GIS spatial analysis Topic 1: Searching bird habitat

1. Background

A new road is planned to be built in a certain area, but the road will affect the habitat environment of a protected bird. Therefore, this issue must be considered in road planning. The purpose of this case is to find a suitable place for the bird habitat in the region for reference by the highway planning department. These ecological protected areas can be avoided during road construction.

2. Living conditions of birds

According to expert research, the areas adapted to the lives of such birds should meet the following requirements:

1)
Vegetation is a favorite food of this bird.

2)
The slope is less than 40 degrees.

3)
There is a certain distance from the road.

4)
The area cannot be too small. It must be greater than 1089000 square feet.

Based on the above conditions, we can find the most suitable place for the lives of birds.

3. CASE Data

1)
Road data for the region. Including the location of each Highway and the affected distance of the highway.

(Road spatial data and level data impact scope and other attribute data)

2)
Vegetation data.

(Spatial data such as vegetation type attribute data and area data in the region)

3)
Slope data.

Generated by slope analysis of DEM 3D data in the region)

4. Habitat search

1) implementation process

Figure 1 implementation process of bird Habitat search

2) implementation steps

Step 1: select a vegetation type suitable for the survival of birds

Right-click "vegetation type" layer> open Attribute Table> table Options> select by attribute> "habit = '1 '";

Figure 2 identifying vegetation types suitable for the survival of birds

Right-click the "vegetation type" layer> SELECT> Create a layer based on the selected options:

Figure 3 create a layer based on the selected elements

Step 2: select the terrain where the slope of the vegetation type is less than 40:

First, "Editor"> start editing;

Second, use the cropping tool under the editor to make sure that the cropped area has only one record. Therefore, merge the layer data with a slope of less than 40:

Figure 4 merge layer elements with a slope less than 40

Finally, use the "crop" tool under the "Editor" to crop:

Figure 5 obtain the terrain where the slope of the vegetation type is less than 40

Figure 6 getting data files

Step 3: remove the affected area from the area that meets the vegetation type and slope:

Different road levels have different impacts on habitat selection. According to expert suggestions, the impacts of road level information on Bird's habitat are classified into two categories: level 1 and level 2 and 3, 4 is the first type. The procedure is as follows:

(1) create a blank surface template with the same geographic projection information, and store the analysis results of highway-level buffer zones for major users;

(2) First-class road element extraction:

Figure 7 extraction of first road level elements

(3) road buffer analysis

Figure 8 select factor (Highway level 1) buffer zone Analysis

Figure 9 Highway Level 1 buffer zone distance 1312 feet

After the preceding buffer result is generated, according to the requirements of the cropping tool under the editor, the buffer result needs to be merged into a factor class, the same method: "Editor"> start editing> merge. Then, based on the preceding cropping function, the "vegetation type selection" layer and the newly generated "surface template" are used for cropping. The cropping requirements are as follows:

Figure 10 highway Level 1 buffer area pruning

(4) road element selection in Category 2

Figure 11 extraction of level 2 Elements

(5) obtain the area affected by Level 2 road according to the above (3) operation steps

Figure 12 Highway Level 2 buffer zone distance: 820 feet

Then, use the merge tool to obtain the area affected by the second-level road.

Figure 13 areas affected by Level 2 Road

Step 4: The best area for bird survival-area over 1089000 square feet:

Figure 14 optimal regions for birds

Figure 15 Export qualified elements

Figure 16 Export results

Step 5: Result Display

Figure 17 optimal bird habitat

3) build a model

The above methods can be used to eliminate the influence of factors that do not meet the survival condition of birds one by one according to the condition restrictions, so as to find the best bird habitat area. How can we find a way to simplify and streamline the above complex workflow? This section describes how to perform the preceding operations based on the modeling tool in the toolbox provided by ArcGIS:

(1) create a toolbox-ecological zone Selection

Figure 18 create a toolbox

(2) create a model-Ecological Zone

Figure 19 create a model

(3) add operation process

Figure 20 ecological zone Selection Model

(4) Result Display

Figure 21 process-based bird best habitat selection