,Hydrologic data, primarily precipitation and runoff, have been collected on experimental watersheds operated by the U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) and on other lands in southeastern Arizona since the 1950s. These data are of national and international importance and make up one of the most comprehensive semiarid watershed data sets in the world. The USDA-ARS Southwest Watershed Research Center has recently developed an electronic data processing system that includes an online interface (https://tucson.ars.ag.gov/dap) to provide public access to the data. The goal of the system is to promote analyses and interpretations of historic and current data by improving data access. The publicly accessible part of the system consists of an interactive Web site, which provides an interface to the data, and a relational database, which is used to process, store, and manage data. In addition, DAP was expanded to put sediment, meteorological, soil moisture and temperature, vegetation, CO2 and water flux, geographic information system (GIS) and aircraft and satellite spectral imagery data on line and to publish metadata for all WGEW long-term measurements.,,

,The USDA-ARS Southwest Watershed Research Center (SWRC) operates the Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona as an outdoor laboratory for studying semiarid rangeland hydrologic, ecosystem, climate, and erosion processes.,Since its establishment in 1953, the SWRC in Tucson, Arizona, has collected, processed, managed, and disseminated high-resolution, spatially distributed hydrologic data in support of the center's mission. Data management at the SWRC has evolved through time in response to new computing, storage, and data access technologies. In 1996, the SWRC initiated a multiyear project to upgrade rainfall and runoff sensors and convert analog systems to digital electronic systems supported by data loggers. This conversion was coupled with radio telemetry to remotely transmit recorded data to a central computer, thus greatly reducing operational overhead by reducing labor, maintenance, and data processing time. A concurrent effort was initiated to improve access to SWRC data by creating a system based on a relational database supporting access to the data via the Internet. An SWRC team made up of scientists, IT specialists, programmers, hydrologic technicians, and instrumentation specialists was formed. This effort is termed the Southwest Watershed Research Center Data Access Project (DAP).,The goal of the SWRC DAP is to efficiently disseminate data to researchers; land owners, users, and managers; and to the public. Primary access to the data is provided through a Web-based user interface. In addition, data can be accessed directly from within the SWRC network. The first priority for the DAP was to assimilate and make available rainfall and runoff data collected from two instrumented field sites, the WGEW near Tombstone, Arizona, and the Santa Rita Experimental Range (SRER) south of Tucson, Arizona.,,

This data release contains Soil Water Assessment Tool (SWAT) outputs (.shp) for three precipitation scenarios for the Los Planes watershed in Baja California Sur, Mexico. The inputs used are publicly available low-resolution data from international sources to produce uncalibrated baseline model conditions. The outputs for each scenario include annual average surface runoff (mm), sediment yield (t/ha), percolation (mm), and evapotranspiration (mm) for planes and channels within the study area.

This data release contains Soil Water Assessment Tool (SWAT) outputs (.shp) for three precipitation scenarios for the Los Planes watershed in Baja California Sur, Mexico. The inputs used are publicly available low-resolution data from international sources to produce uncalibrated baseline model conditions. The outputs for each scenario include annual average surface runoff (mm), sediment yield (t/ha), percolation (mm), and evapotranspiration (mm) for planes and channels within the study area.

These data include image-based classifications of total vegetation from 1965, 1973, 1984, 1992, 2002, 2004, 2005, and 2009, and characteristics of the river channel along the riparian area of the Colorado River between Glen Canyon Dam and Lake Mead Reservoir.

These data include image-based classifications of total vegetation from 1965, 1973, 1984, 1992, 2002, 2004, 2005, and 2009, and characteristics of the river channel along the riparian area of the Colorado River between Glen Canyon Dam and Lake Mead Reservoir.

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) (https://earthdata.nasa.gov/about/competitive-programs/measures) SRTM, which includes the Water Body Data Shapefiles and Raster Files (~30 m) product. Version 3.0 contains the vectorized coastline masks used by National Geospatial-Intelligence Agency (NGA) in the editing, called the SRTM Waterbody Data (SWBD), in shapefile and rasterized formats.The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the NGA (previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. This collaboration aims to generate a near-global digital elevation model (DEM) of Earth using radar interferometry. SRTM was the primary (and virtually only) payload on the STS-99 mission of the Space Shuttle Endeavour, which launched February 11, 2000, and flew for 11 days.The SRTM swaths extended from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km), creating swaths ~225 km wide, and consisted of all land between 60 degrees N and 56 degrees S latitude to account for 80 percent of Earth’s total landmass.Known Issues* Known issues in the NASA SRTM are described in the following publication:Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249Improvements/Changes from Previous Versions* Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED)

A three-dimensional groundwater flow model, MODFLOW-NWT, was developed to simulate saturated groundwater hydrology, streamflow, and groundwater/surface-water interaction within the Colorado Plateau principal aquifer system. The model was used to evaluate and compare the hydrologic responses of groundwater and streamflow to natural and anthropogenic drivers of change between a recent wet period (1982-1999) and drought period (2000-2022) for four headwater subregions in the Upper Colorado River Basin. This child item contains all of the MODFLOW-NWT input and output files for the simulations described in the associated journal article (https://doi.org/10.1016/j.ejrh.2025.102554).

Co-developed surface and subsurface hydrologic models for the Upper Colorado River Basin and the Colorado Plateaus principal aquifer system were used to investigate the drivers of change in hydrologic water budget components during contrasting recent wet (1982–1999) and drought (2000–2022) periods in select headwater subregions of the Upper Colorado River Basin. The hydrologic system was simulated with separate model codes to represent watershed and groundwater hydrology. A Precipitation-Runoff Modeling System (PRMS) model was used to simulate surface and near-surface watershed hydrology of the model area from the plant canopy to the lower limit of the soil zone. A MODFLOW-NWT model was used to simulate streamflow, surface-water/groundwater interactions, and three-dimensional saturated groundwater hydrology. Outputs of recharge, surface runoff, and interflow from the PRMS model were used as inputs to the MODFLOW-NWT model. This data release details the development of these models and contains the model input and output files for each of the models for the simulations described in Tillman and others, 2025 (https://doi.org/10.1016/j.ejrh.2025.102554). This page includes the file 'modelgeoref.txt' that describes the projection, datum, and coordinates of the four corners of the model grid (common to both models) in decimal degrees. The two child items,' Upper Colorado River Basin MODFLOW-NWT Model Application Data', and 'Upper Colorado River Basin Precipitation-Runoff Modeling System (PRMS) Model Application Data' contain the input and output files for each model, descriptions of the model files, and instructions for running the models.

This dataset was produced in by the Delaware Geological survey in cooperation with the US Geological Survey and Delaware Department of Transportation for the purpose of delineating gage basins and performing hydrologic analysis in the Delaware 2020 StreamStats application. These datasets are raster representations of the fundamental dataset layers necessary for the functionality of StreamStats application within the Delaware StreamStats 2020 study area. The StreamStats application provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, get basin characteristics and estimates of flow statistics, and more. The datasets include a study area defined by all HUC12 watersheds flowing into or out of the state of Delaware, which includes portions of HUC08 watersheds 02040202, 02040205, 02040207, 02040303, 02060002, 02060005, 02080109, 02080110, and 02080111.