Building an Interface for Extreme Climate Analysis in Indonesia and India

Challenge

Communities and agencies need accessible ways to explore extreme rainfall and related drivers across river basins.

Solution

Develop an interactive online tool and research methods that show space–time patterns of extremes and their climate links.

Overview

Floods and droughts threaten livelihoods in Indonesia and India, and the patterns and drivers of rainfall and climate extremes vary across space and time. This project, supported by the Asia-Pacific Network for Global Change Research (APN) and led by Yanto (Jenderal Soedirman University, Indonesia), focused on two representative basins – Serayu in Indonesia and Krishna in India – to help users explore rainfall data, visualize extremes, and understand links to well-known climate patterns.

A core output was a web‑based graphical user interface (GUI) that lets users explore rainfall at daily, monthly, seasonal, and annual scales. The tool shows basin maps and time‑series graphs for any selected period. It also offers three analysis options: copula analysis to examine how variables move together, self-organizing maps to group similar patterns, and non-stationary extreme value analysis to estimate rare events under changing conditions. Together, these features help users see how heavy rainfall varies across places and time and how it relates to broader climate patterns.

A peer‑reviewed study linked to the project reported additional findings for the Serayu Basin. The study summarized sea-surface temperature patterns, tested statistical links between ocean regions and heavy rainfall in the basin, and used a time-varying model to see how those links shifted. From 1985 to 2014, very wet days increased while seasonal totals decreased. The influence of the Indian Ocean Dipole (IOD) and El Niño–Southern Oscillation (ENSO) also changed over time. These results showed how the tool and methods could help planners, engineers, and residents read patterns and possible drivers.

Application basins

The work used two representative river basins to ground the methods and the interface in real planning contexts, and testing both made the tool more useful and transferable.

Serayu served as the Indonesian test basin, and the interface supported visualization of heavy-rainfall days and seasonal totals and exploration of links to well-known climate patterns, such as the IOD and ENSO.

Krishna served as the Indian test basin, and the interface supported exploration of rainfall variability and extreme-event metrics across time scales with a consistent analysis approach.

Tools and data products

• Web‑based GUI for rainfall visualization and extreme‑event analysis (Serayu and Krishna Basins).
• Basin maps for Serayu and Krishna.
• Configurable time-series graphing tool (daily, monthly, seasonal, annual) for the basins.
• Copula analysis module (dependence between variables).
• Self‑organizing maps (SOMs) module (pattern clustering).
• Non-stationary extreme value analysis (NEVA) module for estimating rare events under changing conditions.

Outcomes and results

• Results were presented at a European Geosciences Union conference in Vienna (Austria) in April 2019, and at stakeholder workshops in Hyderabad (India) in January 2020 and Purbalingga (Indonesia) in August 2021.
• Deployed a web‑based GUI to visualize rainfall and apply advanced techniques for extreme climate analysis in the Serayu and Krishna Basins. This tool remains openly available.
• Obtained gridded precipitation and temperature from the India Meteorological Department for 1901–2017 for Krishna Basin.
• Obtained precipitation data for 80 rainfall gauges over Serayu Basin for 1997–2018.
• Compiled Niño 3.4 and IOD indices for 1985–2014 and a record of floods, droughts, and landslides in Serayu for 2010–2019, plus infrastructure layers.
• Identified 37 Serayu stakeholders across agencies.
• A peer‑reviewed article documented findings for Serayu and identified differing trends in daily vs. seasonal extremes and changing influences of ENSO and IOD.

Project details

Acknowledgements

This project was supported by the Asia-Pacific Network for Global Change Research (APN) under its Collaborative Regional Research Programme (CRRP). Acknowledgments also go to Jenderal Soedirman University (Indonesia); University of Colorado Boulder (United States); Indian Institute of Technology Hyderabad (India); and National Agency for Disaster Countermeasure (Indonesia).

Related information

• Project Permalink
• Project Final Report
• Yanto, Rajagopalan, B., & Regonda, S.K. (2023). Linear and copula model for understanding climate drivers of hydroclimatic extremes: A case study of Serayu river basin, Indonesia. Acta Geophysica, 72, 1067–1078. https://doi.org/10.1007/s11600-023-01078-5
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