Rising Groundwater Levels Research Articles

Impacts of Human Activities on Archeological Sites in Southern Egypt Using Remote Sensing and Field Data

The famous archaeological sites of Egypt are potentially affected due to human activities that constitute the main threats through rising of groundwater level as a result of seepage of drainage and sewage water, despite of the arid and hyper arid conditions. This area witnessed several changes during the last four decades, particuarly loss of agricultural/arable lands to residential and commercial development. The characterization and evolution of human activities were examined and discussed based on spatial and temporal analysis and interpretation of remote sensing data and field survey. Multi-temporal analysis using Principal Component Analysis (PCA), classification and Normalized difference vegetation index (NDVI) techniques were applied to a series of satellite images. Increasing population and the lack of reticulated wastewater systems allowed recharging and pollution of groundwater in the study area. Results of the chemical analysis of the collected groundwater samples indicate that sodium chloride and sodium sulphate are the two most common destructive salts in the groundwater. Such salts were observed in the deteriorated monuments of the studied temples and foundations. The dewatering processes help in preserving the monuments from deterioration by reducing the groundwater level from 73 to 71.30 and from 73 to about 71 at Karnak and Luxor temples, respectively.

Experimental and Numerical Analysis on Hydraulic Characteristics of Coastal Aquifers with Seawall

In this study, hydraulic model experiments were conducted to measure the saltwater–freshwater equilibrium interface in a coastal aquifer with underground obstructions such as an impermeable seawall. To analyse the hydraulic characteristics inside the coastal aquifer, numerical analysis was conducted using a non-hydrostatic Navier-Stokes solver based on the Porous Body Model (PBM), which can directly analyse groundwater flow. A unique saltwater–freshwater equilibrium interface that does not appear in typical coastal aquifer analyses was observed in a sandy tank experiment. In the experiment, the rise of the groundwater level behind the seawall increased the pressure gradient and groundwater flow rate, causing the saltwater–freshwater interface to move towards the sea and a freshwater region to form on the seabed in front of the seawall. The numerical analysis enabled close examination of the groundwater level distribution, groundwater flow, seawater–freshwater interface, and pore water pressure characteristics of the coastal aquifer with underground obstructions. The sandy tank experiment also provided an understanding of the hydraulic characteristics of groundwater in the coastal aquifer with a seawall, which previously could not be accurately analysed. The experimental and analytical results demonstrated that the rise of groundwater level due to underground obstructions in the coastal aquifer increased the pressure gradient and groundwater flow rate and slowed seawater intrusion. This principle can be employed to sufficiently reduce seawater intrusion of coastal aquifers.

Monitoring temporal variations in groundwater levels in urban areas using ground penetrating radar

Monitoring temporal variations in groundwater levels provides a key to sustainable freshwater resource utilization and management, sustainable land use, and sustainable crop acreage, yield, and production. This study used ground penetrating radar (GPR) to monitor temporal variations in groundwater levels in urban areas, and to define the factors that control these variations. The city of Ismailia, Egypt, was selected as a test site because it is experiencing a rise in groundwater levels that poses potential environmental risks, and it lacks the groundwater wells necessary for monitoring and mitigation. Three main GPR profiles were collected in summer (July 2017) and winter (March 2018) using a 100-MHz antenna. On the collected GPR data, water table was defined as a continuous linear reflector of high amplitude. The water table appeared at 8.6 m and 9.5 m (below ground surface) in the summer and the winter surveys, respectively. The depths to the water table, as extracted from GPR surveys, are identical to those measured at a nearby water supply. The higher depth to the water table in the winter is related to excessive groundwater extraction and/or exceptional drought conditions and associated baseflow recession. Results highlight the importance of using GPR in urban areas as a unique, significant, practical, comprehensive, and cost-effective tool to image the subsurface and map the temporal variations in depth to the water table.

