Jessica J Walker
Jessica started with the USGS as a Mendenhall Postdoctoral Researcher in 2014.
Jessica's broad research interests center on the analysis of landscape change using remote sensing data. Past projects have included tracking the vegetative trajectories of areas recovering from fire events, both in the semi-arid, high-elevation forests of Arizona and the boreal forests of Alaska. Additional recent work includes examining surface inundation patterns via Landsat and MODIS imagery as part of the PLACE project (Patterns in the Landscape - Analyses of Cause and Effect).
Education and Certifications
2012 - Ph.D. Geospatial and Environmental Analysis, Virginia Tech
2000 - M.A. Geography, University of Arizona, Tucson
1991 - B.A. Applied Math, Williams College
Science and Products
Filter Total Items: 13
National Surface Water Maps using Daily MODIS Satellite Data for the Conterminous United States, 2003-2019 National Surface Water Maps using Daily MODIS Satellite Data for the Conterminous United States, 2003-2019
Members from the U.S. Geological Survey (USGS) Patterns in the Landscape - Analyses of Cause and Effect (PLACE) team are releasing monthly surface water maps for the conterminous United States (U.S.) from 2003 through 2019 as 250-meter resolution geoTIFF files. The maps were produced using the Dynamic Surface Water Extent (DSWE) algorithm applied to daily Moderate Resolution Imaging
DSWEmod surface water map composites generated from daily MODIS images - California DSWEmod surface water map composites generated from daily MODIS images - California
USGS researchers with the Patterns in the Landscape ? Analyses of Cause and Effect (PLACE) project are releasing a collection of high-frequency surface water map composites derived from daily Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. Using Google Earth Engine, the team developed customized image processing steps and adapted the Dynamic Surface Water Extent (DSWE) to...
Data release associated with the journal article "Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States" Data release associated with the journal article "Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States"
This dataset supports the following publication: "Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States" (DOI:10.1016/j.rse.2020.112013). The data release allows users to replicate, test, or further explore results. The dataset consists of 4 separate items based on the analysis approach used in the...
Implementation of a Surface Water Extent Model using Cloud-Based Remote Sensing - Code and Maps Implementation of a Surface Water Extent Model using Cloud-Based Remote Sensing - Code and Maps
This data release comprises the raster data files and code necessary to perform all analyses presented in the associated publication. The 16 TIF raster data files are classified surface water maps created using the Dynamic Surface Water Extent (DSWE) model implemented in Google Earth Engine using published technical documents. The 16 tiles cover the country of Cambodia, a flood-prone...
Phenology pattern data indicating recovery trajectories of ponderosa pine forests after high-severity fires Phenology pattern data indicating recovery trajectories of ponderosa pine forests after high-severity fires
This tabular, machine-readable CSV file contains annual phenometrics at locations in ponderosa pine ecosystems across Arizona and New Mexico that experienced stand-clearing, high-severity fire. The locations represent areas of vegetative recovery towards pre-fire (coniferous/pine) vegetation communities or towards novel grassland, shrubland, or deciduous replacements. Each sampled area...
Datasets for analyzing stream gage discharge and Landsat imagery integration in the greater Central Valley, California from 1984 to 2015 Datasets for analyzing stream gage discharge and Landsat imagery integration in the greater Central Valley, California from 1984 to 2015
This data release comprises the data files and code necessary to perform all analyses presented in the associated publication. The *.csv data files are aggregations of water extent on the basis of the European Commission's Joint Research Centre (JRC) Monthly Water History database (v1.0) and the Dynamic Surface Water Extent (DSWE) algorithm. The shapefile dataset contains the study area...
Filter Total Items: 19
Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019 Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019
Satellite imagery is commonly used to map surface water extents over time, but many approaches yield discontinuous records resulting from cloud obstruction or image archive gaps. We applied the Dynamic Surface Water Extent (DSWE) model to downscaled (250-m) daily Moderate Resolution Imaging Spectroradiometer (MODIS) data in Google Earth Engine to generate monthly surface water maps for...
Authors
Roy Petrakis, Christopher E. Soulard, Eric K. Waller, Jessica J. Walker
DSWEmod - The production of high-frequency surface water map composites from daily MODIS images DSWEmod - The production of high-frequency surface water map composites from daily MODIS images
Optical satellite imagery is commonly used for monitoring surface water dynamics, but clouds and cloud shadows present challenges in assembling complete water time series. To test whether the daily revisit rate of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery can reduce cloud obstruction and improve high-frequency surface water mapping, we compared map results...
