GIS Applications in Climate and
Scott T. Shipley, Ira A. Graffman,
Joseph K. Ingram
Commercial-Off-The-Shelf (COTS) GIS applications in climate and meteorology are addressed, including traditional GIS strategies for hydromet database analysis and management, but also emerging techniques which exploit COTS GIS for hydromet data analysis in the GIS operating environment. Specific GIS applications are examined to address precision mapping shortcomings in current hydromet practice. Movement towards GIS in the National Weather Service (NWS) is also addressed, most notably the NWS GIS Forum. The authors are aware of several applications where ESRI ArcView GIS enabled substantial reductions in Life Cycle Costs for hydromet applications, and some of these are presented.
Recent efforts using Commercial-Off-The-Shelf (COTS) Geographic Information Systems (GIS) for applications in climate and meteorology include traditional GIS strategies for hydromet database analysis and management, and the fusion of hydromet data with traditional GIS applications. But new techniques are emerging which exploit COTS GIS features and capabilities to support the analysis of hydromet data in the GIS operating environment.
Many of today's hydromet Interactive Information Processing Systems (IIPS) are data viewers, providing limited data analysis capabilities, usually in the form of "canned" menus for common analysis functions. One IIPS operating paradigm rapidly merges data from established and trusted sources to support the "forecaster in the loop", who makes the call - a form of office automation. The GIS paradigm provides a richer analysis environment, with flexible general-purpose topological and algebraic functions supporting analysis "on-the-fly". This generality is usually achieved at high spatial resolution, but with a related sacrifice in processing speed. In addition, meteorologists find the GIS operating model to be "different and strange" enough to require a lot of retraining (many personal communications). After all, "GIS was developed only recently to map cartographic data which change on geologic time scales, right?" Wrong - GIS has been around for 25+ years, and it does more than just "mapping".
This paper surveys several GIS hydromet applications known to the authors, but is clearly not an exhaustive survey of the rapidly expanding field of "GIS Meteorology". Attention is given in section 2 to a few problems in current hydromet practice which are solved by GIS, such as the impact of rawinsonde position assumptions on surface analyses, and satellite image collocation. Emerging techniques are coupling GIS and hydromet data, including numerical forecast models such as the NCAR/PSU MM5 and other published GRIB datasets. Movement towards GIS in the Weather Services is described in sections 3 and 4, most notable this past year being the NWS GIS Forum ( Schultz and Reeves, 1999).
A key factor in comparing COTS GIS with special-purpose Weather Processing Systems is long-term maintenance and logistics support, or Life Cycle Cost (LCC). Consider the costs not only to duplicate GIS functionality in an IIPS, but to upgrade and maintain that capability as well. The authors are aware of several applications where ESRI ArcView GIS has demonstrated substantial reductions in Life Cycle Cost, some of which are described here.