အဆင့်(၆) မြစ်ဝှမ်းဒေသများ

အဆင့်(၆) မြစ်ဝှမ်းဒေသများ

Production date: 2013

Source: HydroBasins; Lehner, B., Grill G. (2013): Global river hydrography and network routing: baseline data and new approaches to study the world’s large river systems. Hydrological Processes, 27(15): 2171–2186. Data is available at www.hydrosheds.org.
The HydroBASINS product has been developed on behalf of World Wildlife Fund US (WWF), with support and in collaboration with the EU BioFresh project, Berlin, Germany; the International Union for Conservation of Nature (IUCN), Cambridge, UK; and McGill University, Montreal, Canada. Major funding for this project was provided to WWF by Sealed Air Corporation; additional funding was provided by BioFresh and McGill University.

Description: Hydro-basins provide hydrographic data layers that allow for the derivation of watershed boundaries for any given location based on the near-global, high-resolution SRTM digital elevation model.
Watersheds were delineated in a consistent manner at different scales, and a hierarchical sub-basin breakdown was created following the topological concept of the Pfafstetter coding system (Verdin & Verdin 1999). The resulting polygon layers are termed HydroBASINS and represent a subset of the HydroSHEDS database.
There are 12 levels. Level 6 represent sub-basins typically at a scale used for sub-national political units.

Processing: This data was dissolved on level 6 or the Pfafstetter coding system. See http://www.hydrosheds.org/images/inpages/HydroBASINS_TechDoc_v1c.pdf for detailed documentation on this hierarchical system of attributing basin flow order and relationships. Open Development Initiative visualised the data in CartoDB and created a custom legend and information windows for data points. Subsets of this data were created for presentation at country level.