International Journal of Environment (ISSN: 2186-0009)  


Landuse changes over 21 years and impact on groundwater aquifer in and around Cox's Bazar town, Bangladesh
Ashraf Ali Seddique, S.K. Sabbir Hossain, M.R Shaibur, M. Ashraful Haque, K. Matin Ahmed, Nur Alam, and Moklesur Rahman
Abstract:
In recent years, landuse pattern of the Cox's Bazar town has changed significantly where with the rapid expansion of settlement area. To explore the environmental consequences of landuse changes were assessed in the Cox's Bazar town and its adjoining area at south-eastern part of Bangladesh. Archived remotely sensed images of Landsat 4 & 5 TM during the period of 1989-2010 and QuickBard QB1 of 2011 were interpreted using ERDAS Imagine image processing software along with ArcGIS 9.3.1 to produce landuse maps of the area. Due to rapid expansion of urbanization, the impact on groundwater aquifer was also assessed by the changes of groundwater level (GWL), and electrical conductivity (EC). Landuse maps derived from Landsat imageries for 1989 to 2010 shows that landuse change pattern has increased substantially over the last 21 years. Due to the rapid urban sprawl, the agricultural land has a net decrease of 61.46%, settlement has increased by 245.64% and water bodies have decreased 63.41%. Detailed landuse map based on QuickBird image of 2011 shows that the main landuse was settlement (49.25%), agricultural (21.30%), and water bodies (5.03%). High EC values ranged from 300-2200μS/cm (in dry season) to 200-1800μS/cm (in wet season) during 2012 and also EC (with maximum of 7070μS/cm) in June, 2013 showed a general trend parallel to coastline and values indicated that saline water moves towards land. Groundwater salinization has also been arising from isolated areas were also assessed by high EC. GWL hydrograph shows a declining trend which is conducive for saline water intrusion. This study have significant implications for urban planning and decision making in an effort to protect the groundwater resource in the area studied, and the techniques described here can be used in other areas as a base line for projections of alternative future landscapes.
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