VictoriaJarvisMaps.com

A good map shouldn't need interpretation. I wanted a place where my favorite maps could be more easily viewed so I will no longer be updating this blog, maps will now be here: 

 https://www.victoriajarvismaps.com/

Hydrologic analysis

To establish stream order for a watershed using GIS is quite complex despite the simplicity of the end visualization. Using a DEM you can establish flow direction. This tool uses the elevation data in the DEM to calculate per pixel what direction water would flow. Then you can calculate the flow accumulation. This calculates how many pixels flow of water would into any given pixel. Once you know this you can establish hydrology "stream orders." A stream order of 1 is a stream with no other streams flowing into it, or headwaters. A stream order of 2, has 2 or more stream orders of 1 flowing into it. A stream order of 3, has 2 or more stream orders of 2 flowing into it. And a stream order of 4, has 2 or more stream orders of 3 flowing into it. The "threshold" is the lowest value of a pixel in the flow accumulation raster considered for inclusion in your watershed orders.

Alpine Lakes Wilderness fire restrictions

The idea behind this map was to give a visual reference for Cle Elum Ranger District Wilderness Rangers. With this map they can easily see fire restrictions for the areas most commonly patrolled. In the Alpine Lakes there are elevational fire bans and there are also specific areas that have 1/2 mile closures to fires below the elevational ban zone

 

 

1993 campfire and camping regulations for Alpine Lakes

 

Habitat modeling for Northern Gannets

Northern Gannets are coastal seabirds that nest on cliffs. By running GIS analysis on steepness (slope greater than or equal to 80%), proximity to coat (within 100 meters of the coast), distance from roads (300m from roads) and size (at least 1 hectare), I could isolate and visualize potential habitats preferred by the bird in an area of Maine.

Hypothetical snail habitat modeling

I really don't like any of Esri's basemaps so I took the time to generate my own hillshade and contour layers from DEM data as well as some point data for nearby cities labels. The habitat polygons were generated by isolating the following habitat requirements for this snail:

• Land cover of: grassland, open water, or riparian (from raster data of landcover classifications)
  
• 100 meters of a stream (from USGS stream lines)
  
• Elevation of 1200 – 1600 meters (highly suitable) and 1600m – 2000 meters (moderately suitable) (from USGS DEM data)