Quantifying Land Cover Change in the Delta of the Colorado River

摘要

We mapped the distribution of vegetation and habitat types in the Colorado River delta, in Mexico, and used satellite remote sensing techniques to monitor spatial and temporal changes in the landcover classes. Our objectives were to compare the responses of native and invasive plant types in riparian and wetland communities to water flow and pulse flood releases, and to contrast the vegetation response in Mexico, where the river is unconflned, to the U.S., where the river is channelized. Although the invasive species, saltcedar, is still the dominant plant in the delta, native cottonwood and willow trees have regenerated due to flood releases from the U.S. since 1981. Tree populations are dynamic, with a mean age of less than five years. Biomass intensity in the floodplain, as measured by NDVI, responds positively even to low-volume flood events. In addition to riparian habitat, agricultural wastewater has created valuable wetlands in the delta.