Gunnison County Web Map Find Data - Find data - Navigate tools - Mouse over tooltip Make Maps - Layers - Legend - Drawing tools - Printing Analysis - Measurement - Selecting - Queries Spatial SQL - Basic SQL - Spatial About the Data FINDING DATA To find data if you know the data your after (i.e., a property owner s name),then use the Find Data search tool. To find data if you know where on the map to look, use the various Navigation tools or the Zoom to tools. Once you ve navigated to the desired area on the map, you can then use the info tool to click on the map object which will bring up its data table. If the layer contains a linked PDF, uncheck the box Info from all layers clicked? to allow the field containing the link to become clickable. URL hyperlinks within a layer are accessed via the data table or by using the hyperlink tool. By default, the map displays X, Y coordinates of the mouse cursor underneath the map in State Plane, Colorado Central, NAD 83. The coordinates can be changed to display longitude and latitude by clicking the blue text switch to Long/Lat coord. Click the blue label to the left of the readout to toggle between the 3 common forms (DD Decimal degrees, GPS Degree Decimal Minutes, and DMS Degree Minutes Seconds). For quick display of a layer s data as you mouse over map objects, enable the tool tip setting for the desired layer under the Settings dropdown (see image to the right). For faster map redraws if your internet connection is slow, consider switching to a smaller screen size using the dropdown in the bottom left corner.
MAKING MAPS Use the Layers dropdown to turn on/off the desired mapping layers. The Legend dropdown will automatically update with the selected layers. The Drawing toolbar is accessed from the pencil icon and It contains tools to: 1) draw various shapes or labels on the map; 2) edit the data attached to those shapes; 3) delete drawn objects; and 4) export the drawn objects as a shapefile (a GIS interchange format). The objects drawn are placed into a layer called Drawing Layer. Use the Print tool to export your map to a PDF or JPEG format. The PDF format usually provides the best image and allows for turning layers on/off. ANALYZING DATA There are 3 measurement tools to measure distances, areas, as well as optimal routes along roads. The route is determined by indicating the start and end point along the roads. This function will also provide driving directions, however, it simply finds the shortest route and does not consider the type of road (i.e., 4-wheel drive) or if a road is closed in winter. The route is drawn into the Drawing Layer which can be cleared via the delete tools in the Drawing toolbar (see above). There are a variety of preset queries available to do more indepth analysis of the data. Queries can work on the entire dataset or only on a selected group of map objects. In addition, some queries return only data (i.e., area statistics of selected parcels), while others draw objects into the Drawing Layer (i.e., buffer around selected objects). Queries that return data can be modified by first running the query and then opening up the Free SQL box (described below) to expose its parameters. The user can then change parameters and rerun the query in the Free SQL box. Please note that in order to conserve computer resources, queries are limited to display 500 records in the table. However, queries are not limited in the number of objects that can be selected on the map. To select the desired objects, use the selection tool, as well as the selection mode tool to add to, delete from, or replace the current selection.
The table displaying query results can be opened or closed with the table tool and the results can be cleared with the unselect tool. The table contents can be exported to Excel if desired. Advanced users can use the Custom SQL options to write their own queries using either the SQL Builder or Free SQL option. The queries are written in Manifold GIS s implementation of Structured Query Language that includes many spatial functions. These spatial functions create wonderful flexibility but require special knowledge to use. The SQL builder provides a means to build simple queries with minimal understanding while the Free SQL box provides no assistance. BASIC SQL AND SPATIAL FUNCTIONS Always begin with Select. Then determine the desire fields to be returned, list them in this example s format: name, city, state, zipcode or simply use * as a wildcard for all fields. Next enter from and choose what layers contain the data, such as parcels. The next step is to limit your query with a where clause inconjunction with a field name like [Account Type] and an operator, such as =, >, <, etc. If the field contains text then place it within quotes. Only exact case sensitive matches will be returned, so be sure to look at the table first. Also, all text in the parcel layer is in uppercase. Place field names with spaces in brackets, such as [geologic hazards]. EXAMPLES: Select all fields from all parcels that have an agriculture account type. select * from parcels where [Account Type] = "Agricultural" Change query to residential account type and a land actual value of greater than $100,000. select * from parcels where [Account Type] = "Residential" and [Sale Price] > 200000 Change query to a land actual value of greater than $20,000 or less than $100,000. select * from parcels where [Account Type] = "Residential" and [GIS Acres] between 10 and 35 Change query to select several different account types. select * from parcels where [Account Type] in ("Commercial", "Mixed Use") and [Mail State] <> "CO" Change query to select several different account types where RES is exists within data string. select * from parcels where [Owner Name] like ("%SMITH%") Adding spatial functions such as buffer, distance, contains, centroid, clipintersect, union, boundary, linepart, etc. to a SQL query provides a means to create much more interesting analysis but requires more knowledge. The online Manifold help manual provides that knowledge for the adventurous, however it s easier to simply modify a few parameters from an existing query instead. Here are some examples. Also the SQL of preset queries is exposed in the Free SQL box to allow changing their parameters.
