Preliminary Conceptual Model of Hydrogeological System in The Raimanuk and its Surrounding Area on the Timor Island

There are several areas with groundwater potential in Timor island, one of which is the Raimanuk and its surrounding area. This study aims to determine the hydrogeological system in the Raimanuk and its surrounding area. The hydrogeological system is determined by the geological conditions, geomorphology, lithology, and groundwater flow patterns. Geological conditions and groundwater flow patterns are provided by conducting a field investigation. Twenty shallow wells and four springs were measured to provide the groundwater contour. The geoelectrical survey was conducted at eleven points to analyze subsurface lithology. The results show that the geology of the study area is dominated by alluvium (west area), carbonate siltstone, and crystalline limestone (middle to the east area). There are two types of aquifers in the study area: unconfined aquifers and confined aquifers with gravel sandstone lithology. The groundwater flow pattern shows that the groundwater movement is from the east to the southwest. Moreover, the groundwater also moved from the northern, southern, and western of the study area. It is implied that the aquifer’s shape at the Raimanuk area is formed as a bowl-like shape influenced by the geological, geomorphological conditions.

Building a mathematical model for the free groundwater Resources of the plain area in the lattakia basin: بناء نموذج رياضي لموارد المياه الجوفية الحرة للمنطقة السهلية في حوض اللاذقية

The results of the stratigraphic modeling of the study area showed that the stratigraphic formations constitute a hydrogeological system that is hydrodynamically linked to each other represented by a water layer with a free underground flow. The results of the mathematical model that was built for the region also showed that the high values of the leaching factor were concentrated in the northern and central part of the research area, where the faults were located, the difference between the input values and the calibration results in most areas of the hydraulic conductivity distribution of the layer did not exceed 10%. The water resources in the northeastern part of the study area are of good quality, large quantities, and easy to invest, with a total intake of (134607.3) m3/day. The thickness of the carrier ranged about 50 m in the northern section and increased towards the area of the falcon band within the course of the Arab River to reach about 125 m. As for the thickness of the carrier in the southern section, it ranged between (75 – 60) m. the groundwater system in the study area is stable, and the largest part of the amount of water resources formed in the region to the lateral inflow of the ground and and amounted to about 90% of total value of the resources.

Groundwater-Surface Water Interaction in the Nera River Basin (Central Italy): New Insights after the 2016 Seismic Sequence

The highest part of the Nera River basin (Central Italy) hosts significant water resources for drinking, hydroelectric, and aquaculture purposes. The river is fed by fractured large carbonate aquifers interconnected by Jurassic and Quaternary normal faults in an area characterized by high seismicity. The October 30, 2016, seismic sequence in Central Italy produced an abrupt increase in river discharge, which lasted for several months. The analysis of the recession curves well documented the processes occurring within the basal aquifer feeding the Nera River. In detail, a straight line has described the river discharge during the two years after the 2016 seismic sequence, indicating that a turbulent flow characterized the emptying process of the hydrogeological system. A permeability enhancement of the aquifer feeding the Nera River—due to cleaning of fractures and the co-seismic fracturing in the recharge area—coupled with an increase in groundwater flow velocity can explain this process. The most recent recession curves (2019 and 2020 periods) fit very well with the pre-seismic ones, indicating that after two years from the mainshock, the recession process recovered to the same pre-earthquake conditions (laminar flow). This behavior makes the hydrogeological system less vulnerable to prolonged droughts, the frequency and length of which are increasingly affecting the Apennine area of Central Italy.

Hydrogeological Risk Assessment for Groundwater Conservation in the Northeastern Slope Area of Mount Arjuno, Pasuruan Regency, East Java, Indonesia

The northeastern slope of Mount Arjuno, Pasuruan district, East Java province, Indonesia represents a vast and good groundwater resource quality, generally be exploited by some companies for drinking water industries. Water unbalance and quality degradation is presumed to arise because groundwater extraction volume is getting bigger but less control by the regency authority. This study is to figure out the geologic condition and hydrogeological system, conduct groundwater exploitation risk assessment, and develop a conservation program. The study results show that the study area's geomorphological units can be divided into the volcanic summit, volcanic slope, fluvial plain, and anticlinal hills. The lithology comprises sandstone, breccia, and andesite lava of Mount Arjuno and Mount Welirang. The geological structures are anticline, normal fault, and lateral slip fault. Hydrologically, there are three watersheds, including Lumbangrejo, Ketanireng, and Prigen watersheds. The aquifers comprise unconfined to semi-confined aquifers with fissures and intergranular porosity. Based on risk assessment valuation, Pecalukan village of the Ketanireng watershed and Lumbangrejo village of the Lumbangrejo watershed are categorized as very high groundwater vulnerability zones, Karangrejo and Sukoreno villages of the Lumbangrejo watershed, Kedungringin, Kepulungan, and Gunungsari villages of the Ketanireng watershed are categorized as medium vulnerability zone. While, Ngorong village of the Lumbangrejo watershed, Gempeng, Oro-Ombo, Kalisat, and Dukuhsari villages of the Prigen watershed belong to the low vulnerability zone. The proposed conservation programs involve profitable water use safety campaigns, domestic waste, and industrial wastewater management, agricultural activities controlling, sandstone mining regulation, and reforestation.

