This study aims to build on the existing knowledge and improve the overall PSHA results by modifying source, path and site characteristics for Bangladesh. Firstly, six potential seismotectonic zones have been re-defined based on the recent study of Wang et al. (J Geophys Res Solid Earth 119:3576–3822, 2014) and Nath and Thingbaijam (J Seismol 15(2):295–315, 2011), and the updated earthquake catalogue has been declustered using two methods. Important source parameters, such as recurrence b-values and maximum magnitudes, have been determined using the Maximum Likelihood and cumulative moment methods, respectively, and their uncertainties have been addressed using a logic-tree approach. Secondly, based on literature review and studies in neighboring countries, suitable GMPEs have been selected for the seismic zones and the uncertainties have been addressed using a logic tree approach. A significant novelty of the study lies in the consideration of the site effects by integrating Vs30 values throughout the country. The ground motions—PGA and SA (at 0.2, 1.0 and 2.0 s) are computed using GEM’s OpenQuake and presented in form of hazard maps for 2% and 10% probabilities of exceedance in 50 years as well as mean hazard curves and uniform hazard spectra. Disaggregation for capital city Dhaka has also been carried out to show the hazard contributions of magnitude–distance pairs. The spatial distribution of PGA and SA are found remarkably higher than previous findings, likely due to differences in parameters and uncertainties. The results show a marked increase (by almost 20%) in the observed ground motions with respect to those carried out previously by uniformly characterizing the whole country as a firm rock.

中文翻译：

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改进孟加拉国的概率地震灾害评估

本研究旨在通过修改孟加拉国的源、路径和站点特征，在现有知识的基础上改进整体 PSHA 结果。首先，根据 Wang 等人最近的研究，重新定义了六个潜在的地震构造带。(J Geophys Res Solid Earth 119:3576–3822, 2014) 和 Nath 和 Thingbaijam (J Seismol 15(2):295–315, 2011)，更新后的地震目录已使用两种方法进行去聚类。重要的源参数，例如重复 b 值和最大幅度，已分别使用最大似然法和累积矩方法确定，并且已使用逻辑树方法解决了它们的不确定性。其次，基于文献回顾和周边国家研究，已经为地震带选择了合适的 GMPE，并使用逻辑树方法解决了不确定性。该研究的一个显着新颖之处在于通过在全国范围内整合 Vs30 值来考虑场地效应。地震动——PGA 和 SA（在 0.2、1.0 和 2.0 s）是使用 GEM 的 OpenQuake 计算的，并以 50 年内超过 2% 和 10% 的概率以及平均危险曲线和统一危险谱的危险地图的形式呈现. 还对首都达卡进行了分解，以显示震级-距离对的危害贡献。发现 PGA 和 SA 的空间分布明显高于以前的发现，可能是由于参数和不确定性的差异。