Thursday, October 6, 2011

Online Interactive Geological Map Of India

I keep tabs on the India Biodiversity Portal, one of the best India based open access web mapping applications focusing on natural resources.

They have online now an interactive geological layer created by digitizing likely 1 : 1 million scale Geological Survey Of India geology maps. The contributor is R. Ravindranath of the Foundation of Ecological Security. You can click on geological units and get a description of the unit. You can also thematically style the geology based on Geological Age and Lithology. And you can control transparency so as to get an idea of the relationship between say physiography and geology. The physiography layer is one of the Google base layers available for display.

Other geology related overlay layers are India Aquifers, India Soils, India Geomorphology and India River Basins. I wish they had different display styles like transparent cross hatch, dots, symbols and lines and so on to choose from to enable easy visualization of multiple themes but perhaps that is something for the future. Unfortunately none of these geology layers are available as downloads. Government owned vector data is still not being distributed freely in digital format. I hope there is a change in policy on that soon.

But this is an important and growing resource for geology and biodiversity data. You can register and contribute layers to the natural resources database. Most Layers not under government control are downloadable (as shape files, GML and text) but contributors are free to choose the level of restrictions they want under a Creative Commons license.

1 comment: