scholarly journals Assessment of Groundwater Resources in Coastal Areas of Pakistan for Sustainable Water Quality Management Using Joint Geophysical and Geochemical Approach: A Case Study

2020 ◽  
Vol 12 (22) ◽  
pp. 9730 ◽  
Author(s):  
Muhammad Hasan ◽  
Yanjun Shang ◽  
Mohamed Metwaly ◽  
Weijun Jin ◽  
Majid Khan ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Seawater Intrusion ◽  
Saltwater Intrusion ◽  
Water Quality Management ◽  
Coastal Areas ◽  
Silty Clay ◽  
Freshwater Resources ◽  
Saline Groundwater ◽  
Wide Range

Delineation of fresh/saline groundwater is essential for sustainable water quality management, especially in the coastal areas all around the globe. Seawater intrusion causes substantial degradation in quality of freshwater resources in the coastal areas. The main reason for saltwater intrusion is the changing environment in terms of sea-level rise, climate change, and over-extraction of freshwater resources to meet the growing demands. In this study, an integrated approach of geophysical and geochemical methods was used to assess saltwater intrusion in the coastal areas of Bela Plain, Pakistan. The inverted electrical resistivity computed from 50 vertical electrical sounding (VES) constrained the subsurface into five layers and two aquifers through 3D imaging, such as silty clay and sandy clay containing saline water, and sand, sandy gravel, and gravel containing freshwater. However, the narrow range of resistivity values shows an overlap of saline/fresh groundwater. Such ambiguity in the resistivity interpretation was removed by Dar-Zarrouk (D-Z) parameters. D-Z parameters, namely transverse unit resistance (Tr), longitudinal unit conductance (Sc), and longitudinal resistivity (ρL) estimated from VES, marked a clear distinction between saline and fresh aquifers with a wide range of values. The geochemical method was performed using 20 water samples for the main cations (K+, Ca2+ Na+, and Mg2+), anions (SO42−, HCO3−, Cl−, and NO3−), and other parameters (TDS, EC, and pH). Fresh/saline aquifers revealed by D-Z parameters are in good agreement with those delineated by physicochemical parameters and local hydrogeological conditions. This study delineates seawater intrusion of about 13–42 km from Sonmiani Bay in the Arabian Sea towards the inlands of Bela Plain. Therefore, it is expected that this investigation will be helpful in future planning for the management and exploitation of freshwater resources in the study area. Our study suggests that D-Z parameters can be used as the most inexpensive alternative to the traditional geotechnical and environmental tests for the demarcation of fresh/saline groundwater with a large coverage in any coastal or contaminated area under a homogeneous or heterogeneous setting.

Water Quality Management of the Hooghly Estuary – A Linear Programming Model

1988 ◽  
Vol 20 (6-7) ◽  
pp. 235-242 ◽  
Author(s):  
S. K. Bose ◽  
P. Ray ◽  
B. K. Dutta
Keyword(s):  
Water Quality ◽  
Linear Programming ◽  
Quality Management ◽  
Programming Model ◽  
Water Quality Management ◽  
Treatment Plant ◽  
Linear Programming Model ◽  
Cost Of Treatment ◽  
Hooghly Estuary ◽  
Wide Range

Rapid and widespread deterioration of water quality in surface water systems has rendered mathematical modelling for predicting water quality indispensable especially in terms of bio-chemical oxygen demand (BOD) and dissolved oxygen (DO) under various system parameters. Model output under a prescribed set of conditions indicates the degree of treatment necessary to make the waste load acceptable. It also analyses the consequences of changes in water quality objectives from a cost/benefit viewpoint. The most appropriate model in this regard would be the one which takes into account the cost of treatment plant installations and their locations. This paper proposes a linear programming model for water quality management of the Hooghly estuary. The linear objective function for the total cost of treatment at selected terminals has been expressed in terms of quantity of BOD removed. Computed data have been presented under reasonably wide range of parameters.

scholarly journals Geophysical Assessment of Seawater Intrusion into Coastal Aquifers of Bela Plain, Pakistan

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3408
Author(s):  
Muhammad Hasan ◽  
Yanjun Shang ◽  
Weijun Jin ◽  
Peng Shao ◽  
Xuetao Yi ◽  
...  
Keyword(s):  
Seawater Intrusion ◽  
Saline Water ◽  
Physicochemical Analysis ◽  
Coastal Areas ◽  
Saline Aquifers ◽  
Freshwater Resources ◽  
Transverse Resistance ◽  
Wide Range ◽  
Electrical Sounding ◽  
Over Exploitation

Seawater intrusion is a major challenge in many coastal areas all around the world, mainly caused by over-exploitation of freshwater resources, climate change, and sea-level rise. Consequently, seawater intrusion reaches several kilometers inland, thus making the freshwater resources polluted and unsuitable for human use. Conventionally, the fresh-saline water interface is delineated by the number of laboratory tests obtained from boreholes. However, such tests suffer from efficiency in terms of data coverage, time, and cost. Hence, this work introduces Dar-Zarrouk (D-Z) parameters, namely transverse resistance (Tr), longitudinal conductance (Sc), and longitudinal resistivity (ρL) computed from non-invasive vertical electrical sounding (VES). Two-dimensional (2D) imaging of D-Z parameters provides a clear distinction of fresh-saline aquifers. Such techniques remove ambiguities in the resistivity interpretation caused by overlapping of fresh and saline aquifers during the process of suppression and equivalence. This study was carried out by 45 VES along five profiles in the coastal area of Bela Plain, Pakistan. D-Z parameters delineate fresh, brackish, and saline aquifers with a wide range of values such as freshwater with Tr > 2000 Ωm2, Sc < 3 mho, and ρL > 20 Ωm; saline water with Tr < 1000 Ωm2, Sc > 25 mho, and ρL < 5 Ωm; and brackish water with Tr between 1000–2000 Ωm2, Sc from 3 to 25 mho, and ρL between 5–20 Ωm. The D-Z results were validated by the physicochemical analysis using 13 water samples and local hydrogeological setting. The obtained results propose that D-Z parameters can be used as a powerful tool to demarcate the fresh-saline aquifer interface with more confidence than other traditional techniques. This geophysical approach can reduce the expensive number of borehole tests, and hence contributes to the future planning and development of freshwater resources in the coastal areas.

Water Quality Management – A Total Catchment Management Approach

1989 ◽  
Vol 21 (2) ◽  
pp. 281-288 ◽  
Author(s):  
W. J. Hawkins ◽  
D. A. Geering
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Water Quality Management ◽  
Management Approach ◽  
Catchment Management ◽  
Know How ◽  
Wild And Scenic Rivers ◽  
Resource Managers ◽  
Resource Protection ◽  
Development Resource

Water quality standards set in the past have not helped resource managers in the decisions that they face in seeking sustainable development. Resource managers are looking for meaningful information on water quality so as to evaluate the resource, set priorities for action, and to monitor progress. Resource managers need to know how water quality affects, and is affected by, catchment uses and activities. Examples of three wild and scenic rivers, the Nymboida, Murrumbidgee, and Hawkesbury/Nepean River systems, demonstrate how a ‘Total Catchment Management' approach to resource use and resource protection has advantages for water quality management.

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