EFFECTIVENESS OF A MODERN LANDFILL LINER SYSTEM IN CONTROLLING GROUNDWATER QUALITY OF AN OPEN HYDROGEOLOGICAL SYSTEM, SE LITHUANIA

The work analyzes data of environmental geological mapping, groundwater monitoring of the region municipal waste landfill. This study examines the effectiveness of a modern landfill liner system in minimizing migration of pollutants in the groundwater of an open hydrogeological system. The results showed that dissolution of carbonates and dilution were the major processes controlling groundwater quality. In the landfill’s direct impact zone, groundwater was only weakly polluted with biogenic components. Increase in concentrations of these chemical components in this zone was related with the groundwater and surface runoff water flowing from adjacent areas. We can state that the modern landfill liner system we analysed is efficient and has no adverse effects on groundwater quality under hydrogeological conditions favourable for the spread of pollutants. However, in case of an accident, pollutants might pose a great threat on the safety of groundwater. Therefore, even modern landfill liner systems are not recommended to be constructed in open hydrogeological systems.

Hydrogeological System of Injana Formation in Salahaddin Governorate/ Iraq

Injana Formation is the most extended geological formation in Salahaddin Governorate/ Iraq. About 10% of the studied area is covered by the outcrops of the formation as a recharge area. The formation is a subsurface within the unsaturated zone in 5% of the total studied area, while it exists within the saturated zone in about 85%; it is a major confined groundwater aquifer. Therefore, the hydrogeological system of the layers needs to be re-evaluated to describe the successions of aquifers and confining layers and their relation with each other. The lithology, depths, water table, saturated thickness, hydraulic characteristics of the aquifers, and the lateral and vertical variations of these characteristics were adopted to classify the hydrogeological system. The lithological composition is mainly composed of alternating successions of claystone, siltstone and sandstone with some differentiation within the studied area. The Quaternary and, occasionally, the Mukdadiya Formations are dry or of secondary aquifer, except in limited areas of the governorate. Injana Formation represents the major upper aquifer in the area, especially in the western bank of Tigris River. The outcrops of the formation are adjacent to Makhul and Hamrin anticlines; while Al-Tharthar valley represents a recharge area for the groundwater. In the remaining parts of the studied area, the formation represents the main deeper of a confined to semi-confined groundwater aquifer. The general direction of the groundwater movement in this hydrogeological system is towards the discharge area represented by Tigris River and Tharthar Lake, which is compatible with the topographic slope. The formation is classified as a multi-layer aquifer hydrogeological system.

A GIS-BASED DRASTIC MODEL: THE BOUMAIZA PLAIN (NORTH-EAST ALGERIA)

The plain of Boumaiza is located in the north east of Algeria in the wilaya of Skikda. This region is characterized by agricultural activity and is subject to a mediterranean climate. This agricultural development is liable to contaminate the groundwater heavily loaded by the local population for its drinking water needs. In order to highlight the state of vulnerability to groundwater pollution of the captive aquifer, which is composed of sands and gravels and pebbles, it is based on a marly substratum, GIS-based DRASTIC Index method has been applied in the aquifer of Boumaiza Plain. This method is presented in the form of numerical rating systems based on consideration of the different factors influencing the hydrogeological system, where a note and a weight are affected and varying with each parameter used. This method is based in the parameters like depth to the groundwater, net recharge, Aquifer media, soil media, topography, impact of the vadose zone, and hydraulic conductivity. The results show that the study area is characterized by a low and medium vulnerability to pollution.

Impact of climate change on the water balance of the Apuo-Versilia plain acquifer (Tuscany, Italy)

The authors drafted the water balance of the multi-layer aquifer of the Apuo-Versilia Plain, (Provinces of Lucca and Massa- Carrara) extending for about 152 km2. The water budget, relating to the average year of the period 2010-2012, includes both natural and anthropic terms. Availability of data allowed to calculate with a good approximation some terms (rain water infiltration, groundwater pumping, losses of aqueduct pipelines and sewers) while others (infiltration from water courses, draining of land reclamation systems) have been calculated with methods designed ad hoc but with poor validation. The budget closes with a positive balance of 56 million m3/year, which correspond to the outflow from the aquifer to the sea minus the marine intrusion: there is no data to calculate this term, which we have taken as the unknown term of the balance equation. Therefore, the budget is rough, but it allowed us to estimate the effects of climate change for two decades in the near future (2030-2040 and 2050-2060) according to two emission scenarios, RCP4.5 and RCP8.5: the recharge would be reduced 11% in 2036 and 15% in 2056. In these budgets, we have not considered the variations in anthropic terms because we have no elements to predict them. Climate change, which also will bring about an increasing of marine intrusion, will probably cause a greater use of groundwater. This could alter the balance of the hydrogeological system, which has so far shown a substantial stability, as demonstrated by the monitoring of piezometric levels in the Plain.

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.

Groundwater Withdrawal-Induced Land Subsidence

This entry presents a comprehensive review of models used to predict land surface displacements caused by rock mass drainage, as well as (2) recent advances and (3) a summary of InSAR implementation over recent years to support the aquifer compaction modelling process. Therefore, the study presented would be of benefit to readers who are interested in the topic of interaction between the human population and the hydrogeological system in different regions. The research presented allows readers to better understand the factors, developments and effects of groundwater drainage and thus facilitate large - scale risk assessment and preventive planning.