Final Project for Introduction to GIS Programming:
Krysta RogersGeography 375Spring 2011
Assessment of the proposed critical habitat for the threatened coastal California gnatcatcher (Polioptila californica californica)
Peter Knapp
Introduction:California gnatcatcherSmall, non-migratory songbirdInhabits specific vegetation community called coastal sage scrubListed as threatened under the Endangered Species Act in 1993
Threats include: Loss of habitat due to development, exotic plants, & fireReproductive loss from invasive species (e.g. brown headed cowbird)
Richard Stern
Introduction:Coastal sage scrubPlant community dominated by shrubs & other species adapted to arid conditions
California sage brush, sages, California buckwheat, redberry, lemonade-berry & cacti
90% decline from its original rangeThreats include urban development, agriculture, & population growth
University of California, Santa Barbara 2011
Less than 10% of remaining habitat is protected
Introduction:Project goalsUse Python to evaluate the designated critical habitat for the California gnatcatcher in relation to a vegetation layer for Orange CountyIdentify coastal sage scrub habitat not included within the designated critical habitat developed by USFWS
Methods:Original filesCalifornia gnatcatcher proposed critical habitat
ds131 – shapefileCalifornia counties
county100k – feature classOrange County vegetation
oraveg – feature classoraveg.lut – info tableoraveglookup – dBase table
Methods:Data preparationArcCatalog, placed all the feature classes & shapefile into a single folder labeled “Data”Explored feature classes & shapefile in ArcMapDetermine field names for queries & how vegetation is named & coded
Methods:Data preparationCounties layer into shapefile
CAcounties – shapefileCondensed vegetation layer into layer only including coastal sage scrub plant species
CoastalSageScrub – shapefileSageScrubCommunities – shapefile
Excluded “non-habitat” data from gnatcatcher critical habitat layer
cagn crithab – shapefile
Methods:Data preparation
Methods:Data preparation
Methods:Python script developmentAdded import, arcpy, sys, traceback modulesIdentified workspaceAdded framework for try: & except: blocksIdentified file names for each process
Methods:Python script development
import
try:
Methods:Python script development
except:
Methods:Python script development
File names
Methods:Python script developmentDeveloped script
Make Feature Layer for countiesQuery Orange County
Clip for critical habitat by Orange CountyErase analysis to evaluate habitat outside of critical habitatAdd Join to add lookup table to vegetation layer
IndexSave to Layer
Methods:Python script developmentMake Feature Layer for counties
Make Feature Layer, Query, & Select by Attribute
Methods:Python script developmentClip for critical habitat by Orange County
Clip
Methods:Python script developmentErase analysis to evaluate habitat outside of critical habitat
Erase
Methods:Python script developmentChecked script for errors
Methods:Python script developmentFixed the errors & re-ran the code
Methods:Preliminary results in ArcMapLooked at the resulting layers in ArcMap
Methods:Python script developmentAdd Join to add lookup table to vegetation layer
Add Join
Methods:Python script developmentRan script again, error – need to add an index before performing the Add Join
Methods:Python script developmentResearched the Add Index routine
Methods:Python script developmentAdd Index, Add Join, & Save To Layer to make join permanent
Add Index, Add Join, & Save To Layer
Methods:Python script developmentRan script, no errors!
Results:ArcMapFiles produced in ArcMap for use in Python
CACountiescagn_crithabCoastalSageScrubSageScrubCommunities
Results:PythonFiles produced in Python
cagn_crithab_clip.shpOrange_County.shpscrub_outside_crithab.shpscrub_table_join
Discussion:Lessons learnedTackled this project with a step-by-step approachParceled out input/output file names for each processUtilized help files & class materials for referenceLook for syntax errors, misspellings, & incorrect path names
Discussion:Critical habitatCoastal sage scrub habitat does exist outside the designated critical habitat for the California gnatcatcherWarrants monitoring to determine if habitat might be utilized by gnatcatchers in the future
Peter Gallagher
