RFainFallViz.m: Visualization of Statewise Rainfall

This MATLAB script visualizes rainfall data over India, overlaying state boundaries to provide geographical context. It reads rainfall data from a netCDF file and state boundary information from a shapefile, then generates an animated GIF showing the rainfall distribution over time.

Key Functionality

1. Data Loading:

   • Reads rainfall data (longitude, latitude, time, rainfall values) from a netCDF file (RainFall.nc).
   • Loads coastline data from coastlines.mat.
   • Loads state boundary data from a shapefile (india27-11.shp).

2. Time Handling:

   • Converts time data from the netCDF file into MATLAB datetime objects, creating a sequence of daily dates.

3. Visualization Loop:

   • Iterates through a subset of the time steps (limited to 100 for efficient GIF creation).
   • For each time step:
     • Plots the coastline.
     • Generates a pcolor plot of the rainfall data, using shading interp for smooth color transitions.
     • Overlays state boundaries from the shapefile as white lines.
     • Adds a colorbar and sets the colormap to jet.
     • Adds a title indicating the date of the rainfall data.
     • Captures the current figure as an image frame.

4. GIF Animation Creation:

   • Combines the captured image frames into an animated GIF file (RainFall_1981-2014.gif).
   • Sets the GIF to loop infinitely and adjusts the frame delay.
   • Uses imwrite to write the image data to the gif file.

Purpose

The script aims to provide a visual representation of rainfall patterns across Indian states over time. This visualization can be useful for:

• Analyzing rainfall distribution.
• Identifying regional rainfall variations.
• Understanding temporal changes in rainfall.

Dependencies

• MATLAB
• NetCDF Toolbox (for reading netCDF files)
• Mapping Toolbox (for reading shapefiles and plotting coastlines)
• coastlines.mat file containing coastline data.
• RainFall.nc netCDF file containing rainfall data.
• india27-11.shp shapefile containing the state boundaries.

Usage Notes

• Ensure that the netCDF file and shapefile are in the same directory as the MATLAB script or provide the correct file paths.
• The script limits the animation to the first 100 time steps for efficiency in GIF creation. If you want to create a longer animation, modify the loop limits.
• The output GIF file will be saved in the current working directory.