GIS Tools for Land Managers

Transcription

1 Citation: Karl, J GIS Tools for Land Managers. Sound Science White Paper Series #05. GIS Tools for Land Managers Most land managers recognize that geographic information systems (GIS) are no longer just useful but necessary to assessing and monitoring conservation lands and natural resources areas. Many have at least some training and experience with GIS, and software is now readily available. Even a basic understanding of GIS opens up many new possibilities for capturing, integrating, and analyzing data. However, understanding how to perform those analyses can be a challenge to a part-time GIS user. Luckily, there are many GIS tools available to help collect, use, and turn spatial data into useful information. This white paper provides an overview and examples of several readily available GIS toolsets that are useful for achieving land management objectives. A description of each toolset is given along with information on how to obtain the tools and any associated costs (many of these tools are free). The focus of this white paper is on tools for ESRI's ArcGIS software suite (version 9.2 or higher). These tools take the form of ArcGIS extensions, stand-alone applications, scripts, or in some cases, tools already integrated into ArcGIS. It is important to note that all of the tools listed below are established, well documented and supported. For the most part, the tools discussed in the white paper do not add new functionality to ArcGIS, but make it easier to accomplish common tasks or analyses. Accordingly, these tools are not just for non-expert users, but are also staples in the expert GIS user's toolbox. Tools for Data Management and Documentation ArcCatalog This powerful "tool" is part of the ArcGIS software suite and is automatically installed with ArcGIS. ArcCatalog is underutilized and largely misunderstood and so warrants discussion here. The purpose of ArcCatalog is to facilitate the management and organization of spatial data. ArcCatalog was designed to work in tandem with its more commonly used partner ArcMap and many aspects of working with spatial data can more easily be done in ArcCatalog than anywhere else. GIS Tools for land managers 1

2 Move, copy, rename, and delete spatial datasets - Any moving, copying, renaming or deleting of spatial datasets should be done in ArcCatalog. A single spatial dataset is typically made up of many files (e.g., shapefiles, geodatabases, images). Maintaining the integrity of the names (and in some cases the relative locations) of these files is important to their integrity. This presents challenges for basic file Figure 1. ArcCatalog provides an easy way to manage spatial data and geodatabases. operations like organizing, moving, or renaming datasets. ArcCatalog handles this seamlessly so that the user can interact with and organize spatial datasets in a familiar file-explorer environment. Figure 1 illustrates the user interface of ArcCatalog. Organize spatial data - ArcCatalog presents users with a file-explorer environment, similar to Windows Explorer, where directories and workspaces can be created to organize datasets. Additionally, ArcCatalog displays unique icons for different types of data (e.g., points, lines, polygons, tables, images) which can be a helpful way to organize data. Create new spatial datasets - Without the use of a third-party ArcGIS tool (see XTools and ET GeoWizard below), it is not easy to create new, empty spatial data layers (e.g., shapefiles) within ArcMap. This function is built into ArcCatalog. Assign, change, edit projections and coordinate systems - Projections and coordinate systems relate the X and Y values stored in spatial data to real locations on the ground. ArcCatalog has a robust set of tools for assigning or modifying projection/coordinate system and for converting data from one projection/coordinate system to another. While some of these operations can be completed in ArcMap using ArcToolbox, ArcMap locks layers that are currently loaded and prevents properties like projection information from being changed. Additionally, ArcCatalog offers additional options for working with projections and coordinate systems through its layer properties dialog. Manage Geodatabases - The geodatabase is an advanced ESRI format for storing spatial data. Geodatabases allow for the definition of schema (i.e., rules for what attributes are used to describe spatial features) and topology (i.e., spatial relationships GIS Tools for land managers 2

3 between features - for example a critical riparian buffer must always occur next to a stream feature). ArcCatalog is used to create and modify these advanced properties using ArcCatalog's layer properties dialog and tools available through ArcToolbox. Again, the Toolbox tools are available in ArcMap, but given the locks put on layers to protect them while being used in ArcMap, these operations are best performed in ArcCatalog. View, Create, Edit Metadata Metadata (data about data) is the documentation that accompanies a dataset and describes it in terms of its purpose, background, structure, and appropriate uses. ArcCatalog is used for viewing the metadata of a dataset as well as to create and edit new metadata. Creator: ESRI Tool Type: ArcGIS Application Download: Installed with ArcGIS Documentation/Help: See ArcGIS help or Cost: Included with all licensed versions of ArcGIS FGDC 3-Tab Metadata Editor The FGDC (Federal Geographic Data Committee) 3-Tab Metadata Editor, shown in Figure 2, is an easier-to-use alternative to ArcCatalog's standard metadata editor. The 3-Tab Metadata Editor is a free ArcGIS extension that works within ArcCatalog. The benefits of this replacement metadata editor are several-fold: It offers condensed forms that put critical, mandatory metadata fields on four pages (it used to be three - hence the name of the tool). This makes it easier and faster to enter metadata than the standard ESRI metadata editor. Figure 2. The FGDC 3-Tab Metadata Editor is used to ensure that all FGDC required data are appropriately managed. Names and contact information are stored in a database so that they only have to be typed in once and can be reused between metadata for different datasets. GIS Tools for land managers 3

