Exercise – 14 / Select by Location in QGIS తెలుగులో నేర్చుకుందాం

Exercise – 14 / Select by Location in QGIS

Select by Location

Spatial queries are core to many types of GIS analysis. Spatial queries allow you to select features in a layer by their spatial relationships (intersect, contain, touch etc.) with features from another layer.

The criteria for selecting features is based on the spatial relationship between each feature and the features in an additional layer.

Add Polygon/Line/Point Layer to Layers panel

Figure 153 - QGIS canvas with Line, point & polygon layers loaded

Choose Vector → Research tools → Select by Location
Select features from (Line / Point / Polygon) for selection
Choose the relationship with other features from other layer with intersect, contain, touch, with in etc.
Select comparing feature.
Select options from modify current select by

create new selection
add to current selection
selecting within current selection
removing from current selection

Click on Runand close select by location window to see the selection of point which are with in polygons.

Note: Process of Select by Location for Line & Polygon remains the same.

Figure 154 - Select by location window

Figure 155 - Points which are within polygon layers are selected

Comments

How to Rename attribute fields in QGIS & How to Rearrange attribute fields in QGIS | తెలుగులో నేర్చుకుందాం

How to Rename attribute fields & Rearrange attribute fields in QGIS Refactor fields Refactor fields, allows editing the structure of the attribute table of a vector layer. Fields can be modified in their type and name, using a field’s mapping. The original layer is not modified. A new layer is generated, which contains a modified attribute table, according to the provided fields mapping. Refactor layer fields allows to: Change field names and types Add and remove fields Reorder fields Calculate new fields based on expressions Load field list from another layer Add Vector Layer to Layers panel to Drop field(s) Choose Processing → Toolbox → Vector table → Refactor fields Figure 178 - Vector layer with attribute table before Refactor fields Select Input Layer (Ex: Ind_adm1) Select fields to be renamed and reorder (Ex: in the below given example Name_0 has to rename as Name with Length from 75 as 100 and change order of Name_1 under Name_0 [Name after rename] ) Figure 179 - Fi...

Exercise – 15 / How to Create Topology in QGIS తెలుగులో నేర్చుకుందాం

Exercise – 15 / How to Create Topology in QGIS Topology Creation Topology describes the relationships between points, lines and polygons that represent the features of a geographic region. With the Topology Checker plugin, you can look over your vector files and check the topology with several topology rules. These rules check with spatial relations whether your features ‘Equal’, ‘Contain’, ‘Cover’, are ‘CoveredBy’, ‘Cross’, are ‘Disjoint’, ‘Intersect’, ‘Overlap’, ‘Touch’ or are ‘Within’ each other. It depends on your individual questions which topology rules you apply to your vector data (e.g., normally you won’t accept overshoots in line layers, but if they depict dead-end streets you won’t remove them from your vector layer). QGIS has a built-in topological editing feature, which is great for creating new features without errors. But existing data errors and user-induced errors are hard to find. This plugin helps you find such errors through a list of rules. It is ve...

What is Survey Of India (SOI) Framework?

What is Survey Of India (SOI) Framework? The Survey of India (SoI) framework is a geospatial reference system used in India for mapping, surveying, and geodetic purposes. The framework is maintained by the Survey of India, which is the national mapping organization of India and the oldest scientific department of the Government of India. The SoI framework is based on the Indian Terrestrial Reference Frame (ITRF) and the Indian National Spatial Reference System (IN-SRS), and is used to determine the location and height of points on the Earth's surface with high accuracy. The framework is also used to define the horizontal and vertical reference systems for mapping and surveying purposes in India. The SoI framework provides a consistent and accurate basis for various geospatial applications, such as land management, urban planning, navigation, disaster management, and environmental monitoring. The framework is also used for the production of topographic maps, cadastral maps, and othe...

తెలుగులో GIS నేర్చుకుందాం

Search This Blog