Hydrogeological Situation Research Articles

Borehole transient electromagnetic response calculation and experimental study in coal mine tunnels

Water damage seriously threatens the safe production of coal mines, so it is necessary to carry out advanced detection to determine the hydrogeological situation, and the preliminary survey often involves the drilling of on-site drill holes in the tunnel. The use of directional drill holes, combined with advanced geophysical prospecting technology, enables advanced water disaster detection with long distance and high precision and is independent of the tunnel environment influence. The transient electromagnetic method (TEM) is highly sensitive to low-resistivity anomalies and plays a crucial role in water damage detection. To address the size limitation of borehole detection, in this study, a small rectangular multi-turn loop borehole advanced detection method was developed (borehole TEM, BTEM) to detect low-resistivity anomalies within 10 m of the borehole in the radial direction. To satisfy the size requirements for borehole detection and the detection distance, a small rectangular multi-turn loop device with a width of 6 cm and a length of 50 cm was designed. To resolve the issue of self-inductance and mutual inductance enhancement caused by multi-turn coils, a uniform full-space low-resistivity abnormal body model was established using the Ansys Maxwell software, and we analyzed the vertical magnetic field component of the rectangular multi-turn small loop at different time points and the transient electromagnetic response of the different turns. Then, we determined the appropriate parameters for the transmitting and receiving device. The developed method was applied to several different experimental scenarios to obtain the electrical distribution of the anomalous body in front of the device, and the measured data were inverted and interpreted to obtain the apparent resistivity-depth profile. The results demonstrate that the inversion results align well with the actual situation, confirming the effectiveness of the BTEM. This research offers a potential solution for borehole advance detection and provides a solid theoretical foundation for further studies.

Study of the first aquifer on the territory of the former test site “Azgir” to determine potential migration routes of radionuclides

The article presents the results of the study of the hydrogeological situation of the first aquifer of the former test site “Azgir” with the purpose of determining possible ways of radionuclide migration from the underground cavities of the former test site “Azgir” established more than 50 years ago. It was demonstrated that groundwater of the first aquifer lies in the form of separate scattered lenses, as well as a local basin, which has the role of a potential groundwater reservoir. Currently, there are no processes of technogenic radionuclides migration from underground cavities into the first aquifer.

Possible effects of underground nuclear explosions (UNE) for peaceful purposes on the ecological and hydrogeological situation

Possible effects of underground nuclear explosions (UNE) for peaceful purposes on the ecological and hydrogeological situation

Технологические решения по обеспечению надежной эксплуатации системы водоотведения на руднике «Удачный»

Drainage from the underground mines and coal mines is one of those technological processes, the degree of reliability of which, first of all depends on the continuity and safety of the mining of solid mineral deposits. In the process of pumping mine water to the surface, it is required to pay close attention to the operation of the water-drainage installation. Practice shows that at present the reliability of the functioning of the main water drainage system of the flooded kimberlite mine Udachny is quite low. The level of its reliability of functioning significantly decreased over the past 6 years. The main reasons for the transition to a lower level of operational safety of the drainage plant are the deterioration of the hydrogeological situation in the area of the kimberlite pipe being developed, as well as the operational reliability of pumping equipment of the drainage plant. It is dictated by the highwater content of the deposit, especially in the warm season, and the degree of contamination of the pumped mine waters with abrasive mechanical impurities. It is established that an increase of the water inflow in the warm season can lead to more intensive hydroabrasive wear of the pumping equipment parts. In order to limit the additional slip of surface water flows into the mine due to the planned dismantling of a local quarry drainage system, it is proposed to build two water catchments in the area of the non-working Udachny quarry, where the capacity of each is about 300 m3. Introduction of design clarification tanks № 5, 6 with a capacity of 3430 and 4030 m3, respectively, into the technological scheme of the main drainage of the Udachny mine will allow to reduce the average concentration of mechanical impurities in mine waters at the outlet of the water collectors from 17 to 4 g/l.

