This dataset, created in support of USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18, represents the groundwater discharge area (GDA) for the Stump Springs riparian area and Area of Critical Environmental Concern (ACEC). Vegetated areas within the GDA are composed of phreatophytic shrubs interspersed with xeric vegetation and bare soil. The GDA was delineated by visual interpretation of 1-meter National Agriculture Imagery Program (NAIP) aerial imagery acquired in May of 2015. The ACEC boundary was determined by the Bureau of Land Management.

This USGS data release, supporting USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Southern Nevada, 2016–18, consists of five datasets - Normalized Difference Vegetation Indexes (NDVI) and a mapped groundwater discharge areas (GDA) for two spring areas, and a two-class land cover classification for Stump Springs and the Area of Critical Environmental Concern (ACEC) adjacent to Stump Springs. The mapped GDAs are the area within each spring’s riparian area where discharge from evaporation by open water or bare soil and transpiration from phreatophytic plants exceeds the volume of water contributed by precipitation. The GDAs were delineated from visual interpretation of 2015 National Agricultural Imagery Program (NAIP) imagery and 2016 and 2017 WorldView 2 imagery. The WorldView 2 imagery, NDVI based on the Worldview 2 imagery, and two-class land cover classification each were used to estimate the area of riparian vegetation within the GDA.

This USGS data release, supporting USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Southern Nevada, 2016–18, consists of five datasets - Normalized Difference Vegetation Indexes (NDVI) and a mapped groundwater discharge areas (GDA) for two spring areas, and a two-class land cover classification for Stump Springs and the Area of Critical Environmental Concern (ACEC) adjacent to Stump Springs. The mapped GDAs are the area within each spring’s riparian area where discharge from evaporation by open water or bare soil and transpiration from phreatophytic plants exceeds the volume of water contributed by precipitation. The GDAs were delineated from visual interpretation of 2015 National Agricultural Imagery Program (NAIP) imagery and 2016 and 2017 WorldView 2 imagery. The WorldView 2 imagery, NDVI based on the Worldview 2 imagery, and two-class land cover classification each were used to estimate the area of riparian vegetation within the GDA.

This dataset, created in support of USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18, represents the groundwater discharge area (GDA) for the Hiko Springs area. Vegetated areas within the GDA are composed of phreatophytic shrubs interspersed with xeric vegetation and bare soil. The GDA was delineated by visual interpretation of 1-meter National Agriculture Imagery Program (NAIP) aerial imagery acquired in May of 2015. Areas of channel scour within the GDA resulting from a flood event in September 2015 were delineated from a 1.84 meter resolution 2016 Worldview 2 image.

This dataset, created in support of USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18, represents the groundwater discharge area (GDA) for the Hiko Springs area. Vegetated areas within the GDA are composed of phreatophytic shrubs interspersed with xeric vegetation and bare soil. The GDA was delineated by visual interpretation of 1-meter National Agriculture Imagery Program (NAIP) aerial imagery acquired in May of 2015. Areas of channel scour within the GDA resulting from a flood event in September 2015 were delineated from a 1.84 meter resolution 2016 Worldview 2 image.

This dataset, created in support of USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18, represents a two class land cover classification consisting of moderate to dense vegetation and bare to sparsely vegetated areas within the Groundwater Discharge Area and Area of Critical Environmental Concern boundaries for Stump Spring, Nevada. The classification is based on a 2015 1-meter National Agricultural Imagery Program (NAIP) image and a maximum likelihood classification algorithm provided in ENVI software (https://www.harrisgeospatial.com/docs/Classification.html#ClassSupervised).

