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320 The availability and utility of Geographical Information Systems (GIS) has increased greatly within the past 20 years. For general descriptions of GIS, see Clarke (1997), Heywood et al. (1998), and Krzysik (1998a). In the past, GIS required expensive workstations, software that was difficult to use, expert technicians , and considerable resources for acquiring spatial data in a digital format. Now, systems using relatively inexpensive desktop computers and programs (e.g., ArcView) have the ability to perform many workstation GIS functions. The software is easier to use, training is widely available, and large amounts of spatial data in digital format can be obtained on CD ROM and over the Internet. For many survey projects, it is now expected that the results will be provided in a format that can be readily brought into the sponsoring organization’s GIS. The role of GIS in designing animal surveys, analyzing survey results, and sharing information will undoubtedly continue to increase in the future. The objective of this paper is to introduce (rather than comprehensively describe) how to use a GIS for designing amphibian surveys. Although several amphibian studies have used GIS for measuring landscape variables (e.g., Richter and Azous, 1995; Bosakowski, 1999; Diller and Wallace, 1999; and Knutson et al., 1999), relatively little has been written about how to use GIS to plan amphibian surveys (but see Hayek and McDiarmid , 1994; Fellers, 1997). Here we indicate what is possible, how to get started, some limitations, and where to go for further information. Examples are taken primarily from our experiences using GIS to design amphibian surveys in the Northern Intermountain West for a variety of state and federal agencies, private corporations, and conservation organizations. GIS can aid in designing amphibian surveys in several ways. A GIS can give biologists a better understanding of the landscapes in which they will be working (e.g., topography, geology , hydrology, climate, vegetation, and roads). It facilitates the organization and visualization of pre-existing amphibian data and, thus, helps to identify data gaps. It can incorporate a variety of constraints (e.g., access) into the site selection process. Probably most importantly, a GIS can help identify areas of suitable amphibian habitat for sampling. If the appropriate data are available, a GIS can be used to select sampling sites in an efficient and less biased way (e.g., implementation of systematic, random, and/or stratified sampling approaches). In addition to helping with the design of surveys, GIS also can play an important role after the surveys are completed, through visualizing and analyzing results and modeling the effects of habitat change or management actions. The task of developing an appreciation for the characteristics of a study area has been greatly facilitated by the increasing availability of GIS data (see below and Appendix 47-A). Much of this information, such as USGS topographic maps, aerial photographs, and National Wetland Inventory (NWI) maps (Cowardin et al., 1979), has been available in non-digital format for a number of years. After being digitized, this information can be layered in a GIS with other data, which provides a better understanding of the landscape in a study area. For instance , aerial photos in the form of DOQQs (digital ortho quarter quads) are useful in identifying topographic features. Color DOQQs are available in many areas of the country making it easier to identify potential wetalnds. The availability of other types of GIS data, such as vegetation, soil type, precipitation, and temperature, makes it more feasible to incorporate these variables into a survey design. Until recently, detailed GIS data availability for regions was limited, but now it is common for an organization such as a national forest or timber company to have an extensive GIS database available. Existing data can be used to derive data layers (e.g., slope and aspect from Digital Elevation Models [DEMs]). Spatial relationships, such as the isolation of wetlands from other wetland habitat or the distance of sites to roads, can also be determined through the use of GIS. Available GIS data are listed as follows (many sources are available via the Internet; see Tabel 47-1 for URLs of selected sources): Digital Line Graphics (DLG) Digital Elevation Models (DEM) Digital Raster Graphics of USGS Topographic Maps (DRG) Digital Orthophoto Quadrangles (DOQ) or Quarter Quadrangles (DOQQ) National Wetland Inventory (NWI) classification maps Satellite Imagery (Landsat, SPOT, etc.) Temperature Precipitation FO RTY-S EVE N Geographical Information Systems and Survey Designs CHARLES R. PETERSON, STEPHEN R. BURTON, AND DEBRA A. PATLA published literature, and...

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