A Synthesis of Studies on Land Use and Land Cover Dynamics during 1930–2015 in Bangladesh (original) (raw)
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Dynamics and drivers of land use and land cover changes in Bangladesh
Regional Environmental Change, 2020
Bangladesh has undergone dramatic land use and land cover changes (LULCC) in recent years, but no quantitative analysis of LULCC drivers at the national scale exists so far. Here, we quantified the drivers of major LULCC in combination with biophysical and socioeconomic observations at the sub-district level. We used Landsat satellite data to interpret LULCC from 2000 to 2010 and employed a Global Surface Water Dataset to account for the influences of water seasonality. The results suggest that major LULCC in Bangladesh occur between agricultural land and waterbodies and between forest and shrubland. Exclusion of seasonal waterbodies can improve the accuracy of our LULCC results and driver analysis. Although the gross gain and loss of agricultural land are large on the local scale, the net change (gross gain minus gross loss) at a country scale is almost negligible. Climate dynamics and extreme events and changes in urban and rural households were driving the changes from forest to ...
Dynamics and drivers of land use land cover changes in Bangladesh
2017
Land is scarce in Bangladesh: Bangladesh occupies ~0.03 % of world’s land area, but supports over ~2% of human population. This high population to land ratio, combined with socioeconomic development has placed tremendous pressure on Bangladesh’s land resources for food, feed, and fuel. This study assesses the dynamics of land use land cover changes and its subsequent drivers at national and sub-national scales. We show contemporary spatial estimates of land change in Bangladesh using national-level analysis of Landsat imageries for 2000 and 2010. This analysis uses our newly compiled extensive socioeconomic database which covers ~480 sub-districts along with biophysical data. We also synthesized information from over 80 survey-based case studies on land use drivers in Bangladesh to complement our macro-scale analysis. We present a detailed analysis of contemporary land change both in terms of national extent and the use of detailed spatial information on land change, socioeconomic f...
With little known and explored urban morphology in the fastest growing countries like Bangladesh in South Asia, this study aims at exploring urban spatial signature and explaining spatiotemporal land use and land cover patterns in the five cities (Rajshahi, Rangpur, Sylhet, Khulna, and Barisal) in Bangladesh. Using time series Landsat imagery, socioeconomic data and, other geospatial information with ecological analysis tools, this study quantifies and characterize the spatial-temporal landscape patterns and urban growth trajectory across the five selected sites. The spatial representation of these five sites demonstrates a continuous increase in urban/built-up areas replacing arable agricultural land, waterbodies, vegetation cover and wetlands, which thereby substantially altering the structure and function of the ecosystem surrounding the cities. Built up areas, representing impervious surface as observed from land cover maps in these five cities, are expanding quickly. The total built-up cover within the five cities grew from 2,356 hectares in 1973 to 13,435 hectares in 2014 with a net increase of approximately 468%, while vegetation cover and crops field within same time period declined at 27.77% and 61.91%, respectively. This dramatic urban/built-up expansion has resulted in an increasingly faster alteration in the landscape composition causing to structural complexity at both class level and landscape level. Such rapid and unplanned urban expansion further has brought an overwhelming challenge to planners and policy makers, and has put a strain on local authorities to properly manage and utilize its limited land-based resources due to lack of time series geospatial information. The resulting thematic map and spatial information from this study is, therefore, to facilitate an understanding of urban growth dynamics and land cover change pattern in the five cities in Bangladesh. The result further can aid planners, stakeholders, and other interested groups to make the best possible choices regarding limited land-based resources to achieve an economically prosperous and environmentally sustainable future.
Driving Forces of Landuse and Landcover Changes in the North-eastern Part of Dhaka Conurbation
The Dhaka University Journal of Earth and Environmental Sciences
The study identifies decadal landuse and landcover (LULC) changes during 1988-2017 in north-eastern Dhaka conurbation of Bangladesh. Driving forces behind the changes in the study area have also been investigated.In this study, LULC changes were studied using two Landsat sensors. GIS post-processing technique was used for satellite image classification, while an in-depth literature review was conducted to identify the drivers of land cover change. Accuracy for the classified maps ranged from 79percent to 86percent. It was found that agricultural land decreased 47.02 percent while homestead vegetation land cover has increased about 88 percent in the last thirty years (1988-2017).The in-depth analysis result indicates that Dhaka metropolitan area expansion, increased population, internal migration, ongoing housing development projects, and lack of proper landuse and land management implementation are the main drivers of LULC changes in the study area. The development control approach ...
