Mapping of groundwater potentiality index parameters using remote sensing and GIS techniques in the southern mountain, Yogyakarta Special Region

In the hydrogeological map sheet of the Special Region of Yogyakarta, the Mountain Zone is categorized as an area of scarce groundwater. This research is intended to determine the parameters of groundwater potential in the area of scarce groundwater according to the Groundwater Potentiality Index (GPI) methods, including; fractures, lithology, slope, topography, and rainfall. Fracture parameters, distribution, and topography were collected from the Indonesia Geospatial Portal and the Digital Elevation Model (DEM). The lithological parameters were obtained from data from the Geological Agency due to the Interpretation of Remote Sensing Images. Rainfall data for the last ten years was obtained from reports. Results show that most of the research area is a fairly massive rock area, and there are some local faults. The lithological parameters indicate that the research area is composed of breccias, sandstones, and tuffs. Distribution parameters obtained information that most distribution is notated river orders 1, 2, and 3 with several river orders notation 4, 5, and 6. The slope varies from <3% to> 65%, and the intensity of rainfall almost evenly ranges from 1600-2100 mm/year.

Transient Electromagnetic (TEM) Surveys as a First Approach for Characterizing a Regional Aquifer: The Case of the Saint-Narcisse Moraine, Quebec, Canada

Geological contexts that lack minimal stratigraphic and piezometric information can be challenging to produce an initial hydrogeological map in remote territories. This study proposes an approach to characterize a regional aquifer using transient electromagnetic (TEM) surveys. Given the presence of randomly dispersed boreholes, the Saint-Narcisse moraine in the Mauricie region of Quebec (Canada) is an appropriate site for collecting the required geophysical data, correlating the stratigraphic and piezometric information, and characterizing regional granular aquifers in terms of stratigraphy, geometry, thickness, and extent. In order to use all TEM results (i.e., 47 stations) acquired in the moraine area, we also correlated 13 TEM stations, 7 boreholes, and 6 stratigraphic cross-sections to derive an empirical and local petrophysical relationship and to establish a calibration chart of the sediments. Our TEM data, combined with piezometric mapping and the sedimentary records from boreholes and stratigraphic cross-sections, revealed the compartmentalization of a multi-kilometer morainic system and indicated the presence of two large unconfined granular aquifers overlying the bedrock. These aquifers extend more than 12 km east to west across the study area and are between 25 and >94 m thick. The TEM method provides critical information on groundwater at a regional scale by acquiring information from multiple stations within a short time span to a degree not possible with other existing methodologies.

Total Alpha activity and Radon-222 activity in the underground water of some regions of Ukraine

Objective: We aimed to analyze the results of the measurements of the total alpha activity and activity of radon-222 in the water of artesian wells to establish the geographical regions of Ukraine which require a deep attention to the assessment of the radioactivity of the groundwater. Methods: We used empirical, analytical, radiometric, spectrometric methods and method of mathematical statistics in the study. Materials: We carried out a statistical analysis of the results of the measurements of the total alpha activity and the activity of radon-222 in water samples from the artesian wells of 23 administrative regions of Ukraine studied during 2016 - 2020. Results: Analysis of the results of the measurements of the total alpha-activity and radon-222 activity in the water of artesian wells showed their significant heterogeneity for different regions of Ukraine and a connection with the geological features of the area. The statistical distribution of the values of the total alpha activity and the activity of radon-222 in water samples, diagrams of the range of measured values within the regions of Ukraine and between regions are presented in the work; the measurement results were plotted on the hydrogeological map of Ukraine. Conclusion: The values of the total alpha activity and the activity of radon-222 indicate that these indicators are extremely heterogeneous for the territory of Ukraine and reflect the geological features of the area. The results of the analysis can be useful for making recommendations to collective and individual water consumers, well owners regarding the need in more detailed study of the content of natural radionuclides in the sources of water and the use of the appropriate methods of water treatment in cases of non-compliance with the accepted standards. It is shown that it is necessary to develop a strategy for radiation monitoring of the groundwater quality in the country in order to study objectively the existing state and the achievement of an acceptable quality of the water consumed by the population.

