Sites Overview
Our CZO extends over the entire 6th order Christina River Basin (CRB, 1440 km2), from first-order streams to tidal and salt-water marshes in Delaware Bay. It consists of 4 sub-watersheds: White Clay Creek (WCC, 277 km2); Red Clay Creek (RCC, 140 km2); Brandywine Creek (BC, 842 km2); and the tidal Christina River (CR, 202 km2)—that straddle SE Pennsylvania and N Delaware and flow into the Delaware Estuary.
Six Intensive CZO Research Catchments
The impacts of three landuse end-members on hydrological, pedological and geomorphological processes will be studied intensively within three 1st order catchments: mature forest; row crop agriculture; continuous excavation (landfill). In addition, the 3rd order east branch of White Clay Creek will integrate forest and agricultural landuses over a larger scale, and the floodplains and mouths of the two largest tributaries—Brandywine Creek and White Clay Creek—will be intensively studied as large-scale integrators. Explore these sites with our Dynamic Map.
Complementary Research Sites
The Christina River Basin and its four sub-basins may be one of the best studied watersheds of its size in the nation. There are 19 USGS stream/river gauging stations (6 in DE, 13 in PA) and 5 of the PA stations continuously monitor water quality properties (i.e. turbidity, pH, conductivity, dissolved oxygen). Stroud Water Research Center has historically maintained continuous discharge and other datasets at 3 stations. Non-continuous data collected by USGS and Stroud Water Research Center are available for 141 stations. Weather data has been continuously recorded by 5 USGS stations and a NOAA Climate Reference Network station. Explore these sites with our Dynamic Map.
Geology & Landuse
The Christina River Basin transitions from Piedmont into Atlantic Coastal Plain, the two most populated physiographic provinces in America. The human footprint within the region spans centuries and current land covers include mature forest, agriculture, suburbia, urban, commercial and industrial, providing an ideal natural laboratory to study the gradient of human impacts on critical zone processes. A diverse lithology—ranging from micaceous schist and gneiss to quartzite to marble—is overlaid by deep, unglaciatied soils of diverse chemical and physical characteristics—from Entisols to Ultisols to Histosols. Nearly all stream valleys are filled with 1-3+ m of “Legacy Sediment” eroded and deposited during intensive colonial deforestation, agriculture and mill damming. White Clay Creek is the only entire watershed designated within the Wild and Scenic Rivers System.