EXAMPLES: Select all parcels that are within 50 feet of Gothic Avenue. select * from parcels where distance(parcels.id, (select id from roads where fullname = "GOTHIC AVE")) < 50 Select all parcels touching Ohio Creek. select * from parcels, streams where touches(parcels.id, streams.id) and Streams.name = "OHIO CREEK" Return the acres of geologic hazards contained in a parcel. select [Description], round(sum(area(clipintersect(parcels.id, [geologic hazards].id))/43560),2) as Acres from parcels, [geologic hazards] where [Parcel number] = "317700000025" group by [Description] Note: queries that return several thousand records or that involve complex spatial functions may take awhile to run. Queries that are too involved for our web server may time-out all together. ABOUT THE DATA LAYERS Parcels - Gunnison County GIS updates this layer continually as changes occur or for corrections. It varies widely in accuracy from < 10 ft in towns and some subdivisions to hundreds of feet in mining claim areas were survey land positions are not in our system. Information regarding survey land positions are always welcome. Subdivisions Gunnison County GIS maintains this layer and updates the information as changes occur. Section Lines Originally from the U.S. BLM Public Land Survey System, but many sections have been modified by Gunnison County GIS to fit the parcel layer. Towns Created by Gunnison County GIS, using annexation information from the towns. Addresses Gunnison County GIS updates this layer continually as changes occur or errors are fixed. This point layer was originally created in 2007 from center of parcels using Assessor situs addresses for E911. The layer has been greatly improved from its beginnings by fixing incorrect addresses, readdressing poorly addressed locations, and moving address points to overlay structures on aerials. Roads Gunnison County GIS created this layer in 2006 by digitizing from the 2005 NAIP aerial photography. It gets updated as needed with new roads, road name changes, and corrections. Places Downloaded from the USGS at http://geonames.usgs.gov/ This point layer contains most of the labels found on USGS topographical maps. The accuracy is unknown but locations should be considered very approximate. Streams and Lakes Downloaded from the Colorado State Division of Wildlife at http://ndis.nrel.colostate.edu/ftp/index.html The data has been slightly modified by Gunnison County GIS, such as modifying data tables and merging stream records.
Geologic Hazards Created by Colorado State Geologic Survey in the late 1970s. More info available at http://dnr.state.co.us/geostore/category.aspx?categoryid=226. Mapping was based on 1:24,000 topographical maps from the USGS. Wildfire Hazards This layer was created jointly by the Colorado State Forest Service (CSFS) and Gunnison County GIS in 2003, using a methodology provided by CSFS that involves vegetation type, slope, aspect, forest density, low vegetation, and insects/disease. The vegetation was mapped using 1:24,000, black and white aerial photography with field checks and the terrain used 30 meter DEMs. Aerial Photography The 2005 and 2009 aerials come from the National Agriculture Imagery Program, USDA. They are 1 meter resolution, county mosaics. The 2007 aerial provides 6-inch resolution and was flown for the Standard Mine Superfund cleanup, but expanded for the Crested Butte area. USGS topographical Maps This is a mosaic of 1:24,000 scale USGS maps. Recent Sales This layer shows the parcels with sales within the last 4 years of the current year. The layer is linked to the following query: select [geom (I)], year(saledt) as [Year] from parcels where [SaleDT] > DateAdd("yyyy", -4, Current_Date) General Data Disclaimer: The data herein is general in nature and not assumed to be complete nor accurate in its entirety and is therefore to be used with all discretions necessary. The data portrayed should not be relied upon to establish legal title, boundary lines, the precise location of improvements, ownership, maintenance, easements or public right-of-ways.