Authors
Christopher E. Soulard, Eric Waller, Jessica J. Walker, Roy Petrakis, Britt Windsor Smith
Tamm review: Postfire landscape management in frequent-fire conifer forests of the southwestern United States Tamm review: Postfire landscape management in frequent-fire conifer forests of the southwestern United States
The increasing incidence of wildfires across the southwestern United States (US) is altering the contemporary forest management template within historically frequent-fire conifer forests. An increasing fraction of southwestern conifer forests have recently burned, and many of these burned landscapes contain complex mosaics of surviving forest and severely burned patches without surviving...
Authors
Jens T. Stevens, Collin Haffey, Jonathan D. Coop, Paula J. Fornwalt, Larissa Yocom, Craig D. Allen, Anne Bradley, Owen T. Burney, Dennis Carril, Marin E. Chambers, Theresa B. Chapman, Sandra L. Haire, Matthew D. Hurteau, Jose M. Iniguez, Ellis Q. Margolis, Christopher Marks, Laura A. E. Marshall, Kyle C. Rodman, Camille S. Stevens-Rumann, Andrea E. Thode, Jessica J. Walker
Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States
Satellite-derived phenology metrics are valuable tools for understanding broad-scale patterns and changes in vegetated landscapes over time. However, the extraction and interpretation of phenology in ecosystems with subtle growth dynamics can be challenging. US National Park Service monitoring of evergreen pinyon-juniper ecosystems in the western US revealed an unexpected winter-peaking
Authors
Jodi R. Norris, Jessica J. Walker
Community for data integration 2018 funded project report Community for data integration 2018 funded project report
The U.S. Geological Survey Community for Data Integration annually funds small projects focusing on data integration for interdisciplinary research, innovative data management, and demonstration of new technologies. This report provides a summary of the 10 projects funded in fiscal year 2018, outlining their goals, activities, and accomplishments.
Authors
Leslie Hsu, Caitlin M. Andrews, John B. Bradford, Daniel D. Buscombe, Katherine J. Chase, Wesley M. Daniel, Jeanne M. Jones, Pam Fuller, Benjamin B. Mirus, Matthew E. Neilson, Hans W. Vraga, Jessica J. Walker, Dennis H. Walworth, Jonathan A. Warrick, Jake Weltzin, Daniel J. Wieferich, Nathan J. Wood
Implementation of a surface water extent model in Cambodia using cloud-based remote sensing Implementation of a surface water extent model in Cambodia using cloud-based remote sensing
Mapping surface water over time provides the spatially explicit information essential for hydroclimatic research focused on droughts and flooding. Hazard risk assessments and water management planning also rely on accurate, long-term measurements describing hydrologic fluctuations. Stream gages are a common measurement tool used to better understand flow and inundation dynamics, but gage...
Authors
Christopher E. Soulard, Jessica J. Walker, Roy E. Petrakis
Science and Products
Filter Total Items: 13
National Surface Water Maps using Daily MODIS Satellite Data for the Conterminous United States, 2003-2019 National Surface Water Maps using Daily MODIS Satellite Data for the Conterminous United States, 2003-2019
Members from the U.S. Geological Survey (USGS) Patterns in the Landscape - Analyses of Cause and Effect (PLACE) team are releasing monthly surface water maps for the conterminous United States (U.S.) from 2003 through 2019 as 250-meter resolution geoTIFF files. The maps were produced using the Dynamic Surface Water Extent (DSWE) algorithm applied to daily Moderate Resolution Imaging
DSWEmod surface water map composites generated from daily MODIS images - California DSWEmod surface water map composites generated from daily MODIS images - California
USGS researchers with the Patterns in the Landscape ? Analyses of Cause and Effect (PLACE) project are releasing a collection of high-frequency surface water map composites derived from daily Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. Using Google Earth Engine, the team developed customized image processing steps and adapted the Dynamic Surface Water Extent (DSWE) to...
Data release associated with the journal article "Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States" Data release associated with the journal article "Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States"
This dataset supports the following publication: "Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States" (DOI:10.1016/j.rse.2020.112013). The data release allows users to replicate, test, or further explore results. The dataset consists of 4 separate items based on the analysis approach used in the...
Implementation of a Surface Water Extent Model using Cloud-Based Remote Sensing - Code and Maps Implementation of a Surface Water Extent Model using Cloud-Based Remote Sensing - Code and Maps
This data release comprises the raster data files and code necessary to perform all analyses presented in the associated publication. The 16 TIF raster data files are classified surface water maps created using the Dynamic Surface Water Extent (DSWE) model implemented in Google Earth Engine using published technical documents. The 16 tiles cover the country of Cambodia, a flood-prone...
