TITLE:
Landsat Time Series Analysis of Vegetation Changes in Solar Energy Development Areas of the Lower Colorado Desert, Southern California
AUTHORS:
Christopher Potter
KEYWORDS:
Landsat, Shrubland, Solar Energy Development, Lower Colorado Desert, DRECP
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.4 No.2,
February
2,
2016
ABSTRACT: Land cover change from renewable energy development in southern
California is receiving increasing attention due to potential impacts on
protected area conservation, endangered species, and greenhouse gas emissions.
This study was designed to quantify and map, for the first time, variations
desert vegetation canopy density and related growth rates using 30 consecutive
years of Landsat satellite image data across the Lower Colorado Desert. The
time-series for mean normalized difference vegetation index (NDVI) values
sampled from each of the three major land cover types (shrubland, barren sand
dune, and developed urban) showed no significant positive or negative trend in
vegetation canopy density. Three periods of significant decrease in NDVI were
detected during the drought periods of 1989-1990, 2002-2003, and 2013-2015,
indicating that annual precipitation has been the main controller of shrubland
canopy growth and green cover. Shrubland canopy cover has been relatively
stable in renewable energy development zones since the mid-2000s. NDVI change
in the period after nearly all southern California solar energy developments
were initiated (post-2010) could be attributed largely to topographic water
flow pathways through canyons and desert washes, both in and around all solar
energy development zones.