Hydrogeological Mapping Research Articles

Hydrogeological mapping of fracture networks using earth observation data to improve rainfall–runoff modeling in arid mountains, Saudi Arabia

Abstract Rainfall–runoff modeling is essential for the hydrological analysis of basins; however, the traditional modeling approach does not incorporate geological features such as fractures and fissures in the modeling task. These features are significant in the water loss during a rainstorm, which should be incorporated to obtain realistic rainfall–runoff results. A novel approach is presented here in to quantify the geological features and link them to the curve number (CN) method. The proposed methodology has not been applied in the literature. This approach is validated on five gauged basins, namely, Yiba, Al Lith, Liyya, Habawnah, and Tabalah, in the southwest part of Saudi Arabia. Four major stages are conducted. The first stage is the extraction of the geological lineaments using remote sensing and geographical information system technology; the second stage is estimating CN from rainfall–runoff data; the third stage is developing a relationship between CN and lineament density (LD); and the final stage is evaluating the developed equations on hydrological response. The least-squares method is employed to minimize the difference between observed and predicted runoff and determine the optimum range of CN. The research provides a comprehensive understanding of hydrological processes in fractured geologic systems and explores the influence of fractures on curve number. This study identifies two major lineament trends aligned with the Arabian trend direction, namely, north-northwest (NNW)–south-southeast (SSE) and north-northeast (NNE)–south-southwest (SSW). Furthermore, a moderate inverse correlation is established between LD and CN, highlighting the significance of geologic fractures on the hydrological response. The findings of this study provide insight into how the geological fissures in the mountainous region affected the rainfall–runoff response that leads to a low value of CN due to the water loss in the fissures and faults. As a result, this study clearly demonstrates the importance of the geological structures on rainfall–runoff responses.

Groundwater in Katowice - center of a large urban and deep coal mining area in Poland

The paper presents the groundwater resources of Katowice and the results of studies conducted to identify prospective areas in aquifers with sufficient water resources for the location of public water intakes. The city of Katowice is the capital of Upper Silesia, the largest urban-industrial area in Poland, the region with a highly developed hard coal mining and many other different industries covering almost the entire scope of the economy. Due to long term drainage of mines causing the depletion and deterioration of groundwater and surface water resources, the main municipal water intakes have been located outside Katowice. Most of the pumped mine water is discharged into surface waters, causing significant salinity of water and disallow its use for municipal or industrial purposes in Katowice. The water collection and supply system is very extensive and covers a significant part of the Silesian agglomeration which is why Katowice is supplied with water from surface water intakes located outside the city. According to older published materials, such as the Hydrogeological map of Poland, there were no aquifers in the city that could have been used to supply the city with drinking water, however recent studies have shown that groundwater in the Quaternary aquifers in the western part of the city can be used to supply the city with public water. Less productive, Quaternary aquifers in north-eastern parts of the city may constitute the basis for drinking water supply in emergency situations, when surface intakes cannot be used, such as toxic, radiological or viral contamination or damage to the water supply network eg. as a result of an earthquake or warfare.

Water Management in Hariwan Municipality of Nepal: Groundwater Harvesting from Riverbeds and Aquifers

Most of the regions of the Siwalik and Northern Terai (Bhabar) have a scarcity of water due to the water level beyond the suction limit of ordinary centrifugal pumping. In the present study, the Lakhandehi River section in the Sarlahi district is selected for shallow aquifer prospecting. The objective of this study was to assess potential zones of shallow aquifers including riverbeds. It was also aimed to assess the status of the existing subsurface water conditions, and distribution system, and find out suitable locations for groundwater harvesting and uses. The methodological part of the present study covers the field data collection and finding the appropriate shallow aquifer for groundwater extraction. In the field study, both the geological as well as hydrogeological maps were prepared on a 1:25,000 scale to assess the aquifer condition. A social survey was also carried out to find the most water scarcity areas and water availability conditions in the region. The main water scarcity area is found in the Hariwan Municipality, around the northern part of Bhabar and the southernmost region of the Chure region. The water insufficiency area for the present study was found in the places like Hariyon Khola section (Dumrighari), Sano Dume and Dume Khola sections (Samari Bhanjyang), Kothi Khola section (Kothikholagaun), and Attrauli Khola section (Atrauli village) of Hariwan Municipality due to the presence of impermeable layers in shallow depth. The concept of the development of swamp wells by retaining the groundwater flow from the shallow depth of the river channel is proposed in areas like the Samari Bhanjyang and Atrauli villages. Similarly, the development of shallow wells is proposed for the other two regions. To ensure a cost-effective water supply to the communities, it is advisable to implement a water lifting system to elevate the reservoir, followed by gravity-flow distribution.

