RIPARIAN LAND COVER CHANGE IN THE LOWER GRAND CANYON, 1998 TO 2016

Sustained drought conditions have contributed to a significant decrease in the volume of the Colorado River and the Lake Mead reservoir in the lower portion of the Grand Canyon. As a result, changes in riparian conditions have occurred in the region, including sediment exposure and highly variable vegetative cover. These changes negatively affect ecological health, such as aquatic, terrestrial, and avian habitats, as well as air and water quality. The change in riparian areas have also lead to increased invasive species land cover within the Grand Canyon. Our research sought to quantify the change of these ecologically important land coverages within the 1998 to 2016 drought period. Landsat satellite imagery was utilized to detect changes of the water surface and land cover area from 1998 to 2016 to assess the effects of long-term drought on the riparian zone. As a result of this research, a 62% decrease of water surface area in the lower Colorado River and Lake Mead delta was shown. Of this 62% change, by 2016 10% became riparian vegetation, 15% became riparian sediment, 17% became dead vegetation, and 20% became exposed lakebed. The land cover classification script, GC-ReDI, created for this research, will allow for continued annual monitoring of land cover changes within Grand Canyon National Park.