Groundwater Recharge Level Estimation from Rainfall Record Probability Match Methodology

Groundwater reservoirs’ assessment and management studies present more difficulties compared to surface water resources, because their storage media are geological formations, which have spatial heterogeneities that cannot be expressed by empirical or deterministic methodologies easily. Especially, their recharge possibilities are dependent not only on the precipitation features, but also on uncertainties including heterogeneous porosity, specific yield, storage, hydraulic conductivity, permeability and transmissivity quantities. The best way to treat such uncertainties is through the probability distribution function (PDF) methods, which reflect the spatial and temporal randomness in the meteorological and hydrogeological variabilities. In general, this paper presents temporal PDF behaviors of the rainfall variation and groundwater level fluctuation in addition to the probabilistic correlation between them. For this purpose, the cumulative distribution functions (CDF) of rainfall and groundwater level rise departures are considered from respective mean values. The two CDFs are related to each other on the valid assumption that the more the rainfall cumulative departure from the mean the more is the groundwater fluctuation. The application of this probabilistic methodology is presented to available data from the south eastern part of Turkey.

Evaluating Climate Change Impacts on Soil Moisture and Groundwater Resources Within a Lake‐Affected Region

AbstractThe impact of climate change on surface water resources is reasonably well studied. However, the impact on groundwater resources has only been considered by a few studies worldwide. Here we present an analysis of climate change impacts on groundwater resources in a well‐instrumented 6,800‐km2 watershed in the Laurentian Great Lakes Basin. We employ a physics‐based modeling pipeline consisting of an ensemble of high‐resolution regional climate model projections based on the Weather Research and Forecasting model and the fully integrated three‐dimensional hydrologic model HydroGeoSphere. The Weather Research and Forecasting model is run at a resolution as fine as 10 km using two different physics configurations, while HydroGeoSphere simulates the terrestrial hydrosphere at subkilometer scale, from deep groundwater to surface water, including surface water‐groundwater interactions. The two Weather Research and Forecasting model physics configurations exhibit opposite climate change responses in summer precipitation. The hydrologic simulations follow the climate forcing, but due to the memory of the subsurface, differences in summer affect the entire seasonal cycle. In the drier climate scenario groundwater levels and recharge decline, while in the wetter scenario groundwater levels rise (recharge remains unchanged). Soil moisture changes accordingly, but primarily in late summer. It is also shown that the magnitude of climate change impacts on groundwater is strongly modulated by local physiographic features. In particular, regions where the groundwater table is deep (below 2 m; 15% of the area) show a high sensitivity to changes in climate forcing. Furthermore, changes in groundwater levels, recharge, and soil moisture typically occur in the same regions, suggesting potentially compounding impacts.

Zamanda Sürekli ve Süreksiz Yeraltısuyu Kot, Sıcaklık ve Özgül Elektriksel İletkenlik Verileri Işığında Demre Kıyı Akiferinde (Antalya) Yeraltısuyu Akım Dinamiği

The main source of livelihood in the Demre plain is greenhouse agriculture and the irrigation water demand is provided by groundwater. Groundwater level is affected by the use of groundwater over time in Demre coastal aquifer. The security of long term water and food production in the plain depends on sustainable use of the alluvium aquifer. In this study, groundwater level is measured at 24 wells located in Demre plain between January 2014 - May 2015 for 6 periods. In addition, electrical conductivity-temperature-level measurements are taken in 4 wells at different periods by automatic data-loggers. When data obtained from the data-loggers are associated with the daily precipitation data, it is determined that groundwater level increases after the precipitation in all wells. The long-term groundwater level rise continuation shows that alluvium aquifer feds firstly by precipitation over aquifer and then later seepage from limestone. When the change of the specific electrical conductivity of groundwater in the Demre coastal aquifer is examined over time, there is no significant change in conductivity in some wells during the year, while in some cases it is determined that there is diluted in groundwater ion concentration when precipitation reached the ground directly or with a short infiltration. In this study, it is determined that Demre coastal aquifer which is fed by precipitation and lateral seepage has quasi steady-state groundwater level in long term. This indicates that aquifer storage is not changed.

