Evolving synergistic adaptation strategies for climate extremities in a perennial river basin environment perennial river south tamil nadu

Abstract

The earth s environment has been continuously disturbed by anthropogenic action, and almost many species are on the verge of extinction. It is prominently indicated by the change in climate and weather patterns in different aspects of humankind. Any deviation in the climate from its standard profoundly impacts the earth s surface water and its resources as they are connected internally. Unexpected and non-manageable climatic conditions over the past decades necessitate that it affects our livelihoods by all means. The impacts of climate change on water resources are already greatly affected through direct and indirect ways. There is a notable widespread spatial variation that has been witnessed by climate impacts which are likely to affect the water resources in a balanced contrast. Developing countries that fall under lower latitudes are the current targets already threatened economically and in sustainability. Coastal regions face severe challenges like sea-level rise and extreme events like floods and droughts. The concept of climate change is a global phenomenon that has to be examined with its impacts on regional/local scales. This study concentrates on climate impacts and challenges on water resources at a more exemplary level is an essential one. Analysing the impacts of climate change on water resources for the historical and future projections in different hydrological perspectives is a complex task. As per the above context, this research focused on examining the present climate and evaluating the future projections on climate impacts at regional/local scales. The climate change impacts are evident in the perennial type of streams where the chances of extreme events are more often, like river flooding that may be periodical or flash floods. Therefore, the study was carried out in one of the perennial river basins of South Tamil Nadu, India, named Thamirabarani River Basin. Approaches through simulation models were engaged to project the future climate extremities and proposed adaptation strategies in this selected watershed. For the study of change in climate and its pattern, the observed rainfall data (1971-2020) with 50 years of the period was taken into account, and statistical analysis was performed. For greater accuracy, the Rain Gauge (RG) station and IMD Rainfall grids as observed data have been considered for statistical analysis to detect the presence of climate signals through its trend patterns. However, at first, the statistical factors were examined with mathematical formulations. The statistical analysis methods such as Mann-Kendall, Spearman s Rho, and Linear Regression tests were conducted to detect observed rainfall data trend patterns using e-Water trend software. The rainfall pattern is examined for annual and seasonal patterns that include south-west monsoon, north-east monsoon, winter, and summer. As a result, both RG stations and IMD Rainfall grids concluded with 40% change in rainfall patterns. Nevertheless, the pattern of trends has more significant change detection in IMD grids, and thus, it is considered an input for the simulation models newline