DeLong,S.B., Pelletier,J.D. and Arnold,L.(2007): Bedrock landscape development modeling: Calibration using field study, geochronology, and digital elevation model analysis. GSA Bulletin, 119(1/2), 157-173.

『基盤岩の地形発達のモデル化:野外研究・地球年代学・数値標高モデル解析を利用した検定』


Abstract
 Stream power-based models of bedrock landscape development are effective at producing synthetic topography with realistic fluvial-network topology and three-dimensional topography, but they are difficult to calibrate. This paper examines ways in which field observations, geochronology, and digital elevation model (DEM) data can be used to calibrate a bedrock landscape development model for a specific study site. We first show how uplift rate, bedrock erodibility, and landslide threshold slope are related to steady-state relief, hypsometry, and drainage density for a wide range of synthetic topographies produced by a stream power-based planform landscape development model. Our results indicate that low uplift rates and high erodibility result in low-relief, high drainage density, fluvially dominated topography, and high uplift rates and low erodibility leads to high-relief, low drainage density, mass wasting-dominated topography. Topography made up of a combination of fluvial channels and threshold slopes occurs for only a relatively narrow range of model parameters. Using measured values for hypsometric integral, drainage density, and relief, quantitative values of bedrock erodibility can be further constrained, particularly if uplift rates are independently known.
 We applied these techniques to three sedimentary rock units in the western Transverse Ranges in California that have experienced similar climate, uplift, and incision histories. The 10Be surface exposure dating and optically stimulated luminescence (OSL) burial dating data indicated that incision of initially low-relief topography there occurred during the last 〜60 k.y. We estimated the relative dependence of drainage area and channel slope on erosion rate in the stream power law from slope-area data, and inferred values for bedrock erodibility ranging from 0.09 to 0.3 m(0.2〜0.4) k.y.-1 for the rock types in this study area.

Keywords: landscape development; erosion; modeling; DEM; Cuyama Basin』

Introduction
 Previous bedrock landscape development model calibration
Modeling approach
 Characterization of synthetic and real topography
Results: Synthetic landscape development
 Model behavior and classification of model topography
Model calibration: Geological constraints
 Surface exposure dating, burial dating, uplift rate, and model calibration
  10Be surface exposure dating
  OSL burial dating
  Application of geochronology to model calibration
Discussion
 Values of K and relationship between K and U
 Model calibration using real topography
Conclusions
Acknowledgments
References cited


戻る