This USGS data release represents supplemental tabular data for an annual groundwater discharge by evapotranspiration (ET) from areas of spring-fed riparian vegetation, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18. The raw ET dataset contained multiple data gaps that were simulated and gap-filled with the water-level model utility in SeriesSEE, a USGS developed Microsoft Excel® addin. Continuous time-series data, including net radiation, sensible-heat flux, latent-heat flux, and ground-heat flux, from before and after the data gap(s) were used to simulate turbulent fluxes with multivariate regressions and the gramma transform, used for latent heat gaps after precipitation events. ET data were gap filled using methods outlined in A process to estimate net infiltration using a site-scale water-budget approach, Rainier Mesa, Nevada National Security Site, Nevada, 2002–05. Data used to simulate gap periods for Stump Spring and Hiko Springs were acquired from USGS ET stations 364555117412401 and 355846116160401, respectively. This release consists of the following: (1) inventory of latent-heat flux, sensible-heat flux gap-filled periods, and model goodness-of-fit, Stump Springs, Clark County, NV, 2016, (2) inventory of net radiation, latent-heat flux, sensible-heat flux, ground-heat flux gap-filled periods, and model goodness-of-fit, Hiko Springs, Clark County, NV, 2017-18, (3) gap-filled latent-heat flux and sensible-heat flux data, Stump Spring evapotranspiration station, Clark County, NV, 2016, and (4) gap-filled net radiation, latent-heat flux, sensible-heat flux, and ground-heat flux, Hiko Springs evapotranspiration station, Clark County, NV, 2017-18.

This USGS data release represents supplemental tabular data for an annual groundwater discharge by evapotranspiration (ET) from areas of spring-fed riparian vegetation, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18. The raw ET dataset contained multiple data gaps that were simulated and gap-filled with the water-level model utility in SeriesSEE, a USGS developed Microsoft Excel® addin. Continuous time-series data, including net radiation, sensible-heat flux, latent-heat flux, and ground-heat flux, from before and after the data gap(s) were used to simulate turbulent fluxes with multivariate regressions and the gramma transform, used for latent heat gaps after precipitation events. ET data were gap filled using methods outlined in A process to estimate net infiltration using a site-scale water-budget approach, Rainier Mesa, Nevada National Security Site, Nevada, 2002–05. Data used to simulate gap periods for Stump Spring and Hiko Springs were acquired from USGS ET stations 364555117412401 and 355846116160401, respectively. This release consists of the following: (1) inventory of latent-heat flux, sensible-heat flux gap-filled periods, and model goodness-of-fit, Stump Springs, Clark County, NV, 2016, (2) inventory of net radiation, latent-heat flux, sensible-heat flux, ground-heat flux gap-filled periods, and model goodness-of-fit, Hiko Springs, Clark County, NV, 2017-18, (3) gap-filled latent-heat flux and sensible-heat flux data, Stump Spring evapotranspiration station, Clark County, NV, 2016, and (4) gap-filled net radiation, latent-heat flux, sensible-heat flux, and ground-heat flux, Hiko Springs evapotranspiration station, Clark County, NV, 2017-18.

This dataset, created in support of USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18, represents a Normalized Difference Vegetation Index calculated for vegetated areas in the Hiko Springs groundwater discharge area. Vegetated areas within the GDA are composed of phreatophytic shrubs interspersed with xeric vegetation and bare soil. The GDA was delineated by visual interpretation of 1-meter National Agriculture Imagery Program (NAIP) aerial imagery acquired in May of 2015. Areas of channel scour within the GDA resulting from a flood event in September 2015 were delineated from a 2016 1.84-meter resolution Worldview 2 image. The NDVI was calculated from the same WorldView 2 with bare ground areas masked and calculated as "no data".

This dataset, created in support of USGS Scientific Investigations Report 2020-5075, Estimates of Groundwater Discharge by Evapotranspiration, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18, represents a Normalized Difference Vegetation Index calculated for vegetated areas in the Stump Spring groundwater discharge area (GDA) and Area of Critical Environmental Concern (ACEC). Vegetated areas within the GDA are composed of phreatophytic shrubs interspersed with xeric vegetation and bare soil. The GDA was delineated by visual interpretation of 1-meter National Agriculture Imagery Program (NAIP) aerial imagery acquired in May of 2015. The NDVI was calculated from a June 2017 WorldView 2 image resampled to 1-meter cell size and masked to remove bare ground areas identified from a supervised classification based on the same 2015 NAIP image used to define the GDA.