Initiating rain water harvest technology for climate change induced drought resilient agriculture: scopes and challenges in Bangladesh
Bangladesh is primarily an agrarian economy. Agriculture is the single largest producing sector of the economy since it comprises about 18.6% of the country's GDP and employs around 45% of the total labor force. The performance of this sector has an overwhelming impact on major macroeconomic indicators like employment generation, poverty alleviation, human resource development and food security. The agriculture sector is extremely vulnerable to disaster and climate induced risks. Climate change is anticipated to aggravate the frequency and intensity of extreme weather events in Bangladesh. Drought is one of the major setbacks for the agriculture and its development. Therefore, disaster and climatic risk, especially drought management in agriculture is a major challenge for Bangladesh in achieving sustainable agricultural development. There are some regions in Bangladesh where every steps of agriculture from field preparation to ripening of crops dependents on rainfall. Consequently, drought affects annually 2.5 million ha in kharif (wet season) and 1.2 million ha in dry season. Water is a natural resource with spatial scarcity and availability. Additionally, Cross-country anthropogenic activities caused a severe negative impact on water resources and eco-systems of Bangladesh in the recent years. The rivers and cannels dry up during the dry season and make the people completely dependent on groundwater (Abdullah, 2015). Accordingly the contribution of groundwater as a source of irrigation has increased and surface water has declined. It is now inevitable to look for alternate water source for agriculture. Water harvest technologies (WHTs) can play an important role in this regard. WHTs can provide an additional source of water for crop production at the most critical stages of the growing season, thereby increasing yields and food security. The study is consists of drought scenario analysis, GIS based drought mapping and systematic literature review on RWHTs as drought mitigation option in Bangladesh. Twenty eight (28) weather station locations of Bangladesh Metrology Department (BMD) were considered for the analysis and mapping of drought. SPEI data were classified for severe and extreme drought event. Inverse Distance Weight (IDW) method was used to interpolate the point data for spatial mapping of drought severity using standard GIS procedure. There are potentials for conserving and utilizing rain water for agriculture use but it is still far from being utilized as unresolved challenges prevent its wide scale adoption.