The CCD-Plugin uses Google Earth Engine to get Landsat or Sentinel2 datasets and run the Continuous Change Detection (CCDC) algorithm to analyze the trends and breakpoints of change over multi-year time series at a given coordinate.

The plugin uses Google Earth Engine (GEE) to retrieve data for the specified coordinates for all available Landsat satellites, including 4, 5, 7, 8, and 9, from Collections 1 or 2, or Harmonized Sentinel-2 collection. It filters for high-quality data only. Then plugin run over Google Earth Engine the Continuous Change Detection algorithm to find temporal breakpoints of the image collection by iteratively fitting harmonic functions to the data.

• Landsat C1 (30m resolution): ~1983 → 2021
• Landsat C2 (30m resolution): ~1983 → present
• Sentinel-2 (10m resolution): ~2018 → present

The sub-datasets to visualize and compute the CCDC algorithm and its breakpoints are:

• Bands: Blue, Green, Red, NIR, SWIR1, SWIR2

• Indices: NDVI, NBR, EVI, EVI2, BRIGHTNESS, GREENNESS, WETNESS

• Zhu, Z., & Woodcock, C. E. (2014). Continuous change detection and classification of land cover using all available Landsat data. Remote sensing of Environment, 144, 152-171. https://doi.org/10.1016/j.rse.2014.01.011

• Arévalo, P., Bullock, E.L., Woodcock, C.E., Olofsson, P., (2020). A Suite of Tools for Continuous Land Change Monitoring in Google Earth Engine. Front. Clim. 2. https://doi.org/10.3389/fclim.2020.576740

The plugin needs to work:

• Google Earth Engine plugin: The user needs to have this plugin installed and an active Google Earth Engine (EE) account.
• Plotly. Most of the Qgis versions have this library inside, otherwise the plugin install it automatically.

QT without WebKit: The plugin uses the QT WebKit module for plotting, QtWebEngine is very unstable for Qgis. We recommend installing Qgis with the QT WebKit module (by default in Windows and Mac packages), other systems like Linux with QT >= 5.15 without QT WebKit module by default install python QtWebKit module (e.g. python3-pyqt5.qtwebkit or python-pyqt5-webkit) or use alternative installation of Qgis (e.g. using conda).

CCD-Plugin was developing, designed and implemented by the Group of Forest and Carbon Monitoring System (SMByC), operated by the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM) - Colombia.

Author and developer: Xavier C. Llano [email protected]
Collaborator and co-developer: Daniel Moraes [email protected]
Theoretical support, tester and product verification: SMByC-PDI group

CCD-Plugin is a free/libre software and is licensed under the GNU General Public License.