తెలుగులో GIS నేర్చుకుందాం

Exercise – 10 /  How to export ShapeFiles to KML & Import KML to ShapeFile in QGIS Export / Import KML files in QGIS. QGIS supports a wide range of file types including KML (Keyhole Markup Language). You can then open this KML file on other software such as Google Earth. Export Shape file as KML Add Vector Layer to Layers panel to export to KML and choose symbology for the added layer Figure 200 Shapefile before exporting to KML Right-click the layer and select Export → Save Feature As Select Keyhole Markup Language (KML) from the format list Specify the file name and location Optionally, you can also specify the layer name also Select the CRS (Ex: EPSG 4326 – WGS84) Select other options as per the requirement Click OK Figure 201 - Save Vector layer window to export as KML KML layer will be created and added to Layer panel .  Now open Google Earth and go to File → Open and browse to the KML file. Figure 202Select KML file . Figure 203 KML in Google earth Import K...

Exercise – 9 /  How to use Join & Spatial Join functions in QGIS Join Attributes by Location (Spatial Join) Join Attributes by Location (Spatial Join) is transferring attributes from one layer to another based on their spatial relationship.  Add Polygon/Line/Point Layer to Layers panel for spatial join. Figure 156 - QGIS canvas with point & polygon layers loaded for spatial join In this exercise we will join the data from Parcel_point to Parcel (Polygon) layer, open attribute tables of both the shapefiles to check the attribute data. Figure 157 - Attribute data of Point layer Figure 158 - Attribute data of Polygon layer Choose Vector → Data Management tools → Join Attributes by Location Figure 159 - Join by Location window Select Base Layer (Parcel – Data will be joined to ) Select Join Layer (Parcel_point – Data will be joined from ) Select Geometric predicate from Intersect Overlap Contains With in Equals Crosses Touches Select Join type and leave remaining ...

Exercise – 8 /  How to use Intersection , Dissolve & Union in QGIS Dissolve The Dissolve Tool unifies boundaries based on common attribute values. In other words, dissolve merges neighboring boundaries if the neighbors have the same attributes.The dissolve geoprocessing tool erases borders and unifies them into one. Add Polygon Layer to Layers panel Figure 109 - Shapefile before Dissolve Choose Vector → Geoprocessing tools →Dissolve to open dissolve window Select Input layer (Ex: IND_adm1) Open Attribute table to choose the field on which Dissolve tool will be executed, in this case TYPE_1 has choose. Figure 110 - Attribute table with selected attribute value Figure 111 - Dissolve window Click on Dissolve field(s) [optional] and select the attribute value and click on OK and Run . Figure 112 - Attribute field selection window for dissolve Temporary layer will be created and added to Layer panel with Dissolved layer. Right click on the layer and save to destination f...

Exercise – 7 /  How to use CLIP tool in QGIS Clip The clip tool is an overlay function that cuts out an input layer with the extent of a defined feature boundary. The result of this tool is a new clipped output layer. Clip – Line Add Line Layer to Layers panel Add polygon boundary for clip Figure 100 - Input Layer and Overlay layer before Clip Choose Vector → Geoprocessing tools →Clip to open clip window Select Input Layer (Ex: Network) Select Overlay Layer (Ex: Clip_Boundary) Figure 101 - Clip Window Temporary layer will be created and added to Layer panel with Clipped layer. Right click on the layer and save to destination folder. Figure 102 - Layer after Clip Clip – Point Add Point Layer to Layers panel Add polygon boundary for clip Figure 103 - Input point Layer and Overlay layer before Clip Choose Vector → Geoprocessing tools →Clip to open clip window Select Input Layer (Ex: Location) Select Overlay Layer (Ex: Clip_Boundary) Figure 104 – Clip Window for Point Temporar...