scholarly journals Assessment of the Vulnerability of the Shallow Aquifer of the City of Sarh in Chad, using the Drastic Approach

2021 ◽  
pp. 1-10
Author(s):  
Abderamane Hamit ◽  
Mahamat Nour Abdallah ◽  
Moussa Abderamane ◽  
Tan-IM Abdallah Brahim ◽  
Bakhit Diki Bakay ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Unsaturated Zone ◽  
Critical Parameter ◽  
Groundwater Resources ◽  
Shallow Aquifer ◽  
Critical Factors ◽  
Drastic Model ◽  
Drastic Method ◽  
Vulnerability Map ◽  
The City

The demography (3.4%) and the development of anthropic activities in the city of Sarh, constitute a risk of groundwater pollution. That is why a vulnerability map is determined to contribute to the protection of groundwater resources against possible pollution for future decision and allocation of land and activities. The present study interested the city of Sarh and had the objective to elaborate a vulnerability map to pollution by applying the DRASTIC method. The data required for this study are summarized in seven critical factors specific to the model applied (depth of the water table, net recharge, aquifer lithology, soil type, topography (slope), unsaturated zone lithology and hydraulic conductivity). They were acquired from several sources and converted by the GIS into thematic maps. For each critical parameter, a coefficient and a weight were assigned according to its importance in the DRASTIC model. The resulting map shows three classes of vulnerability; 36% of the Sarh region has very low vulnerability, 35% has low vulnerability and 29% has medium vulnerability.

scholarly journals GROUNDWATER VULNERABILITY ASSESSMENT USING DRASTIC MODEL OF UP AL-KHASSA DAM SUB-BASIN, KIRKUK, NE IRAQ

2020 ◽  
Vol 53 (2E) ◽  
pp. 12-24
Author(s):  
Madyan Al-Gburi
Keyword(s):  
Vulnerability Assessment ◽  
Groundwater Vulnerability ◽  
Aquifer Vulnerability ◽  
Drastic Model ◽  
Drastic Method ◽  
Groundwater Vulnerability Assessment ◽  
Arc Gis ◽  
Vulnerability Map ◽  
Gis Software ◽  
Program Version

Several studies and assessments have been conducted of areas exposed to pollution, especially areas that contain aquifer. The final extraction of the vulnerability map of the groundwater was constructed through the use of the DRASTIC method by applying the linear equation of the seven coefficients in the Arc GIS software program (Version 10.4). The aim of the study to assess aquifer vulnerability to pollution. Results, vulnerability map range between 75-126 (very low, low, and medium), the study area consists of very low and low vulnerability, except some areas medium vulnerability close to the center of the sub-basin in the standard vulnerability map (s) and 91-149 (very low, low, and medium) for the agriculture or pesticide vulnerability map (p), the medium vulnerability occupies a greater area the center of the sub-basin.

scholarly journals Studi Kerentanan Air Tanah Terhadap Kontaminan Menggunakan Metode Drastic di Kota Pekalongan

Teknik ◽  
2016 ◽  
Vol 37 (1) ◽  
pp. 26
Author(s):  
Thomas Triadi Putranto ◽  
Dian Agus Widiarso ◽  
Fatir Yuslihanu
Keyword(s):  
Hydraulic Conductivity ◽  
Total Population ◽  
Shallow Groundwater ◽  
Groundwater Vulnerability ◽  
Unconfined Aquifer ◽  
Shallow Aquifer ◽  
The North ◽  
Drastic Method ◽  
Dug Wells ◽  
Aquifer Type