Combining of MASW and GPR Imaging and Hydrogeological Surveys for the Groundwater Resource Evaluation in a Coastal Urban Area in Southern Spain

This paper conceptualizes and evaluates the groundwater resource in a coastal urban area hydrologically influenced by peri-urban irrigation agriculture. Adra town in southern Spain was the case study chosen to evaluate the groundwater resource contributed from the northern steep urban sector (NSUS) to the southern flat urban sector (SFUS), which belongs to the Adra River Delta Groundwater Body (ARDGB). The methodology included (1) geological and hydrogeological data compilation; (2) thirteen Multichannel Analysis of Surface Waves (MASW), and eight Ground Penetrating Radar (GPR) profiles to define shallow geological structures and some hydrogeological features; (3) hydrogeological surveys for aquifer hydraulic definition; (4) conceptualization of the hydrogeological functioning; and (5) the NSUS groundwater resource evaluation. All findings were integrated to prepare a 1:5000 scale hydrogeological map and cross-sections. Ten hydrogeological formations were defined, four of them (Paleozoic weathered bedrock, Pleistocene littoral facies, Holocene colluvial, and anthropogenic filling) in the NSUS contributing to the SFUS. The NSUS groundwater discharge and recharge are, respectively, around 0.28 Mm3 year–1 and 0.31 Mm3 year–1, and the actual groundwater storage is around 0.47 Mm3. The groundwater renewability is high enough to guarantee a durable small exploitation for specific current and future urban water uses which can alleviate the pressure on the ARDGB.

Hydrogeology of the southern Middle Tiber Valley (Central Italy)

The aim of this work is to contribute to the hydrogeological knowledge regarding the southern Middle Tiber Valley focusing on the continental and marine units that fill the Paglia-Tiber graben in the northern Latium Region (central Italy). An important hydrogeological survey was performed in the summer of 2008, and a considerable quantity of piezometric, physio-chemical and flow data were collected. Four geological cross sections were realized, and a hydrogeological map and a groundwater quality map of the area were produced to obtain a conceptual groundwater flow model.

Hydrometeorological factors determining the development of water table cave patterns in high alpine zones. The Ordesa and Monte Perdido National Park, NE Spain

This study is focussed on the geomorphological characterization and the processes driving the evolution of the highest karst system in Western Europe, which is located in the Ordesa and Monte Perdido National Park (PNOMP), in the central-southern Pyrenees. The karst system does not seem to have a well-developed epikarst. The studied area shows a karst network of polygenic branchwork type in the vadose zone. Additionally, the explored karst conduits in the epiphreatic zone show a water table cave pattern that is different to the looping one, which is the expected cave pattern development for a karst located in a mountain zone where a high irregular recharge is expected. We have designed a conceptual recharge model through a multidisciplinary approach, which has included the making of a new detailed geological and hydrogeological map of the study area, morphometric analysis of cavities, tests with fluorescent dye tracers and hydrometeorological monitoring of the karst system associated with the Garcés Spring. This spring, together with the Font Blanca Spring, constitutes the main water discharge point of the hydrogeological system. The conceptual recharge model explains how the observed unexpected cave pattern has developed in this karst.

Hydrogeological setting of a Rome city sector: shallow groundwater in the right side of Tiber River inside the G.R.A highway

This paper presents a detailed hydrogeological study of a Rome city sector, in the right side of Tiber River, inside the G.R.A. highway. A hydrogeological model of this city sector has been developed through geologic-stratigraphical analysis also of data provided by the Environmental Protection Department of Roma Capitale (Municipality of Rome) and the observation of historical topographic and thematic maps. This model is more detailed than the most recent Hydrogeological Map of Rome (1:50.000 scale), published in 2015, and allowed identifying the shallowest groundwater flow systems for the first time. This detailed model can be a very useful tool for agencies and administrations managing the protection of groundwater resources.