Introducing View Finder, a web tool for evaluating the visual impact of new transmission corridors.

Placing power transmission lines across the landscape is a necessary to transmit energy from source to destination. Until we get a breakthrough in efficiency, distributed and localized generation, new transmission corridors will be needed.

Choosing where to put corridors is contentious and drawn-out - for example, see the well-documented campaign against new corridors in Virginia run by the Piedmont Environmental Council. Reviews take a long time, and require data, expert analysis, public and stakeholder consultation. What if new tools could help make the processes more effective?

Here are two such tools:

  • View Finder. A visibility analysis for the entire US, running in your browser. Discussed below.
  • Path Finder. A collaborative platform for contributing, assessing and commenting on corridor options.

These two tools alone don’t resolve all the challenges around corridor placement, but they represent small building blocks towards more inclusive and open processes.

What is View Finder?

View Finder uses freely-available datasets to calculate what can be seen from a particular location. While detailed viewshed analysis is expensive and slow, View Finder provides a rough sketch of the same information in seconds, right in your web browser.

From your browser, click a point on a map, or draw a path to represent a transmission corridor (shown green in the screenshot below). View Finder overlays two colors: blue, showing locations that can’t see the point or corridor, and pink for locations that can.

Pre-set options relevant to transmission corridors allow you to specify the height of the pylons. Taller corridor infrastructure increases the size of the possible viewing area.

Vegetation cover data are used to calculate summer and winter views, where the corridor is located in or near a deciduous forest.

The ground cover also affects how likely you are to see the corridor from each location - forest gets in the way more than scrubland, for example.

After tweaking the settings, share, save or print the viewshed.

Behind the scenes, View Finder uses the National Elevation Dataset, and the National Land Cover Dataset. Both are stored in Amazon Elastic Block Storage, and called as needed by a GRASS GIS script running in Amazon Elastic Cloud Compute to calculate the visibility for the current location. Map tiles showing the view shed are generated on the fly by Mapnik and stored for re-use.

View Finder is an integral part of Path Finder - to be covered in a follow-up post.


The Open Neighborhoods Project is an independent, crowd-sourced repository of neighborhood boundaries for the US. Three parts:

  • a web map for anyone to contribute their neighborhood boundary
  • tools to review and agglomerate different neighborhood outlines into commonly-accepted boundaries
  • a data repository of current and previous neighborhood boundaries for download and re-use, forming a People’s Atlas of neighborhoods

map

Why

Only people who live in a neighborhood are able to define its geographic extent. But neighborhoods are the ideal data frame for many activities – local government, map making, planning initiatives, journalism, electoral districts, statistical comparisons, hyper-local news, agglomerations of geo-located data, etc. Most people seeking to describe a neighborhood are ill-informed to define its boundary. Centralized attempts to define neighborhoods will always fail.

A People’s Atlas of neighborhoods is possible, now: the web-based mapping tools are ready. The open process precedents for reviewing neighborhoods are ready. The data exchange standards are ready.

The published neighborhoods will form a foundation for relevant local action. Imagine mapping city-wide data using districts that were relevant to their residents. Imagine making statistical comparisons between areas that respected local definitions of place. Imagine re-drawing electoral districts from a base of non-partial local boundaries. Imagine your hyper-local news actually reflecting the place you live in. Imagine historians reviewing the changes in neighborhoods over time.

#1 The mapper

The Open Neighborhoods Project website is built around an open source, standards compliant web map. Any visitor to the website can register, adjust the map to show their area, and draw a boundary. This boundary can be named, and saved.

Optionally, the boundary can be constrained to snap to existing local boundaries, such as Census Blocks, county line, etc.

#2 Tools for analysis and review

Learning from open source software projects, the process for storing, reviewing and analyzing the neighborhood data is completely transparent. Individual boundaries can be recalled, or all boundaries overlapping a particular area. Comments can be attached to particular boundaries, and reviewed when inspecting a map.

A toolkit allows visitors to review all boundaries for a particular neighborhood, and select from present interpretations that dynamically processes the lines into a common boundary. Different methods of interpretation give different results.

Decisions about which interpretation to use as the “published” boundaries are made through open discussions via mailing lists, with guidance from an advisory committee of cartographers and demographic data experts.

#3 Data streams

The neighborhood boundaries are offered as dynamic feeds in all modern formats.

Users can download the neighborhoods into any map tool, including Google Earth, and other GIS platforms.

Feeds allow direct integration into other software tools. News sites can adjust their news coverage as borders are changed. Analysis built with census data on the neighborhoods will update to reflect the changed consensus of a boundary location.

Historic review allows anyone to inspect a boundary at any point in time.