Assessment of groundwater resources from geophysical and remote sensing data in a basement complex environment using fuzzy-topsis algorithm

This study addresses the pressing global water challenge by focusing on a typical basement complex area experiencing acute water shortage. Indiscriminate well siting without reliable hydrogeological maps has resulted in failed attempts to address water shortages. To overcome these challenges, this research aims to enhance the accuracy and reliability of groundwater potential assessments by incorporating crucial groundwater-related factors.The Fuzzy Technique for Order Preference by Similarity to Ideal Solution (FTOPSIS) method was adopted due to its ability to improve multi-criteria decision-making (MCDM) techniques for effective groundwater resource management. Unlike TOPSIS, FTOPSIS better reflects decision-makers' intentions, especially concerning geological boundaries and natural phenomena. To achieve the objectives of the study, geophysical and remote sensing datasets were utilized. The study employed the electrical resistivity method, utilising the Vertical Electrical Sounding (VES) technique with the Schlumberger array while the remote sensing data used were the Digital Elevation Model (DEM) image and Landsat ETM image which were processed to generate key groundwater conditioning factors. These factors were integrated using the FTOPSIS algorithm. This algorithm facilitated the calculation of the groundwater potential indices by assigning weights based on their level of significance to influencing groundwater potential in order to generate the groundwater potential map (GPM). The GPM was classified into five zones of varying groundwater potential, with very low and low potential occupying 74 % of the total area. Validation with well data yielded an impressive 79 % accuracy, showcasing the model's enhanced precision. Beyond improved accuracy, the study's implications extend to practical applications in groundwater resource management. By providing a clearer understanding of groundwater potentiality, the research can inform more robust decision-making frameworks, promoting sustainable water use not only in the study area but also in similar geological settings of the world.

Wykorzystanie metody radaru penetrującego grunt w badaniu gleby zanieczyszczonej węglowodorami w obszarze Navodari - Rumunia

Ground penetrating radar (GPR) is a very useful geophysical method for use in hydrogeologic and near-surface mapping studies. It can be used to study contaminants in groundwater, subsurface faulting, and underground cavities (natural or man-made), all of which pose potentially dangerous geological hazards. The GPR technique is similar in principle to seismic reflection and sonar techniques. The propagation of the radar signal depends on the frequency-dependent electrical properties of the ground.Electrical conductivity of the soil or rock materials along the propagation paths introduces significant absorptive losses which limit the depth of penetration into the earth formations and is primarily dependent upon the moisture content and mineralization present.Reflected signals are amplified, and transformed to the audio-frequency range, recorded, processed, and displayed. From the recorded display, subsurface features such as soil/ soil, soil/rock, and unsaturated/saturated interfaces can be identified. In addition, the presence of floating hydrocarbons on the water table, the geometry of contaminant plumes, and the location of buried cables, pipes, drums, and tanks can be detected. The GPR data are presented as a two-dimensional depth profile along a scanned traverse line in which the vertical axis is two-way travel time measured in nanoseconds. The location of hydrocarbon contamination in the ground using the GPR method is based mainly on information taken from reflected signals. In the cases investigated in Romania contaminated sites (Navodari area), such signals were very rarely recorded. A long time after spillage, contamination takes the form of plumes with different size and distribution, which depends on the geological and hydraulic properties of the ground. The survey discussed in this paper was carried out using the GPR system-Noggin with two antennas (250 and 500mHz) Data collected were processed using software(EKKO_Project™ GPR Data Analysis) to produce 2D radargram in time scale. The presence of contaminant plumes as well as the water table are observed in the GPR sections at depths approximately of 0.5 to 1.5 m. In the GPR section, the oil contaminated layer exhibits discontinuous, subparallel, and chaotic high amplitude reflection patterns. Promising results were also obtained in the GPR survey where three obvious reflection patterns representing the top sand-silt layer, oil-contaminated zone and, the underlying thick soft clay were detected in all 2D radargrams of the GPR traverse lines.

