Tracking land-use is a vital task for understanding changes in ecosystem structures, highlighting potential threats, and monitoring the effectiveness of current plans and legislation. By knowing the size, nature and location of change, we can help inform how different land uses affect important areas for conservation such as riparian habitat along streams and shorelines.
Remote sensing can provide a complete view of the landscape from above but translating data to useful information is a large task. Traditionally land-use mapping and change detection have been conducted for small local projects through manual photo interpretation or regionally from satellite data, typically Landsat data which is captured at a single pixel resolution of 30m. Advances in digital imaging and Federal initiatives to monitor agriculture have led to the acquisition of state-wide 1-m aerial imagery for 2006, 2009, 2011, 2013 and 2015 (hereafter referred to as the NAIP data).
In 2009, the Salmon Recovery Funding Board (SRFB) provided a grant to the Habitat Science Division of WDFW to develop and test a change detection method that would utilize the NAIP data. This process called High Resolution Change Detection (HRCD) was used to track major vegetation changes in 4 of 19 water resource inventory areas (WRIAs) in the Puget Sound Basin. At the time the primary existing product for tracking changes in land-use and land cover was the Coastal Change Analysis Program (CCAP) change product, which is a NOAA program tasked with providing change data for all US coastal areas. Since the initial SRFB grant HRCD has been applied to the entire Puget Sound basin for three time periods: 2006 – 2009, 2009 – 2011, and 2011 – 2013. The HRCD has demonstrated high accuracy rates with improved accounting of forest conversion to urban uses relative to CCAP. HRCD quantifies canopy loss and new impervious and semi-pervious surface and provides information as to the likely cause of change (e.g. forestry, development, stream migration) for events as small as 1/20th of an acre. The high accuracy, fine scale, and broad scope of this data set provides a unique opportunity to address land use and land cover questions like never before. In order to begin deploying the HRCD to real-world applications, WDFW has offered technical assistance to organizations interested in exploring how the HRCD can be relevant to them through a pilot project that began in summer 2014.
Since the start of the HRCD Pilot Project, the data has been employed in a number of land use analysis applications at a variety of scales. Working with state agencies, county and city governments, and other organizations, WDFW staff created case studies relevant to our local partners demonstrating the utility of the HRCD data. These analyses included riparian canopy loss, change rates within and outside of designated urban growth areas, changes to SMP areas, and more. Please contact WDFW for more information on these case studies:
Kenneth B. Pierce Jr.
Landscape Spatial Analytics Section Lead, Habitat Science Division
Land-Use Outreach Coordinator
PHS Section Manager
To view and download the HRCD, or to learn more about how the data is generated and funding sources, please visit the project site: www.pshrcd.com.