Affiliation:
1. Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York
Abstract
Abstract
The northeastern edge of the Bolivian Eastern Cordillera is an example of a tectonically active plateau margin where orographically enhanced precipitation facilitates very high rates of erosion. The topography of the steepest part of the margin exhibits the classic signature of high erosion rates consisting of high-relief V-shaped valleys where landsliding is the dominant process of hillslope erosion and bedrock rivers are incising into the landscape. The authors mapped landslide scars on multitemporal aerial photographs to estimate hillslope erosion rates. Field surveys of landslide scars are used to calibrate a landslide volume versus area relationship. The mapped area of landsliding, in combination with an estimate of the time for landslide scars to revegetate, leads to an erosion rate estimate. The estimated revegetation time, 10–35 yr, is based on analysis of multitemporal aerial photographs and tree rings. About 4%–6% of two watersheds in the region considered were affected by landslides over the last 10–35 yr. This result implies an erosion rate of 9 ± 5 mm yr−1 assuming that 90% of a single landslide reaches the river on average. Classified Landsat Thematic Mapper images show that landslides are occurring at approximately the same rate all across an approximately 40-km-wide swath within the high-relief zones of the cordillera.
Publisher
American Meteorological Society
Subject
General Earth and Planetary Sciences
Reference65 articles.
1. Geomorphic controls on Andean denudation rates.;Aalto;J. Geol.,2006
2. Contemporary uplift and erosion of the Southern Alps, New Zealand.;Adams;Bull. Geol. Soc. Amer.,1980
3. The evolution of the Altiplano-Puna plateau of the Central Andes.;Allmendinger;Annu. Rev. Earth Planet. Sci.,1997
4. A critical evaluation of late Tertiary accelerated uplift rates for the Eastern Cordillera, central Andes of Bolivia.;Anders;J. Geol.,2002
5. Modele cinematique de la zone subandine du coude de Santa Cruz (entre 16 degrees S et 19 degrees S. Bolivie) deduit de la construction de cartes equilibrees. [Kinematic model of the subandean zone of the Santa Cruz Bend (between 16 degrees S and 19 degrees S. Bolivia) deduced from balanced mapping].;Baby;C. R. Acad. Sci., Ser. 2,1993
Cited by
29 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献