Reduced rate of land subsidence since 2016 in Beijing, China: evidence from Tomo-PSInSAR using RadarSAT-2 and Sentinel-1 datasets

ABSTRACTLand subsidence associated with groundwater extraction in the city of Beijing, China, has been a problem for decades. Remote sensing has been used extensively in prior studies to monitor subsidence in Beijing. However, given recent changes in precipitation and groundwater management, there is an urgent need to update the subsidence record and to evaluate whether the long-term spatiotemporal patterns of subsidence have changed. This study therefore investigates the recent spatiotemporal patterns of land subsidence in Beijing by tomography-based persistent scatterer interferometry SAR (Tomo-PSInSAR) technology, using 39 RadarSAT-2 images from 2012 to 2015 and 33 Sentinel-1 images from 2016 to May-2018, and drawing upon Geographic Information System (GIS) spatial analysis methods. Vertical ground deformation rates in Beijing were found to range from −176.2 to +12.3 mm year−1 from 2012 to 2015, but subsequently decreased to −119 to +8 mm year−1 from 2016 to May 2018. Three spatial scale of subsidences are evident: At the metropolitan regional-scale, the total area of subsidence area is about 1235.2 km2, and comprises four main subsiding regions, located in the northern and eastern parts of the city. More than 85% of the subsiding area is located between the Fifth and Sixth Ring Roads. At a more local scale, eight main subsidence bowls are characterized by different patterns of subsidence. Some of the subsidence bowls are separated by active faults. Time-series data of the displacement show that the decreasing subsidence rate after 2016 could be due to the 1 m rise in mean groundwater level from the end of 2014 to mid-2018. This change in groundwater level is likely due to an increase in precipitation since 2016, and water transfers, which reached 2.3 × 109 m3 by 2017 from the South-North Water Transfer Project. At the scale of individual infrastructure projects, the Beijing subway, main roads and the Capital Airport all show severe uneven subsidence, which is a cause for concern. To our knowledge, this research is the first study using satellite SAR remote sensing methods to document the change in the land subsidence rate of Beijing. Starting in 2016, the rate notably declined, suggesting that subsidence mitigation strategies are beginning to have an effect.

The effect of the reciprocal relations of the deterioration symptoms in different building materials in some of historic Cairo's buildings

In the present study, since historic Cairo established, limestone and woods have been used for building construction alongside. The building materials representingcase studies in historic Cairo are affected by different deterioration factors, such as rising ground water level, the salt weathering, air pollution, frequency between temperatureandrelative humidity, and microbiological deterioration.From case studies survey various types of weathering forms were observed, such as granular disintegration, splitting in the wooden lintel, the efflorescence of salt, pitting in limestone surface, black spots in limestone surface due to microbiological deterioration, black crust and peeling, flaking of painting layers, etc. The aim of this study is to identify on the reciprocal relations ofthe deterioration symptoms in different building materials (limestonewood) used in some of historic Cairo's buildings. The samples were collected from different sites, investigated by several scientific techniques such as X-Ray Diffraction (XRD), EDX analytical methods, Fourier Transform Infrared Microscopy (FTIR) to detect the changes of the main wood components (cellulose,, lignin), Scanning Electron Microscopy (SEM), Polarizing Light Microscopy (PLM), Stereo Microscopy, and microbiological investigation were also done. The results of the study indicated that there was a fungal infection on the surface of limestone, in particular which is found close to the wooden elements, microbiological investigation was shownthe following fungi:,,,,,. From investigation of wood samples are shown that there is a rise moisture content in the wood materials, due to direct connection between them and adjacent the stones, in addition to crystallized salts found in wood fiber and internal structure of limestone, such as NaCl, CaSO4.2H2O, CaSO4; due to the effect ofbuilding material properties on each other. Furthermore, the physical and mechanical properties tests of building materials indicated that reduction in its properties.

Spatial variation of groundwater response to multiple drivers in a depleting alluvial aquifer system, northwestern India

Unsustainable exploitation of groundwater in northwestern India has led to extreme but spatially variable depletion of the alluvial aquifer system in the region. Mitigation and management of groundwater resources require an understanding of the drivers behind the pattern and magnitude of groundwater depletion, but a regional perspective on these drivers has been lacking. The objectives of this study are to (1) understand the extent to which the observed pattern of groundwater level change can be explained by the drivers of precipitation, potential evapotranspiration, abstraction, and canal irrigation, and (2) understand how the impacts of these drivers may vary depending on the underlying geological heterogeneity of the system. We used a transfer function-noise (TFN) time series approach to quantify the effect of the various driver components in the period 1974–2010, based on predefined impulse response functions ( θ). The dynamic response to abstraction, summarized by the zeroth moment of the response M0, is spatially variable but is generally large across the proximal and middle parts of the study area, particularly where abstraction is high but alluvial aquifer bodies are less abundant. In contrast, the precipitation response is rapid and fairly uniform across the study area. At larger distances from the Himalayan front, observed groundwater level rise can be explained predominantly by canal irrigation. We conclude that the geological heterogeneity of the aquifer system, which is imposed by the geomorphic setting, affects the response of the aquifer system to the imposed drivers. This heterogeneity thus provides a useful framework that can guide mitigation efforts; for example, efforts to decrease abstraction rates should be focused on areas with thinner and less abundant aquifer bodies.

