Reconstruction of a reliable long daily rainfall dataset for the Northeast India (NEI) for climate change impact and extreme rainfall studies

For both food security and biodiversity management in NEI, a biodiversity hot spot, is required dependable, consistent estimates of trend and modes of variability of rainfall, so that policy makers have an idea of the rainfall that can be expected during the coming decades. Hence, daily rainfall data over the North East India (NEI) for more than 100 years is required for any climate change impact assessment. However, the region is poorly sampled and none of the weather stations have operated continuously for such a period. This technical note describes combining conventional weather station records with rain-gauge records from a number of sources like privately owned tea estates to create a continuous daily rainfall record from 1 January 1920-31st December 2009 for the north-eastern region of India. We have been successful in creating a daily rainfall data set on a set of 24 well distributed fixed stations. The data extent back into the 1920 and stem from a variety of station observations. Remaining data gaps are less than 3% of the total data in each station. Every effort has been made to reconstruct the data gaps with the aim to improve assessments of the long-term changes in climate variability in NEI. The final reconstructed data set for NEI is well suited to estimate both long-term trend and multi-decadal variability of rainfall over the region.

作为生物多样性热点区域，印度东北部（NEI）的粮食安全与生物多样性管理工作，均亟需可靠且一致的降雨趋势与变率模态估算结果，以便决策者能够预判未来数十年的降雨态势。因此，开展任何气候变化影响评估，均需获取印度东北部（NEI）超过百年的逐日降雨观测数据。但该区域气象观测站点稀缺，且无任何一座气象站能够连续运行如此长的时段。本技术报告通过整合常规气象站记录与多类来源的雨量计观测数据（如私有茶园的观测记录），构建了1920年1月1日至2009年12月31日期间印度东北部的连续逐日降雨序列。我们已在24个分布均匀的固定气象站点上成功构建逐日降雨数据集，该数据集的观测记录可追溯至1920年，源自多类站点的观测资料。各站点的数据缺失量均低于总数据量的3%。研究团队已尽最大努力填补数据缺口，以期提升对印度东北部气候变率长期变化的评估精度。最终构建的印度东北部重建数据集，可有效用于估算该区域降雨的长期趋势与年代际变率。

搜集汇总

背景与挑战

背景概述

该数据集是一个为印度东北部重建的长期日降雨量数据集，覆盖1920年至2009年，包含24个固定站点的数据，数据缺失率低于3%。它通过整合多种来源（如传统气象站和私人茶园记录）创建，旨在支持气候变化影响评估和极端降雨研究，特别适用于分析长期趋势和多年代际变率。