This paper quantifies the extent to which Chakaria Sundarbans mangrove has been depleted through ... more This paper quantifies the extent to which Chakaria Sundarbans mangrove has been depleted through human interference using Landsat imagery of 1972 and 2017. The images were corrected for radiometric and atmospheric effects. To improve the classification process, the Chakaria Sundarbans's Landsat 2017 image was pan-sharpened. The earlier image which comprises of the virgin forest was classified into three classes (water, mangrove, wetland) while the later was classified into four classes – waterbody, mangrove, pond scum and saltpan using supervised classification method and support vector machine classifier. Using the statistical bias adjustment, precise area estimates for each land cover class was obtained. The result shows that between 1972 and 2017, Chakaria Sundarbans mangrove forest has reduced by about 87.5% (from 6000.27 to 877.76 hectares). Currently, about 21% of the land is being used for salt mining, 45% for shrimp farming while the water body takes 26%. It is observed that the river has reduced in width; however, water surface area increased by 2%. The bias-adjusted overall classification accuracy yields 95.44% and 94.70% for classified maps of 1972 and 2017, respectively. Evidently, the mangrove has been completely lost to over-exploitation of resources.
Remote sensing images are representation of the earth's surface as seen from space without any ph... more Remote sensing images are representation of the earth's surface as seen from space without any physical contact. It generally detects the surface feature through reflectance of matter and represents various Digital Number (DN) values. In the context of water it also represent DN values according to reflectance of water properties, whatever it can detect from the space. Landsat Operational Land Image (OLI) is more effective to detect the surface features. It has been used to detect water body. The surface water quality is not same all over the surface so the energy absorption and relaxation is not the same. The DN value of surface water is changed due to the change of chemical properties of water. It will be a fundamental study to explore the relationship between DN value and water quality. This research explores a complete integration of DN values of Landsat OLI satellite image with same surface water quality, which are collected from several points. The chemical properties of collected surface water, which are analyzed through lab and is integrated with DN value of the Landsat OLI satellite images. The variations among the chemical properties of collected surface water and the DN values of the exact Landsat OLI images are categorized within an index. The correlations between surface water quality and DN values of Landsat OLI are investigated in this research.
This paper quantifies the extent to which Chakaria Sundarbans mangrove has been depleted through ... more This paper quantifies the extent to which Chakaria Sundarbans mangrove has been depleted through human interference using Landsat imagery of 1972 and 2017. The images were corrected for radiometric and atmospheric effects. To improve the classification process, the Chakaria Sundarbans's Landsat 2017 image was pan-sharpened. The earlier image which comprises of the virgin forest was classified into three classes (water, mangrove, wetland) while the later was classified into four classes – waterbody, mangrove, pond scum and saltpan using supervised classification method and support vector machine classifier. Using the statistical bias adjustment, precise area estimates for each land cover class was obtained. The result shows that between 1972 and 2017, Chakaria Sundarbans mangrove forest has reduced by about 87.5% (from 6000.27 to 877.76 hectares). Currently, about 21% of the land is being used for salt mining, 45% for shrimp farming while the water body takes 26%. It is observed that the river has reduced in width; however, water surface area increased by 2%. The bias-adjusted overall classification accuracy yields 95.44% and 94.70% for classified maps of 1972 and 2017, respectively. Evidently, the mangrove has been completely lost to over-exploitation of resources.
Remote sensing images are representation of the earth's surface as seen from space without any ph... more Remote sensing images are representation of the earth's surface as seen from space without any physical contact. It generally detects the surface feature through reflectance of matter and represents various Digital Number (DN) values. In the context of water it also represent DN values according to reflectance of water properties, whatever it can detect from the space. Landsat Operational Land Image (OLI) is more effective to detect the surface features. It has been used to detect water body. The surface water quality is not same all over the surface so the energy absorption and relaxation is not the same. The DN value of surface water is changed due to the change of chemical properties of water. It will be a fundamental study to explore the relationship between DN value and water quality. This research explores a complete integration of DN values of Landsat OLI satellite image with same surface water quality, which are collected from several points. The chemical properties of collected surface water, which are analyzed through lab and is integrated with DN value of the Landsat OLI satellite images. The variations among the chemical properties of collected surface water and the DN values of the exact Landsat OLI images are categorized within an index. The correlations between surface water quality and DN values of Landsat OLI are investigated in this research.
Uploads
Papers by Mehedi Iqbal