Monitoring regional groundwater flow and contaminant transport in Southern Punjab, Pakistan, using numerical modeling approach

A three-dimensional groundwater flow model was developed using Visual MODFLOW to characterize the groundwater regime and simulate groundwater flow behavior in Multan District of Pakistan from 1962 to 2015. The multi-layered model was calibrated in which arsenic concentration was used as a point source for solute transport modeling in the flow domain. The model calibration indicated a close agreement between the simulated and observed head values achieving residual mean value of 0.1 m and a correlation coefficient (R) value of 0.9 during the steady-state condition. The study revealed a gradual rise in groundwater levels from 1972, i.e., at a rate of about 0.08 m/year followed by a gradual decline after 1990 at a rate of about 0.39 m/year likely due to overexploitation of groundwater. The other reasons of depletion of the aquifer may include lesser natural recharge due to reduction in canal command area and increasing water demand and pumpage due to growing urban/rural development. The findings of contaminant transport modeling depicted flow path representation of arsenic movement mostly towards the rivers in the model domain. Overexploitation of groundwater needs to be controlled for effective development of groundwater resource, and proper purifying/filtering techniques have to be adopted to ensure safe groundwater use in the area.

Increasing Groundwater Availability and Seasonal Base Flow Through Agricultural Managed Aquifer Recharge in an Irrigated Basin

AbstractGroundwater aquifers provide an important “insurance” against climate variability. Due to prolonged droughts and/or irrigation demands, groundwater exploitation results in significant groundwater storage depletion. Managed aquifer recharge (MAR) is a promising management practice that intentionally places or retains more water in groundwater aquifers than would otherwise naturally occur. In this study, we examine the possibility of using large irrigated agricultural areas as potential MAR locations (Ag‐MAR). Using the California Central Valley Groundwater‐Surface Water Simulation Model we tested four different agricultural recharge land distributions, two streamflow diversion locations, eight recharge target amounts, and five recharge timings. These scenarios allowed a systematic evaluation of Ag‐MAR on changes in regional, long‐term groundwater storage, streamflow, and groundwater levels. The results show that overall availability of stream water for recharge is critical for Ag‐MAR systems. If stream water availability is limited, longer recharge periods at lower diversion rates allow diverting larger volumes and more efficient recharge compared to shorter diversion periods with higher rates. The recharged stream water increases both groundwater storage and net groundwater contributions to streamflow. During the first decades of Ag‐MAR operation, the diverted water contributed mainly to groundwater storage. After 80 years of Ag‐MAR operation about 34% of the overall diverted water remained in groundwater storage while 66% discharged back to streams, enhancing base flow during months with no recharge diversions. Groundwater level rise is shown to vary with the spatial and temporal distribution of Ag‐MAR. Overall, Ag‐MAR is shown to provide long‐term benefits for water availability, in groundwater and in streams.

The Influence of Groundwater Level Rise on Bearing Capacity of Sand Foundation

Along with the development of city construction, the underground space is exploited widely. This paper simulated the natural basement in sandy foundation by the way of laboratory test. Then through the SLT test we will get the change laws of bearing capacity, porewater pressure, effective stress and settlement in sandy foundation after analyzing change of underground water level. These may provide reference for the engineering application.

