Geographic Information System (GIS) is no more a new name these days as almost any kind of infrastructural project requires the GIS analysis for sake of better analysis for various aspects in multidisciplinary fields. This powerful tool is capable of performing different kinds of analysis with Vector as well as Raster Data. Different Kinds of Projects requires the task of identifying the building footprint and counting them along with their built-up area for purpose like Feasibility Study, Disaster Risk Analysis, Valuation works etc. This Process can be done very easily using GIS based Software but is still less known to alot of people. So let’s dive into how it can be done.
So for this purpose, Let’s take a very crowded area of kathmandu valley in Nepal – Sankhamul. And Let’s count the no of buildings within 1km peripheri of the Bagmati river (500m on either side). So, Let’s break down the tasks we follow into procedures to make it more clear and easier.
Procedures:
1) Creating the 1km buffer around the Bagmati river
Using Buffer tool , 500m buffer on either sides of digitized river shapefile can be created. The new feature created will be used for further analysis.
2)Downloading Building Footprint data
The most critical part that makes this analysis very easy and many people are unfamiliar to is using a vector data for the footprint of the buildings which can be accessed from open Source data platform named Open Street Maps (OSM). OSM is the biggest source for worldwide open Source vector data of entire globe. The data can also be extracted. The site ID is : www.osm.org . It can also be downloaded from other mirror sources as shapefile like: extract.bbbike.org
3)Clipping Building footprint Data
As our Area of interest is only 1km around Bagmati River, the AOI is clipped from Building footprint Data using Buffered feature. The attribute of such created new feature can help us see the number of building with detail of area of new buildings and their total numbers within the buffer.
Result
By following above mentioned procedures, Total no of Buildings was counted along 1km periphery of Bagmati River which was found to be total of 14,663 Buildings. Furthermore, It can be then used for works like rough estimation of Compensation that should be made to displace those structures , effect of flood on structures etc and many more other works.
Conclusion :
To conclude, No of buildings can be calculated easily using Open Street Maps in GIS with pretty accurate Built-up Area which becomes very useful for different Kinds of Analysis Works.