Phenology pattern data indicating recovery trajectories of ponderosa pine forests after high-severity fires Phenology pattern data indicating recovery trajectories of ponderosa pine forests after high-severity fires
This tabular, machine-readable CSV file contains annual phenometrics at locations in ponderosa pine ecosystems across Arizona and New Mexico that experienced stand-clearing, high-severity fire. The locations represent areas of vegetative recovery towards pre-fire (coniferous/pine) vegetation communities or towards novel grassland, shrubland, or deciduous replacements. Each sampled area...
Datasets for analyzing stream gage discharge and Landsat imagery integration in the greater Central Valley, California from 1984 to 2015 Datasets for analyzing stream gage discharge and Landsat imagery integration in the greater Central Valley, California from 1984 to 2015
This data release comprises the data files and code necessary to perform all analyses presented in the associated publication. The *.csv data files are aggregations of water extent on the basis of the European Commission's Joint Research Centre (JRC) Monthly Water History database (v1.0) and the Dynamic Surface Water Extent (DSWE) algorithm. The shapefile dataset contains the study area...
Filter Total Items: 19
Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019 Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019
Satellite imagery is commonly used to map surface water extents over time, but many approaches yield discontinuous records resulting from cloud obstruction or image archive gaps. We applied the Dynamic Surface Water Extent (DSWE) model to downscaled (250-m) daily Moderate Resolution Imaging Spectroradiometer (MODIS) data in Google Earth Engine to generate monthly surface water maps for...
Authors
Roy Petrakis, Christopher E. Soulard, Eric K. Waller, Jessica J. Walker
DSWEmod - The production of high-frequency surface water map composites from daily MODIS images DSWEmod - The production of high-frequency surface water map composites from daily MODIS images
Optical satellite imagery is commonly used for monitoring surface water dynamics, but clouds and cloud shadows present challenges in assembling complete water time series. To test whether the daily revisit rate of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery can reduce cloud obstruction and improve high-frequency surface water mapping, we compared map results...
Authors
Christopher E. Soulard, Eric Waller, Jessica J. Walker, Roy Petrakis, Britt Windsor Smith
Tamm review: Postfire landscape management in frequent-fire conifer forests of the southwestern United States Tamm review: Postfire landscape management in frequent-fire conifer forests of the southwestern United States
The increasing incidence of wildfires across the southwestern United States (US) is altering the contemporary forest management template within historically frequent-fire conifer forests. An increasing fraction of southwestern conifer forests have recently burned, and many of these burned landscapes contain complex mosaics of surviving forest and severely burned patches without surviving...
Authors
Jens T. Stevens, Collin Haffey, Jonathan D. Coop, Paula J. Fornwalt, Larissa Yocom, Craig D. Allen, Anne Bradley, Owen T. Burney, Dennis Carril, Marin E. Chambers, Theresa B. Chapman, Sandra L. Haire, Matthew D. Hurteau, Jose M. Iniguez, Ellis Q. Margolis, Christopher Marks, Laura A. E. Marshall, Kyle C. Rodman, Camille S. Stevens-Rumann, Andrea E. Thode, Jessica J. Walker
Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States Solar and sensor geometry, not vegetation response, drive satellite NDVI phenology in widespread ecosystems of the western United States
Satellite-derived phenology metrics are valuable tools for understanding broad-scale patterns and changes in vegetated landscapes over time. However, the extraction and interpretation of phenology in ecosystems with subtle growth dynamics can be challenging. US National Park Service monitoring of evergreen pinyon-juniper ecosystems in the western US revealed an unexpected winter-peaking
Authors
Jodi R. Norris, Jessica J. Walker
Community for data integration 2018 funded project report Community for data integration 2018 funded project report
The U.S. Geological Survey Community for Data Integration annually funds small projects focusing on data integration for interdisciplinary research, innovative data management, and demonstration of new technologies. This report provides a summary of the 10 projects funded in fiscal year 2018, outlining their goals, activities, and accomplishments.
Authors
Leslie Hsu, Caitlin M. Andrews, John B. Bradford, Daniel D. Buscombe, Katherine J. Chase, Wesley M. Daniel, Jeanne M. Jones, Pam Fuller, Benjamin B. Mirus, Matthew E. Neilson, Hans W. Vraga, Jessica J. Walker, Dennis H. Walworth, Jonathan A. Warrick, Jake Weltzin, Daniel J. Wieferich, Nathan J. Wood
Implementation of a surface water extent model in Cambodia using cloud-based remote sensing Implementation of a surface water extent model in Cambodia using cloud-based remote sensing
Mapping surface water over time provides the spatially explicit information essential for hydroclimatic research focused on droughts and flooding. Hazard risk assessments and water management planning also rely on accurate, long-term measurements describing hydrologic fluctuations. Stream gages are a common measurement tool used to better understand flow and inundation dynamics, but gage...
Authors
Christopher E. Soulard, Jessica J. Walker, Roy E. Petrakis