Find water source from River

http://www.ibama.gov.br

Luiz MottaFebruary, 2016

Brazilian Institute of Environment and Renewable Natural ResourcesCOTIG – Coordination of Geotechnology

● SQL for water source(point ) from rivers(line)

● Data: Rio Doce Watershed from ANA sitehttp://hidroweb.ana.gov.br/HidroWeb.asp?TocItem=4100

● Processing with PostgreSQL/PostGIS and GDAL/OGR

Find water source from River

Methodology for find the Water source point:

● Get the nodes of all arcs (Start and End Points)* The orientation of arc not have water direction, need get both nodes of Arcs

● Nodes connect with ONLY one Arc* Applied a little buffer for points, can be a missed connection between lines

Find water source from River

Get the nodes of all arcs (Start and End Points)

Find water source from River

Nodes connect with ONLY one Arc

Find water source from River

Spatialite syntax

Find water source from River

GDAL/OGR

1)Shapefile of example:http://hidroweb.ana.gov.br/baixar/mapa/Bacia8.zip

2)Create file without space and only field COTRECHO:ogr2ogr -overwrite -select COTRECHO hidrocotrecho.shp "Hidrografia 1000000.shp"

3)Creating water source:ogr2ogr -overwrite -dialect SQLITE -sql "SELECT ..." water_src.shp hidrocotrecho.shp

Find water source from River

Sources codes● water_src_postgis.sql:

https://www.dropbox.com/s/j8wxqpjr5nt45mv/water_src_postgis.sql

● water_src_sqlite.sqlhttps://www.dropbox.com/s/s3you7i18257lii/water_src_sqlite.sql

● water_src_from_river.sh (Shell/Linux for ogr2ogr):https://www.dropbox.com/s/w2hc0xbkc29apy4/water_src_from_river.sh