Assessment of remote sensing-based indices for drought monitoring in the north-western region of Bangladesh

Ashim C Das; Shihab A Shahriar; Md A Chowdhury; Md Lokman Hossain; Shahed Mahmud; Md Kamruzzaman Tusar; Romel Ahmed; Mohammed Abdus Salam

doi:10.1016/j.heliyon.2023.e13016

Assessment of remote sensing-based indices for drought monitoring in the north-western region of Bangladesh

Heliyon. 2023 Jan 21;9(2):e13016. doi: 10.1016/j.heliyon.2023.e13016. eCollection 2023 Feb.

Authors

Ashim C Das¹, Shihab A Shahriar^{1

2}, Md A Chowdhury³, Md Lokman Hossain^{4

5}, Shahed Mahmud¹, Md Kamruzzaman Tusar¹, Romel Ahmed⁶, Mohammed Abdus Salam¹

Affiliations

¹ Department of Environmental Science and Disaster Management, Noakhali Science and Technology University, Noakhali, 3814, Bangladesh.
² Department of Earth and Atmospheric Sciences University of Houston, TX, 77004, USA.
³ Department of Climate and Disaster Management, Jashore University of Science and Technology, Jashore, 7408, Bangladesh.
⁴ Department of Environment Protection Technology, German University Bangladesh, Gazipur, Bangladesh.
⁵ Department of Geography, Hong Kong Baptist University, Hong Kong, China.
⁶ Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh.

Abstract

Drought is a widespread hazard that can tremendously affect the biodiversity, habitat of wild species, and ecosystem functioning and stability, especially in the dry region. Due to its geographic location, the north-western region of Bangladesh has a comparatively arid climate which is very much susceptible to drought occurrence and is marked as a red zone. Despite the growing evidence of the impact of drought on food security and ecosystem functioning, little effort has been paid to mitigate the drought in this region. The present study aimed to assess the drought condition of the north-western region of Bangladesh using earth observation techniques. For this purpose, Landsat data from 1990 to 2020 was used to determine various vegetation indices such as Normalized Difference Vegetation Index (NDVI), Water Index (NDWI), Moisture Index (NDMI) and Soil Adjusted Vegetation Index (SAVI), along with Land Surface Temperature (LST). Results show that the depletion of forests (2832 km²) and water bodies (6773 km²) resulted from the expansion of settlement (6563 km²) and agricultural land (1802 km²) for the period 1990-2020. Examination of the temporal changes of vegetation indices and LST showed that the values of all indices decreased while the LST increased. The negative correlation between NDVI value and LST indicates that the vegetation in our study was subject to drought-induced shocks. This study reveals the current situation of the vegetation health in the north-western region of Bangladesh in relation to the drought conditions. The findings of this study have practical implications for the policymakers in implementing necessary measures for agriculture, forests, water development, and economic zone planning.

Keywords: Climate change; Drought; Land use; Natural hazard; Remote sensing; Vegetation health; Vegetation indices.