The Houston-Galveston Area Council of Governments (HGAC) encompasses over 12,000 square miles of southeast Texas (fig. 1). It is an area undergoing rapid development and population growth due to the presence of vast agricultural, mineral, and energy resources, expanding industrial activity, and diverse recreational areas.

Cracked pavements, undulating road surfaces, broken curbs, stairstep fractures of brick and stone building walls, and tilted power poles are common occurrences in areas underlain by cracking, expansive clay soils of the Vertisol order.

The Canyon Group (Missourian Series) is a sequence of westward-dipping, genetically related carbonate and terrigenous clastic facies that crop out in a northeast-southwest belt across North-Central Texas. The section includes stratigraphic units between the base of the Palo Pinto Limestone and the top of the Home Creek Limestone.

Historical monitoring along Brazos and south Padre Islands records the nature and magnitude of changes in position of the shoreline and vegetation line and provides insight into the factors affecting those changes.