Rex Baum
Rex works as a research geologist in the Landslide Hazards Program of the U.S. Geological Survey. He is currently the chief of the Landslide Initiation Processes and Probability Project.
Biography
While at the USGS Rex has conducted research on landslide processes, monitoring, forecasting and warning, and hazards in the Colorado Plateau, Colorado Front Range, southern Rocky Mountains, southwest Ohio, central California, Hawaii, the Pacific Northwest, Puerto Rico, Poland, and El Salvador, Central America.
Science and Products
Sitka, AK
On August 18, 2015, heavy rainfall triggered around 60 landslides in and around the city of Sitka, AK. The landslides moved downslope rapidly; several were damaging and one of these demolished a home on South Kramer Avenue killing three people.
Preliminary Landslide Susceptibility Maps and Data for Hawaii
Landslide Susceptibility Data and Maps provide tools for hazard assessment prior to an event that may cause landslides.
Seattle Area, Washington
Monitoring at this site is for researching rainfall thresholds for forecasting landslide potential. Shallow landslides are common on coastal bluffs overlooking Puget Sound.
Portland, Oregon
Landslides in the West Hills of Portland pose a hazard to people and property.
Millicoma Meander, Elliott State Forest, Oregon
The USGS and its cooperators have installed instruments in a steep, recently clear-cut basin in the Elliott State Forest.
Knife Ridge, Elliott State Forest, Oregon
The USGS and its cooperators have installed instruments in a steep hillside about 20 km southeast of Reedsport in the Elliott State Forest.
Landslides Can Cause More Landslides
Release Date: MAY 15, 2018
The deadliest individual landslides in the U.S. recently were in places where there had previously been a landslide. Why do landslides happen in the same place instead of on nearby slopes that appear to be just as likely, if not more likely, to slide?
Integrating Disparate Spatial Datasets from Local to National Scale for Open-Access Web-Based Visualization and Analysis: A Case Study Compiling U.S. Landslide Inventories
Spatial data on landslide occurrence across the U.S. varies greatly in quality, accessibility, and extent. This problem of data variability is common across USGS Mission Areas; it presents an obstacle to developing national-scale products and to identifying areas with relatively good/bad data coverage. We compiled available data of known landslides into a national-scale, searchable online map...
Reconstruction of an Avalanche: The West Salt Creek Rock Avalanche
Release Date: MAY 25, 2016
The West Salt Creek Rock Avalanche, Colorado, May 25, 2014
Incorporating the effects of complex soil layering and thickness local variability into distributed landslide susceptibility assessments
Incorporating the influence of soil layering and local variability into the parameterizations of physics-based numerical models for distributed landslide susceptibility assessments remains a challenge. Typical applications employ substantial simplifications including homogeneous soil units and soil-hydraulic properties assigned based only on...
Fusco, F.; Mirus, Benjamin B.; Baum, Rex L.; Calcaterra, D.; De Vita, P. Rapid sensitivity analysis for reducing uncertainty in landslide hazard assessments
One of the challenges in assessing temporal and spatial aspects of landslide hazard using process-based models is estimating model input parameters, especially in areas where limited measurements of soil and rock properties are available. In an effort to simplify and streamline parameter estimation, development of a simple, rapid approach to...
Baum, Rex L. Landslides across the United States: Occurrence, susceptibility, and data limitations
Detailed information about landslide occurrence is the foundation for advancing process understanding, susceptibility mapping, and risk reduction. Despite the recent revolution in digital elevation data and remote sensing technologies, landslide mapping remains resource intensive. Consequently, a modern, comprehensive map of landslide occurrence...
Mirus, Benjamin B.; Jones, Eric S.; Baum, Rex L.; Godt, Jonathan W.; Slaughter, Stephen Lee; Crawford, Matthew; Lancaster, Jeremy T.; Stanley, Thomas; Kirschbaum, Dalia; Burns, William J.; Schmitt, Robert G.; Lindsey, Kassandra O; McCoy, Kevin Physically based estimation of rainfall thresholds triggering shallow landslides in volcanic slopes of southern Italy
On the 4th and 5th of March 2005, about 100 rainfall-induced landslides occurred along volcanic slopes of Camaldoli Hill in Naples, Italy. These started as soil slips in the upper substratum of incoherent and welded volcaniclastic deposits, then evolved downslope according to debris avalanche and debris flow mechanisms. This specific case of slope...
