DATA FOR FLOOD FREQUENCY ANALYSIS OF BHAKRA NANGAL DAM SITE BY STATISTICAL AND MATHEMATICAL COMPUTATION METHOD USING DISCHARGE DATA

A flood frequency analysis is a notable idea which helps in avoiding the casualties occurred during flood. It aids in finding out the frequencies of flood, is to come over specific area. In this research, statistical approach is used for three mathematical computing methods as Gumbel’s method, Log-Pearson method and Log-Normal method to find the frequency of floods at Sutlej River of Bhakra Nangal Dam site. These methods are compared and lowest value of D-index by Gumbel’s is considered as the most appropriate for flood analysis. Mathematical computation is done to predict the discharge of river Sutlej with their corresponding return period in which various distributions is done to estimate the statistical parameter such as mean standard deviation coefficient of variance, coefficient of skewness. As per CWC report, discharge data for the Sutlej River from 1954 to 2018 is used for flood frequency analysis, and also to estimate flood magnitude for different return periods for gauged catchment of the basin is 75369 km2, and the risk assessment calculated for 1000 years return period.洪水频率分析是一项可有效规避洪水灾害人员伤亡的重要研究方法，其核心功能为研判特定区域内的洪水发生频率。本研究采用统计分析路径，选取耿贝尔法（Gumbel's method）、对数皮尔逊法（Log-Pearson method）与对数正态法（Log-Normal method）三种数学计算方法，对巴克拉楠加尔大坝（Bhakra Nangal Dam）场址所在的萨特累季河（Sutlej River）开展洪水频率分析。 对上述三种方法进行对比后可知，耿贝尔法得到的D指数值最低，因此该方法为本次洪水频率分析的最优选择。本研究通过各类分布模型开展数学计算，以估算均值、标准差、变异系数与偏态系数等统计参数，进而预测萨特累季河在不同重现期下的径流量。 依据中央水利委员会（Central Water Commission, CWC）的公开报告，本研究采用1954年至2018年的萨特累季河径流量数据开展洪水频率分析；同时针对集水面积为75369平方千米的实测流域，估算不同重现期下的洪水洪峰量级，并完成了1000年一遇重现期的风险评估。