scholarly journals GROUNDWATER VULNERABILITY ASSESSMENT OF SYLHET SADAR USING GIS

2020 ◽  
Vol 32 (2) ◽  
Author(s):  
Md. Ashikur Rahman ◽  
Md. Jahir Alam

Groundwater has been treated as a vital water supply because of its comparatively low vulnerability to pollution compared to surface water. Due to the health and economic impacts of groundwater contamination, steps to measure groundwater vulnerability are necessary for sustainable groundwater protection and management planning. In this study, an attempt has been made to assess groundwater vulnerability using the overlay index method and to prepare a groundwater vulnerability map using Geographic Information System (GIS) of Sylhet Sadar, a northeastern region of Bangladesh. Also, for the water depth-wise vulnerability assessment, the Water index was generated to observe the effect on chemical concentration for the depth of water. By assigning weight to each pollutant map in the overlay index approach, a combined hazard map was successfully created. The combined hazard map shows a total of 16.04%, 41.36%, and 42.59% of the studied area located in a less, moderate, and severely vulnerable zone, respectively. The combined effect of the chemical concentrations of water gradually decreases with the increase in water depth. Therefore, the developed map can be used as a tool for the management to take initiatives for sustainable use of groundwater.

2020 ◽  
Vol 32 (2) ◽  
Author(s):  
Md. Ashikur Rahman ◽  
Md. Jahir Alam

Groundwater has been treated as a vital water supply because of its comparatively low vulnerability to pollution compared to surface water. Due to the health and economic impacts of groundwater contamination, steps to measure groundwater vulnerability are necessary for sustainable groundwater protection and management planning. In this study, an attempt has been made to assess groundwater vulnerability using the overlay index method and to prepare a groundwater vulnerability map using Geographic Information System (GIS) of Sylhet Sadar, a northeastern region of Bangladesh. Also, for the water depth-wise vulnerability assessment, the Water index was generated to observe the effect on chemical concentration for the depth of water. By assigning weight to each pollutant map in the overlay index approach, a combined hazard map was successfully created. The combined hazard map shows a total of 16.04%, 41.36%, and 42.59% of the studied area located in a less, moderate, and severely vulnerable zone, respectively. The combined effect of the chemical concentrations of water gradually decreases with the increase in water depth. Therefore, the developed map can be used as a tool for the management to take initiatives for sustainable use of groundwater.


Groundwater is one of the important source to humankind, but there has been an increasing load to this precious resource which has become necessary to study it in detail. In the present study such an attempt has been made to account the groundwater vulnerability using as overlay index method, DRASTIC which is used to prepare a vulnerability map using GIS Technique for Mahi river basin, Rajasthan, India. This method accounts for the aquifer parameters like depth to water, net recharge, aquifer media, soil media, impact of vadose zone and hydraulic conductivity. The DRASTIC Vulnerability index (DVI) is calculated as the sum of product of ratings and weights assigned to each of the parameter on the scale of 1 to 10 and 1 to 5 respectively. The vulnerability index is then classified into five different classes and it was deduced that lies as Very Low (20.6 %), Low (28.23 %), Medium (29.11 %), High (18.82 %), and Very High (3.24 %) Vulnerability zones. Further research is conducted in order to assess the general threat to groundwater growth by the multiple industries, showing that the district will quickly collapse into a Exploited Zone, as the present pattern of growth in the agricultural and Industrial sector remains Continued. The map created for the sustainable use of the aquifer can be used as a managerial assessment in order to track and further Preventive Measures can be taken in advance to control the Growth of various Vulnerability Zones.


Author(s):  
Abdelhakim Lahjouj ◽  
Abdellah El Hmaidi ◽  
Ali Essahlaoui ◽  
M. J. B. Alam ◽  
Mohammed S. A. Siddiquee ◽  
...  

Author(s):  
Stefania Stevenazzi ◽  
Marco Masetti ◽  
Giovanni Pietro Beretta

Groundwater is among the most important freshwater resources. Worldwide, aquifers are experiencing an increasing threat of pollution from urbanization, industrial development, agricultural activities and mining enterprise. Thus, practical actions, strategies and solutions to protect groundwater from these anthropogenic sources are widely required. The most efficient tool, which helps supporting land use planning, while protecting groundwater from contamination, is represented by groundwater vulnerability assessment. Over the years, several methods assessing groundwater vulnerability have been developed: overlay and index methods, statistical and process-based methods. All methods are means to synthesize complex hydrogeological information into a unique document, which is a groundwater vulnerability map, useable by planners, decision and policy makers, geoscientists and the public. Although it is not possible to identify an approach which could be the best one for all situations, the final product should always be scientific defensible, meaningful and reliable. Nevertheless, various methods may produce very different results at any given site. Thus, reasons for similarities and differences need to be deeply investigated. This study demonstrates the reliability and flexibility of a spatial statistical method to assess groundwater vulnerability to contamination at a regional scale. The Lombardy Plain case study is particularly interesting for its long history of groundwater monitoring (quality and quantity), availability of hydrogeological data, and combined presence of various anthropogenic sources of contamination. Recent updates of the regional water protection plan have raised the necessity of realizing more flexible, reliable and accurate groundwater vulnerability maps. A comparison of groundwater vulnerability maps obtained through different approaches and developed in a time span of several years has demonstrated the relevance of the continuous scientific progress, recognizing strengths and weaknesses of each research.


2020 ◽  
Vol 53 (2E) ◽  
pp. 12-24
Author(s):  
Madyan Al-Gburi

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.


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