Analysis of spatial variability in unsaturated flow is critical to evaluating contaminant transport in areas of focused or preferential flow. This study examined spatial variability at a variety of scales from focused flow through playas to preferential flow in macropores. A total of 39 boreholes from 7 playa and adjacent interplaya settings on the Southern High Plains of Texas were sampled for hydraulic and hydrochemical parameters. To evaluate preferential flow in surficial sediments, we applied bromide and organic dyes.

Changes in shoreline position along the southeastern Texas Gulf coast between 1974 and 1996 were documented by conducting a kinematic real-time differential global positioning system (DGPS) field survey in 1996 and comparing that shoreline with other shorelines archived in a geographic information system. Results show that (1) beach morphology, shoreline movement, and the regional geologic framework are closely interrelated, (2) Gulf beaches are generally retreating, and (3) the rates of retreat have accelerated locally.