Probable reasons for interruption of the flow of the Iskrets karst spring

The object of research is the Iskrets spring, one of the large and important karst springs in Bulgaria. A characteristic feature of its regime is the temporary interruptions of its outflow. The purpose of the research is to establish the probable causes and mechanism for these interruptions. After analyzing the hydrogeological situation and data from the results of continuous measurements of changes in water quantities, it is assumed that the main cause of this phenomenon is the processes of erosion, transport and deposition of cave alluvial sediments.

Tracing sources and fate of nitrate in multilayered karstic hydrogeological catchments using natural stable isotopic composition (δ15N-NO3− and δ18O-NO3−). Application to the Toulon karst system (Dordogne, France)

• Nitrate contents and isotopes are measured in a large multilayered karst aquifer. • Primary and secondary sources of nitrate are determined, at the local scale, using nitrate isotopes. • Origins of nitrate, over a karstic hydrogeological catchment, are assessed by nitrate isotopes. • The fate of nitrate in a karst aquifer is specified/ elucidated/ quantified/ combining isotopes and hydrogeological approaches. In groundwater management, the determination of the origins of nitrate (NO 3 – ) endmember sources is the first step in improving the management over a hydrogeological catchment. The generally multiple source contamination by nitrate over the karst systems makes it difficult to identify the exact nitrate origins in surface water and groundwater. This work aims to assess nitrate vulnerability of a karst system fed by several karst aquifers. The Toulon karst system offers the opportunity to study the relationships between two multilayered karst aquifers. It shows an increase in mean NO 3 – concentrations over decades. However, the origins of the NO 3 – remain unclear. Natural stable isotopic composition of NO 3 – (δ 15 N -NO3 – and δ 18 O -NO3 – ) measurements combined with concentrations were used to identify the origins of nitrogen causing this increase. This information was also integrated into the local hydrogeological situation to improve knowledge of the contamination of both confined and unconfined karst aquifers. δ 15 N -NO3 − and δ 18 O -NO3 − in potential nitrate sources over the hydrogeological catchment were analysed in order to identify the range of values that can be measured in both rivers and groundwater. Over the Toulon Springs catchment, rivers are contaminated with nitrate coming from N synthetic fertilizer mineralized in agriculturalsoils. Most of the springs are also contaminated by this nitrate source, but some record an isotope composition of nitrate coming from sewage effluents. Toulon Springs are only contaminated with nitrate from N synthetic fertilizer mineralized in agricultural soils. Finally, from a hydrogeological point of view, the analysis of δ 15 N -NO3 − and δ 18 O -NO3 − values improves knowledge on the functioning of the study area and shows that the upper Jurassic karst confined aquifer has nitrate of the same origins (sources) as the upper Cretaceous unconfined aquifer. The results here highlight that the lower aquifer can be fed by the Upper Cretaceous unconfined aquifer, contrary to previous belief that the lower aquifer was confined. From a more fundamental standpoint, this work provides a set of parameters adapted for karstic hydrogeological catchment. It lays the foundation for the use of isotope biogeochemistry as a powerful tool for understanding the recharge of drinking water catchments and beyond the efficient management of water quality at the scale of karstic hydrogeological catchment.

Study of the Trends of Chemical–Physical Parameters in Different Karst Aquifers: Some Examples from Italian Alps

The results of a series of continuous characterizations of physical parameters (flow, temperature, water conductivity) and chemical analyses in water springs fed by karst aquifers located in the Piedmont region (northwestern Italy) are presented in this work. Rock masses in carbonate rocks, characterized by very different hydrogeological situations, linked to a different degree of karstification, fracturing, and development of the saturated zone, were examined. A series of data-loggers were installed, operating for several years, and different water sampling missions and subsequent chemical analyses (main ions, metals, and rare earth elements) under different hydrodynamic conditions were carried out. The results show very different trends of chemical–physical water parameters, particularly following significant infiltrative events. Aquifers characterized by a high karstification and reduced saturated zone highlight water mineralization decreases, even within a few hours, as a result of significant flow rate increases (prevalent substitution). Aquifers with a well-developed saturated zone, during an entire flood event, highlight an increase in mineralization linked to the remobilization of water present in the less permeable sectors of the aquifer (piston flow phenomenon). Lastly, aquifers fed by very fractured rocky masses and reduced karstification have a water flow rate with mild annual variations and constant chemical–physical parameters over time (homogenization phenomenon).