4 Filling out the fields in the four attribute tables will create FGDC-compliant metadata. Creator: Coeur d'alene Tribe, Idaho Tool Type: ArcGIS Extension Download: Documentation/Help: Cost: Free GIS Tools for land managers 4

5 Tools for Automating and Documenting Workflows and Creating Custom Tools ArcGIS Model Builder ArcGIS Model Builder is a part of the ArcToolbox built into ArcMap and ArcCatalog. Model Builder is an intuitive, graphic workspace where you can document your analysis workflows or create new tools by linking together different data layers and GIS analysis functions. Model Builder is accessed by creating a new toolbox, right-clicking on it and selecting New Model. Within blank Model Builder canvas, shapefiles or other data layers can be dragged from ArcMap or ArcCatalog onto the canvas. Likewise, other tools from ArcToolbox can be dragged onto the canvas. Figure 3 shows an example of a Model Builder canvas. With the linking tool, datasets can be linked as inputs to the analysis tools. Tool output layers can be designated as temporary (i.e., are not saved after the whole model has run - useful for intermediate products) or permanent. Additionally, input and output data layers and options for individual model components can be set as "model parameters" so that the model can be used from ArcToolbox just like any other tool. Figure 4 illustrates the use of an ArcGIS model used as an installation-specific parameter. Model Builder can serve two important functions for GIS activities: 1. It can be used to document the steps taken to process original data layers into final results, and Figure 3. An example model constructed in Arc Model Builder. 2. It can be used to create custom GIS tools that can be used to automate commonly performed analyses or to share analysis processes with other people. GIS Tools for land managers 5

6 Consider the following example: Soil erosion at an installation in the Southwest can create large gullies that pose hazards for training activities. Regular inventories are conducted and the gullies are assigned to two classes - those that are traversable and those that are not. It is necessary to produce a map showing the location and class of the gullies, and to show a buffer zone around each one so that troops are aware that a gully is nearby. Traversable gullies will have a smaller buffer than the larger ones. As this map needs to be updated regularly, this analysis is a good Figure 4. Running a model created in Arc Model Builder candidate for a custom GIS Tool using Model Builder. The following model was constructed with Model Builder using the gully inventory shapefile as an input parameter. By doubleclicking on the model in ArcToolbox, a standard ESRI analysis tool dialog box allows the inputs and outputs to be specified. This tool not only documents the analysis procedure for creating the gully hazard map, but also greatly simplifies updating the map by automating the analysis steps. Creator: ESRI Tool Type: Built into ArcGIS Applications Download: Installed with ArcGIS Documentation/Help: See ArcGIS help or Cost: Included with all licensed versions of ArcGIS Tools for Simplifying Common GIS Tasks Xtools Xtools is a collection of GIS analysis and data processing functions for ArcMap. It is one of the most helpful ArcGIS extensions for GIS projects. Xtools only offers a modest number of new or unique tools, and for the most part, it does not do anything that an experienced GIS user could not do. The value of Xtools is that it makes many common GIS tasks much easier. As a result, Xtools is valuable to both new GIS users to accomplish otherwise complex processes and to experienced GIS users because it speeds up their workflows. Figure 5 shows the diversity of tools within the Xtools toolkit. Examples of useful functions available in Xtools include: Calculate area and perimeter length of polygon features using a variety of units. Results of the calculations are written to the attribute table of the dataset GIS Tools for land managers 6

7 Calculate the X and Y coordinate values of features. The locational information is written to the data layer's attribute table Create new feature classes (i.e., shapefiles or geodatabases) within ArcMap. Without Xtools or some other extension, you must create new feature class datasets (e.g., points, lines, polygons) in ArcCatalog. Export attribute tables to Microsoft Excel. Without Xtools, attribute tables can be exported to a Dbase (.dbf) format and opened in Excel, but the Xtools extension makes it much easier. Delete multiple fields from a feature class' attribute table. Through successive GIS analysis operations (e.g., intersects, buffers), the attribute tables of feature classes grow in the number of fields (i.e., columns) they contain because many GIS operations merge the attribute tables of all input layers. It is good practice to remove unnecessary fields from attribute tables to avoid confusion and prevent wrong data values being mistakenly used. Without Xtools, it is only possible to delete a single field at a time. Create a layer of centroids (i.e., the geometric center of a feature) from line or polygon features. This feature can be very handy, for instance, when uploading locations of a polygon into a GPS Figure 5. Structure of the Xtools toolkit. unit is required. Create lines from points. Data downloaded from a GPS unit typically come in tabular files that must be converted to point, line, or polygon features. If a line route needs to be established from the GPS tracklog, Xtools can easily turn the timesequenced points into line features. Import data from or export data to Google Earth's GIS Tools for land managers 7