Geostatistical inverse modeling for the characterization of aquitard heterogeneity using long-term multi-extensometer data

The classical aquitard drainage model COMPAC was used to simulate the deformation of a one-dimensional vertically heterogeneous aquitard (i.e. Heter-COMPAC). By coupling Heter-COMPAC with the quasi-linear geostatistical inversion approach, the vertical heterogeneities of hydraulic conductivity (Kv), elastic specific storage (Sske) and inelastic specific storage (Sskp) fields could be characterized with the availability of long-term multi-extensometer data. The methodology was first tested through a group of ten synthetic cases with randomly generated Kv, Sske and Sskp fields. Results of the synthetic cases revealed that a geostatistical model could characterize the variability of aquitard hydraulic parameter fields, and yields improved fits of simulated versus observed zone deformation than a geological model that treats each zone to be homogeneous. Subsequently, the methodology was applied to a research site situated in Changzhou city, Jiangsu Province, China, where long-term deformation behaviors of the strata within the aquifer-aquitard system have been monitored. Vertical heterogeneities of Kv, Sske and Sskp fields of the investigated aquitard at the site were characterized using the quasi-linear geostatistical approach. The correlation length of the three fields that yielded the best-quality fit was assessed to be approximately 50 m, and the fitting quality was slightly improved in comparison with that produced from calibrating a geological or zonation model. Through Monte Carlo analysis of aquitard deformation utilizing the inversed parameters and corresponding uncertainties, the investigated aquitard is estimated to have compacted −914.8 ± (42.6) mm before the rise in groundwater levels in adjoining aquifers.

THE MOST IMPORTANT AGRICULTURAL PROBLEMS AND OBSTACLES LEADING TO THE WIDENING OF THE FOOD GAP OF AGRICULTURAL CROPS IN EGYPT

An achievement food security in Egypt is facing many problems resulting in the inability of the agricultural sector to meet the needs of population of food, clothing, and the further widening the gap between food production and national consumption of agricultural crops. The study aims at sheding light on the problems and difficulties facing the Egyptian agricultural production and a study, analysis the productive and economic efficiency of plant production. problems and obstacles of plant production and the increase in the self-sufficiency ratio of Egyptian food crops. The research used descriptive and quantitative analysis of the economic variables, in addition to on secondary data. The research tackles the problems and difficulties faced by the Egyptian agricultural sector and how to overcome them, which are: The fragmentation of agricultural holdings, and the dominance of dwarf holdings, where about 92.1% of the total number of owners in the Republic owns an area of ​​agricultural land about 47.2% of the total area of ​​agricultural owned, thus leaving about 8% of the total number of owners in the Republic owns the area of the agricultural land, amounting to about 52.8% of the total agricultural land owned. Increasing the encroachment on agricultural land for urban expansion and also by excavation, especially in the period from 25/1/2011 to 18/3/2014. Neglecting the maintenance of agricultural economic resources by land clearing, poor service operations, wasteful irrigation and poor drainage. The risks of climate change on land, leading to high salinity of soil, land development, rising groundwater level, coastal erosion and displacement of the northern coastal population. Social and economic problems, namely, the complete liberalization of the agricultural sector in 1990, and the release of agricultural land rents in full in 1997, which led to the increase in the value of production inputs in addition to the increase in wages of agricultural workers and fuel prices. An abolition of subsidies on agricultural loans and hence the increase in interest rates on it agricultural loans. A decline of role cooperative marketing and cooperative societies, which led to high production costs in addition to the cancellation of the agricultural cropping system, which led to increase the size of the food gap in the main crops in the average period (2011-2015) to 45% for wheat, 50% for 94% for lentils, 88% for vegetable oils, 70% for municipal beans, 30% for sugar, 23% for dairy products and 25% for red meat. This gap is covered by imports from the dollar markets. Exchange of the dollar in Egyptian pounds. The negative role in some cases for many of the farmers and the state in the improvement and development of agricultural production in Egypt, represented by the neglect of the farms in the purification and maintenance of small agricultural banks, leading to poor drainage. The absence of a national plan for the state to exploit groundwater, especially in the area of ​​Siwa, With the increase of the number of chemical fertilizers and pesticides, or the specific rates of crops, to an increase in the incidence of liver and kidney diseases and cancers among consumers. Low efficiency of agricultural marketing methods. The ratio of agricultural GDP to GDP declined to about 9.8% between 2000 and 2015. The ratio of agricultural investments to total national investments decreased to 56.64% between 2000 and 2015. The migration of agricultural labor in general and trained in particular from the countryside to the city or abroad to improve their standard of living. The relative importance of total agricultural employment in the country has decreased to about 9.8% between 2000 and 2015. Also, the research indicates that the obstacles of agricultural development in Egypt during the study period (2000-2015) is the slow increase of agricultural land resources in the face of population increase. Therefore, it is necessary to increase reclaimed land within available water resources at a rate greater than population growth rate. As a political commodity of a strategic nature, which is used as a tool for the pressure of exporting countries on importing countries for food commodities.