Problems Threatening Sustainability in Siwa Oasis and Recommendations for Understanding the Sources of Water Quality Deterioration

Siwa Oasis has been chosen as the location for the current investigations. Siwa Oasis is an isolated closed depression located in Egypt’s Western desert. It is surrounded by the Mediterranean Sea to the north (about 330 km), to the west by the Libya-Egypt border (70 km) and Cairo to the east (560 km). There are three major activities in Siwa Oasis: that are represented by agriculture (palm tree, olive, fruits and vegetables), industry, (e.g. mineral water bottling and olive oil extraction), and tourism (medical treatment, safaris). The climate of the Western Desert, particularly in Siwa, is generally torrid and arid. The Siwa depression is occupied by Quaternary deposits (aeolian deposits and lakes), Middle Miocene, Upper Cretaceous (sandstone), and Precambrian (basement complex). The groundwater system in Siwa Oasis hastwo main productive aquifers: a Miocene aquifer (fractured limestone) and a Lower Cretaceous aquifer (Nubian Sandstone). Besides, the Quaternary (clay and sand) uppermost layer is water-bearing because of waterlogging. Siwa Oasis is suffering from waterlogging, increasing soil salinity, and deterioration of water quality in the aquifers. This review includes the problems in Siwa Oasis and recommendations for understanding hydrogeological situations and sources of water quality deterioration to avoid waterlogging and soil salinization through integration of flow modeling, geochemistry and isotopic tracers.

The impact of petroleum contamination on the ecological conditions of the Dendrological park “Oleksandriya”

Within the territory of the Dendrological park Oleksandriya subsurface contamination with petroleum prod- ucts, the source of which is a former aircraft repair plant, has existed for a long time. The circumstances of the formation of ecological and hydrogeological situation on the territory of the dendrological park under the influence of petroleum con- tamination from the technogenic loaded area are considered in order to create the system of control of potentially negative impact on the environment and planning of remediation actions. The creation of the eco-industrial park Bila Tserkva will minimize the man-made impact on the state of the underground hydrosphere of the dendrological park.

Hydrogeological aspects of the hydrocarbon deposit formation within the northern framing of the Caspian Lowland

The formation of oil and gas deposits in the near-port zones of the Caspian Basin is associated with the generation of hydrocarbons in deep-submerged zones and its subsequent migration to the near-port zones. The migration of oil and gas occurs together with reservoir waters. Under these conditions, the identified gas-hydrochemical anomalies in the instrument zones of the depression are important in determining the routes of hydrocarbon migration and oil and gas accumulation zones. The article analyzes the hydrogeological situation in the subsalt Paleozoic sediments in the junction zone of the Volga-Ural anteclise and the Caspian basin, describes the salt composition of reservoir waters, and the composition of water-dissolved gases. The waters of anomalous composition are identified, which indicate the predominant migration of reservoir waters towards the Volga-Ural anteclise. In the Devonian sediments of the region, anomalies are distinguished by the appearance of reservoir waters of a reduced degree of metamorphization, or their reduced mineralization (desalinated water). The identified anomalies allow us to identify zones favorable for the migration of reservoir waters and hydrocarbons, zones of oil and gas accumulation. These studies can be used to interpret the results of geological exploration for oil and gas in the port zones of the Caspian Basin.