Analysis Of The Potential Of Volcanic Aquifers In Supporting The Development Of Groundwater Resources In Bogor District, West Java

This research is crucial for understanding the aquifer potential of volcanic deposits as a sustainable groundwater source, especially in regions experiencing rapid urbanization and agricultural expansion. It aims to analyze the aquifer potential of volcanic deposits in Bogor Regency, focusing on the Bogor Groundwater Basin, the upper Cisadane watershed, the eastern slopes of Mount Salak, and the western slopes of Mount Pangrango. The methods used include secondary data collection from regional geological maps and primary data collection through field surveys, geological mapping, and hydrogeological mapping. The results show that the volcanic rock units in this area, consisting of stony tuff, tuff breccia, lava, and andesite lava, have unique characteristics with significant potential as aquifers. Detailed geomorphological and hydrogeological mapping revealed different types of springs and physical properties of water that support the sustainability of groundwater resources. These findings contribute significantly to the development of better groundwater management policies, effective water infrastructure development, and environmental conservation strategies in Bogor District, ensuring clean water availability for the future.

A multi-method approach for assessing groundwater vulnerability of shallow aquifers in the Marchfeld region (Austria)

Study regionMarchfeld region (Austria) Study focusA multi-method and multi-scale assessment of the intrinsic groundwater vulnerability to generic pollutants was carried out. At the regional scale, a parametric method, to assess the intrinsic groundwater vulnerability, and a transfer function model, to assess the travel time of a generic and non-reactive pollutant through the unsaturated zone, were applied. At the site-specific scale, the travel time of the peak concentration was evaluated by using a physically-based hydrological model. The comparison of results of different approaches allowed mutual validation and advanced the knowledge about the assessment of groundwater vulnerability. New hydrogeological insights for the regionTo assess the groundwater vulnerability, a detailed hydrogeological map of the study area was reconstructed. A large variability of hydrogeological, morphological and anthropic conditions was recognized. Alluvial aquifers formed by high-permeability deposits hosting shallow groundwater circulation are characterized by the highest groundwater vulnerability. Contrarily, lower groundwater vulnerability was recognized for aquifers formed by low-permeability deposits, favoring a reduction of infiltration processes and a major attenuation of pollutants’ potential effects. The presented multi-method approach revealed how comparing the results of a DRASTIC-like method and two process-based models can deliver hints regarding their suitability, different spatial densities and quality of required inputs, and effectiveness. Finally, the potential strong impact of some agricultural practices was confirmed.

Effects of hydraulic conductivity on simulating groundwater–land surface interactions over a typical endorheic river basin

Hydraulic conductivity is the key variable in subsurface configuration that is important in modeling groundwater and its interactions with land surface processes. However, an acquisition of quantitatively distributed hydraulic conductivity is challenging due to limitations on data availability, accuracy and resolution, which inhibits an advanced understanding of hydrologic and energy cycles at the basin scale. This study investigated the role of hydraulic conductivity in simulating groundwater-land surface interactions over a typical endorheic river basin in northwestern China. A 3D variably saturated groundwater model coupled to a land surface model was configured to account for interactions between groundwater dynamics and land energy fluxes. Four scenarios of hydraulic conductivity were tested and inter-compared, adopting both homogeneous and heterogeneous parameterization strategies based on Global Soil Dataset for use in Earth System Models (GSDE) and HYdrogeology MaPS (GLHYMPS). The overall objectives are to diagnose effects of hydraulic conductivity on simulating groundwater–land surface interactions, with a particular focus on differences in spatial distributions and statistical characteristics between scenarios, as well as the dynamics and feedback mechanisms between groundwater and land surface energy fluxes. Comprehensive simulations and analyses were conducted to discern spatial distributions and statistical characteristics of key hydrological variables (streamflow, water table depth, latent heat flux, sensible heat flux) under different scenarios. Results showed that the hydraulic conductivity of the saturated zone had a significant control over water table depth, while the combine hydraulic conductivity in the vadose zone and the saturated zone governed the evolution of streamflow. Moreover, the water table critical range—where the land energy budget is highly sensitive to groundwater table—was 0.1 m–5 m and the area might expand approximately 4.5 % after considering the heterogeneity of hydraulic conductivity. Compared to the homogeneous scenario, the spatial heterogeneity of hydraulic conductivity amplified water table depth variability while diminishing land energy fluxes variability.

