Automated SWAT Weather File Generation for India Region

[Lakhwinder Singh]

IMD Observed Gridded Climate Data and Automated SWAT Weather File Generation

Dear SWAT researchers and hydrological modelling community,

I am pleased to share IMD Gridded Data Analyzer v2.0.0, a Windows-based application developed to simplify the preparation of observed meteorological inputs for the Soil and Water Assessment Tool (SWAT).

Preparing long-term climate inputs for watershed simulations often requires downloading historical datasets, extracting daily observations, formatting precipitation and temperature files, and preparing station metadata, including geographical coordinates and elevation.

The application integrates these procedures into a streamlined workflow using observed gridded rainfall and temperature data from the India Meteorological Department (IMD).

𝗞𝗲𝘆 𝗙𝗲𝗮𝘁𝘂𝗿𝗲𝘀 𝗳𝗼𝗿 𝗦𝗪𝗔𝗧 𝗠𝗼𝗱𝗲𝗹𝗹𝗶𝗻𝗴

1. Historical IMD Climate Data

The software includes a bundled offline archive containing:

• Daily rainfall: 1901–2025 (0.25° resolution)

• Daily minimum temperature: 1951–2025 (1.0° resolution)

• Daily maximum temperature: 1951–2025 (1.0° resolution)

The historical archive can be processed without repeatedly downloading annual datasets.

2. Regional Climate Data Extraction

Users can extract climate observations for individual locations, multiple stations, or a rectangular study region.

The application supports IMD-grid snapping, custom 0.25° coordinate spacing, native temperature-grid extraction, and temperature resampling to rainfall-grid locations.

3. Automated SWAT Weather Files with Station Elevation

The application generates the following files for subsequent SWAT model setup:

✓ Daily precipitation station files (.pcp)

✓ Daily temperature station files (.tmp)

✓ Precipitation station index (pcpINDEX.txt)

✓ Temperature station index (tempINDEX.txt)

✓ Automatic retrieval of station elevation using NASA POWER MERRA-2

✓ Automatic inclusion of elevation and geographical coordinates in SWAT station index files

𝗦𝗪𝗔𝗧 𝗦𝘁𝗮𝘁𝗶𝗼𝗻 𝗜𝗻𝗱𝗲𝘅 𝗙𝗼𝗿𝗺𝗮𝘁

ID,NAME,LAT,LONG,ELEVATION

The software retrieves elevation information for the extracted station locations and incorporates it directly into the precipitation and temperature index files.

This eliminates the need to manually prepare station elevation records for routine weather-file generation.

Precipitation, temperature, and station index files are organized together within the project directory.

4. Additional Climate Analysis

The application also generates daily and monthly Excel outputs and provides descriptive statistics, Mann–Kendall trend analysis, and Sen's slope estimation.

These functions can support preliminary investigations of historical climate variability and trends within a watershed.

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𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗔𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻

The principal objective of this software is to reduce repetitive climate-data preparation and facilitate the use of IMD gridded observations in SWAT-based hydrological studies.

The generated precipitation and temperature files, together with station coordinates and automatically retrieved elevation, can be used for subsequent watershed model setup.

Researchers should verify the spatial representativeness of the meteorological data and the accuracy of station elevations before simulation. If elevation retrieval fails, the application reports the issue and assigns a placeholder value of 0.00 m, which must be checked and corrected before modelling.

The application may be particularly useful for researchers working on rainfall–runoff simulation, watershed hydrology, water-resource assessment, and historical climate analysis in Indian river basins.

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📥 Download IMD Gridded Data Analyzer v2.0.0

https://github.com/IndianRemoteSensing/IMD-Gridded-Data-Analyzer/releases/tag/v2.0.0

🎥 Software Demonstration and Tutorial

https://www.youtube.com/watch?v=_SuX9cs5xl8

💻 Software Licensing and Activation

https://www.indiaremotesensing.com/p/buy-imd-gridded-data-analyzer.html

For technical questions or feedback regarding SWAT weather-file generation:

Dr. Lakhwinder Singh

#SWAT #SWATModel #HydrologicalModelling #IMDData #WatershedModelling #ClimateData #WaterResources