Walker, J.J. Soulard, C.E. Petrakis, R.E. 20190913 tabular digital data https://doi.org/10.5066/P9XPA5AK Jessica J. Walker Christopher E. Soulard Roy E. Petrakis 202002 publication International Journal of Applied Earth Observation and Geoinformation vol. 84 n/a Elsevier BV ppg. 101973 https://doi.org/10.1016/j.jag.2019.101973 The dataset comprises a Landsat-derived assessment of monthly surface water extent within the study area (California's greater Central Valley). The surface water dataset is based on the algorithm for the Dynamic Surface Water Extent (DSWE) (Jones, 2019), which was adapted to the Google Earth Engine JavaScript environment. The level of spatial aggregation is by level-8 hydrologic unit code (HUC). The data provide a time series of surface water extents across the great Central Valley on a monthly basis. The dataset is designed to be ingested by the R processing script associated with this project. 19840101 20150801 observed Complete None planned -124.1016 -115.4443 41.9563 33.3948 None Landsat surface water mapping time series USGS Thesaurus surface water (non-marine) image collections multispectral imaging USGS Metadata Identifier USGS:5d64655be4b09b198a26bc30 Common geographic areas California California Valley California Mountain None Central California Valley Sierra Nevada Mountains None None Jessica J Walker U.S. Geological Survey, PACIFIC REGION Research Geographer mailing address

520 North Park Avenue

Tucson AZ 85719 United States 520-670-5019 520-670-5113 jjwalker@usgs.gov Environment as of Metadata Creation: Microsoft [Unknown] Version 6.2 (Build 9200) ; Esri ArcGIS 10.6.1 (Build 9270) Service Pack N/A (Build N/A) No formal accuracy assessment tests were conducted on the surface water values determined in this study. GEE outputs resemble corresponding imagery downloaded from EROS. All values vary appropriately with observed seasonal precipitation patterns in the study area. Dataset is considered complete for the information presented over the given time period. All relevant satellite accuracy specifications can be found online. No formal horizontal accuracy tests were conducted in this study. All relevant satellite accuracy specifications can be found online. No formal vertical accuracy tests were conducted in this study. USGS 2019 Raster Digital Data Set Google Earth Engine USGS https://code.earthengine.google.com Digital and/or Hardcopy 19850101 20120505 ground condition Landsat 5 Source information used in support of the development of the data set. USGS 2019 Raster Digital Data Set Google Earth Engine USGS https://code.earthengine.google.com Digital and/or Hardcopy Resources 19990101 20151231 observed Landsat 7 Source information used in support of the development of the data set. USGS 2019 Vector Digital Data Set Google Earth Engine USGS https://code.earthengine.google.com/ Digital and/or Hardcopy Resources 20130411 20190618 observed Landsat 8 Source information used in support of the development of the data set. We generated DSWE datasets by porting the DSWE algorithm to the GEE JavaScript environment and producing scenes of surface water extent on the basis of Landsat 5, Landsat 7, and Landsat 8 data. We created monthly composites of water/no water classes aggregated by study area HUC and output the results to csv format. 2019 Jessica J Walker U.S. Geological Survey, SOUTHWEST REGION Research Geographer mailing address

520 North Park Avenue

Tucson AZ 85719 United States 520-670-5019 520-670-5113 jjwalker@usgs.gov dswe2_0_monthly_HUC_summaries_1984_2016_hlshd9.csv Comma Separated Value (CSV) file containing data. Producer Defined date Date (month and year) Producer Defined Date is recorded as DSWE_YYYYMM huc8 Hydrologic unit code (HUC) label Producer Defined The 8-digit HUC 0 Class 0 ("Not water") Producer Defined 0.0 10871453.0 30m pixel 1 1 Class 1 ("Water - high confidence") Producer Defined 0.0 695196.0 30m pixel 1 2 Class 2 ("Water - moderate confidence") Producer Defined 0.0 346295.0 30m pixel 1 3 Class 3 ("Partial surface water") Producer Defined 0.0 643453.0 30m pixel 1 4 Class 4 ("Water or wetland, low confidence") Producer Defined 0.0 1802489.0 30m pixel 1 9 Class 9 ("Cloud, cloud shadow, or snow") Producer Defined 0.0 7983970.0 30m pixel 1 null No imagery available Producer Defined 0.0 10898066.0 30m pixel 1 areasqkm Area of HUC Producer Defined << empty cell >> No Data Producer defined 757.62 9808.28 sq km 0.0009 U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov None Digital Data https://doi.org/10.5066/P9XPA5AK None 20200830 Jessica J Walker U.S. Geological Survey, PACIFIC REGION Research Geographer mailing address

520 North Park Avenue

Tucson AZ 85719 United States 520-670-5019 520-670-5113 jjwalker@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998