Systems Approach. A systems approach to geomorphic and engineering problems must be developed if serious and unforeseen consequences of human actions are to be avoided. The geomorphologist has the long-term perspective of landform change that is needed in meeting and dealing with many engineering and land management programs, and familiarity with the effects of time, landform evolution, and thresholds of instability are critical for prediction of future events and landform responses.
Extreme Events. The effect of extreme events in modifying or conditioning the landscape is a developing field. For example, rainfall-runoff floods and floods from natural-dam failures may be accompanied by massive erosion and sedimentation. A related field is the interdependency of events, as illustrated by the 1980 eruption of Mount St. Helens. The eruption and huge landslide formed several large lakes, and groundwater disruption became the cause of new instability of the natural dam. Sediment eroded from the debris avalanche in the Toutle River valley continues to plague downstream channel capacity, fish habitat, and water quality. A huge and expensive dam will be required to mitigate this problem.
Geographic Information Systems (GISs). The way in which solid-earth science information is used with other kinds of societally important information requires the information-layering capability that is the essence of GISs. The solid-earth scientist has an important role in establishing appropriate standards for the way in which specialized data are used in GISs, as well as to ensure that such information is up to date and of high-quality.
Land Use and Reuse. The effects of geological constraints on land use and reuse will continue to be a significant issue for the future. Society must become a deferential part of the environment, not its master; human actions have profound and far-reaching impacts on the rest of the earth system.
Hazard-Interaction Problems. A shift in perspective is needed from the incrementalism of individual site-specific hazards to the broader systems approach, dealing with single or multiple hazards common to broader physiographic regions. Increasingly, earth scientists, civil engineers, land-use planners, and public officials are noting the existence of interactive natural hazards that occur simultaneously or in sequence and that produce synergistic cumulative impacts that differ from those of their separately acting component hazards.
Detection of Neotectonic Features. Identifying these features, which are key data links to a better understanding of a long-term seismicity, requires geological mapping of each seismically active region of the country. Such assessments are critical to the siting and design of safe facilities that are of critical-performance nature or serve housing-dependent populations (hospitals and schools) and to the establishment of realistic building codes.
Soil Processes and Microbiology. New theories of the relations between microbiology and soil processes, which are important because food production is tied to soil science, can be established with new chemical and instrumental techniques. Large-scale remote sensing can monitor growth patterns on different soil types and enhance land management to preserve our precious soil bank.
Rock-Bearing Capacity. Research on the bearing capacity of the weathered rock zone together with better definition, identification, and classification of strong soil/weak rock could save considerable money, both in design and construction of buildings.
Urban Planning and Underground Space. If we are to unclog our cities with the limited financial resources at hand, planning must start to take into account utilization of the subsurface. The use of underground space is an undeniable necessity of the future, to be undertaken as population centers are redeveloped. There is only so much room on the land, and the prime space must be used for human habitation. With the predicted increase in usage of underground space, new technologies for characterization and sealing of rock fractures against groundwater inflow will become a necessity.
Geophysical Subsurface Exploration. Improved geophysical techniques for subsurface exploration and computer-based methods for data processing offer new opportunities to predict and control human-induced land subsidence. Techniques such as ground-penetrating radar are now commonly used to detect underground cavities, such as caverns and abandoned mines at shallow depths, and seismic tomography is being experimented with to evaluate the conditions of pillars in abandoned mines of such urban areas as Pittsburgh, Birmingham, and Kansas City.
Underground Void Detection. The detection of underground voids by indirect methods needs to be greatly improved. Many subsidence problems are associated with either carbonate-solution caverns or abandoned underground mines, and it is usually