Spatiotemporal dynamics of new land development in Bangladesh coast and its potential uses

Globally, the land has direct links with food security, economic growth, and overall development. The demand for land is increasing, but the amount of available land is diminishing every year due to population pressure. This situation is an immediate reality in smaller countries like Bangladesh where land scarcity is a critical problem due to high population density. The only way to create new land is to develop land on the coast, restore eroded land, and enhance the new-land development process through accretion in the delta. We analyzed Landsat satellite images (1996, 2006 and 2015)to quantify the spatiotemporal change in the land area in the coastal Bangladesh. Random forest (RF)and support vector machine (SVM)classification algorithms were used to classify coastal area into two classes, land and water. The results indicate that the net gain of land was 39.67, 39.12 and 78.79 km ² during 1996–2006, 2006–2015 and 1996–2015, respectively. This approach revealed the dynamics of land gain and loss in the Bangladesh coast, where spatial information on coastal land are sparse. If this new land brought under cultivation, it would fulfill a growing demand for cultivable land and would produce 41,898 tons of cereal, supporting an additional 210,543 people per year. Alternately, the same amount of land would produce 285,061 Mg ha ⁻¹ forest biomass under afforestation. These results can serve as a baseline for policy and planning in Bangladesh regarding new land development, restoration, and future use.