Calculating Topographic Wetness Index in ArcGIS | 2023

Welcome to our comprehensive tutorial on calculating the Topographic Wetness Index (TWI) using ArcGIS! 🌊
In this video, we'll walk you through the step-by-step process of deriving TWI, a crucial parameter in hydrology and environmental studies. Whether you're a GIS professional, a student, or someone interested in understanding the science behind terrain wetness, this tutorial has got you covered.
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What is Topographic Wetness Index (TWI)?
Topographic Wetness Index (TWI) quantifies terrain driven variation in soil moisture.
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The Topographic Wetness Index (TWI) was developed by Beven and Kirkby (1979) within the runoff model TOPMOD.
It is defined as ln(a/tanβ) where a is the local upslope area draining through a certain point per unit contour length and tanβ is the local slope.
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 SRTM 1 Arc-Second Global – 30m (Used for this Study), USGS Website https://earthexplorer.usgs.gov/
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Link for Downloading Word Document on TWI:
https://drive.google.com/file/d/1Tvdd...
How to Download SRTM DEM - Video Guide:
   • Downloading 30m SRTM DEM data from US...  
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Steps in Calculating Topographic Wetness Index:
00:00 Introduction
00:30 Adding DEM Data
00:46 Project Raster GCS to PCS
02:11 Fill DEM
03:13 Flow Direction
04:03 Flow Accumulation
04:47 Slope in Degree
05:37 Radians of Slope
07:30 Tan Slope
09:14 Flow Accumulation Scaled
10:43 Topographic Wetness Index (TWI)
11:38 Changing Color / Symbology
12:58 Clipping Raster
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Other Important Links:
To know more about Degrees to Radians Conversion visit:
https://www.wikihow.com/Convert-Degre...
Topographic Wetness Index:
https://www.sciencedirect.com/science...
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#topographicwetnessindex #TWI #arcgis #hydrology #geospatial #DEM