Investigating the Hydrological Relationship between the North Taihang Tunnel and Tianshengqiao Nine Falls

The impact of a tunnel construction on the groundwater system depends on various parameters and cannot be easily predicted. Along these lines, a deep understanding of the hydrological relationship between tunnels and surface water is considered of vital importance for ensuring safety during railway construction. Upon completion, the North Taihang Tunnel will be one of four extra-long railway tunnels running through the natural ecotope and level-3 protection areas of the Tianshengqiao National Geological Park in Fuping County, Hebei Province. It will be 1 km away from the Tianshengqiao Nine Falls, which is known as a breathtaking landscape feature in Northern China. Local government, societies, and railway design units have raised concerns about whether the construction and operation of the North Taihang Tunnel will affect the Tianshengqiao Nine Falls. To effectively address this issue, in this work, hydrogeological mapping and hydraulic potential-energy calculations were performed in conjunction with hydrochemical and geological structure analyses. The groundwater system units in the study area were divided and the water source of the nine-level waterfall was determined retrospectively. In addition, the recharge of groundwater to the nine-level waterfall was calculated, the hydrogeological properties of the linear structure were analyzed, and the dominant channels of underwater discharge in surface water were compared and studied. The extracted results indicated that: (1) The Tianshengqiao Nine Falls represent a seasonal fall landscape, which is mainly supplied by surface water formed by precipitation and a low proportion of groundwater supply. (2) The water bodies of the North Taihang Tunnel project and Tianshengqiao Nine Falls belong to two independent groundwater systems. (3) No linear structure that connects these two groundwater systems has yet been discovered. It is widely accepted that a minor possibility of hydraulic connection might be present between the North Taihang Tunnel and Tianshengqiao Nine Falls. This work analyzed the water quantity of Nine Falls, determined the hydraulic relationship between the tunnel project and the waterhead of the Nine Falls, and addressed all stakeholder concerns. The conclusions could provide technological support for the scheduled construction projects.

Prediction of Peak Discharge Using the SCS Curve Number Method in the Manikin Watershed

Surface runoff is a crucial hydrological variable in the analysis of water infrastructure planning. A reliable method for predicting surface runoff resulting from rainfall in an ungauged watershed is the SCS CN method. This research aims to represent the effectiveness of the Curve Number (CN) method in calculating peak discharge in the Manikin Watershed. The data used for this analysis includes rainfall data from three rain stations, each with a 25-year dataset, water level data of 11 years, digital elevation model (DEM) data, land use maps, and hydrogeological maps. The SCS curve number method is the most commonly used method for the estimation of peak discharge in a watershed. The calculated flood discharge values for the Manikin River Basin, with return periods of 5, 10, 20, 25, 50, 100, 500, and 1000 years, are as follows: 60.32 m3/s, 84.74 m3/s, 111.98 m3/s, 121.41 m3/s, 153.25 m3/s, 188.79 m3/s, 287.24 m3/s, and 337.30 m3/s, respectively. The reliability testing of the method in the Manikin Watershed was determined by a Nash–Sutcliffe efficiencies (NSE) value of 0.93 and root mean square error (RMSE) value of 19.70. As a result, the Curve Number Method proves to be highly reliable in representing the peak discharge in the Manikin Watershed.

Study on Migration Characteristics of Pollutants in Groundwater at a Proposed Hazardous Waste Landfill

Objective: The paper aims to analyze the hydrogeological conditions of a proposed hazardous waste landfill and the migration characteristics of lead, zinc, and nickel in fractured aquifers and porous aquifers under accident conditions and provide a reference for the influence of the proposed landfill on groundwater. Methods: In this study, based on a 1:50000 regional hydrogeological survey and 1:2000 site hydrogeological mapping, the hydrogeological conceptual model was established. Finite difference software GMS was used to analyze the migration characteristics. Results: The study demonstrated that when the pollutants in the hazardous waste landfill leaked, they migrated from northeast to southwest along the gully. The pollutants in the porous aquifer migrated quickly, and the polluted area expanded rapidly from point to surface. The pollutants migration in fractured aquifers was slow, and the groundwater quality was deteriorating continuously. During the simulation period, the pollutants of lead, zinc and nickel all polluted the aquifer. Among them, the lead pollution range w reported to be the largest, with an exceeding distance of 216.7 m; the zinc pollution range was the smallest, with an exceeding distance of 33.3 m, and the exceeding distance of nickel was 165.1 m. Conclusion: In order to ensure the safety of the groundwater environment in the simulated area, the impervious treatment must be carried out according to the requirements of the proposed hazardous waste landfill. Meantime, an emergency plan should be formulated.

