THE PRIMARY OBJECTIVE OF THIS RESEARCH IS TO DETERMINE HOW AND WHY INTERACTIONS BETWEEN EXTREME PRECIPITATION WILDFIRES EARTHQUAKES AND MASS MOVEMENTS CAN LEAD TO CASCADING EVENTS AND LARGE-SCALE DISASTERS. WE WILL USE MULTIPLE NASA REMOTE SENSING DATA SETS IN CONJUNCTION WITH IN SITU OBSERVATIONS AND ADVANCED HYDROLOGIC AND FLUVIAL MODELING TO TRANSFORM OUR UNDERSTANDING OF THE POTENTIAL TRIGGERING MECHANISMS OF INITIAL MASS MOVEMENT EVENTS AND ASSOCIATED CASCADING HAZARDS. WE WILL INVESTIGATE FOUR STUDY REGIONS IN WESTERN NORTH AMERICA WITH WELL-OBSERVED CASCADING HAZARD HISTORIES UTILIZING NASAFUNDED REMOTE SENSING DATA. WE WILL CHARACTERIZE THE HYDROLOGIC COMPONENTS USING GPM/TRMM AND PRECIPITATION GAUGE DATA TO PROVIDE ESTIMATES OF RAINFALL PATTERNS RATES AND INTENSITIES WHILE SMAP AMSR-E AND LAND SURFACE MODEL OUTPUTS WILL BE USED TO EXAMINE TIME-VARYING SURFACE WETNESS. SWOT PROXIES WILL BE USED TO EXAMINE SURFACE-WATER STORAGE. LANDSAT AND MODIS WILL PROVIDE MEASUREMENTS OF LANDCOVER CHANGE AND WILDFIRE. TOPOGRAPHY DERIVED FROM ASTER AND WORLDVIEW DEMS WILL PROVIDE SURFACE SLOPES SURFACE ROUGHNESS AND TOPOGRAPHIC CHANGE. OPTICAL IMAGERY AND DINSAR WILL BE USED TO ESTIMATE MASS MOVEMENT RATES. AT A LIMITED NUMBER OF LOCATIONS WE WILL EMPLOY LOCAL SURVEYS TO DERIVE FINE-SCALE DETAILS IMPORTANT FOR IDENTIFYING THE PRE-CONDITIONING CAUSAL MECHANISMS OF MASS MOVEMENT. BY INTEGRATING THESE OBSERVATIONS WITH PHYSICALLY-BASED COUPLED HYDROLOGIC MASS MOVEMENT AND HYDRAULIC MODELS WE WILL PARSE OUT THE PRE-CONDITIONING ENVIRONMENTAL FACTORS AND PHYSICAL MECHANISMS THAT RESULT IN CASCADING HAZARDS. IN PARTICULAR WE WILL INVESTIGATE THE INTERACTION OF LARGE PRECIPITATION EVENTS WILDFIRE AND MASS MOVEMENTS IN COLORADO EARTHQUAKES DEBRIS DAMS AND MASS MOVEMENTS IN CALIFORNIA WILDFIRE AND MASS MOVEMENTS IN WASHINGTON STATE AND CLIMATE CHANGE GLACIAL RECESSION AND MASS MOVEMENTS IN SOUTHEASTERN ALASKA. ONCE THE MECHANISMS AND RELATIONSHIPS OF THE INTERACTING HAZARDS AT THE STUDY SITES ARE UNDERSTOOD SUFFICIENTLY THESE RELATIONSHIPS WILL BE UTILIZED IN REGIONAL-SCALE ASSESSMENTS OF HYDROLOGIC AND TOPOGRAPHIC CHARACTERISTICS THAT DIRECTLY IMPACT THE SCALE AND LIKELIHOOD OF MASS MOVEMENT EVENTS AND ASSOCIATED CASCADING HAZARDS. THESE LARGER SIMULATIONS FOR REGIONS IN WESTERN NORTH AMERICA WILL BE VALIDATED AGAINST REGIONAL MASS MOVEMENT INVENTORIES. THE VALIDATION AND SENSITIVITY ANALYSES OF THESE REGIONAL SIMULATIONS WILL PROVIDE IMPORTANT INSIGHTS INTO THE REMOTELY-SENSED MEASUREMENTS OF KEY PHYSICAL PROCESSES THAT GOVERN THE INTERACTIONS BETWEEN THE INDIVIDUAL AND CASCADING HAZARDS AND THE OPTIMAL SPATIAL AND TEMPORAL SCALES FOR THE REMOTE MEASUREMENTS. THE PROPOSED RESEARCH DIRECTLY ADDRESSES THE GOALS OF THE INTERDISCIPLINARY RESEARCH IN EARTH SCIENCE (IDS) SCIENTIFIC AND PROGRAMMATIC SUBELEMENT #3 UNDERSTANDING THE LINKAGES AMONG FLUVIAL AND SOLID EARTH HAZARDS DEFINED AS: (1) TO ADVANCE OUR FUNDAMENTAL UNDERSTANDING ABOUT THE LINKAGE BETWEEN AND AMONG HYDROLOGY AND SOLID EARTH HAZARDS (2) TO DEVELOP PREDICTIVE MODELS THAT IDENTIFY POSSIBLE SOLID EARTH-HYDROLOGY RELATED CASCADING HAZARDS AND ESTIMATE THEIR SCALE SPATIAL MAGNITUDE AND LOCATION (AS APPROPRIATE FOR THE HAZARD) BASED ON THE INITIAL TRIGGER EVENT AND RELEVANT PRECONDITIONING OBSERVATIONS AND (3) TO DEVELOP HYDRO-TOPOGRAPHY SCALING PARAMETERS THAT TRANSFORM OUR UNDERSTANDING OF LOCAL PROCESSES AND ADDRESS REGIONAL AND GLOBAL SEDIMENT TRANSPORT AND MASS WASTING PROCESSES. THE WORK UNDER THIS PROPOSAL WILL USE REMOTE SENSING DATA SETS FROM NASA AND OTHER SOURCES AND ADVANCED HYDROLOGIC AND FLUVIAL MODELING TO BETTER CHARACTERIZE THE INTERACTIONS BETWEEN LARGE MASS MOVEMENTS AND TIMEDEPENDENT PRECIPITATION AND WATER STORAGE PARAMETERS IN CONJUNCTION WITH THE POTENTIAL TRIGGERING FROM EXTREME STORMS EARTHQUAKE AND WILDFIRE AND IDENTIFY THE CRITICAL PARAMETERS AND DATA SCALING IN ORDER TO BETTER QUANTIFY HYDROLOGIC AND SOLID EARTH HAZARDS.