GIS in the Sciences ERTH 4750 38031 Literate

GIS in the Sciences ERTH 4750 (38031) Literate Programming and the Process of GIS Steve Signell, Instructor (signes@rpi. edu) Robert Poirier, TA (poirir@rpi. edu) School of Science Rensselaer Polytechnic Institute Monday, March 17, 2014

Literate Programming

The process of GIS • • What is the task? What data do I need What analyses do I need to perform. How is the data to be presented (Maps/Reports/Web applications…) 3

The process of GIS One example in action…

The process of GIS

The process of GIS One question that immediately comes to mind with this dataset is "just how many Ecocodes, Domains, Divisions, Provinces, and Sections are present in this map? " Fortunately, we can answer this with a simple SQL query.

The process of GIS Here is SQL that gives a table of names of the domains, along with area in km

The process of GIS Here is SQL that gives you a map of the domains

The process of GIS Here is SQL that gives a table of names of the divisions, along with area in km

The process of GIS Here is SQL that gives you a map of the divisions

The process of GIS Example, continued…

Projects & Grading: Review Short written assignments & quizzes (25%) Participation in lab, lecture & group project (25%) Individual project (50%) Vector and raster data Written & Oral Reports Must have dynamic web map component

Group Projects • • Several layers: vector and/or raster 3 -4 data analysis components. Basic web map with layers & layer selector. Various assignments along the way

Individual Projects Most proposals are very ambitious– this is good! Doing the following will get you 75%: • • • Several vector & at least one raster component (or vice versa) 3 -4 data analysis components. Written report with static (print) maps. This will be in the style of literate programming. Basic web map with layers & layer selector. Oral report (~7 minutes, last day of class) Remaining 25%-- excel in one or more areas: • • • Data Analysis Written Report Static Maps Web Map Oral report

Individual Projects

Individual Projects

Individual Projects

Individual Projects

Individual Projects

Individual Projects

Individual Projects

Homework for Thursday • Sections 10 -13, 18 -19, Boundless Post. GIS Tutorial http: //workshops. boundlessgeo. com/postgis-intro/ 22

Homework: quick overview--demo 23

Tip: Loading Post. GIS layers in QGIS I’ve found the DB Manager to work best (Database DB Manager). 24

Tip: Loading Post. GIS layers in QGIS I’ve found the DB Manager to work best (Database DB Manager). • Click and drag layers to add to map. • SQL window is awesome. . . 25

Tip: DB Manager SQL Window DB Manager SQL window is awesome. . . 26

Tip: DB Manager SQL Window DB Manager SQL window is awesome. . . 27

Tip: Getting Post. GIS views to work in QGIS This will not work in QGIS because QGIS requires a primary key CREATE OR REPLACE VIEW orangeline AS SELECT nyc_subway_stations. geom, nyc_subway_stations. color, nyc_subway_stations. name FROM nyc_subway_stations WHERE nyc_subway_stations. color: : text = 'ORANGE’ 28

Tip: Getting Post. GIS views to work in QGIS Add the red highlighted code to make a fake primary key CREATE OR REPLACE VIEW orangeline AS SELECT nyc_subway_stations. geom, nyc_subway_stations. color, nyc_subway_stations. name, row_number() OVER() AS id_qgis FROM nyc_subway_stations WHERE nyc_subway_stations. color: : text = 'ORANGE’ 29