THE MAZE - Contour Download

DOWNLOAD CONTOUR FOR ANY PLACE IN AUTOCAD

This article explains how to get the rough contour data for a specific place in AutoCAD. Here I have explained two ways but do keep it mind that this contour data is based on Google Elevation API, which means the contour lines generated from both these methods (and any other methods that you find in Youtube) is just a rough interpretation based on satellite data and is not bound to be accurate in small scale. Nonetheless this is better than nothing. For countour data of Kathmandu Valley you can use the more accurate KVMP map.

CADMAPPER.COM

Link: https://cadmapper.com

Using CADMapper we can download contour map of any area (1 sq.km limit for free version). The added bonus is we can include data from Openstreetmap which includes buildings, roads, river etc. The only problem with CADMapper is minimum contour interval is 4 meters i.e. It cannot export contour interval less than 4m.The process is straight forward

Create a new user account. if you don't want to go through hassle for quick use you can use this username and password
Username: solutionmaze@gmail.com

Password: demo215

Search for the area by name or co-ordinates
Check 3D buildings only if you are downloading .skp file for 3D. 3D data of buildings (from OSM) for Nepal is generally not available so you will have to input the assumed height in meters.
For 2D works uncheck 3D buildings. Select appropriate parameter for roads - centerline or outline (you will get option to assume the width)
Select Create File to download the zip file
Warning: Remember that the dxf files that we open in AutoCAD is a 3D file. If you want to work on 2D you need to convert the content to 2d by using FLATTEN command in AutoCAD.

CONTOUR MAP CREATOR

We will use the contour Map Creator to get the rough contour of the area. Use this only if you need contour data of less than 4m which is not available in previous method. The problem with this method is you will have to trace the features like road and buildings manually.

Link: https://contourmapcreator.urgr8.ch/

STEP 1: GETTING CONTOUR OF THE AREA IN KML FORMAT

Open the above link
Search for the area by name or co-ordinates
Mark the location by clicking two ends in the map
Click [Get Data]
In Plot Options put appropriate interval in [contour interval] say 1m. The default Plot option is Number of levels
Use [Download KML data] to download the KML file which can be viewed in Google earth

STEP 2: CONVERTING TO DXF FORMAT

Use https://mygeodata.cloud to convert the KML file to DXF file which can be opened in AutoCAD.
- Upload the file for conversion, Select AutoCAD DXF in Output Format
- IMPORTANT: Under coordinate system choose WGS 84/UTM zone 45N for eastern Nepal or WGS 84/UTM zone 44N for western Nepal and select Convert Now to convert. Otherwise the contour will be distorted and will not align with google image in later step.
- NOTE: Only 3 conversion is allowed per month from one PC under free version.
- This DXF file is 2d so no need for conversion but you need to map all the features like building and roads by using image from Google Earth

STEP 3: DRAWING THE FEATURES AND CONTEXT

To map the features like buildings and roads we will have to use aerial image from Google Earth.
Open the previous KML file in Google earth. Turn off the terrain in Google Earth and reset the image's alignment by pressing the R key.
Export the image of the location with the contour from KML file visible.
Open the exported image [with contour] in Auto CAD and align the image to the dxf file.
Now map the features manually to complete

Page updated

Google Sites

Report abuse