Through an analysis of land use and land cover (LULC) data for the years 2005 and 2017 from the Advanced Wide Field Sensor onboard the Indian Remote Sensing satellite, we find considerable changes in the LULC in three major states of south India, namely, Tamil Nadu, Telangana and Kerala. This change is mainly due to increasing urbanization, in addition to the change of prevalent mixed forest into deciduous needle/leaf forest in Kerala. Motivated by this finding, we study the impact of these LULC changes over a decade on the extremes of twelve heavy rainfall events in these states through several sensitivity experiments with a convection‐permitting Weather Research and Forecasting model, by changing the LULC boundary conditions. We particularly focus on three representative heavy rainfall events, specifically, over (a) Chennai (1 December 2015), (b) Telangana (24 September 2016), and (c) Kerala (15 August 2018). The simulated rainfall patterns of the three heavy rainfall events are found to be relatively better with the use of the 2017 LULC boundary conditions. The improvement is statistically significant in the case of the Chennai and Kerala events. On analysis of these simulations, and output from additional simulations we have conducted for nine other heavy rainfall events, we suggest that the recent LULC changes result in higher surface temperatures and sensible heat fluxes, and a deeper and moist boundary layer. This causes a relatively higher convective available potential energy and, consequently, heavier rainfall. We find the LULC changes in the three states, mainly dominated by the increasing urbanization in Telangana and Tamil Nadu, enhance the rainfall during the heavy rainfall events by 20–25%. This is the first extensive investigation of multiple and multi‐regional cases over the Indian region.

中文翻译：

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由于土地用途和土地覆盖的变化，印度南部的强降雨事件增多

通过对印度遥感卫星上的先进广域传感器2005年和2017年的土地利用和土地覆盖（LULC）数据进行分析，我们发现印度南部三个主要州（泰米尔）的土地利用和土地利用变化很大Nadu，Telangana和喀拉拉邦。这种变化主要是由于城市化程度的提高，以及喀拉拉邦主要的混交林变成针叶林的落叶。基于这一发现，我们通过改变对流边界条件的边界条件，通过对流允许天气研究和预报模型的几个敏感性实验，研究了这些十年来这些变化对这些州的十二次强降雨事件的极端影响。我们特别关注三个有代表性的强降雨事件，特别是（a）钦奈（2015年12月1日），（b）泰兰加纳（2016年9月24日）和（c）喀拉拉邦（2018年8月15日）。使用2017 LULC边界条件，发现三场强降雨事件的模拟降雨模式相对较好。在金奈和喀拉拉邦事件中，这种改善具有统计意义。通过对这些模拟的分析以及我们对其他9次强降雨事件进行的其他模拟的输出得出的结果，我们认为最近的LULC变化导致较高的表面温度和明显的热通量，以及较深且潮湿的边界层。这导致对流可用势能相对较高，因此降雨量更大。我们发现三个州的土地利用，土地利用变化变化主要是由Telangana和Tamil Nadu的城市化进程加剧所致，在大雨期间将降雨量增加20-25％。这是对印度地区多个和多个地区案件的首次广泛调查。