Kota Pekalongan berada di Pulau Jawa bagian Utara. Jumlah penduduk kota pekalongan setiap tahunnya mengalami peningkatan. Tahun 2008 jumlah penduduk Kota Pekalongan sebanyak 271.990 jiwa kemudian menjadi 290.347 di Tahun 2012.. Untuk memenuhi kebutuhan air, peduduk Kota Pekalongan menggunakan sumur gali yang menyadap air dari akuifer bebas atau akuifer dangkal. Air tanah bebas sangat rentan terhadap pencemaran akibat pengaruh letaknya yang dangkal dan aktivitas manusia. Oleh sebab itu diperlukan suatu kajian mengenai kerentanan air tanah terhadap kontaminan. Analisis dilakukan denganmenggunakan metode DRASTIC. Metode ini merupakan metode pombobotan berdasarkan beberapa parameter, yaitu: kedalaman muka air tanah (D), jumlah area recharge (R), litologi akuifer (A), jenis media tanah (S), topografi (T), jenis media zona tak jenuh air (I), dan konduktivitas hidrolika (C). Berdasarkan hasil analisis DRASTIC, terdapat tiga tingkat kerentanan yaitu: daerah tingkat kerentanan sedang dengan nilai DRASTIC Indeks (DI) 101-140, daerah tingkat kerentanan tinggi dengan nilai DI 141-180, dan daerah tingkat kerentanan sangat tinggi dengan nilai DI >180.[An Assessment of Groundwater Vulnerability of Contaminant Using DRASTIC Method in Pekalongan City] Pekalongan city which located on the north of Java Island is growing fast, in particular in the population growth. In 2008, total population in Pekalongan city was 271.990 inhabitants increased then up to 290.347 inhabitants in 2012. To fill the water necessary, people in Pekalongan city are using dug wells which are abstracted groundwater from the unconfined aquifer or shallow aquifer. Shallow groundwater can be vulnerabe which are influenced by surface and human activities. Thus, it requires an assessment of the groundwater vulnerability and risk of contaminant. It was analyzed by DRASTIC method. The DRASTIC method is applied by using weighted of some parameters, i.e.: groundwater Depth (D), amount of Recharge (R), Aquifer type (A), Soil type (S), topography (T), Impact of unsatuated zone (I), and hydraulic Conductivity (C). DRASTIC Index (DI) results in three vulnerability levels which are medium with DI 101-140, high with DI around 141-180 and above 180 for high vulnerable of contaminant.

scholarly journals Application of Aquifer Vulnerability Index (AVI) method to assess groundwater vulnerability to contamination in Semarang urban area

2018 ◽  
Vol 159 ◽  
pp. 01036 ◽  
Author(s):  
Thomas Triadi Putranto ◽  
Narulita Santi ◽  
Dian Agus Widiarso ◽  
Dimas Pamungkas
Keyword(s):  
Hydraulic Conductivity ◽  
Urban Area ◽  
Unsaturated Zone ◽  
Groundwater Vulnerability ◽  
Vulnerability Index ◽  
Aquifer Vulnerability ◽  
Vulnerability Map ◽  
Two Parameters ◽  
Sediment Layers ◽  
Sedimentary Layer

An approach to assess groundwater to contamination is developing groundwater vulnerability map. Groundwater vulnerability is formulated as an intrinsic relative, the dimensionless property of a groundwater system that depends on its sensitivity to unfavourable human and natural impacts. Thus, to assess groundwater vulnerability to contamination in Semarang urban area is the objective of this research by using Aquifer Vulnerability Index (AVI). This method considered of two parameters related to the unsaturated zone, i.e. thickness (d) of each sedimentary layer in the unsaturated zone and Estimated hydraulic conductivity (K) of these sedimentary layers. There are five levels of groundwater vulnerability by using AVI method, i.e. extremely low, low, moderate/medium, high, and extremely high. The thinner the layer covers the aquifer, and the higher the value of the hydraulic conductivity of sediment layers will be increasingly vulnerable to pollution.

scholarly journals Groundwater vulnerability assessment and mapping in shallow groundwater