The activity plan for the realization of the Hydrogeological Map of Italy at 1:500,000 scale

[Article in Italian] Le attività avviate per la realizzazione di una Carta Idrogeologica d’Italia alla scala 1:500.000

Geohydrologic units of Ischia Island (Southern Tyrrhenian Sea, Italy)

ABSTRACT The first hydrogeological mapping of Ischia Island at the 1:10,000 scale is presented and discussed. The ‘Map of the geohydrologic units of Ischia Island’ and the accompanying hydrostratigraphic sequence at a basin scale are based on the most recent geological maps and data from the CAR.G Project, and on new volcanological and hydrogeological surveys and studies. Data sources include the database stored by the INGV, Sezione di Napoli, Osservatorio Vesuviano and field investigations, including a survey of the springs and thermo-mineral springs which has been neglected up to now. In total 130 volcanostratigraphic units and 18 geohydrologic units were recognized; the distribution of fumaroles sites was enhanced, and 60 springs/thermal springs were identified/rediscovered. The proposed hydrogeological map provides an overview of the volcano-tectonic evolution of Ischia Island and upgrades the hydrogeological model, becoming a catalyst for the effort to acquire better data and to manage natural both resources and risks.

The impact of watershed characteristics on flood behaviour in the Noelmina River region

Timor Island has two river regions, one of which is the Noelmina River Region. There are 91 watersheds in the Noelmina River Region, covering a total area of 5,418.85 km2. Each watershed possesses unique characteristics that influence the amount of flood discharge. The key watershed features that can be analysed to assess their impact on floods include shape, area, river length, slope of the watershed, slope of the river, and runoff coefficient. The aim of this study was to identify the specific characteristics of watersheds within the Noelmina River Region that contribute to significant flood discharge. The study focused on examining 20 watersheds within the Noelmina River Region, utilising spatial data such as the Timor Island DEM, land use, and hydrogeological map. The rainfall analysis was performed using the Log Pearson III distribution method with a return period of 500 years. Analysis of flood discharge using the SCS-CN method. The results obtained are that the shape of the watershed, the land use, and the curve number values have a greater impact on the amount of flood discharge produced. The time required to reach peak flood discharge in the Noelmina River Region typically ranges from 7-12 hours.

Investigation of hydrogeology condition in Manikin Dam Diversion Tunnel, Timor Island, Indonesia: A Case Study

The seepages phenomenon happened in the construction site of the Manikin Dam Diversion Tunnel, Timor Island, Indonesia, has hampered the progress of construction. It seems impossible since the tunnel construction site was at the Bobonaro Complex. This condition leads to an investigate the possibility of another seepage occurrence along the tunnel construction site since more than 500 m long tunnel remains to be excavated. This study was conducted by direct observation method of the geological and hydrogeological conditions. Interpretation to direct field of geological mapping result, 10 borehole cutting samples, 6 lines of geo-electrical survey data, and face-mapping of tunnel excavation data resulting the surface and subsurface geological conditions. Hydrogeological mapping was performed to portray groundwater conditions at the tunnel site. The research reveals that the study area consists of scaly clay (fragmented with exotic block) and carbonate sandstone units. The scaly clay is impermeable, while the carbonate sandstone is permeable, but the fractured exotic blocks also act as an aquifer. The groundwater flows to the tunnel comes from this fractured zone in the exotic blocks. Based on this condition, other seepage phenomena could happen, as shown in the interpretation of the geo-electrical survey.

Analysis of hydrogeological conditions in the middle and upper reaches of the Xinachuan River Basin of the Huangshui River

Groundwater resources provide the basis for the development of industry and agriculture. It also plays a role in promoting urbanization. Groundwater investigation and hydrogeological research in the Xinachuan Basin of the Huangshui River can provide a hydrogeological basis for the development of urbanization. This study takes the middle and upper reaches of the Huangshui Xinachuan River Basin as an example. Based on field investigation data, this paper passes through hydrogeological mapping, hydrogeological drilling, pumping test, sample collection and other work. The hydrogeological conditions in the middle and upper reaches of Xinachuan River have been basically identified. Zone the loose rock pore water-rich section of the river valley. It is calculated that the amount of water inrush is greater than 5000m3/d. The degree of mineralisation is less than 0.5g/L. Excellent quality and abundant quantity. It can be used as urban drinking water and farmland irrigation water.

