38.32%, 267.7%, and 137.1% in IIR, SIR, and AIR. The GLM analysis results revealed that root properties had a greater contribution to the soil infiltration capability. The key factors controlling the soil water infiltration process have been quantified as RL and RV. The present study indicates that leguminous forage presented greater soil infiltration capability during root decomposition. A great decrease in RL and RV within the upper soil layers increased the soil porosity and facilitated the formation of soil aggregates, thereby promoting water flow and ultimately improving the soil infiltration capability.

The role of wild red deer on soil physical properties in a Mediterranean ecosystem: insights from a Portuguese mountain.

In this study we aimed to assess the role of wild red deer, along with other ungulates such as roe deer and wild boar, in the soil's physical properties, namely soil penetration resistance and depth (used as a proxy for soil compaction), hydraulic conductivity (a proxy for water infiltration), and the proportion of soil stable aggregates. Results showed that, at the density level found in our study area, red deer have a neutral effect at the soil level, not causing significant soil compaction or significantly influencing measured soil functions.