LANDSLIDES ARE THE DOWNSLOPE MOVEMENT OF SOIL AND/OR ROCK UNDER THE INFLUENCE OF GRAVITY WHICH IS AN IMPORTANT GEOMORPHIC PROCESS SCULPTING THE LANDSCAPES BY TRANSPORTING LARGE VOLUMES OF SEDIMENT FROM SLOPES TO CATCHMENTS THROUGH THE FLUVIAL SYSTEM. ANNUALLY LANDSLIDES COST $3.5 BILLION (IN 2005) AND RESULT IN 25 50 CASUALTIES NATIONWIDE. THE MOUNTAINOUS NORTHWESTERN US IS PARTICULARLY PRONE DUE TO HEAVY RAINFALL IN WINTER WHICH RESULTS IN HUNDREDS OF LANDSLIDES AND THE EXPENSE OF FEDERAL AND STATE BUDGETS FOR FIXING RAILWAYS HIGHWAYS AND DAMS. THERE EXISTS AN OBVIOUS LINKAGE BETWEEN TWO DISTINCT GEOHAZARDS (PRECIPITATION AND LANDSLIDES) BUT WHILE THE ANALYSIS OF THESE TWO HAZARDS HAS BEEN THEORETICALLY APPROACHED IT HAS BEEN RATHER FRAGMENTED IN PRACTICE AND HAS LACKED A FULL INTEGRATION OF ALL THE ASSOCIATED DATA. THIS PROJECT AIMS TO CHARACTERIZE THE MAJOR HYDROLOGY-DRIVEN LANDSLIDES IN THE NORTHWESTERN US (WASHINGTON OREGON) AT A LARGE SCALE WITH HIGH RESOLUTION AND ACCURACY USING RADAR REMOTE SENSING TECHNIQUES THE ADVANCED INSAR (INTERFEROMETRIC SYNTHETIC APERTURE RADAR) METHOD TRMM (TROPICAL RAINFALL MEASURING MISSION) PRECIPITATION PRODUCT AND SMAP (SOIL MOISTURE ACTIVE PASSIVE) SOIL MOISTURE. IN OUR STUDY WE WILL BRING THESE FRAGMENTED OBSERVATIONS AND MEASUREMENTS TO A SINGLE FRAMEWORK FOR THE MODELING (E.G. LANDSLIDE AND DEBRIS-FLOW DYNAMICS) OF RAPIDLY ACCELERATING AND SLOWMOVING LANDSLIDES. INSAR TIME-SERIES DISPLACEMENT WITH DENSE SCATTERERS ON THE SLOPE WILL GIVE AN INDICATION OF LANDSLIDE SUSCEPTIBILITY AND HELP CHARACTERIZE THE SLIDE-BODY VOLUME AND BASAL SLIP SURFACE BASED ON GEOMECHANICAL MODELING. PRECIPITATION AND SOIL MOISTURE SENSED FROM SPACE WILL CONTRIBUTE TO CREATING HYDROGEOLOGIC MODELS WITH SOIL PROPERTIES AND TOPOGRAPHIC FEATURES. THESE CRUCIAL PARAMETERS WILL BE PLUGGED INTO STATE-OF-ART LANDSLIDE DYNAMICS MODELS AND THE TRIGGERS THAT CONTROLLED THE INITIAL SLOPE FAILURE THROUGH SLOPE STABILITY ANALYSIS AND ITERATIVE NUMERICAL SIMULATIONS CAN BE IDENTIFIED. THIS STUDY WILL HELP PROVIDE A MORE COMPLETE KNOWLEDGE FOR UNDERSTANDING THE MECHANISMS AND DYNAMICS OF PREVIOUS LANDSLIDES MITIGATING POTENTIAL AND FUTURE LANDSLIDES AND IMPROVING THE CURRENT TECHNIQUES FOR COUPLING OBSERVATION AND MODELING. OUR PROPOSAL RESPONDS DIRECTLY TO THE FOCUS FIELDS OF THIS NASA IDS SOLICITATION THROUGH EXPLORING THE RELATIONSHIP BETWEEN EXTREME PRECIPITATION (HYDROLOGY HAZARD) AND LANDSLIDES (SOLID EARTH HAZARD). OUR PROPOSED RESEARCH WILL ENHANCE OUR UNDERSTANDING ABOUT THE INTER-RELATIONSHIPS BETWEEN TOPOGRAPHIC AND GEOLOGIC SETTINGS HYDROLOGIC FORCES LANDSLIDE MECHANISMS AND KINEMATICS INFERRED FROM TIME-SERIES MEASUREMENTS AND LANDSLIDE MODELING ON A REGIONAL SCALE.