# Research Areas

## Environmental Geostatistics and Statistics

Geostatistics is a specialized form of statistics that focuses on understanding the spatial distribution of a variable. Geostatistical analysis can provide quantitative estimates of the values of environmental, geological, and hydrological variables at unsampled locations, as well as an assessment of the uncertainty attached to the estimates. Thus, geostatistics can be used to map the probability that the concentration of a contaminant in groundwater, or other medium, exceeds regulatory standards. Geostatistics can be used to design sampling programs that will reduce the uncertainty with which parameters are estimated.

Geostatistics can also be used to provide conditional simulations of hydrogeological parameters, such as hydraulic conductivity, which can then be used as input to fate and transport models to estimate relevant probabilities (e.g., the probability that a plume will reach a specified location in a given period of time). One powerful aspect of geostatistics is that it provides data fusion tools to incorporate secondary data, such as seismic velocities or geophysical well log data, into the estimation and simulation of hydrogeological variables, thus decreasing the level of uncertainty and increasing the efficient use of all relevant data. Example projects include the following:

- Geostatistical Mapping of Contaminated Groundwater at the Hanford Site, Southeast Washington
- Geochemical and Physical Aquifer Property Heterogeneity
- Geostatistical Mapping of Effluent-Affected Sediments off the Coast of Southern California
- Geostatistical Modeling of Subsurface Geology at the Hanford Site, Southeast Washington
- Risk Management and Modeling: Geostatistics and Uncertainty Quantification