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# How to Create NDVI Maps in ArcGIS

## What is NDVI?

Normalized Difference Vegetation Index or NDVI maps are being used in agriculture, forestry, ecology and more. But what is NDVI?

Healthy vegetation (or chlorophyll) reflects more near-infrared (NIR) and green light compared to other wavelengths. It absorbs more red and blue light.

This is why our eyes see vegetation as the color green. This is also why more near-infrared is reflected back into satellite sensors.

NDVI Definition:

NDVI is an index describing vegetation by showing the difference between near-infrared (which is strongly reflected by vegetation) and red light (which is absorbed by vegetation).

## The NDVI Formula

Normalized Difference Vegetation Index (NDVI) uses the NIR and red channels to measure healthy vegetation.

NDVI Formula:

NDVI = $(NIR - red) \over (NIR + red)$

The result of this formula generates a value between -1 and +1. If you have low reflectance (or low values) in the red channel and high reflectance in the NIR channel, this will yield a high NDVI value. And vice versa.

It’s really using the difference between these two bands to output a standardized way to measure healthy vegetation. When you have high NDVI values, you have healthier vegetation.

Many satellites like Sentinel-2, Landsat and SPOT are equipped with sensors with that can delivernear infrared images.

READ MORE: 15 Free Satellite Imagery Data Sources

### How to create NDVI maps in ArcMap

You can create NDVI maps with the image analysis toolbar in ArcGIS 10. All you need is imagery with red and NIR bands.

The main objective is to classify high and low vegetation. This NDVI tutorial shows you step-by-step how to create NDVI maps in ArcMap.

In this NDVI example, we use Worldview-2 (WV-2). Worldview-2 is multispectral imagery. We say multispectral because it has red, green and blue – and other bands as well. The band configuration for WV-2 is:

Worldview-2 Band Configuration
Band 1: Coastal Band
Band 2: Blue
Band 3: Green
Band 4: Yellow
Band 5: Red
Band 6: Red Edge
Band 7: Near Infrared 1 (NIR-1)
Band 8: Near Infrared 2 (NIR-2)

To display true (visible) color composite, in layer properties – change the “Red” channel to band 5, “Green” channel to band 3 and the “Blue” channel to band 2. We say true color because it is the same as how our eyes see.

To display near-infrared (NIR) false color composite, you need band 7 (NIR-1) as the “Red” channel, band 5 (red) as the “Green” channel, and 3 (green) as the “Blue” channel. We say near-infrared false color because this configuration uses NIR in the “Red” channel. The vegetation should already be shouting out at you in bright red!

#### Step 1: Enable Image Analysis Toolbar

Enable the Image Analysis Toolbar (Windows > Image Analysis). The image analysis window will be displayed in ArcMap.

#### Step 2: Check Scientific Output Properties

Under image analysis options, select the red band and the near infrared band.

For Worldview-2 imagery, under the NDVI tab – the red band is “band 5” and the NIR band is “band 7”.

Optionally select “Scientific Output” so your values range from -1 to 1.

#### Step 3: Click NDVI Icon

Highlight your layer by clicking it.

Under properties, Select the NDVI icon which looks like a leaf.

#### Step 4: Export Raster

Highlight the new NDVI layer that you want to export by selecting it in the image analysis toolbar.

Right click layer, and export raster to save into memory.

High positive NDVI values (green) means high vegetation. While water usually has negative NDVI values (yellow and red), urban features usually are near zero.

### Where is NDVI being used?

NDVI maps have numerous uses and applications across different sectors. For example, NASA is using NDVI and EVI to measuring global vegetation.

But there are other fields:

• Agriculture: Precision farming, crop insurance fraud, biomass and food security
• Ecology: Animal migration patterns, environment change and population dynamics
• Forestry: Leaf area index, forest supply and fire danger

#### 10 Comments on How to Create NDVI Maps in ArcGIS

1. Ayana

This is really very nice and helps for analysis. However, usually strict NDVI values aren’t declared. It is true that NDVI values range from -1 to 1 but in strict form the intervals aren’t given. So, that creates the problem to reclassify the NDVI values and impossible to estimate the area coverage and the like of the vegetation cover. Could you please help us the clear values (ranges) of the computed NDVI to estimate to generate more results.

2. Wanna Mid

Where is the “Scientific Output” tool or tick box located in Step 2?I can’t find it.Please help.

3. GISGeography

In the image analysis toolbar, click the top-left for the options. In the NDVI tab, “scientific output” is the bottom option. Click the check mark.

4. Wanna Mid

Thank you for your advice but I’m using ArcGIS version 10.0 and the option is not there. What version are you using?

5. GISGeography

We’re using 10.3. Sorry but not sure how to do it in 10.0

6. Curious

How is this performed with Landsat 8 imagery, exactly? The images are separated into the bands. If I open 5 and 7, and run the options are described here, the NDVI button remains grayed out.

7. GISGeography

Here are the band designations for Landsat-8:
Band 1: Coastal / Aerosol – 0.433 – 0.453 µm (30 m)
Band 2: Visible Blue – 0.450 – 0.515 µm (30 m)
Band 3: Visible Green – 0.525 – 0.600 µm (30 m)
Band 4: Visible Red – 0.630 – 0.680 µm (30 m)
Band 5: Near Infrared – 0.845 – 0.885 µm (30 m)
Band 6: Short Wavelength Infrared – 1.56 – 1.66 (30 m)
Band 7: Short Wavelength Infrared – 2.10 – 2.30 (30 m)
Band 8: Panchromatic – 0.50 – 0.68 (15 m)
Band 9: Cirrus – 1.36 – 1.39 µm (30 m)
Band 10: Long Wavelength Infrared – 10.3 – 11.3 µm (100 m)
Band 11: Long Wavelength Infrared – 11.5 – 12.5 µm (100 m)

So you will need bands 4 and 5. If you have these bands as separate images, then you should use the “composite band” tools. This will combine bands into a single image. After running this tool, you should be able to follow these steps and create an NDVI map.

8. tuando

Version 10.1 up to 10.x uses NDVI the same as this.

9. david

To create NDVI in ArcGIS 10.0, you can also use arctoolbox-raster calculate

10. mashal

How do you follow the same process with modis data in ArcGIS 10.2, I intend to make natural color image so can I use the combination of band 1,2,1 as RGB???