Practical Winery
58-D Paul Drive, San Rafael, CA 94903-2054
phone:415/479-5819 · fax:415/492-9325
email: Office@practicalwinery.com
Winegrowing - page 2

November/December 1998


GIS
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GIS software is the organizational tool, allowing today’s super-fast computers to handle the numerous (and sometimes quite extensive) layers with ease. The software tools Camera and others at Hess Collection are using include ArcView® with the Spatial Analyst® extension (by ESRI) and VESTRA AgPlan® (by VESTRA Resources, Inc.).

GIS introduction at Hess Collection

Don Gordon, a Senior GIS Analyst with VESTRA Resources, Inc., initially presented the capabilities of the ESRI and VESTRA software products to Camera. In addition to Gordon’s demonstrations, Camera explains, "The free GIS software that is available from ESRI’s website was very instrumental in convincing me that [GIS] would be of great value to us as a company."

Value of a good database design

One key element critical to the success of a GIS is the initial database design. The completeness and accuracy of the initial database determines the type and quality of analysis possible, as well as the products available in the final system. Some of the first questions to be answered are: What are the problems to be solved? What are the final products to be made — reports, working maps, presentation-quality maps — and how frequently might each be generated? Who is the intended audience for these products?

Gathering answers to the questions — What are the problems? Who is going to use the system? What final products are needed? — is the needs assessment phase of the project" explains Dean Roczen, VESTRA’s GIS analyst supervising the Hess Collection project.

The needs assessment is used for the subsequent database design. Then the database design ensures our client receives a final product that gives them the information and analysis they need. We will standardize information in the database so our clients are able to have consistent expectations. A mouse-click on any vineyard map display will identify the information they expect, such as block and sub-block numbers, rootstock, clones, date planted, and so forth."

Importance of positional accuracy

Another essential element to the success of a GIS is the positional accuracy of the geographic data. Remember that old computer saying "Garbage In, Garbage Out"? The same holds true for today’s modern GIS. Going back to our analogy, if the quilts (the layers) are not positioned correctly on the bed (the project area), the result (the GIS) looks very messy.

One solution to geographically control the GIS is the use of the Global Positioning System (GPS) to orient the precise locations of "patches" within the "quilt." Another solution is the use of orthophotographs (aerial photographs corrected not only for variations in terrain but also for other geographic errors inherent to aerial photographs). Hess Collection uses a GPS technician from VESTRA to gather position coordinates of various features, such as vineyard blocks, preservation oak trees, project boundaries, and underground pipeline locations.

On one property I needed to isolate several areas that were restricted from planting," explains Camera. "There were two archeological sites, one historical site, and at least two botanical sites. We used a GPS unit to precisely outline these sites, so our compliance to the law is well-documented."

Aerial or satellite imagery is another data-rich source that can provide a wealth of information about where things are located and what they look like.

Multi-spectral aerial or satellite imagery (similar to that used in the NASA GRAPES project), uses different bands of light. These bands can be either visible or not visible to the naked eye (red, green, and blue bands are visible, and near infrared is not visible.) The different bands can be combined to show the presence of chlorophyll and moisture in vegetation. For instance one combination of bands, familiar as infrared imagery, can show vigorous vegetation as bright red in the imagery.

Additional image analysis, such as an NDVI (normalized difference vegetation index) helps compensate for changing illumination conditions, surface slope, aspect, and other extraneous features, to give a more refined picture of vineyard health.

Multi-spectral imagery has been shown effective in detecting vigor or stress in vegetation. Camera expects to use multi-spectral aerial or satellite imagery to help assess plant health, especially as spatial control is established throughout his project. This spatial control will allow him to compare one year’s multi-spectral imagery with next year’s imagery to get a picture of subtle changes in vine health over time.

Additional benefits of a GIS

At the Hess Collection, one major goal is to incorporate information currently held by various consultants and other external sources into the GIS. For example, CAD (computer-aided design) files depicting irrigation layout diagrams and other vineyard design elements from engineers, easement maps locating natural gas and water pipelines, underground and overhead power lines from the local utilities and municipalities, erosion control plans, topographic maps, and soil data will all be in the GIS and instantly available to Camera.

One property we purchased recently came with its own CAD files that were created and compiled as part of the seller’s development plans," notes Camera. "As part of our work with VESTRA, these CAD linework files were converted to GIS layers that include descriptive information, such as acres, length, or name, so the features are more information-rich for analysis beyond simple mapping. Now, I have plantable acres, restricted areas, a slope survey, soils maps, roads, fences, utilities, well sites, culverts, tree lines, buildings, and more. I wanted this data at my fingertips. We are at a time technologically where this can all be stored, manipulated, analyzed, and displayed in-house."

An additional benefit of a GIS is the ability to do spatial analysis, that might include a query selecting everything within 30 feet of a certain point or creating an avenue of 50 feet in a vineyard layout design. Within that queried space, spatial statistics are available quickly, such as how many acres you are removing from your plantable acres, if the spatial database is set up properly to give accurate information.

Vineyard design is a perfect exercise for a robust spatial database and sophisticated software. Camera will use VESTRA AgPlan software to anticipate vineyard development problems and resolve them. For example, by using a contour-derived digital elevation model, which describes topography, to overlay a proposed vineyard layout, he will be able to use a spatial query of the slope on the proposed layout to look at potential slope problems and then design vineyard blocks or row orientation to create a favorable layout. This process of testing and design adjustment can be run many times, until Camera is confident he has a successful design.

Conclusion

"The last thing that needs to be said about GIS," adds Camera, "is that it is fun and challenging, and very useful. It has given me a greater interest in the data that is generated and helped me think about our vineyards in new ways. Very few things have been as professionally stimulating to me as my involvement with GIS."

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