Haider Shanjana, Karim Md Rezaul, Islam Md Saiful, Megumi Tanzilla Aktar, Rahnama Quazi Shahnewaz
Department of Civil and Environmental Engineering, Islamic University of Technology (IUT), Gazipur 1704, Bangladesh.
Heliyon. 2024 Feb 27;10(5):e27118. doi: 10.1016/j.heliyon.2024.e27118. eCollection 2024 Mar 15.
Bangladesh is susceptible to climate change, thus a detailed study, including the analyses of trends, sub-trends, extreme events and indices was conducted to obtain a complete picture of the climate change pattern in Bangladesh utilizing daily rainfall, maximum, minimum and average temperature data of 26 stations from 1975 to 2019 using R 4.0.2 software. For the trend analysis Mann Kendal (MK), modified Mann Kendall (mMK), Innovative Trend Analysis (ITA) and Sen's slope methods were used. Sub-trend analysis was conducted using ITA. Standard Anomaly Index (SAI) has been used to identify the frequency and severity of extreme events. ClimPACT2 software was used to check the homogeneity and calculate the extremes of temperature and rainfall data. Our analysis showed that during the last four decades, climate variables changed their patterns and trend heterogeneously over Bangladesh. Most stations showed decremental rainfall trend when central part of the country showed a substantial decrease. The northern and central parts of the country showed significant growth of trend for annual average temperature. The temperature in the monsoon season increased, whereas those in dry season decreased. The rainfall and maximum temperature were inversely related during monsoon whereas during dry season both of them decrease. The pre-monsoon and post-monsoonal rainfall also showed decreasing trends, indicating prevailing drought conditions especially in northern and central parts of the country. The SAI analysis showed alternating drought and wet years in almost all the stations. In the past 20 years, the country's western region experienced more drought years than before whereas the coastal region experienced more wet years. The analysis of climate extreme indices suggests that, Consecutive Dry Days (CDD), Hot Days (TX90P) and Hot Nights (TN90P) show significant increasing trend throughout the country. The agricultural productivity, water resource management and food security are anticipated to benefit from this study.
孟加拉国易受气候变化影响，因此利用1975年至2019年26个站点的日降雨量、最高温度、最低温度和平均温度数据，使用R 4.0.2软件进行了一项详细研究，包括趋势、子趋势、极端事件和指数分析，以全面了解孟加拉国的气候变化模式。趋势分析使用了曼-肯德尔（MK）法、修正曼-肯德尔（mMK）法、创新趋势分析（ITA）法和森斜率法。子趋势分析使用ITA法。标准异常指数（SAI）用于识别极端事件的频率和严重程度。使用ClimPACT2软件检查数据的同质性并计算温度和降雨数据的极值。我们的分析表明，在过去四十年中，孟加拉国的气候变量模式和趋势变化存在异质性。大多数站点降雨量呈下降趋势，而该国中部地区降雨量大幅减少。该国北部和中部地区年平均气温呈显著上升趋势。季风季节温度上升，而旱季温度下降。季风期间降雨量与最高温度呈负相关，而旱季两者均下降。季风前和季风后的降雨量也呈下降趋势，表明该国特别是北部和中部地区普遍存在干旱状况。SAI分析表明，几乎所有站点都交替出现干旱年和湿润年。在过去20年中，该国西部地区干旱年份比以前更多，而沿海地区湿润年份更多。气候极端指数分析表明，连续干旱日（CDD）、炎热日（TX90P）和炎热夜（TN90P）在全国范围内呈显著上升趋势。预计这项研究将有助于提高农业生产力、水资源管理和粮食安全。
