Tuesday, September 29, 2009

How to Analyze Slopes for LEED Certification in Neighborhood Development

Leadership in Energy and Environmental Design for Neighborhood Development (LEED-ND) is a certification program that promotes a green approach to community development. In fact, the US Green Building Council (USGBC) plans to designate LEED-ND as an American National Standard (ANSI). I first blogged about LEED-ND a few months ago where I demonstrated how to use buffer analysis to assess the density of an area based on the number of street intersections for LEED-ND certification. Recently, I posted a short video that introduced how to use geospatial analysis in LEED-ND certification efforts. Geoff Zeiss also blogged about LEED-ND and the progress being made towards finalizing LEED certification criteria.

This post looks at how to use geospatial tools to examine the suitability of a site in the Slope Protection category of the
LEED-ND score card. The objective of this category is to minimize erosion of slopes to protect habitat and waterways by preserving steep slopes in their natural state. Specifically, one option to accumulate maximum LEED-ND accreditation points, requires that project sites avoid disturbing areas with slopes greater than 15%. A quick way to check whether a proposed site qualifies for maximum points in this category is to superimpose a 2D CAD drawing of the site and a 3D Digital Elevation Model (DEM) and then perform a simple thematic map on the DEM based on slope. Note that if you don’t have a DEM for your specific site, a quick web search reveals a number of sources for this type of data including the GIS Data Depot.

One of the key benefits of this approach is that candidate sites can be easily and quickly short-listed against specified criteria without huge expense. Another benefit is that better designs are possible because more candidate sites can be evaluated against LEED-ND criteria.

Check out the video to see the process in action using AutoCAD Map 3D.

Monday, September 28, 2009

Dispelling the Myths of CAD/GIS Integration

Psst - it's no secret! CAD and GIS technologies have advanced considerably in the last couple of decades. However, in spite of these advancements, there is still an outdated view of GIS software that is closely integrated with CAD technology. Myths regarding the integration of these two technologies also continue to exist. Unfortunately, the perpetuation of these myths can negatively impact data quality, process efficiency and ultimately an organization’s bottom line.

During the last several months, I tweeted using my Twitter name
@engis about the top myths which I feel continue to prevail about today’s CAD in spite of many technological advancements. I have collected these tweets (modified slightly for improved readability) below.

How many of these myths are still prevalent or being perpetuated in your organization?

  • Myth: CAD cannot do geospatial topology.
    Reality: Today’s CAD supports both CAD and GIS topologies including node, network and polygon topology and analysis.

  • Myth: You can’t query a CAD drawing.
    Reality: Today’s CAD supports geospatial queries including both geographic and attribute based filters.

  • Myth: CAD doesn’t do geospatial analysis.
    Reality: Today’s CAD supports topology analysis including overlays, dissolves, buffering, tracing and more.

  • Myth: CAD doesn’t do thematic maps.
    Reality: Today’s CAD does support theming. Stylize points, lines, polygons, text without affecting source data.

  • Myth: CAD only supports simple points, lines and text.
    Reality: Today’s CAD also supports complex GIS features (eg networks, nested polygons, surfaces and more).

  • Myth: CAD is single file, single user.
    Reality: Today’s CAD supports multi-file, multiuser access; object locking; databases; long transactions and more.

  • Myth: CAD doesn’t do 3D surfaces.
    Reality: Today’s CAD supports flood plain analysis, slope analysis, volume calculations, draping, overlays and more.

  • Myth: CAD data is file based.
    Reality: Today’s CAD supports storing data in files, SQL databases and external GIS data repositories like Oracle.

  • Myth: CAD is for creating paper drawings.
    Reality: Today’s CAD merges design and GIS data with outputs to paper, desktop, Internet and mobile.

  • Myth: CAD does not support raster.
    Reality: Today’s CAD supports raster/vector overlays, vectorization, image processing and GIS analysis.

  • Myth: CAD doesn’t understand geographic coordinates.
    Reality: Today’s CAD supports thousands of datum, projection and coordinate systems.

  • Myth: CAD requires you to import/convert other CAD and GIS data.
    Reality: Today’s CAD supports connection to many data formats without import/export and conversion.

Avoid being a secret agent. Please check-out AutoCAD Map 3D and AutoCAD Civil 3D for more information about the reality of today's CAD and it's ability to integrate CAD and GIS data and workflows. Spread the word.