Hydrogeological dissimilarity of geodynamically different terranes

The article presents and analyzes the data on ground waters of active (suprapermafrost) and hindered (subpermafrost) water exchange of geodynamically different terrains in order to prove the hydrogeological importance of their historical and tectonic characteristics. On the example of Trans-Polar Chukotka it is shown that, under suprapermafrost conditions, the ubiquitous eluvial-deluvial nappes are the most water-abundant on the terrane – a fragment of the passive continental margin, whereas they are the least water-abundant on the terrains of the active margin. Hydrogeological situation changes under subpermafrost conditions: more permeable and water-retaining rocks compose the terranes of the active margin. These differences are associated with the level of rock tectonic decompaction and, accordingly, with different intensity of weathering processes in the terrane rocks of different geodynamic origin in suprapermafrost and subpermafrost conditions. The hypergenesis zone on the terranes of the passive continental margin features coarse-grained rock weathering products accumulated in relatively calm geological and historical environments, the aggregate is sandy. The terranes of the active margin, which underwent long-term subvertical and subhorizontal displacements contain more fine-grained weathering products; the aggregate includes sandy loam and clay sand. Since the permafrost strata in both Trans-Polar Chukotka and Eastern Siberia is greater than the depth of hypergene transformations, the terranes of the active continental margin, the rocks of which were impacted by tectonic decompaction processes, mainly of a strike-slip and thrust nature, feature greater water abundance in subpermafrost conditions.

Assessment of state of earth dam of Elchovka settling pond by combination of electromagnetic soundings and polarization methods

Earth dams are constantly under the hydraulic pressure. Their long-term operation leads to arising of zones of increased water cut and filtration in body and base of dams. This weakens dam’s strength. Geophysical methods can be used to control condition of the soil structures. We describe the research results of the Elchovka earth dam by a complex of electrometric methods, as they are most sensitive to changes in soil moisture. We applied the self-potential (SP) method, the vertical electrical soundings (VES) and the remote induction soundings (RIS) with the study of the frequency dispersion of electrical resistivity. Main pathways of the water filtration were identified by the self-potential method. According to the results of RIS, the boundary between bulk and natural soils as well as the boundary between sedimentary and bedrock are clearly distinguished. Electric soundings on direct current (VES) allowed us to localize places with reduced resistivities due to increased soil moisture. Frequency dispersion anomalies, which can also indicate water filtration in bulk soils and bedrock, were found. On the investigated dam, anomalies of the electrical conductivity and the frequency dispersion coincide with anomalies of the self-potential. This indicates increased filtration. Thus, the use of the remote induction soundings and the frequency dispersion methods together with widely applied VES and SP methods enhances the reliability of research and provides additional information about the hydrogeological situation in the area of the dam.

Analysis of water supply sources in Kormilov district of Omsk region

The article describes the sources of water supply inKormilovka district of Omsk region. The main sources of water are surface waters of the Om and Taburga rivers, lakes and artificial reservoirs, groundwater. In general, the territory of Kormilovka district lacks fresh groundwater. Currently, water is supplied by hydraulic structures on the Omriver as part of water intake and treatment facilities, water pipelines and a pressure distribution network. Water supply from underground sources is carried out from tubular wells with a depth of 5.0 - 9.0 m, from wells with a depth of 200 m and deep-water wells of about 1100 m. Water intakes from underground sources are available in almost all rural settlements, but they are used for technical and (or) economic purposes. An ecological assessment of the state of surface and underground sources isprovided. The results of an analysis of the geological and hydrogeological situation are presented. Of greatest interest are Neogene-Quaternary, Upper Oligocene-Lower Miocene and Lower Upper Cretaceous (Pokursky) complexes. According to the generalized characteristics of quality of groundwater from three underground aquifers in Kormilovka district, the most acceptable is the Pokursky aquifer, since itsgroundwaters are less mineralized, softer, more protected, and, consequently, their microbiological and parasitic indicators comply with the sanitary standards. When using both surface and groundwater for household and drinking purposes, it is environmentally safe for the population only after adjusting such indicators as turbidity, color, chlorine, iron, and dry residue content and bringing the microbiological indicators to SanPiN 2.1.4.1074-01 and SanPiN 2.1.4.544-96.

