Fattah Md Abdul, Gupta Sudipta Das, Farouque Md Zunaid, Ghosh Bhaskar, Morshed Syed Riad, Chakraborty Tanmoy, Kafy Abdulla-Al, Rahman Muhammad Tauhidur
Department of Urban and Regional Planning, Khulna University of Engineering and Technology, Khulna, 9203, Bangladesh.
Center for Environmental Research, Bangladesh.
Heliyon. 2023 Sep 10;9(9):e19991. doi: 10.1016/j.heliyon.2023.e19991. eCollection 2023 Sep.
The frequency and intensity of climate change and resulting impacts are more prevalent in South Asian countries, particularly in Bangladesh. Relative humidity (RH) is a crucial aspect of climate, and higher RH variability has far-reaching impacts on human health, agriculture, environment, and infrastructure. While temperature and rainfall have gained much research attention, RH studies have received scant attention in the research literature. This study investigated the trends and variability of RH levels in Bangladesh and the influence of other meteorological factors over the past 40 years. Variabilities in the meteorological factors were identified by calculating descriptive statistics. Innovative trend analysis (ITA) and Mann-Kendall test (MK-test) methods were utilized to assess monthly, seasonal, and annual trends. The magnitude of temperature, rainfall, and windspeed influences on RH variability were identified using Pearson's correlation, Spearman rank correlation, and Kendall correlation model. Variability analysis showed higher spatial variations in RH levels across the country, and RH skewed negatively in all stations. Results reveal that daily, monthly, seasonal, and annual trends of RH exhibited positive trends in all stations, with an increasing rate of 0.083-0.53% per year in summer, 0.43-0.68% per year in winter, and 0.58-0.31% per year in the rainy season. Both ITA and MK-test provided consistent results, indicating no discrepancies in trend results. All three models indicate that temperature, rainfall, and windspeed have weak to moderate positive influences on changing RH levels in Bangladesh. The study will contribute to decision-making to improve crop yields, health outcomes, and infrastructure efficiency.
气候变化的频率和强度及其产生的影响在南亚国家更为普遍，尤其是在孟加拉国。相对湿度（RH）是气候的一个关键方面，较高的相对湿度变率对人类健康、农业、环境和基础设施有着深远影响。虽然温度和降雨已受到大量研究关注，但相对湿度研究在研究文献中却很少受到关注。本研究调查了孟加拉国过去40年相对湿度水平的趋势和变率以及其他气象因素的影响。通过计算描述性统计量来确定气象因素的变率。利用创新趋势分析（ITA）和曼-肯德尔检验（MK检验）方法来评估月度、季节和年度趋势。使用皮尔逊相关、斯皮尔曼等级相关和肯德尔相关模型来确定温度、降雨和风速对相对湿度变率的影响程度。变率分析表明，全国相对湿度水平存在较高的空间差异，且所有站点的相对湿度均呈负偏态。结果显示，所有站点相对湿度的日、月、季节和年度趋势均呈上升趋势，夏季每年上升速率为0.083 - 0.53%，冬季每年上升速率为0.43 - 0.68%，雨季每年上升速率为0.58 - 0.31%。ITA和MK检验均给出了一致的结果，表明趋势结果没有差异。所有三个模型均表明，温度、降雨和风速对孟加拉国相对湿度水平变化具有弱到中等程度的正向影响。该研究将有助于做出决策以提高作物产量、健康状况和基础设施效率。
