Lab 6: Volunteered Geographic Information (VGI) Application Creation

Goal and Background

The purpose of this lab was to develop a web GIS VGI application. Specifically, the creation of enterprise geodatabase features that contain settings outlining domains and subtypes capable of being edited will be shown. Next, a web GIS VGI JavaScript template was modified to incorporate the feature service that we published to the UWEC ArcGIS Server to allow for the specific data to be collected by the public using the application.

Methods and Results

Part 1 & 2

First, a map document to support the feature services and web editing was authored. Specifically the features to be edited and authored included types of fire hydrants, conditions of sidewalks, and the health of green spaces. Within each feature, domains and subtypes were created to define specific rules that govern the values within the fields of a feature class or non-spatial attribute table. For fire hydrants the domain “Type” was set to include coded value subtypes for the description of either Red or Yellow. For sidewalks the domain “Condition” was set to included coded value subtypes for the description of either very good or needs repair. For green spaces the domain of “Health” was set to include coded value subtypes for the description of lush or needs fixing. After the domains and subtypes were set within our map document, point, line, and polygon feature classes were created to represent the various types of fire hydrants, sidewalks, and green spaces within our geodatabase. All feature classes were projected using the WGS 1984 Web Mercator (auxiliary sphere) projection, and included a corresponding field name to incorporate its respective domain and subtype as well as a comments field name. After symbolizing each feature with a representative symbol for a cartographically pleasing application that included the Light Gray Canvas ESRI Basemap, the entire enterprise geodatabase was ready to be published to the UWEC ArcGIS Server. The feature service was published using the same guidelines as outlined by Lab 2 shown in the blog post below. Next, it was necessary to customize a web GIS VGI JavaScript template to incorporate our feature enabled service created earlier in this lab. To reposition the map to center on UWEC, the Lat & Long coordinates were collected from Latlong.net. Next, the URL address was obtained for each feature layer from the UWEC GIS Server REST endpoint to then be input within the template to replace the existing code with that of the desired feature. After adjusting some stylistic elements of the code to change the title container. The application can be accessed by the following link: file:///Z:/Topper_index.html

Part 3

In this part of the lab, another independent VGI application to collect additional data was created. Using the same methodology outlined above, I chose to create a VGI application to map benches, paths, and trees in Madison, WI. This application can be accessed by the following link: file:///Z:/Topper2_index.html

Sources

1.       Lab6data.zip (provided by Dr. C. Wilson)

2.       Wilson. C. (2013). Lab 6: Voulunteered Geographic Information (VGI). GEOG455: Web GIS, UW-Eau Claire.