The estimates can support a range of hydrological, hydraulic and climate-related applications, including:

• Hydrological and rainfall–runoff modelling
• Flood-risk assessment
• Urban stormwater and drainage planning
• Hydraulic infrastructure design
• Infrastructure planning
• Climate-change impact and adaptation studies

Select or click on any location on the interactive map. The platform displays the corresponding IDF curve and rainfall intensity table for the selected location.

The platform provides IDF estimates for rainfall durations ranging from 1 to 72 hours (1, 3, …, 72 hours). Available return periods are 2, 5, 10, 25, 50, and 100 years.

A return period represents the statistical frequency of an extreme rainfall magnitude.

For example, a 100-year rainfall intensity corresponds to an estimated 1% annual exceedance probability under the statistical framework used. A 100-year event does not mean that the event occurs only once every 100 years.

The confidence intervals quantify the sampling uncertainty in the estimated rainfall intensities, derived from the finite rainfall record used for extreme-value estimation. The uncertainty generally increases for longer return periods.

Yes. In addition to historical IDF estimates, the platform provides climate-change IDF projections for different future periods under SSP2-4.5 and SSP5-8.5.

The climate-change IDF projections use an ensemble of eight CMIP6 Global Climate Models (GCMs). The models were selected from the available CMIP6 models based on their spatial and temporal performance in representing observed rainfall characteristics over India. The selected models were then used to construct the multi-model ensemble.

CMIP6 rainfall projections are bias-adjusted using Quantile Delta Mapping (QDM) and subsequently integrated with the extreme-rainfall and rainfall scale-invariance framework to derive IDF estimates across different durations.

SSP2-4.5 and SSP5-8.5 are CMIP6 climate scenarios representing different greenhouse-gas forcing pathways. SSP2-4.5 represents an intermediate forcing pathway, while SSP5-8.5 represents a high forcing pathway.

Yes. The climate-change IDF estimates can support climate-resilient infrastructure planning, hydrological and hydraulic modeling, adaptation assessment, and climate-risk analysis.

For critical infrastructure design, the estimates should be considered together with site-specific rainfall information, applicable design standards, catchment characteristics, and relevant engineering requirements.

The historical framework integrates rain-gauge observations and multiple gridded rainfall products with extreme-value analysis and rainfall scale-invariance relationships to develop spatially continuous, high-resolution IDF estimates across India.

Yes. The framework provides spatially continuous IDF estimates, including locations where long-term sub-daily rainfall observations are limited or unavailable.

Multiple GCMs are used to account for inter-model variability in simulated precipitation and extreme rainfall characteristics. The eight GCMs were selected based on their spatial and temporal performance in reproducing observed precipitation characteristics, and the resulting ensemble is used to characterize uncertainty in projected changes in rainfall return levels across different durations and return periods.

The estimates are intended to support hydrological analysis, hydraulic assessment, planning, and design studies. For the final design of critical infrastructure, users should evaluate the estimates alongside site-specific observations, applicable design standards, catchment characteristics, and relevant safety requirements.