2021 ◽  
Vol 926 (1) ◽  
pp. 012047
Author(s):  
K Aribowo ◽  
W Wilopo ◽  
D H Barianto
Keyword(s):  
Land Use Planning ◽  
Unsaturated Zone ◽  
Shallow Groundwater ◽  
Primary Source ◽  
Groundwater Vulnerability ◽  
Research Area ◽  
A Value ◽  
Groundwater Vulnerability Assessment ◽  
Vulnerability Map ◽  
Very High

Abstract The increasing population density can contaminate groundwater. So far, groundwater is still the primary source to fulfill clean water and drinking water in Muntilan, Salam, and Ngluwar Sub-District. Studies on groundwater vulnerability are essential to minimize the contamination risks as a piece of basic information for land use planning. This research aims to assess groundwater vulnerability in Muntilan, Salam, and Ngluwar Sub-District. The simple vertical vulnerability (SVV) method with GIS was selected to develop a groundwater vulnerability map. The parameters of this method consist of the type of soil/rock, the thickness of the water-unsaturated zone, and the recharge value. The results show that the research area can be divided into three vulnerability classes: very low, moderate, and high groundwater vulnerability. Very low groundwater vulnerability has a value of more than 70 with very high protection effectiveness. The class is distributed in Muntilan and Salam Sub-Districts. Moderate groundwater vulnerability has a value less than 35 to 65 with moderate protection effectiveness, and high groundwater vulnerability has a value ranging from 24 to 35 with low protection effectiveness. Both of the class is evenly distributed in Muntilan, Ngluwar and Salam Sub-Districts.

scholarly journals Hydrological processes and water resources management in a dryland environment IV: Long-term groundwater level fluctuations due to variation in rainfall

1999 ◽  
Vol 3 (3) ◽  
pp. 353-361 ◽  
Author(s):  
J. A. Butterworth ◽  
R. E. Schulze ◽  
L. P. Simmonds ◽  
P. Moriarty ◽  
F. Mugabe
Keyword(s):  
Groundwater Resources ◽  
Water Levels ◽  
Shallow Aquifer ◽  
Balance Model ◽  
Specific Yield ◽  
Evaporative Demand ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Modelling Methods

Abstract. To evaluate the effects of variations in rainfall on groundwater, long-term rainfall records were used to simulate groundwater levels over the period 1953-96 at an experimental catchment in south-east Zimbabwe. Two different modelling methods were adopted. Firstly, a soil water balance model (ACRU) simulated drainage from daily rainfall and evaporative demand; groundwater levels were predicted as a function of drainage, specific yield and water table height. Secondly, the cumulative rainfall departure method was used to model groundwater levels from monthly rainfall. Both methods simulated observed groundwater levels over the period 1992-96 successfully, and long-term simulated trends in historical levels were comparable. Results suggest that large perturbations in groundwater levels area a normal feature of the response of a shallow aquifer to variations in rainfall. Long-term trends in groundwater levels are apparent and reflect the effect of cycles in rainfall. Average end of dry season water levels were simulated to be almost 3 m higher in the late 1970s compared to those of the early 1990s. The simulated effect of prolonged low rainfall on groundwater levels was particularly severe during the period 1981-92 with a series of low recharge years unprecedented in the earlier record. More recently, above average rainfall has resulted in generally higher groundwater levels. The modelling methods described may be applied in the development of guidelines for groundwater schemes to help ensure safe long-term yields and to predict future stress on groundwater resources in low rainfall periods; they are being developed to evaluate the effects of land use and management change on groundwater resources.

scholarly journals Hydrogeological conceptual model of andesitic watersheds revealed by high-resolution heliborne geophysics

2019 ◽  
Vol 23 (5) ◽  
pp. 2321-2338 ◽  
Author(s):  
Benoit Vittecoq ◽  
Pierre-Alexandre Reninger ◽  
Frédéric Lacquement ◽  
Guillaume Martelet ◽  
Sophie Violette
Keyword(s):  
Hydraulic Conductivity ◽  
Conceptual Model ◽  
Preferential Flow ◽  
Groundwater Resources ◽  
Watershed Scale ◽  
Volcanic Island ◽  
Multidisciplinary Study ◽  
Hydrogeological Characteristics ◽  
Volcanic Islands ◽  
Very High

