Chemical and physical approaches are used to study unsaturated flow; however, few studies include an in-depth analysis of data from both approaches. Detailed chemical tracer studies were conducted at a site in the Chihuahuan Desert of Texas, and the results were compared with hydraulic attributes of the system. Estimated soil-moisture fluxes from both chemical and physical approaches were compared to better understand the hydrologic processes in the unsaturated zone.Chemical tracer studies included mass balance of the chloride ion.

Regional and local hydrologic investigations were conducted in Trans-Pecos Texas as part of a study to evaluate potential sites for a low-level radioactive waste repository. The area is approximately 40 mi (65 km) southeast of El Paso in the Hueco Bolson, a fault-bounded desert basin that developed in the late Tertiary. Ground water in the principal study area is found in Hueco Bolson silts and sands at depths of 361 ft (110 m) and 478 ft (146 m), and at depths of 592 ft (180 m) in Cretaceous limestones.

The Plio-Pleistocene hydrocarbon fairway of offshore western Louisiana is restricted to the outer continental shelf and upper continental slope where a thick wedge of nearshore and deep-marine sediments was deposited. Electric logs, paleontological reports, and seismic profiles form the basis for (1) dividing the wedge of Plio-Pleistocene strata into eight genetic sequences, (2) establishing the structural framework, (3) determining the timing of deformation, and (4) mapping the principal depositional systems of the West Cameron and western Garden Banks Areas during the past 5 m.y.