## 这是一篇关于如何使用光栅数据的作业代写。

In this tutorial, you will learn how to work with raster data. You will load and manipulate various raster files to assess the suitability of land for agricultural purposes. You will perform raster arithmetic in order to generate a single suitability raster that takes multiple factors into consideration.

Part 1

Download the project files and guide from the following link:

https://hed.esri.ca/resourcefinder/data/files/Suitability.zip

From the extracted files, follow the steps in the Suitability_Tutorial.pdf guide.

Once all steps from the guide have been completed, save and archive your project files as Tutorial_4_Base.zip.

Important Notes:

Guide Part 2 – Step 1: You may find that upon loading the layer, an exclamation mark is displayed in the Contents pane next to the layer name indicating that the data source could not be found. If this occurs,click the exclamation mark to manually identify the data source. Navigate to the project folder and point the source to “Project” -> “Suitability” -> “Data” -> “slope” -> “slope”. The same will need to be done when loading the subsequent layers as well.

Part 2

Complete the following additional tasks. Once all tasks have been completed, save and archive your project files as Tutorial_4_Tasks.zip.

Task 1: Determine the proportion of the Suitability raster (produced from Part 5 of the base tutorial) that consists of highly suitable land. Highly suitable land is defined as raster cells with a value greater than or equal to 75. Store the result in a table named Highly_Suitable_Proportion. It is sufficient if the table just gives a count of how many cells are highly suitable and how many are not. You don’t have to explicitly calculate the proportion. (Hints: Start by using the “Raster Calculator” tool to produce a binary raster of highly suitable land. Next, look up the “Zonal Statistics as Table” tool.)

Task 2: Produce a new suitability raster that avoids using land too close to developed areas. To do this,create a new version of the land cover raster where everything within 50 cells of developed land is also given a value of 0 (all other values should remain as set in the base tutorial). Use this new raster along with the slope and soil quality rasters from the base tutorial to produce an updated version of the suitability raster named Rural_Suitability. Use the same type of symbology as described in Part 6 of the base tutorial. (Hint: Look up the “Expand” tool. Note that the tool may take a few minutes to run.)

Task 3: Produce a new suitability raster that gives preference to land that is near water. To do this,create a new raster with cell values based on the distance to the nearest water cell. Cells within distance 0-50 should be given a value of 3, cells within distance 50-100 should be given a value of 2 and all other cells should be given a value of 1. Use this new raster as an additional factor for the suitability calculation from Part 5 of the base tutorial (i.e., you are now multiplying 4 rasters rather than 3). Name the output raster Suitability_Water and apply the same type of symbology as described in Part 6 of the base tutorial. (Hints: Look up the “Euclidean Distance” tool. Don’t forget that you can use the “Reclass” tool to create useful intermediary rasters.)