Long-term hydrodynamic effects of the All-American Canal lining in an arid transboundary multilayer aquifer: Mexicali Valley in north-western Mexico

The construction of the 42-km long All-American Canal in southern California (USA) near the border with Mexico in the 1940s generated infiltration which raised groundwater levels in the area inducing groundwater to flow into the Mexicali Valley aquifer (Mexico). In the late 2000s, the USA started a controversial lining project to reduce infiltration below the canal, with far-reaching consequences. This investigation implemented a numerical groundwater flow model to determine the hydrodynamic effects of the lining of the All-American Canal on the Mexicali Valley aquifer. For this purpose, plenty of information was acquired with a 32-year span of data and 88 monitoring wells in the area of interest. Field evidences and the model approach suggest that seepage from the All-American Canal resulted in the rise of groundwater levels to 14 m in the northern Mexicali Valley aquifer. However, continuous drawdowns were observed after concluding the lining in 2008, with the result of a drop in the water table to 5.8 m after 4 years of monitoring. A forecast shows that groundwater levels will tend to stabilize to those levels that existed prior to the infiltration produced by the canal. At the existing wetlands in the Mesa de Andrade in Mexico, a 1-m drawdown will be registered due to the lining, which could affect the existing ecosystem. Any additional extraction done on the Mesa de Andrade will likely dry the wetland.

Environmental effects of the groundwater rebound in the eastern plain of Naples (Italy)

Since 1990, in the eastern plain of Naples a generalized groundwater rebound phenomenon has occurred, caused by the sharp reduction of the withdrawals which had overexploited the plain aquifer until 1989.The present study aims to investigate, for 1989-2013 period, the groundwater flooding and ground uplift related to the groundwater rebound, by a coupled analysis of multi-temporal hydrogeological and DInSAR data of this area.Results show a generalized rise of groundwater levels from 1990, varying from 6.0 to 16.0 m, whereas localized impacts of groundwater flooding on buildings and agricultural soils have started since 2006.An uplift trend is observed in ground deformations (up to +40 mm), caused by the increase of pore water pressure in the aquifer system, following to groundwater rebound.This result opens new perspectives in assessment, mitigation and management of geohazards not considered by the Italian legislation.

Revisiting the White method for estimating groundwater evapotranspiration: a consideration of sunset and sunrise timings

The well-known White method (A method of estimating ground-water supplies based on discharge by plants and evaporation from soil: Results of investigation in Escalante Valley, Utah. Washington D.C, US Geological Survey. Water Supply Paper 659-A United States Department of the Interior, 1932) based on diurnal water table observations has been widely applied to estimate groundwater evapotranspiration (ETG) from phreatophyte vegetation. One of the limitations of this method is its large uncertainties in quantifying the daily groundwater recovery rate (r), which is assumed to be equal to the average rate of groundwater level rise between midnight (i.e., 00:00 h) and 04:00 h. Recent studies pointed out that ETG is highly dependent on the shape and duration of the diurnal clear-sky solar radiation curve and that using the groundwater recovery rate over a short interval of nighttime hours to represent the daily r may lead to large uncertainties in ETG estimates. In this study, we analysed the dependence of the estimated daily r on the sunset and sunrise timings. Numerical experiment results showed that the estimated r is highly sensitive to the duration between sunset and sunrise, which varies seasonally. Instead of using fixed time spans (TSs), e.g., from midnight to 04:00 h, we recommend a more universal method for determining the TS, which is associated with the sunset and/or sunrise timings and used to estimate the daily r. This dynamic TS approach was tested at a Tamarix ramosissima-dominated riparian site with a hyper-arid climate (precipitation of 35 mm a−1) in northwestern China. Compared with the observed evapotranspiration (ET), our approach showed better performance and less subjectivity in estimating ETG than the traditional White approach.