Fusco, F.; De Vita, P.; Mirus, Benjamin B.; Baum, Rex L.; Allocca, V.; Tufano, R.; Calcaterra, D. Constraining parameter uncertainty in modeling debris-flow initiation during the September 2013 Colorado Front Range storm
The occurrence of debris flows during the September 2013 northern Colorado floods took the emergency management community by surprise. The September 2013 debris flows in the Colorado Front Range initiated from shallow landslides in colluvium. Most occurred on south- and east-facing slopes on the walls of steep canyons in crystalline rocks and on...
Baum, Rex L.; Scheevel, C.R.; Jones, Eric S. Bayesian analysis of the impact of rainfall data product on simulated slope failure for North Carolina locations
In the past decades, many different approaches have been developed in the literature to quantify the load-carrying capacity and geotechnical stability (or the Factor of Safety, F_s) of variably saturated hillslopes. Much of this work has focused on a deterministic characterization of hillslope stability. Yet, simulated F_s values are subject to...
Yatheendradas, Soni; Kirschbaum, Dalia; Nearing, Grey; Vrugt, Jasper A.; Baum, Rex L.; Wooten, Rick; Lu, Ning; Godt, Jonathan W. Field and laboratory hydraulic characterization of landslide-prone soils in the Oregon Coast Range and implications for hydrologic simulation
Unsaturated zone flow processes are an important focus of landslide hazard estimation. Differences in soil hydraulic behavior between wetting and drying conditions (i.e., hydraulic hysteresis) may be important in landslide triggering. Hydraulic hysteresis can complicate soil hydraulic parameter estimates and impact prediction capability. This...
Ebel, Brian A.; Godt, Jonathan W.; Lu, Ning; Coe, Jeffrey A.; Smith, Joel B.; Baum, Rex L. Integrating real-time subsurface hydrologic monitoring with empirical rainfall thresholds to improve landslide early warning
Early warning for rainfall-induced shallow landsliding can help reduce fatalities and economic losses. Although these commonly occurring landslides are typically triggered by subsurface hydrological processes, most early warning criteria rely exclusively on empirical rainfall thresholds and other indirect proxies for subsurface wetness. We explore...
Mirus, Benjamin B.; Becker, Rachel E.; Baum, Rex L.; Smith, Joel B.
THRESH—Software for tracking rainfall thresholds for landslide and debris-flow occurrence, user manual
Precipitation thresholds are used in many areas to provide early warning of precipitation-induced landslides and debris flows, and the software distribution THRESH is designed for automated tracking of precipitation, including precipitation forecasts, relative to thresholds for landslide occurrence. This software is also useful for analyzing...
Baum, Rex L.; Fischer, Sarah J.; Vigil, Jacob C.
Results of hydrologic monitoring of a landslide-prone hillslope in Portland’s West Hills, Oregon, 2006–2017
The West Hills of Portland, in the southern Tualatin Mountains, trend northwest along the west side of Portland, Oregon. These silt-mantled mountains receive significant wet-season precipitation and are prone to sliding during wet conditions, occasionally resulting in property damage or casualties. In an effort to develop a baseline for...
Smith, Joel B.; Godt, Jonathan W.; Baum, Rex L.; Coe, Jeffrey A.; Ellis, William L.; Jones, Eric S.; Burns, Scott F. Hydrologic impacts of landslide disturbances: Implications for remobilization and hazard persistence
Landslides typically alter hillslope topography, but may also change the hydrologic connectivity and subsurface water-storage dynamics. In settings where mobile materials are not completely evacuated from steep slopes, influences of landslide disturbances on hillslope hydrology and susceptibility to subsequent failures remain poorly characterized...
Mirus, Benjamin B.; Smith, Joel B.; Baum, Rex L.
Results of hydrologic monitoring on landslide-prone coastal bluffs near Mukilteo, Washington
A hydrologic monitoring network was installed to investigate landslide hazards affecting the railway corridor along the eastern shore of Puget Sound between Seattle and Everett, near Mukilteo, Washington. During the summer of 2015, the U.S. Geological Survey installed monitoring equipment at four sites equipped with instrumentation to measure...
Smith, Joel B.; Baum, Rex L.; Mirus, Benjamin B.; Michel, Abigail R.; Stark, Ben
