A NodeJS Express App that exposes a REST API for Accela and web tool at http://www.mapwnc.org
Buncombe County Property and City Jurisdiction GIS tables are copied nightly using Bedrock to a Postgres database.
Elevation contours generated from Lidar data for Buncombe County are also stored on the Postgres database.
The application calculates the "natural average slope" for a parcel or parcels of land (see the Section 7-12-4 of the City of Asheville's Unified Development Ordinance )
The slope calculation is costly and cannot be pre-calculated for the entire county (I think it takes like 24hrs to run once). So a sloperesults table is maintained on the Postgres database which contains the calculated slope, the parcel (or parcels) geometry, and some attribute data. At runtime, the application checks if a matching geometry exist in the sloperesults table for the input parcel or parcels geometry (this is fast with PostGIS); if a matching geometry exist then the existing calculated slope and attribute data is returned, if not, the slope is calculated and returned from the API, and a new record is added to the sloperesults table.
Runs as a Lambda function that wraps an Express App using serverless-express.
First run npm install
package.json has these scripts:
- Test Locally:
npm start(or for a Python program:npm run startpy)
- Deploy:
npm run deploy prodnpm run deploy dev
- Destroy: (removes all objects from AWS)
npm run destroy prodnpm run destroy dev
- Clean:
npm run clean(removes local temp files)