Urban Expansion Pattern and Land Use Dynamics in Dhaka, 1989–2014
The Professional Geographer, 2017
Rapid change in land use and land cover (LULC) and unplanned urban expansion in Dhaka City, Bangladesh, receives continuous attention from local policymakers and the international community. This study employed a supervised classification procedure and postclassification change detection technique to estimate major changes between different LULC classes. The study revealed that built-up area increased significantly from 1989 to 2014. The total urban growth of 81.54 percent resulted in a substantial decrease in natural vegetation cover and agricultural land. In addition, water bodies have declined consistently over the last twenty-five years. The overall accuracy of LULC change maps produced from Landsat data ranged from 89.72 percent to 92.97 percent. The results should contribute to ongoing LULC information updates while forecasting possible future LULC change and sustainable development under greater population density.
MONITORING LAND USE AND LAND COVER CHANGES OF DHAKA CITY: A REMOTE SENSING AND GIS-BASED ANALYSIS
SCIENCE INTERNATIONAL (LAHORE), 2022
Green vegetation and blue space (water body) dynamics keep the proper ecosystem of an area. Dhaka is one of the most densely populated cities in the world and continuously reducing its green and blue space. The present study has tried to determine the impact of urbanization in Dhaka city by analyzing the temperature, precipitation, solar radiation, and humidity data for the last 30 years; where the green and blue space dynamics are impacted together. The primary and secondary types of data were used for this study. For the green area, satellite image (mainly Landsat 8 and 5) has been used as raster data to analyze the remote sensing image classification and for the blue space, raster data has been used to find out those areas which are impacted throughout the year. With the help of those data, the study can illustrate the reason behind the degradation and transformation of green and blue space with time. From 1988 to 2020 about 7500 hectares of land have been increased by urbanization and at the same time, 6600 hectares of vegetation land were lost. Also, the research has focused on the actual amount of impacted zone and has tried to predict the condition of land use of Dhaka city in 2050. The present study predicted that a significant amount of vegetation will be lost by 2050 and imposed a significant impact on Dhaka city's climate, which is deteriorating mostly by rapid urbanization with a reduction in green and blue space. The study has the potential to use as a reference work and can be used for other areas in the future.
Bangladesh Journal of Agriculture
The study of land use/land cover dynamics has been increasingly important in the research of earth surface natural resources. The normalized difference vegetation index (NDVI) is a widely used method for observing land use/land cover change detection. The surface land resources are easily interpreted by computing their NDVI. This study aimed at analyzing Land Use/Land Cover (LULC) changes between 1977 and 2019 in the Rangamati district, Bangladesh using reclassify the NDVI values of the Landsat satellite image and identifying the main drivers to change LULC by household survey. Five different years of Landsat images were used to extract the NDVI values January of 1977, 1989, 2000, 2011 and 2019. The NDVI values are initially computed using the user define method to reclassify the NDVI map to create land use land cover map and change detection. The highest NDVI value was found in 1977 (0.88) which indicates healthy vegetation at that time and thereafter it followed a decreasing trend...
Implications of changing national policies on land use in the Chittagong Hill Tracts of Bangladesh
Journal of Environmental Management, 2006
Land use in the Chittagong Hill Tracts (CHT) of Bangladesh had undergone changes over the past several centuries. The landscape, which was mostly covered with forest with interspersed shifting cultivation plots until the beginning of the colonial period, has gradually changed into a landscape with a blend of land uses. Overall, the forest area has gradually declined, while the area under shifting cultivation and sedentary agriculture has expanded. The process of the change was multi-directional. National forestry, land use, land taxation, population migration polices, and development activities, such as construction of a hydroelectric dam and roads, played an important role in this process. Shifting cultivation had inflicted little damage on the forest until the beginning of the colonial period. The pace of deforestation accelerated with the nationalization of forests which abolished tribal people's customary use and management rights to the forest, and allowed large-scale commercial logging both legally and illegally. The pace was further intensified by the policy encouraging population migration to CHT and construction of a reservoir on the Karnafuli River. Efforts were made to replace shifting cultivation with more productive types of sedentary agriculture. However, much change could not take place in the absence of secure land rights, supportive trade policies, and the required support services and facilities, including infrastructure. Locationally suitable land use evolved in areas where transportation facilities were available and farmers were granted land title with the necessary extension services and credit facilities. These findings have important policy implications for the promotion of environmentally and economically sound land use in CHT. r