CORRELATING PARAMETERS OF CATCHMENTS AND DISTRIBUTIVE FLUVIAL SYSTEMS AS PREDICTORS OF FAN SHAPE

The development of the Distributive Fluvial System (DFS) model has provided a new approach for predicting facies distributions in continental sedimentary basins other than traditional models based on tributary drainage networks. DFS are now recognized as a dominant sedimentary feature in these basins. Because of their ubiquity, a robust understanding of DFS form is critical for effective natural resource exploration and understanding depositional patterns and facies. The goal of this project, namely the measurement and analysis of key morphological and spatial parameters within DFS and their related contributing drainages, allows identification of possible correlations between hydrologic basin and DFS morphology. This will allow development of more accurate models for predicting DFS shape.

This preliminary study analyzed the morphology of forty fans and their associated drainages in the Owens Valley, California. Parameters of interest were measured in ArcGIS from mosaicked 90 meter resolution digital elevation models, using both proprietary scripts as well as scripts edited and created specifically for this study. A set of thirty-five morphological variables describing linear, areal, and relief parameters were measured from this group of fans. Principal Component Analysis (PCA) was used to determine underlying relationships between the variables.

Initial results suggest correlation between a few key parameters. This opens the possibility of developing a predictive model from them. We note our results also suggest that many parameters currently used to describe drainage systems are inappropriate when applied to DFS. Developing new shape-parameters specific to DFS as well as algorithms that are appropriate to distributive systems may be necessary in order to further develop models for predicting DFS shape in relation to drainage basin morphology.