Spatio-Temporal Patterns of Land Use/Land Cover Change in the Heterogeneous Coastal Region of Bangladesh between 1990 and 2017

Abstract

Although a detailed analysis of land use and land cover (LULC) change is essential in providing a greater understanding of increased human-environment interactions across the coastal region of Bangladesh, substantial challenges still exist for accurately classifying coastal LULC. This is due to the existence of high-level landscape heterogeneity and unavailability of good quality remotely sensed data. This study, the first of a kind, implemented a unique methodological approach to this challenge. Using freely available Landsat imagery, eXtreme Gradient Boosting (XGBoost)-based informative feature selection and Random Forest classification is used to elucidate spatio-temporal patterns of LULC across coastal areas over a 28-year period (1990-2017). We show that the XGBoost feature selection approach effectively addresses the issue of high landscape heterogeneity and spectral complexities in the image data, successfully augmenting the RF model performance (providing a mean user’s accuracy > 0.82). Multi-temporal LULC maps reveal that Bangladesh’s coastal areas experienced a net increase in agricultural land (5.44%), built-up (4.91%) and river (4.52%) areas over the past 28 years. While vegetation cover experienced a net decrease (8.26%), an increasing vegetation trend was observed in the years since 2000, primarily due to the Bangladesh government’s afforestation initiatives across the southern coastal belts. These findings provide a comprehensive picture of coastal LULC patterns, which will be useful for policy makers and resource managers to incorporate into coastal land use and environmental management practices. This work also provides useful methodological insights for future research to effectively address the spatial and spectral complexities of remotely sensed data used in classifying the LULC of a heterogeneous landscape.

Future Impact of Land Use/Land Cover Changes on Ecosystem Services in the Lower Meghna River Estuary, Bangladesh

“…Bangladesh is a deltaic and agro-economy based developing country with a very high population density and one of the most vulnerable to disaster risks [14][15][16][17]. However, over the last decade, the economic growth of Bangladesh has skyrocketed.…”

“…In fact, Bangladesh is now one of the fastest economic growth countries in the Asian region [18]. Hence, as a result of rapid economic activity along with high population pressure and environmental degradation, LULC in Bangladesh has changed very rapidly [15,16]. Empirical investigations [8,14,15,[19][20][21][22][23] have shown that along with factors like rapid population growth and economic development, land degradation, and sea-level rise are some of the other driving forces in the coastal region of Bangladesh that have led to rapid LULC transformations over different periods, and that these have been arguably more widespread and intense than in any other areas of the globe, and that these conditions continue to worsen, leading to ongoing degradation and damages in the ecological value of these vulnerable environments [8,20,23].…”

“…Over the decades, rapid LULC alterations have threatened the land management sustainability and imbalances the socio-environmental systems of this region [19,20,23]. However, insufficient work has been done in detecting future LULC changes in this vulnerable zone [8,14,15,19,21,22,24,25] and evaluating their impacts on the ESs [23]. Therefore, it is imperative to examine the dynamics of LULC transformation for various future land management scenarios and their effects on ESs in order for ecological restoration of the landscape [23].…”

Elevated Risk of Ecological Land and Underlying Factors Associated with Rapid Urbanization and Overprotected Agriculture in Northeast China

“…To summarize, agricultural occupation and urban expansion were verified as the two main causes of ecological land loss, as well as elevated risks. In light of the current situation, measures such as policy adjustment and ecological restoration should be taken to avoid risk and optimize land use.Previous studies have measured regional ecological security and detected its influencing factors in view of multi-scale and multi-source data [13][14][15]. Jackson et al evaluated the ecological vulnerability caused by land use changes and economic development in the U.S. Mid-Atlantic region by overlaying the maps of land-use change projections and sensitive ecological resources [16].…”

“…Previous studies have measured regional ecological security and detected its influencing factors in view of multi-scale and multi-source data [13][14][15]. Jackson et al evaluated the ecological vulnerability caused by land use changes and economic development in the U.S. Mid-Atlantic region by overlaying the maps of land-use change projections and sensitive ecological resources [16].…”