8 Sound Science White Paper #05 March 2010 KML format. Google Earth is an easy-to-use and powerful tool for communicating GIS analysis results with non-technical audiences, but formatting shapefile or geodatabase data into Google's KML format has been a continual problem. With Xtools, it is an easy operation to convert feature classes for use in Google Earth. These are just a handful of the helpful tools that are available in Xtools. In the newest versions of Xtools, many of the tools can be used in conjunction with ESRI's ArcToolbox Model Builder and included in custom GIS tools or documented in analysis workflows (see description of Model Builder above). Xtools comes with a free trial period that provides access to all of the available tools. After the trial period, many of the tools are deactivated, but some of the most helpful ones (e.g., calculating area and perimeter of features) remain active. Creator: Data East Tool Type: ArcGIS Extension Download: Documentation: Cost: Free version with limited functionality. For full version: $199 for a single license, less for upgrades or multiple licenses. Tools for Sample Design and Spatial Analyses Hawth's Analysis Tools Like the Xtools extension, Hawth's Analysis Tools is an indispensable toolsets for GIS projects and analysis. The focus of Hawth's Tools, however, is on GIS Analysis Tools. Also similar to Xtools, Hawth's Tools offers additional tools that are not found in ArcGIS (or additional features to exiting ArcGIS tools) The following types of tools are available in Hawth's Tools: Vector Analysis Tools overlay and proximity tools for GIS analysis with vector Figure 6. Hawth s sampling tools in the Hawth s Analysis Toolkit. Sampling Tools sophisticated tools to create random or regular selections of existing features or new points for sampling. Figure 6 illustrates the sampling tools available within this toolkit. Animal Movements tools for analyzing animal location and movement data. These tools can also be helpful for analyzing the effects of training location and movement data. GIS Tools for land managers 8

9 Kernel Tools a set of tools for estimating density of occurrences or events from sample data. Raster Tools very helpful tools for working with, summarizing, and modeling with raster (i.e., grid or image) datasets. These tools do not require ESRI's Spatial Analyst Extension. Table Tools Similar to Xtools, a set of tools for performing common, helpful functions to attribute tables such as calculating area or finding X, Y coordinate values. Vector Editing Tools a set of tools that supplements ArcMap's existing editing tools. Figure 7. Random Point generator tool in Hawth s Tools In particular, Hawth's Tools has a welldeveloped set of tools for selecting locations for sampling (i.e., sample design). The following sample design tools are included in Hawth's Tools: Create Random Selection randomly select a number of features from a feature class to sample. Random Selection within Subsets creates stratified random selections of existing features for sampling Generate Random Points create a specified number or density of points. This tool can also be used to create points for stratified random sampling and include layers specifying selection probabilities. Figure 7 shows the interface for generating random points. Generate Regular Points This tool works similarly to the random point generator, but creates points on a regular grid. Figure 8. Sample designtoolin Hawth stools Conditional Point Sampling Tool Create random selections of points clustered around specific features. This feature could be used in monitoring GIS Tools for land managers 9

10 around impact or critical areas. Figure 8 shows the sample design tool interface. As of December 2009, support for Hawth's Tools has been discontinued. The current version of Hawth's Tools can still be downloaded and used, but only for ArcGIS versions 9.2 or earlier. As a replacement to Hawth's Tools, Hawthorne Beyer has developed the Geospatial Modeling Environment (GME). The GME retains all of the same tools as Hawth's Tools and includes new functionality like integration with the professional, open-source statistics program R and the ability to use GME tool within ArcGIS Model Builder. At present, however, GME is not a menu and dialog-driven tool like Hawth's Tools. Until dialog-driven tools for GME are developed, its usefulness to users with limited GIS experience with be somewhat restricted. Creator: Hawthorne Beyer, Spatial Ecology Tool Type: ArcGIS Extension Download: Documentation: Cost: Free NOAA Sample Design Tool for ArcGIS The NOAA Center for Coastal Monitoring and Assessment has created an ArcGIS extension solely for the purpose of assisting with the selection of points or features to sample for assessment or monitoring. This tool has three basic functions: 1) create new sets of random points using either simple random, stratified random, or two-stage sampling; 2) making random selections from an existing set of features with either simple random or stratified random sampling; and 3) analyzing sample data (e.g., calculate means, variances, confidence intervals, power analysis, sample size calculation) that has been collected using one of the supported sample design techniques. Figure9.TheNOAASampleDesignToolenablesusersto designbothsimpleandcomplexsamplingdesignsfor RTLAAssessments. Creator: NOAA Center for Coastal Monitoring and Assessment Tool Type: ArcGIS Extension Download: Documentation: Cost: Free GIS Tools for land managers 10

