$\newcommand\si[1]{\mathrm{#1}} \newcommand\SI[2]{#1\,\si{#2}} \newcommand\matr[1]{\mathbf{#1}} \DeclareMathOperator*{\argmax}{arg\,max} \DeclareMathOperator*{\argmin}{arg\,min}$

# GIS data analysis 2

Institute for Environmental and Spatial Analysis...University of North Georgia

## 1   Reclassification

Reassigns pixel values in raster to simplify the raster.

For example, cells with values = forestry (value 10) should take a new value of 1.

Cells with values not equal to forestry should take a new value of 0.

Creates a newly coded simple raster.

## 2   Zonal statistics

Raster GIS filter operations

## 3   Moving average

(a) Moving average in vector; (b) Moving average in raster

## 5   Aspect

Example of cartographic hillshading techniques

Image source: (a) and (b) from the Institute of Cartography, ETH Zurich, Switzerland, used by permission

## 7   Solar radiation

Modelling incoming solar radiation in Happy Valley (a–d) representing morning to evening during a winter’s day

## 8   Line of sight

Ray tracing for visibility analysis

## 9   Viewshed

Results of viewshed analyses for single point and linear feature

## 11   Exercises

Find some sample layers from nc_spm_08_grass7_exercise.gdb.zip.

### 11.1   Exercise: NLCD reclassification

Keywords: reclassify

Download the NLCD data and reclassify subtly different subclasses of the same class into their parent classes.

### 11.2   Exercise: DEM reclassification

Keywords: reclassify

Reclassify the elevation raster in nc_spm_08_grass7_exercise.gdb.zip into lower (0–1/3 of the elevation range), medium (1/3–2/3), and higher (2/3–1).

### 11.3   Exercise: Major NLCD classes within a radius

Keywords: focal statistics

Find major NLCD classes within a 100-meter radius of each cell

### 11.4   Exercise: Major NLCD classes by census block

Keywords: zonal statistics

Find major NLCD classes by census block in nc_spm_08_grass7_exercise.gdb.zip.

### 11.5   Exercise: Slope

Keywords: slope

Calculate the slope of the elevation raster in nc_spm_08_grass7_exercise.gdb.zip.

### 11.6   Exercise: Aspect

Keywords: aspect

Calculate the aspect of the elevation raster in nc_spm_08_grass7_exercise.gdb.zip.

### 11.7   Exercise: Hillshade

Keywords: aspect

Calculate the aspect of the elevation raster in nc_spm_08_grass7_exercise.gdb.zip.

Overlay the hillshade layer over the elevation layer and adjust its transparency.

## 12   Exercise: Solar radiation

Keywords: area solar radiation

Model incoming solar radiation (insolation) into the elevation raster in nc_spm_08_grass7_exercise.gdb.zip.

## 13   Exercise: Line of sight

Keywords: line of sight

Calculate the light of sight on the the elevation raster in nc_spm_08_grass7_exercise.gdb.zip.

Any issues? I have one.

## 14   Exercise: Viewshed

Keywords: viewshed

Calculate the viewshed on the the elevation raster in nc_spm_08_grass7_exercise.gdb.zip.