An Integrated Method for Identifying Present Status and Risk of Drought in Bangladesh

Abstract

The occurrence and severity of agricultural droughts may not be dependent upon climatic variables alone. Rather increasingly, drought is affected by human interventions such as irrigation. Anthropogenic activity has introduced uncertainty in the assessment of current drought and future drought risk in many parts of the world; neither climatic nor remote sensing data alone are able to assess drought conditions effectively. In response, we present a simple approach to assess drought by combining a remote sensing-based drought index, the Temperature Vegetation Dryness Index (TVDI), climate data (i.e., rainfall and temperature), and field observations to evaluate recent drought conditions in northwestern Bangladesh (NWB). Applying this approach, we gained five insights: (i) the TVDI successfully indicated the drought conditions of NWB and agrees with field observations, (ii) the integrated use of TVDI and climate data (such as rainfall and temperature) provides the best understanding of the difference between meteorological drought and droughts resulting from surface moisture conditions, (iii) the TVDI results agree with rainfall data (r2 = 0.40 in March and r2 = 46 in April) in a part of the study area (NWB) where irrigation is not available, (iv) the TVDI can be used along with climate data to predict the potential risk of drought, and (v) while meteorological drought exists due to low rainfall and high temperature in this NWB in pre-monsoon season, because of widespread irrigation practices, meteorological drought is unable to trigger agricultural drought over most parts of the study area. The findings imply that there is a potential risk of drought in NWB, since any disruption of irrigation water supply could trigger a severe agricultural drought over the whole region. This is similar to what is currently observed over a small part of NWB.

Utilizing TVDI and NDWI to Classify Severity of Agricultural Drought in Chuping, Malaysia

“…The wavelengths of the thermal and visible spectrum have been successful in monitoring vegetation conditions when water stress occurs [76]. Interpretations LST-NDVI relationship is based on vegetation crops, climate, at various scales [77][78][79]. Since the vegetation stays green after the onset of the stress, the NDVI alone as a water stress indicator is less reliable [80].…”

Spatiotemporal drought analysis in Bangladesh using the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI)

“…Our findings confirmed prior findings that the frequency of droughts has increased in the northwest and southwest areas of Bangladesh 10,11,[55][56][57][58][59] . Three main factors, including erratic spatiotemporal rainfall behaviour, geographic position, and high temperature, can lead to a rise in the frequency of drought, all of which is supported by the existing literature 50,[60][61][62] . Prodhan et al 60 used statistical tools to monitor drought status in Bangladesh and discovered that the drought trend in the northwest and southwest regions has gradually increased over the last decades, while the drought trend in the southeast and northeast regions has steadily decreased over the last decade.…”

Climate-adaptive strategies for enhancing agricultural resilience in southeastern coastal Bangladesh: Insights from farmers and stakeholders

“…Although this coastal region has been facing numerous climaterelated challenges [16,35], farmers cultivate crops in large quantities. The southern coastal region is not only prone to severe damages caused by cyclones and their aftermath [12,36,37] but is also gradually experiencing the influence of drought on agriculture [38][39][40]. These climate-induced disturbances affect crop production and food security in the coastal region [19,20].…”