11 Patch Analyst The Patch Analyst ArcGIS extension originated from the widely used landscape analysis toolset FragStats. Unlike its predecessor, Patch Analyst is a collection of easy-to-use tools in an ArcGIS extension. Patch Analyst makes it easy to calculate landscape-level statistics such as diversity indices and fragmentation/ connectivity measures. Patch Analyst can automate common landscape-level analyses (e.g., calculating the area or proportion of vegetation types in different zones) and calculate Figure 10. Patch Analyst toolkit enables landscape scale analysis of both raster and vector data. dozens of landscape measures. The challenge with Patch Analyst can be determining which measures are relevant for analysis objectives and provide meaningful, interpretable information. Patch Analyst can work with either vector (i.e., point, line, polygon) or raster data. Some examples of the types of analyses that can be performed with Patch Analyst are: Patch-level analysis With patch-level analysis, the shape, size, diversity, quantity and connectedness of patches in a landscape are quantified. These measurements can be useful for assessing the condition of a training area and tracking landscape-level changes over time. Region-level analysis Regions are collections of patches with similar values. Patch Analyst has a detailed set of tools for tabulating the area occupied by different regions and quantifying fragmentation Core area analysis The influence of roads or trails extends some distance beyond the actual feature. If this distance is known or can be estimated, then core area analysis can be used to identify zones of impact and quantify unimpacted area. Creator: Centre for Northern Forest Ecosystem Research (Ontario Ministry of Natural Resources) Tool Type: ArcGIS Extension Download: Documentation: GIS Tools for land managers 11

12 Cost: Free Data-related Tools DNRGarmin DNRGarmin is an extension developed by the Minnesota Department of Natural Resources to facilitate transfer of data to and from Garmin GPS units from within ArcGIS. Users can directly attach to a Garmin GPS unit (connected to the computer via a download cable) and download waypoints, track logs, or routes and save them as shapefiles or Google Earth.kml files. Additionally, DNRGarmin can be used to upload points and lines stored in shapefiles into a Garmin GPS unit. DNRGarmin also supports real-time tracking that Figure 11. DNRGarmin transfers data to and from Garmin GPS units. displays the current GPS location on the screen and allows for live data from the GPS unit to be captured into a shapefile. Figure 11 illustrates the DNRGarmin interface for uploading data onto a GPS unit. Creator: Minnesota Department of Natural Resources Tool Type: ArcGIS Extension (version for ArcGIS 8.x, version or higher for ArcGIS 9.x) Download: mis/gis/tools/arcview/extensi ons/dnrgarmin/dnrgarmi n.html Documentation: mis/gis/tools/arcview/extensi ons/dnrgarmin/dnrgarmi Figure 12. NRCS SoilData Viewer incorporates soils data seamlessly into GIS projects. GIS Tools for land managers 12

13 n.html Cost: Free NRCS SoilData Viewer The NRCS SoilData Viewer is an ArcGIS Extension developed by the USDA Natural Resource Conservation Service (NRCS) for more easily displaying and querying soil survey data. Soils data are critical to understanding impacts on, planning for, and sustainably managing training lands. However, the spatial and tabular data associated with soil surveys is very complex, and is spread over more than 50 interrelated tables. The basic spatial unit of a soil survey is the map unit, but each map unit can have multiple components or even soil types within it. Identifying the right information from these tables can be daunting let alone querying them across large areas or producing map products for analysis. The Soil Data Viewer was created to make it easier to work with NRCS SSURGO soils data within a GIS environment. Figure 12 illustrates how soils maps are easily displayed in ARCMap. Using Soil Data Viewer, soil properties can be identified and mapped or output as a report. Soil Data Viewer also incorporates rules to help ensure appropriate uses of the soils data. (Note: At this time the SoilData Viewer is not compatible with Windows Vista or Windows 7. As of this writing there are no plans to upgrade this tool in the near future.) Creator: USDA NRCS Tool Type: ArcGIS Extension for versions 8.3 and 9.x Download: Documentation: Cost: Free Summary There are many more ArcGIS tools and extensions that could be of potential use to land managers. However, the tools presented here are staple items for the majority of GIS Analysts, and they have great potential to assist users of all skill levels. The hallmark of many of the tools presented here is that they make routine GIS analysis or data processing tasks much easier or automated. This translates into more efficient projects and the ability to focus on creating novel, and in some cases more sophisticated GIS analyses. GIS Tools for land managers 13