Overlay of survey converted from AutoCAD to GIS. Even though the mapping capabilities of GIS are pretty amazing, CAD remains the arena for most landscape architecture firms.

Many Landscape Architects stay in the GIS environment to prepare base maps, proposals and concepts, especially for larger projects. ESRI, the largest of the GIS software companies, offers two software programs. The simpler of the two is ArcView ?EUR??,,????'??????????????, which has so many options and extensions there is almost no reason to tackle the bigger, more extensive ArcGIS ?EUR??,,????'??????????????. Both programs generate informative, multicolored maps that equal those produced with CAD.

Autodesk, the dominant CAD software company has developed Autodesk Map 3D ?EUR??,,????'??????????????, a program that works in both CAD and GIS formats. Other, smaller companies have GIS programs available for specific applications. These options translate to lower costs and greater variety.

GIS map showing significant trees in cemetery. Many county planning offices have GIS data available to the public. While some Landscape Architects use this information for regional planning and mapping, the ability to collect accurate and detailed local site data with GPS units provides the opportunity to take full advantage of existing data and generate new information for the client.

Existing geo-referenced maps and aerial photos can now be downloaded from various websites, often for free or at minimal cost to supplement data collected and mapped in the field. Most states now sponsor online public clearinghouses of available GIS data. Other websites, such as Topozone.com and the US Geological Survey website ( usgs.gov) provide downloadable geologic and topographic data.

ArcView ?EUR??,,????'?????????????? and ArcGIS ?EUR??,,????'?????????????? have converters that allow them to read and convert files for CAD and GIS. Autodesk Map3D ?EUR??,,????'?????????????? supports the following file types: ESRI SHP ?EUR??,,????'??????????????, Microstation DGN ?EUR??,,????'??????????????, AutoCAD DWG ?EUR??,,????'?????????????? and DXF ?EUR??,,????'??????????????. In addition to Trimble?EUR??,,????'?????<

How can this be used in the field? Data can be collected for single points, such as a tree or rock, a line such as a trail or edge of woodland, and even a closed polygon for measuring and mapping turf areas. Imagine mapping a two-mile trail through a park in little more time than it takes to walk its length.

For some landscape features, data such as width or material composition may be collected, and for tree mapping, additional information such as size, species, and condition can be collected. This provides useful information for site plans and proposals. In some instances, detailed tree inventories have been completed that include as many as 25 fields of information about each individual tree. This information can then be used to evaluate sites and select those trees considered most valuable to the designer?EUR??,,????'?????<

Original cemetery roads as overlay on ortho-rectified aerial photo.

A detailed inventory of a two and one-half acre condominium site, including 125 trees, a dump area, two rock outcroppings, and an existing footpath through the woods required five hours to complete. This included mapping, converting to a file readable by AutoCAD ?EUR??,,????'?????????????? and incorporating the information into an existing digital survey. Another recent survey of 1,200 trees in a 10-acre historic African-American cemetery in Athens, Ga. required less than 40 hours even though the site was overgrown with vines.

There are still some hurdles for the average Landscape Architect to overcome to use GPS units for site inventories. Precision units with a combined PDA, cost as much as $4,650 and recording data on a small PDA can be slow. Several user groups offer scripts and applets that help with inventories and field data collection. Like most sophisticated software, the learning curve for using all the features is a little steep. However, the ability to generate true as-builts of irrigation systems alone can justify both the cost and learning time. After one day of training, a PDA novice can go out in the field, collect basic site data and create drawings that afternoon.