Miah Md Giashuddin, Abdullah Hasan Muhammad, Jeong Changyoon
GIS and Remote Sensing Lab., Department of Agroforestry and Environment, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, 1706, Bangladesh.
Red River Research Station, AgCenter, Louisiana State University, Bossier, LA, 71112, USA.
Environ Monit Assess. 2017 Oct 9;189(11):547. doi: 10.1007/s10661-017-6235-5.
Drought is a critical issue, and it has a pressing, negative impact on agriculture, ecosystems, livelihoods, food security, and sustainability. The problem has been studied globally, but its regional or even local dimension is sometimes overlooked. Local-level drought assessment is necessary for developing adaptation and mitigation strategies for that particular region. Keeping this in understanding, an attempt was made to create a detailed assessment of drought characteristics at the local scale in Bangladesh. Standardized precipitation evapotranspiration (SPEI) is a new drought index that mainly considers the rainfall and evapotranspiration data set. Globally, SPEI has become a useful drought index, but its local scale application is not common. SPEI (0.5° grid data) for 110 years (1901-2011) was utilized to overcome the lack of long-term climate data in Bangladesh. Available weather data (1955-2011) from Bangladesh Meteorology Department (BMD) were analyzed to calculate SPEI using the SPEI calculator. The drivers for climate change-induced droughts were characterized by residual temperature and residual rainfall data from different BMD stations. Grid data (SPEI) of 26 stations of BMD were used for drought mapping. The findings revealed that the frequency and intensity of drought are higher in the northwestern part of the country which makes it vulnerable to both extreme and severe droughts. Based on the results, the SPEI-based drought intensity and frequency analyses were carried out, emphasizing Rangpur (northwest region) as a hot spot, to get an insight of drought assessment in Bangladesh. The findings of this study revealed that SPEI could be a valuable tool to understand the evolution and evaluation of the drought induced by climate change in the country. The study also justified the immediate need for drought risk reduction strategies that should lead to relevant policy formulations and agricultural innovations for developing drought adaptation, mitigation, and resilience mechanisms in Bangladesh.
干旱是一个关键问题，它对农业、生态系统、生计、粮食安全和可持续性产生着紧迫的负面影响。这个问题已在全球范围内得到研究，但它的区域乃至地方层面有时会被忽视。地方层面的干旱评估对于制定特定区域的适应和缓解策略至关重要。出于这一认识，人们尝试对孟加拉国地方尺度的干旱特征进行详细评估。标准化降水蒸散指数（SPEI）是一种新的干旱指数，主要考虑降雨和蒸散数据集。在全球范围内，SPEI已成为一种有用的干旱指数，但其在地方尺度的应用并不常见。利用110年（1901 - 2011年）的SPEI（0.5°网格数据）来克服孟加拉国长期气候数据的不足。分析了孟加拉国气象部门（BMD）提供的现有气象数据（1955 - 2011年），使用SPEI计算器来计算SPEI。气候变化引发干旱的驱动因素通过BMD不同站点的残余温度和残余降雨数据来表征。BMD 26个站点的网格数据（SPEI）用于干旱制图。研究结果表明，该国西北部干旱的频率和强度更高，这使其易受极端和严重干旱的影响。基于这些结果，进行了基于SPEI的干旱强度和频率分析，将朗布尔（西北地区）作为热点地区，以深入了解孟加拉国的干旱评估情况。这项研究的结果表明，SPEI可能是了解该国气候变化引发干旱的演变和评估的宝贵工具。该研究还证明了迫切需要制定干旱风险降低策略，这应能促成相关政策的制定以及农业创新，以在孟加拉国建立干旱适应、缓解和恢复机制。