ГИДРОГЕОЛОГИЧЕСКИЕ УСЛОВИЯ МЕСТОРОЖДЕНИЯ "ОСЕННЕЕ"

The Osennoye field is located in the Dombarovsky district of the eastern Orenburg region. The territory under study is characterized by a sharp shortage of drinking and industrial water. This hinders the social and economic development of the territory. In complex natural and man-made conditions, the formation of surface and underground waters occurs on the area of the deposit. The purpose of the work is to analyze the hydrogeological situation of the territory in connection with the natural and man-made transformation of surface and underground waters of the studied territory. Research methods include zoning and mapping, routine monitoring of the quality of natural waters, and sources of pollution. As a result of the study, it was found that the surface and underground waters in the area of the deposit have a variegated chemical composition, depending on both natural and anthropogenic factors, this should be taken into account when planning the development of the productive forces of the territory. To improve the situation, it is necessary to introduce new technologies related to the replenishment of reserves at underground water intakes.

Groundwater as a source of water supply for the Krutinsky District of the Omsk Region

The paper presents the results of the analysis of geological and hydro-geological situation in the Krutinsky district of the Omsk region, as well as the assessment of the quality of groundwater in terms of environmental friendliness of their use for potable water supply. In hydro-geological terms, the research area is located within the Irtysh artesian basin, covering a vast territory in the south of the West Siberian lowland. The Cenozoic sediments that compose the described territory contain a number of underground reservoirs, horizons and water-resistant strata separating them. The waters of Quaternary, Neogene and Oligocene sediments are of practical importance as a source of water supply. Groundwater is exploited by wells and shallow waters (in Neogene and Quaternary sediments) are exposed and exploited by many shaft wells. The article provides a generalized characteristic of the quality of underground waters of Quaternary, Neogene and Paleogene deposits, as well as production wells drilled in the Krutinsky district of the Omsk region. As a result of research, it was found that groundwater does not meet the requirements of SanPiN 2.1.4.1074-01. The use of these waters for household and drinking purposes will be environmentally safe for the population only if such indicators as turbidity, color, chlorine, iron, dry residue and microbiological indicators are adjusted.

Monitoring of Groundwater Quality in Arsenic and Salinity Prone Areas of Jashore, Bangladesh

The groundwater contamination by arsenic is a large-scale pollution in drinking water history. Safe water supply is a big challenge due to critical hydrogeological situation and water quality problems in this area. The analytical results show that a range of pH, TDS, chloride, total alkalinity, total hardness, sodium, potassium, calcium, magnesium, manganese, iron and arsenic were found between 7.50-7.23, 504.00-201.00 mg/L, 90.30-31.43 mg/L, 410.81-174.31mg/L, 616.47-202.97 mg/L, 52.59-13.28 mg/L, 17.13-2.87 mg/L, 108.57-44.53 mg/L, 83.87-22.29 mg/L, 1.78-0.01 mg/L, 11.78-1.45 mg/L, 0.42-0.02 mg/L, respectively. This study will help making a future plan for groundwater quality monitoring and its hydrogeological application for safe water source identification

Monitoring of Groundwater Quality in Arsenic and Salinity Prone Areas of Jashore, Bangladesh

The groundwater contamination by arsenic is a large-scale pollution in drinking water history. Safe water supply is a big challenge due to critical hydrogeological situation and water quality problems in this area. The analytical results show that a range of pH, TDS, chloride, total alkalinity, total hardness, sodium, potassium, calcium, magnesium, manganese, iron and arsenic were found between 7.50-7.23, 504.00-201.00 mg/L, 90.30-31.43 mg/L, 410.81-174.31mg/L, 616.47-202.97 mg/L, 52.59-13.28 mg/L, 17.13-2.87 mg/L, 108.57-44.53 mg/L, 83.87-22.29 mg/L, 1.78-0.01 mg/L, 11.78-1.45 mg/L, 0.42-0.02 mg/L, respectively. This study will help making a future plan for groundwater quality monitoring and its hydrogeological application for safe water source identification

Drainage feasibility of a Carboniferous thin-layer limestone aquifer based on a dewatering test: Luxi coal mine, China

