Trails in the Santa Monica Mountains National Recreation Area Liz Baumann, December 2015 CVEN 5381 – Intro to GIS

Trails in the Santa Monica Mountains NRA (SAMO) 1.Introduction 2.Objectives 3.Procedures 4.Results 5.Challenges 6.Conclusions 7.Data Sources

Introduction The Santa Monica Mountains NRA (SAMO): over 150,000 acres or ~240 sq miles east of Los Angeles; north of Pacific Ocean 4 state parks occupy about 1/4 of the area elevation: sea level to over 3,000 feet over 430 miles of trails

Objectives Maps with meaningful backdrop layers Show trails by combination of: Trail use (bikes, dogs, or horses allowed) Trail difficulty rating (how strenuous)

Procedure 1: establish background layers 2: join trails to non-spatial trail use table 3: add elevation and develop trail ratings

Lines: trails, roads, hydrology Polygons: SAMO, state parks, counties, cities, fires Multiple file formats: gdb feature classes, shp, web map Different coordinate systems: NAD83, NAD27, WGS84 1: Background Layers

2: Trail Use Assemble non-spatial table: one column each for bikes, dogs, horses from paper maps, online lists, books large in scope => incomplete; State Parks ok Join to Trails layer Also calculate trail miles and join park name Results: 499 trails, 750 km / 466 miles

2: Trail Use

2: Trail Use: Bikes Allowed?

3: Elevation, Trail Rating Two Elevation (DEM) rasters Added elevation and slope fields to vector Trails 3D Analyst “Add Surface Information” tool analyzed results, developed formula (Z_Max – Z_Min) / Shape_Length * 1000 → easy, mild, moderate, strenuous, very strenuous Added field with applied formula Python scripts for attribute management

3: Elevation, Trail Rating

Results: Map Layout

Results: Multi-featured Report sorted by descending trail rating, miles, trail name also shows if bikes, horses, dogs allowed

Challenges Python with ModelBuilder Data management / scope Reports Field names change after join => layer files issue

Challenges: New Skills Managing bookmarks -- Python -- Editing metadata

Conclusions Trail rating formula is effective Reports show multiple features at once Useful backdrop layers in geodatabase Could be even better if… trail use complete trail rating revisited combine trail segments extend to other parks!

Data Sources Note, in reference to various disclaimers given with below data sources, the data presented in this document should be viewed as a general guide and should not be used for wayfinding, official or legal determinations. ArcGIS Online: Public Trails in the Santa Monica Mountains National Recreation Area, by NPS. Last modified March SAMO small scale base GIS water quality data from IRMA (Integrated Resource Management Applications). Released January, 2001.water quality The National Map, National Elevation Data: 1/3 arcsecond digital elevation models for n35w119 & n35w120. As of January 2013.National Elevation Data Fire perimeters from California Department of Forestry Fire and Resource Assessment Program (CDF-FRAP). Through July 2014.CDF-FRAP California State Park boundaries, as of March 2012.State Park boundaries Census Tiger/Line shapefiles, county boundaries as of National Geographic Maps Trails Illustrated #253-Santa Monica Mountains National Recreation Area (a paper map), 1998.