Linking process and form on alpine talus cone systems: Colorado Front Range, United States

Process and form are inextricably linked in geomorphic research. Analysis of surface form without some relationship to process provides no insight into landform development. Process studies without consideration of topographic boundary conditions provide little or no predictive power for real world systems. A much greater explanatory power is achieved when form and process are examined together. The current study examines the relationship between geomorphic process, surface form, and particle morphology on alpine talus cone systems in the Colorado Front Range.; Digital terrain data derived from terrestrial laser scanning and Airborne Laser Swath Mapping sources provided an unprecedented resolution for the analysis of talus cone system form. A hierarchical framework of spatial scales is utilized to unravel the complexities associated with process-form relations in the talus cones. Three spatial scales were included in this analysis: the particle scale, the feature scale, and the system scale. The particle scale analyses detected relationships between particle morphology and surface form independent of information regarding geomorphic process. Very few clear relationships were identified at this spatial scale.; At the feature scale, rockfall deposits were characterized by a high degree of topographic complexity at the finest length-scales. The form and particle morphology characteristics of debris flow features suggested the importance of dispersive pressures, yield strength, and material shear strength in producing distinctive forms at this spatial scale. Slushflow features were characterized by forms indicative of relatively high yield strength and low material shear strengths.; At the system scale, the propensity of the source area to produce debris flow, slushflow, or rockfall processes was dependent upon the course area's potential to collect water, store debris, and influence the residence time of stored materials. Large, shallow gradient, well-dissected source areas produced a dominance of flow processes, while small, steep and less dissected source areas produced a dominance of rockfall processes.; The ability to decipher these properties using measurements of form from high-resolution digital elevation data allows researchers to interpret geomorphic processes from terrain data. The use of a conceptual hierarchy of relevant spatial scales elucidated the complex relationship between spatial scale, process, and form evident in talus systems.