mb_wetlands_and_riparian

Margin of error has not been quantified. A comparison of aerial photo interpretation and ground truthing results for lower Los Osos Creek revealed that interpretation resulted in 26 polygons including 61.68 acres of wetlands. The ground truthing results for this same area include 29 polygons with 62.89 acres of wetlands. A comparison of aerial photo interpretation and field mapping for Walters Creek revealed that interpretation resulted in 18 polygons including 19.11 acres of wetlands.  The field mapping results for the same area include 44 polygons with 19.81 acres of wetlands.  Both comparisons reveal that the more time-consuming, in the field methods result in higher precision and accuracy for wetland delineation and attribution.  See the CCWGIS final report for more information about these comparative studies.

Dataset has no vertical dimension.

The Morro Bay Watershed Wetland and Riparian Dataset was created to support the Central Coast Wetlands GIS (CCWGIS). Wetlands were mapped using aerial photograph interpretation and field mapping. Existing datasets for the bay, Chorro Creek, and watershed streams supplemented this work.  All wetlands were classified using Wetlands of the Central and Southern California Coast and Coastal Watersheds: 
A Methodology for their Classification and Description by Wayne Ferren, Peggy Fiedler, and Rob Leidy.    

Aerial photograph interpretation was performed using ArcGIS 8.3 and the wetlands were heads up digitized from the 2003 orthophotography using a minumum mapping unit of 0.25 acres.  The June 2001 contact prints supplemented the 2003 photography since 2001 was a wetter year and the intent of the dataset was to capture all wetlands.  The Morro Bay streams dataset was used as a starting point for all creeks, except Chorro Creek. The lines were buffered and edited to reflect the creeks depicted on the aerial photography. The Chorro Creek Habitat Typing dataset formed the basis for the Chorro Creek delineation.  The bay and salt marsh were mapped as part of the USACOE Feasibility Study and the polygons were incorporated into the dataset and reclassfieid using Ferren, Fiedler, and Leidy.

The ground truthing and field mapping were conducted by the California Conservation Corps GIS team. Ground truthing was performed in lower and upper Los Osos Creek, Chorro Creek estuarine/riverine transition, and other problem areas throughout the watershed.  This consisted of checking the gross delineation of the area and attribution.  Field mapping was conducted for the Chorro Creek Ecological Reserve, a portion of Sharks Inlet, and Walters Creek. Wetland delineations were mapped with a minumum mapping unit of 0.10 acre and attributed using Ferren, Fiedler, and Leidy. All ground truthing and field mapping was conducted with a sub-meter GPS and the results supersededthe aerial photo interpretation conducted for those areas.

Internal feature number.

ESRI

Feature geometry.

ESRI

Polygon Number

Generated as new polygons were created and to track ground truthed and field mapped polygons

Number code for Hydrogeomorphic classification

Ferren, Fiedler, and Leidy

Hydrogeomorphic code descriptor

Ferren, Fiedler, and Leidy

Wetland System

Ferren, Fiedler, and Leidy

Wetland Supsystem

Ferren, Fiedler, and Leidy

Wetland Class

Ferren, Fiedler, and Leidy

Full Code (System, Subsystem, Class)

Ferren, Fiedler, and Leidy

Identifies the source and method for identifying the polygon

Was the polygon and attributes groundtruthed

Level of confidence in polygon delineation

Level of confidence in polygon attribution

Wetlands Subclass

Ferren, Fiedler, and Leidy

Wetlands Water Regime

Ferren, Fiedler, and Leidy

Plant Species

Indicator Category

USFWS-National List of Plant Species That Occur in Wetlands (http://www.fws.gov/nwi/bha/list96.html)

precentage of plant species within polygon

Date polygon was mapped in the field

General region of Watershed polygon is located in.