Macro- and micro-scale study and chronology of Late Weichselian aeolian sediments in Estonia, north-eastern European Sand Belt

Patchy aeolian landforms, representing the NE part of the European Sand Belt, occur in NE Estonia, between the Gulf of Finland and Lake Peipsi. The dunes are restricted to the former glacial lakebed, thus lying directly in contact with glaciolacustrine sediments, and have so far prompted different opinions regarding their genesis and age. This study aims to answer these open questions regarding the age and origin of these landforms and to provide information on the associated past sedimentary processes. To achieve this, we combine macro-scale (sedimentary structures and ground-penetrating radar survey) and micro-scale (grain-size, shape and character of quartz grain surfaces and mineral composition) studies with optically stimulated luminescence dating. The glaciolacustrine fines in the study area are wavy stratified, with the occurrence of mica horizons and prevalence of quartz sand grains with aeolian characteristics. Therefore, these sediments argue for near-standing/low-energy water conditions in the glacial lake, where allochthonous material was delivered by wind. A fall in the lake level and the occurrence of dry land on the northern coast of the regressive Late Weichselian Lake Peipsi favoured aeolian activity from ca. 13.5 to 10.5 ka in the region. The aeolian accumulation was brief—as apparent from the results of the micro-scale study—and lacks evidence of sediment recycling. Only easily-removable mica was deflated at the end of the aeolian depositional phase. Aeolian activity terminated ca. 10.5 ka due to a rising groundwater level that is apparent from the onset of paludification in the region.

The influence of Fe(III) and Mn(IV) on the biotransformation of hydrocarbons in groundwater

According to the thermodynamic ladder, microorganisms in groundwater use electron acceptors consistently – for transformation of pollution from the pollution plume edge to its core. However, some researchers come to the conclusion that only methanogenic biotransformation of pollution or reduction of Fe(III) and Mn(IV) from the solid phase can occur in the plume, and due to the kinetic factor microorganisms use electron acceptors from the aqueous phase (O2, NO3- и SO42-) only on the edge of the pollution plume. The purpose of the research was to determine whether microorganisms use Fe(III) and Mn(IV) as acceptors of electrons for hydrocarbons transformation in groundwater in the northern part of the Middle Heilongjiang-Amur River basin aquifer. In the study area, both lenses of petroleum-hydrocarbons (non-aqueous phase liquids) on the surface of groundwater (up to 2.5 m) and high concentrations of dissolved hydrocarbons (up to 1000 mg/l) are noted. Microbiological processes were assessed in situ by the method of geochemical indicators. The most active biogeochemical processes occurred during the spring-summer rise of groundwater level. The seasonal increasing of level led to the entry of Fe(III) and Mn(IV) into the pollution plume and activation of the microbiological processes of its reduction. Microorganisms mostly use electron acceptors from the solid phase – Fe(III) and Mn(IV), but not NO3, SO42 from the aqueous phase. This is confirmed by the close correlation of HCO3- formation and that of Fe(II) and Mn(II) in groundwater (r2 up to 0.93). This says that for the groundwater self-purification the kinetic factor rather than thermodynamic one is decisive; and microorganisms use electron acceptors that are currently available. As a result of microbiological pollution destruction, the content of Fe(II) in groundwater increased up to 100 mg/l, Mn (II) – up to 16 mg/l, which exceeds the natural background 4 and 8 times, respectively. This was also because the regional geochemical background of the study area (Amur River basin) forms Fe and Mn.

Experimental investigation of a catastrophic landslide in northern Pakistan

The territory of Azad Jammu and Kashmir (AJK) is vulnerable to different natural hazards because of its proximity to a geo-dynamically active zone and its tropical and monsoonal climatic pattern. Both factors operate in various combinations and result in the occurrence of disasters generated by natural hazards like floods, earthquakes, and landslides at different intervals. There are numerous landslides in the study area, out of which the Donga Kass landslide has been selected for study due to its ongoing activity which poses a significant risk to the nearby community and infrastructure. Therefore, assessment of two possible triggering factors (i.e., earthquake and rainfall) for this landslide was conducted through the laboratory testing using the DPRI-5 Ring shear simulator. Undrained cyclic loading tests were performed to simulate the dynamic loading and earthquake-induced landslides, while pore pressure control tests simulated the rise of groundwater level during rainfall for rainfall-induced landslides. Based on the laboratory test results, a critical seismic acceleration and a critical pore pressure ratio are suggested for Donga Kass landslide. Using these values and combining with rainfall data and monitored pore water pressure in bore holes, early warning system can be activated to reduce any potential landslide risk in the future.