Identifying potential recharge areas of mountain springs through hydrogeological mapping

Springs are the primary source of water for the people inhabiting in the hills and mountain regions of Nepal. Climate variability, climate change, land use change and management factors together with various human activities including haphazard infrastructure development like urbanization and road construction over the recharge area are responsible for drying up of springs in the hills and mountains, especially in the mid-hill region of Nepal. This study attempts to identify the potential recharge zones of the springs within the four catchments viz. Banlekh and Shikharpur of Baitadi and Doti districts, respectively in far-western Nepal, and the Khaste and Begnas of Kaski district in western Nepal through hydrogeological mapping. Hydrogeological Conceptual Model was adopted while identifying the potential recharge areas. We measured the orientation of the rock outcrops, their types, and discontinuities found around the possible recharge areas. We prepared a conceptual hydro-geological layout of the spring-sheds based on the collected data, and delineated the potential recharge areas. We found the potential recharge zone of the Banlekh Springs at hill slopes and bedding plane within the catchment. However, the recharge zone of the Shikharpur Springs was found on the top and beyond the catchment due to the presence of a number of sinkholes. Moreover, the recharge zone of the Thulopadhero Spring was found to be controlled by the orientation of the rocks and fractures found in the unconsolidated sediments within the catchment and beyond the ridge of the escarpment. The rock orientation within the Falekund-Saunepani-Lapsibot Catchment suggests that the potential recharge zone of the springs consists of unconsolidated sediments. The identified potential recharge areas, the observed rainfall, and the discharge data on springs indicated that the recharge areas were more influenced by the local geology.

Groundwater Sustainability Assessment against the Population Growth Modelling in Bima City, Indonesia

Most of Indonesia’s population lives in areas with volcanic–alluvium geological characteristics. Based on the national hydrogeological map of the Indonesian Geological Agency, areas with volcanic–alluvium geological conditions have high groundwater potential and potential for groundwater damage. This study aims to test the resilience of groundwater areas with volcanic–alluvial characteristics to population growth. The MODFLOW groundwater model was built based on the site’s volcanic and alluvial geological conditions. This groundwater model was tested against pumping scenarios based on population water demand in 2011–2020 and then predicted population growth until 2030. The result shows that groundwater resilience in volcanic–alluvium locations has different characteristics based on lithology and population density characteristics. Urban areas that are mostly located in alluvium areas tend to have a linear groundwater decline pattern but have the sharpest groundwater decline gradient. In contrast, suburban areas in the alluvium-to-volcanic transition area initially experience exponential groundwater decline but change to linear, while rural areas located in volcanic areas that become the main development target have exponential groundwater decline characteristics. To counteract the continuous depletion of groundwater, researchers conducted a scenario for optimizing surface water use. Based on the results of the scenario, a 60% reduction in groundwater use is sufficient to stop continuous groundwater depletion. The results of this study can be used as a recommendation for long-term water resources management targets for volcanic and alluvium areas that are being targeted for development.

Хидрогеоложки условия в Ботевградската котловина

Groundwater in the Botеvgrad Kettle (West Bulgaria) is important for the local population. Despite the information available for this area, the catchment area of this kettle is poorly studied from a hydrogeological perspective. Therefore, the objective of this current study is to assess the hydrogeological conditions based on existing information for the purpose of better water resource utilization. Using GIS and data from the Geological Map 1:100000 and Hydrogeological Map 1:200000, water types in the Botеvgrad Kettle watershed and their spatial distribution in the area have been determined. The primary focus is on the region's most water-abundant hydrogeological unit, the Quaternary aquifer. Using various GIS layers that characterize spatial changes in hydrogeological characteristics, a conceptual model for this horizon has been developed, facilitating the initiation of activities related to numerical modeling.

Analisis Potensi Pencemaran Airtanah di Daerah Dok IV Kota Jayapura

Groundwater contamination is a threat that can endanger human health. Therefore, correct information is needed on the sources of groundwater used by the community. Seeing the development of the community around the Dok IV area which is very rapid and the use of groundwater which is quite large, it is necessary to carry out an investigation regarding groundwater in this area. This groundwater investigation aims to describe the hydrogeological conditions, to determine the chemical elements that are the pollutant load in groundwater and to determine the potential for seawater intrusion. The research method used is the hydrogeological mapping method, namely analysis of recharge and recharge areas, analysis of hydraulic slopes and well geometry. The subsurface investigation uses the subsurface estimation method with Ground Penetrating Radar (GPR). For chemical investigations carried out by taking groundwater samples and analyzing them at the Jayapura regional health laboratory.The results found showed that there were several chemical elements that exceeded the quality standard values. TDS increased in wells 1 and 2, iron increased in well 4, fecal coli in well 1 and coliform in all wells. Based on empirical calculations, the water absorption in this place is 4,069,391.723 m3. The presence of seawater is at a depth of 30 m, so it has not had an intrusive effect on groundwater.