Abstract. We conducted a multidisciplinary study at the watershed scale of an andesitic-type volcanic island in order to better characterize the hydrogeological functioning of aquifers and to better evaluate groundwater resources. A heliborne Time Domain ElectroMagnetic (TDEM) survey was conducted over Martinique in order to investigate underground volcanic structures and lithology, characterized by high lateral and vertical geological variability and resulting in a very high heterogeneity of their hydrogeological characteristics. Correlations were made on three adjacent watersheds between resistivity data along flight lines and geological and hydrogeological data from 51 boreholes and 24 springs, showing that the younger the formations, the higher their resistivity. Correlation between resistivity, geology and transmissivity data of three aquifers is attested: within the interval 10–100 ohm m and within a range of 1 to 5.5 Ma, the older the formation, the lower its resistivity, and the older the formation, the higher its transmissivity. Moreover, we demonstrate that the main geological structures lead to preferential flow circulations and that hydrogeological watersheds can differ from topographical watersheds. The consequence is that, even if the topographical watershed is small, underground flows from an adjacent watershed can add significant amounts of water to such a catchment. This effect is amplified when lava domes and their roots are situated upstream, as they present very high hydraulic conductivity leading to deep preferential groundwater flow circulations. We also reveal, unlike basaltic-type volcanic islands, that hydraulic conductivity increases with age in this andesitic-type volcanic island. This trend is interpreted as the consequence of tectonic fracturing associated with earthquakes in this subduction zone, related to andesitic volcanic islands. Finally, our approach allows characterization in detail of the hydrogeological functioning and identification of the properties of the main aquifer and aquitard units, leading to the proposition of a hydrogeological conceptual model at the watershed scale. This working scale seems particularly suitable due to the complexity of edifices, with heterogeneous geological formations presenting high lateral and vertical variability. Moreover, our study offers new guidelines for accurate correlations between resistivity, geology and hydraulic conductivity for volcanic islands. Finally, our results will also help stakeholders toward a better management of water resources.

scholarly journals Technique of the rapid detection of groundwater based on multidimensional space

2019 ◽  
Vol 19 (7) ◽  
pp. 1986-1993
Author(s):  
Kang Wang ◽  
Qi-gang Jiang ◽  
Xiao-hui Yan ◽  
De-hao Yu ◽  
Fan Long ◽  
...  
Keyword(s):  
Groundwater Resources ◽  
Storage Conditions ◽  
Detection Methods ◽  
Multidimensional Space ◽  
Target Area ◽  
Well Completion ◽  
Exploration Drilling ◽  
Analysis Platform ◽  
The City ◽  
Preliminary Application

Abstract The ability to detect groundwater quickly and accurately is critical to the work of drought resistance. However, conventional groundwater detection methods are inefficient and costly. To solve the difficulties of using water in water-deficient areas, the method of rapid groundwater detection based on multidimensional space was presented. First, using satellite remote sensing (RS) technology, factors related to the occurrence of groundwater, such as lithology, structure, and landforms, were obtained. Then, through quantitative inversion of aeromagnetic data, the lithology and structure were improved. Using geographic information system (GIS) as an information analysis platform, the water storage conditions of various lithologies, structures, and landforms were comprehensively studied; and a water-rich target area was delineated. Based on the above-mentioned achievements, the ground geophysical prospecting work was carried out, the optimum well-position determined, and the target area accuracy verified by drilling data. The method integrates many technical means, such as satellite RS, airborne RS, ground physical exploration, and exploration drilling to detect groundwater, incorporating the advantages of each method. Through the preliminary application in the city of Beipiao, China, the well completion rate is 72.73%. High-quality groundwater resources were exploited in this area, proving it to be an effective method for accurately detecting groundwater.

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