Flood Hazard Risk Analysis with Remote Sensing and GIS/AHP

Create a flood risk analysis folder in ArcGIS Pro, download boundary data from Divide GIS for Chennai, and organize it for projection in the next video.

Define the projection system for the Chennai city study area in ArcGIS Pro, selecting a UTM zone and exporting to a projected coordinate system for accurate spatial analysis.

download the aster global digital elevation model from earth data, create an account if needed, and save tiff files for merging to generate slope and elevation maps.

Merge two ASTER digital elevation model tiles, project to the boundary projection, clip to the study area, and export the result as a TIFF for flood risk analysis.

Download land use and land cover raster data from S3 land cover, Sentinel-2, and ArcGIS Living Atlas, and prepare the rasters to create an LLC map for flood risk analysis.

Download Landsat images for NDVI analysis using USGS Earth Explorer, select Landsat collection two level one, and use bands four and five to assess healthy vegetation for flood risk.

Create an elevation map from a digital elevation model in ArcGIS Pro, classify the DEM into five natural-break classes, and apply color and transparency for flood risk visualization.

Create a print-ready elevation roadmap by building a layout with map elements, legend, north arrow, scale bar, and grid, then export as a geotiff.

Generate a five-class slope raster from the elevation model using degree units, apply natural breaks, customize the color ramp, and export the slope roadmap for next steps.

Create a topographic wetness index raster from a digital elevation model by computing flow direction and accumulation, then derive TVI with slope and classify into five classes.

Create curvature using a digital elevation model to reveal convex, concave, and flat slope areas, and assess flood risk with curvature maps and flow accumulation in ArcGIS Pro.

Create a precipitation map using climate data and the Schreiber method, generate random stations with elevations from the Aster digital elevation model, and compute rainfall values.

Create a precipitation map for Chennai district using the IDF interpolation method in ArcGIS Pro. Convert station rainfall to a raster and export with a Schreiber method layout.

Create a land use and land cover roadmap by preparing a study boundary, extracting by mask, and classifying with Esri land cover and ArcGIS Living Atlas.

Create an ndvi analysis map from Landsat 8 imagery using the ndvi formula (band5 - band4)/(band5 + band4), classify vegetation from -1 to 1, and export a geotiff.

Create a drainage density map in ArcGIS Pro by deriving streams from flow accumulation and flow direction, converting to vectors, and computing line density to assess flood vulnerability.

Create a distance to streams analysis with multiple ring buffers (100, 250, 500, 750 m), union with the study boundary, and clip to produce a flood risk map.

Learn to create a geomorphology factor map with ArcGIS 10.8, building a geomorphology TIFF raster, and exporting a print-ready roadmap using topography tools and a matched digital elevation model.

Perform random reclassification of rasters into integer classes across key layers like elevation, slope, curvature, precipitation, ndvi, and land use, then convert to vectors and prepare hazard risk values.

Convert raster data to vector data using raster to polygon and reclassification steps to produce vector layers such as geomorphology, drainage density, curvature, slope, and the topographic wetness index.

Develop flood hazard risk analysis skills by dissolving raster to vector data, computing slope, topographic wetness index, curvature, precipitation, and assigning hazard risk values to vector subclasses.

Assign hazard risk values to vector data using a 1–5 risk points scale, reclassify rasters, and convert between vector and raster formats to map flood risk by slope.

Assign risk points from vector data to a raster using a digital elevation model, establishing elevation-based flood risk classes with a reverse relationship between elevation and flood probability.

Assign risk points to drainage density in a raster GIS workflow, linking higher drainage density to greater flood hazard risk through runoff and water accumulation.

Assign risk points from precipitation values to a raster and apply a weighted overlay analysis to reveal flood hazard risk, highlighting higher risk in areas with greater precipitation.

Assign risk points to ndvi criteria, noting that negative ndvi marks water and positive ndvi marks vegetation; higher ndvi lowers risk, with water bodies at risk on a 5-point scale.

Assign curvature-based risk points, convert polygon features to a raster using curvature as the value field, and map flood hazard risk across flat, concave, and convex areas.

Assign risk points to map flood hazard by converting vector to raster and using wetness index maps to show topography's influence on runoff and flood potential.

Assign risk points by distance from the river to support flood hazard mapping. Convert stream distance from vector to raster and export the resulting raster.

Assign hazard risk points to land use and land cover based on terrain infiltration and runoff factors, then convert vector risk points to a raster flood risk map.

Assign geomorphology risk points to raster and classify valley, plain, hillside, and mountain terrain, considering slope and flat areas, then convert vectors to raster for weighted analysis.

Use the online analytic hierarchy process calculator to weight elevation, slope, distance to streams, and other flood risk criteria, deriving priority weights for a weighted overlay analysis.

Use a ten-factor weighted overlay analysis in arcgis pro with integer hp weights to combine elevation, slope, distance to streams, drainage density, and precipitation into a flood risk map.

Learn to calculate flood risk areas by converting raster data to vector, then classify zones into high, moderate, and low risk and compute area in hectares and its percentage.