# <font style="font-size:0px"> **地理資訊系統與實習作業區**</font>

# ==地理資訊系統課程作業區==
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###### tags: `地理資訊系統` ` HackMD`
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## **01_Thematic map_主題圖製作與輸出**

### **Step 1 : Open file**

### **Step 2 : View entire layer**
Select the zoom to layer extent menu item

### **Step 3 : Change unit**
Change the unit to meters

### **Step 4 : Show label**
Select the icon with abc, and change the original (no labels) to single labels, and click TNAME

### **Step 5 : Check the area correspond to attribute table**
Slect the open attribute table menu item,and make sure that the selected area will appear different colors

### **Step 6 : Enable scale bar**
Select the view menu item and choose decoration. Next to the decoration options, there will be more options. Please select the scale bar and check Enable scale bar.

### **Step 7 : Population distribution map**
Right-click on the Taipei layer and click Properties again. The toolbar will appear. Please change the value according to the place marked with the highlighter on the picture.

### **Step 8 : Region distribution map**
Repeat the Step 7 again, change Graduated to Catagorized, and POPU to PNAME

### **Step 9 : Layout the map**
Select the population distribution from the Step 7 and export the picture file
**Picture from QGIS software**

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**Picture from ArcGIS software**

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## **02_Map Digitization_建立電腦數值圖籍與資料**

### **Step 1: Open file in Georeferencer**
Click the Raster function and select Georeferencer, click open raster and select jpg. File import


### **Step 2: Add ground control point**
Open the jpg. file, and select add point to mark the points and enter the coordinates, check whether there are any points with too much error in the GCP table, after checking, start Start Georeferencing and save the TEST name


### **Step 3: Add shapefile layer**
Back to the main screen, click New Shapefile Layer and enter File name "NTUT" and New Field name "ID". After deleting the original fiele list, click Add to Field List, and finally click OK


### **Step 4: Digitize a shape**
Click the layer "NTUT", and select the function key Toggle Editing, then click Add Polygon Feature, and then select the building you want to calculate the area


### **Step 5: Draw a hollow shape**
Similar to Step 4, but you must make sure that the gradient fill has adjusted the transparency when changing the color, so that the framed building can see the original layer


### **Step 6: Snap node or line**
To make sure there is no gap between two shapes


### **Step 7: Add column and caculate area**
Right-click the NTUT layer, click Open Attribute Table, then click New column to add an area field, and finally click Open field calculator and select Updat existing field to change area item, find the Geometry menu from the list and find $area and Press (double-click $area) twice to calculate the area field


**Picture from QGIS software**

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**Picture from ArcGIS software**

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## **03_Attribute Query_屬性資料查詢**

### **Step 1: Set coordinate reference system**
Right-click the Taiwan layer and select the Layer CRS function key. Set Layer CRS will appear. After the screen appears, select (TWD97/TM2 zone 121)

### **Step 2: Caculate population density**
Right-click the Taiwan layer, and select Open attribute table, open the screen and select New field (ctrl+W), enter the Name and change the Type to choose Decimal number (real), change the length to 10 and precision to 2, and click again after saving Select Open field calculator (Ctrl+l), check Update existing field, select the calculation item, and enter the formula required by the item

### **Step 3: Filter data**
First click the Toggle Editing function key, then click the Taiwan layer right button, and select Filter. After the screen appears, select the field to be filtered. For example, for Population, you can enter "pop_2012">100000

### **Step 4: Save filtered data**
Right-click on the Taiwan layer and select Export, and Save Feature As will appear. After the screen appears, save it again.

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**Picture from QGIS software**

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**Picture from ArcGIS software**

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## **04_Spatially Join_圖形條件連結**

### **Step 1: XLS to CSV**
Enter the value of the text file in the folder into EXCEL and convert it into a CSV file

### **Step 2: Open CSV file**
After adding the Taipei.shp layer, click Add Layery and then Add Delimited Text Layer and import the ROUTE.CSV file and select the projection coordinate system (EPSG:3826)

### **Step 3:Point to path**
Click Processing and then Toolbox, and go to the screen to view the options. From Vector creation, select Points to path. After the painting appears, select ROUTE{EPSG:3826} from the Input point layer and press the run option and execute

### **Step 4: Intersect**
Select Select by location from Vector selection, and when the screen appears, select Taipei {EPSG:3826} from Select features from and click the run option and execute

### **Step 5: Search**
Select Geoprocessing Tool from Vector and then select intersection. After the screen appears, click run, and then select the option in the PPT screen from the intersection in the layer.

### **Step 6: Add column**
From the intersection layer, click Open Attribute Table and add a new column and change the name to Length, then calculate the length

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**Picture from QGIS software**

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