Mine water damage is one of the main disasters threatening mine safety during production. The key to mine water hazard prevention and control is determining the main aquifer characteristics that threaten the mine and the hydraulic connections between aquifers and water diversion channels and proposing appropriate preventive measures. This paper focuses on the 16104 working face of the lower coal group in the Luxi coal mine of Shandong Province. The main water-filled aquifer that threatens the no. 16 coal mine is the Carboniferous no. 14 limestone thin-karst aquifer. Before adopting hydrophobic pressure-lowering measures, it is necessary to determine the water yield characteristics of the no. 14 limestone aquifer, the strength of recharging, and the hydraulic connection with the Ordovician limestone aquifer and to analyze and evaluate the feasibility of dredging. First, various geophysical exploration methods were utilized to comprehensively identify the anomalous water yield areas of the aquifer, which were verified by drilling methods. By combining these results with drilling and geophysical results, appropriate drainage and observation holes were selected. Second, a special water discharge stage and sequence were designed to carry out water discharge testing. By analyzing the change of water discharge and water pressure in dewatering test and the change of conventional ion concentration in water samples, the hydrogeological parameters were obtained, the hydrogeological situation was ascertained and the hydraulic connection with the Ordovician limestone aquifer was determined. The drainage time required for the aquifer to attain a safe water pressure and the amount of hydrophobicity were calculated. Through combination with the obtained hydrogeological parameters, the feasibility of depressurization was analyzed. The results show that the water yield property of the no. 14 limestone aquifer is not high, but the connectivity is good. There is a hydraulic connection between the no. 14 and the Ordovician limestone aquifers, but the connection is weak. The no. 14 limestone aquifer of the entire working surface was drained at a rate of 240 m3/h, indicating that the aquifer has good depressurization properties.

The hydrogeological situation after salt-mine collapses at Solotvyno, Ukraine

Study regionThe study site is located in the south-western part of the Ukraine, in the area of the historical rock-salt mining town Solotvyno. The former mining area is situated in close vicinity to the River Tisza, the main tributary of the Danube River, the largest river in Europe. Study focusAfter uncontrolled flooding of several salt mines, a one month advisory mission was launched by the European Commission to estimate the impact of the abandoned salt mines (containing large quantities of salt water) on the environment. As a consequence of the flooding, dozens of sinkholes formed and sinkhole forming processes are ongoing, with sinkhole diameters reaching 250 m. As river contamination by the release of large quantities of saltwater would lead to an international disaster, hydrogeological measurements were taken on-site to study the system. New hydrological insights of the regionAt the study site, saturated (hyper-saline) water as well as fresh surface and groundwater were encountered in close vicinity to each other. Electrical conductivity, as a proxy for salinity, and temperature were measured on-site and water samples taken from surface-, ground- and mine waters were analyzed for chemistry and stable isotopes, providing new insights into groundwater flow dynamics. A conceptual model shows the salt dome, and potential flow paths from the mining area to the Tisza River, in the context of the mines and associated sinkholes potentially impacting the river water quality.

Application of isotope techniques to study groundwater resources in the unconsolidated aquifers along the Ping River (Thailand)

ABSTRACTSevere droughts during the dry season and floodings during the rainy season are among the major problems encountered in the valleys along the Ping River in Thailand. Improving our understanding of the groundwater resources in this agricultural area is an important issue for the sustainable development of the region. Hence, in order to gain understanding on the groundwater flow dynamics in the unconsolidated shallow aquifers along the Ping River, stable (13C, 18O, 2H, noble gases) and radioactive (3H, 14C) isotope techniques were combined with hydrogeochemical tools. The comprehensive interpretation of the chemical and isotope data consistently showed different origins for groundwater in the northern and southern areas of the investigated aquifers. Groundwaters in the northern part have younger 3H/3He ages, are less mineralized, and have suffered a stronger evaporation than groundwaters in the southern part of the aquifer. Overall, our results are consistent with the hydrogeological situation of the investigated area, namely shallow groundwaters and a spatially extended recharge. 3H/3He apparent ages indicated that young groundwater (<50 years) is present in all the investigated wells. Elevated concentrations of some pollutants (nitrate and phosphate) in parts of the aquifer evidenced a relatively high vulnerability of the aquifer to surface pollution.