Abstract Analyzing the long-term trend of rainfall and temperature is important for making decisions in water management sectors such as meteorology, agriculture, and policy making. However, localized spatiotemporal investigations that integrate multiple statical trend methods remain limited particularly for the Amaravathi basin, a climatically sensitive sub-basin of the Cauvery watershed. This study bridges the gap by applying a multi-method framework combining three non-parametric and the Innovative trend analysis (ITA) examine the spatial and temporal variation in precipitation, temperature, and extreme indices over the Amaravathi basin. Unlike earlier studies that used single method and basin aggregated analyses, this work disaggregates trends across four sub-basins to detect hidden and non-linear variations. Findings reveal increasing annual precipitation in Sub-basin 4 (SB4) with a rise of 8.46 mm/decade and increasing monsoonal rainfall in Sub-basins 3 and 4, whereas summer precipitation declines across all the sub-basins, suggesting a shift towards drier summers. The average temperature trend shows a consistent warming across the basin. The precipitation extreme R20 mm and PCPTOT in Sub-basin 1 (SB1) and Sub -basin 4 (SB4) are increasing, whereas simple daily intensity index (SDII) in Sub-basin 4(SB4) exhibit a declining pattern, indicating a more frequent but less intense extreme precipitation events. Additionally, the warm indices (WSDI, TX90P, and TN90P) are rising, whereas cold indices (CSDI, TX10P, and TN10P) are decreasing in most of the grid points, which contributes to the overall warming of the sub-basins. The Innovative trend analysis (ITA) found the hidden trends that overlooked by conventional MK test. This study provides a refined understanding of spatial climatic heterogeneity and identifies the region vulnerable to changing climate and extremes. This study highlights the need for climate-responsive water management and policies that can help to build resilience against drought and flood. Research highlights <UnorderedList Mark="Bullet"> <ItemContent> A multi-method framework combining MK1, MK2, MK3, and Innovative Trend Analysis (ITA). </ItemContent> <ItemContent> Amaravathi basin case study employs spatial sub-basin disaggregation for localized climate trend detection. It Supports sustainable development through informed decision-making. </ItemContent> </UnorderedList>

Trends in extreme climate indices of the Amaravathi Basin, India: a spatiotemporal analysis

期刊论文
发表日期：

2026年5月25日

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M Jothi Jeya Sri,
Nisha Radhakrishnan,
Aneesh Mathew,
Surendar Natarajan

摘要

Abstract

Analyzing the long-term trend of rainfall and temperature is important for making decisions in water management sectors such as meteorology, agriculture, and policy making. However, localized spatiotemporal investigations that integrate multiple statical trend methods remain limited particularly for the Amaravathi basin, a climatically sensitive sub-basin of the Cauvery watershed. This study bridges the gap by applying a multi-method framework combining three non-parametric and the Innovative trend analysis (ITA) examine the spatial and temporal variation in precipitation, temperature, and extreme indices over the Amaravathi basin. Unlike earlier studies that used single method and basin aggregated analyses, this work disaggregates trends across four sub-basins to detect hidden and non-linear variations. Findings reveal increasing annual precipitation in Sub-basin 4 (SB4) with a rise of 8.46 mm/decade and increasing monsoonal rainfall in Sub-basins 3 and 4, whereas summer precipitation declines across all the sub-basins, suggesting a shift towards drier summers. The average temperature trend shows a consistent warming across the basin. The precipitation extreme R20 mm and PCPTOT in Sub-basin 1 (SB1) and Sub -basin 4 (SB4) are increasing, whereas simple daily intensity index (SDII) in Sub-basin 4(SB4) exhibit a declining pattern, indicating a more frequent but less intense extreme precipitation events. Additionally, the warm indices (WSDI, TX90P, and TN90P) are rising, whereas cold indices (CSDI, TX10P, and TN10P) are decreasing in most of the grid points, which contributes to the overall warming of the sub-basins. The Innovative trend analysis (ITA) found the hidden trends that overlooked by conventional MK test. This study provides a refined understanding of spatial climatic heterogeneity and identifies the region vulnerable to changing climate and extremes. This study highlights the need for climate-responsive water management and policies that can help to build resilience against drought and flood.

Research highlights

A multi-method framework combining MK1, MK2, MK3, and Innovative Trend Analysis (ITA).

Amaravathi basin case study employs spatial sub-basin disaggregation for localized climate trend detection. It Supports sustainable development through informed decision-making.