Ghosh Satyajit, Barik Dillip Kumar, Renganayaki Parimala, Kang Boosik, Gumber Siddharth, Venkatesh Sundarapandian, Saini Dev Shree, Akunuri Srichander
School of Mechanical Engineering, Vellore Institute of Technology, Vellore, 632014, India.
School of Earth and Environment, University of Leeds, Leeds, UK.
Sci Rep. 2023 Aug 29;13(1):14095. doi: 10.1038/s41598-023-41417-6.
The Cauvery Delta, the 'Rice Bowl' of India follows a time-tested cultivation pattern over several irrigation zones. However, in this era of the Anthropocene, it is now well-established that short-duration, intense precipitation episodes will batter the flood plains year after year. The purpose of this first study is thus to quantify the impacts that such episodes may have on the floodplains of the Cauvery Delta and the concomitant threats to the historic Kallanai Dam. Precipitation events during the North-East monsoon period are driven not just by warm rain microphysics but also by large frozen hydrometeors falling from deep clouds causing undesirable flooding over the region to the extent of 66%. Additionally, from an assessment of the velocity heads and the floodwater depths, this study projects a heightened vulnerability. The total extent of submergence along riverbanks and other flow paths was estimated to be 145.98 [Formula: see text] out of which 65.14% of the submerged area is agricultural land. The most important conceptual advance established in this paper is that sub-zones in major watersheds that are currently safe will get inundated in the RCP8.5 warming scenario in 2050.
印度的“米仓”——高韦里河三角洲在多个灌溉区遵循着经过时间考验的种植模式。然而，在人类世这个时代，如今已明确的是，短时间内的强降水事件将年复一年地冲击洪泛平原。因此，这项首次研究的目的是量化此类事件可能对高韦里河三角洲洪泛平原造成的影响以及对历史悠久的卡纳亚大坝带来的相应威胁。东北季风期的降水事件不仅由暖雨微物理过程驱动，还受到从深厚云层落下的大型冻结水凝物的影响，导致该地区出现了高达66%的不良洪水。此外，通过对速度水头和洪水深度的评估，本研究预测了更高的脆弱性。沿河岸和其他水流路径的淹没总面积估计为145.98[公式：见正文]，其中65.14%的淹没区域为农业用地。本文确立的最重要的概念性进展是，在2050年的RCP8.5变暖情景下，目前安全的主要流域子区域将被淹没。
