Colorado River Project: A compilation of vegetation indices, phenology assessment metrics, estimates of evapotranspiration and change maps for five reaches between Hoover and Morelos Dams on the Lower Colorado River, for nearly the last two decades
Data for journal manuscript: Riparian area changes in greenness and water use on the lower Colorado River in the USA from 2000 to 2020
Dates
Publication Date
2021-04-01
Start Date
2000
End Date
2020
Citation
Nagler, P., Barreto-Muñoz, A., and Didan, K., 2021, Colorado River Project: A compilation of vegetation indices, phenology assessment metrics, estimates of evapotranspiration and change maps for five reaches between Hoover and Morelos Dams on the Lower Colorado River, for nearly the last two decades: U.S. Geological Survey data release, https://doi.org/10.5066/P9MIPBRP.
Summary
These raster and tabular data were compiled to develop time series data of the lower Colorado River (LCR) vegetation greenness, water use, and phenology since the year 2000. An objective of our study was to evaluate short and long-term effects of drought and biocontrol on LCR riparian and aquatic ecosystems south of Hoover Dam. These data represent spatially explicit average Enhanced Vegetation Index (EVI2) derived evapotranspiration (ET) difference, and scaled normalized difference vegetation index (NDVI*) difference maps between two decades (2000 to 2010 and 2011 to 2020) and two 5 year periods (2000 to 2005 and 2016 to 2020). The time-series period statistics data provide estimates of the riparian woodland area ecosystem health [...]
Summary
These raster and tabular data were compiled to develop time series data of the lower Colorado River (LCR) vegetation greenness, water use, and phenology since the year 2000. An objective of our study was to evaluate short and long-term effects of drought and biocontrol on LCR riparian and aquatic ecosystems south of Hoover Dam. These data represent spatially explicit average Enhanced Vegetation Index (EVI2) derived evapotranspiration (ET) difference, and scaled normalized difference vegetation index (NDVI*) difference maps between two decades (2000 to 2010 and 2011 to 2020) and two 5 year periods (2000 to 2005 and 2016 to 2020). The time-series period statistics data provide estimates of the riparian woodland area ecosystem health and its water use for the Lower Colorado River between Hoover and Morelos dams over the past 21 years. These data were compiled by the U.S. Geological Survey (USGS) and University of Arizona, to monitor riparian zone trends and changes in the Lower Colorado, and document riparian ecosystem health and its water use. The growing season ET and EVI2 difference maps were created using both EVI and ET from-Landsat-OLI, and the NDVI* difference maps were created using Landsat OLI 30m data only. These data were processed over time and space along to capture different land cover, management conditions, general geospatial and hydrological conditions (ET-EVI), and areas where riparian plant communities greened or browned over these time frames (NDVI*). The spatial extent of the raster data includes five Reaches (R3..R7) along the LCR riparian corridor between Hoover Dam and Morelos Dam on the Northern International Border (NIB) near Yuma, Arizona. This extent allowed for the evaluation of short and long-term effects on the river's vegetation of drought and hydrological processes in this dryland region. All data associated with this project were acquired from the LP-DAAC and pre-processed to remove and capture issues prior to further analyses. Preprocessing involved projection to a common coordinate system, masking to only retain the area of interest, quality analysis to discard poor data, and then value addition to generate the growing season ET and EVI2 difference maps, as well as water use difference maps produced with ET-from-Landsat-EVI, and the NDVI* difference maps. Data acquisition and analysis were performed at the University of Arizona VIP lab (vip.arizona.edu) using their large Linux cluster of computing and storage resources. A mix of off the shelf software and specialized in-house tools were used to process the data and analyses. These data depict a Landsat time series from three sensors over the 21-year period from the derived ET-EVI2 and NDVI* time-series data. These data can be used to monitor spatial and temporal riparian zone trends and changes, and the impact of both drought, fire, land clearing and/or non-native species biocontrol on riparian habitat, in the LCR from Hoover Dam and Morelos Dam in the United States and document riparian ecosystem health and its water use.
These raster and tabular data were created to continue monitoring riparian zone trends, changes and anomalies in the riparian zone of the lower Colorado River (LCR) between Hoover and Morelos Dams in the United States. The purpose of the time-series period statistics data are to provide estimates of the riparian woodland area ecosystem health and its water use for the Lower Colorado River between Hoover and Morelos dams over the past 21 years. These datasets, while specific to the research questions addressed by this research (see Larger Work Citation), were designed to be accessible and used by others involved in research efforts on the LCR. These maps capture a critical period of the LCR riparian zone over the past 21 years and provide a first synoptic view of how the vegetation responded to salt cedar biocontrol beetle defoliation events since they arrived into the LCR region ca. 2016. The ET-EVI change maps show areas where more or less greening and water use has taken place between the first and last decades and the first and last five-year periods. The riparian corridor vegetation will continue to respond not only to biocontrol activity but also to drought. The NDVI time-series information will continue to be monitored into the future and thus capture additional changes in the natural phenological cycles of these riparian species that could be due to ongoing drought conditions, higher maximum air temperatures, precipitation pattern changes and fire or land clearing activities. These types of events, when tracked using ET-EVI and NDVI data, are very important for land and water managers, and academics who follow up these studies and may spatially compare trends to restoration areas, or temporally, either by comparing to prior years or more likely, by extending the performance period beyond the year 2020.
Rights
The author(s) of these data request that data users contact them regarding intended use and to assist with understanding limitations and interpretation. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.