DRAINAGE NETWORKS AFTER WILDFIRE

Predicting runoff and erosion from watersheds burned by wildfires requires an understanding of the three-dimensional structure of both hillslope and channel drainage networks. We investigate the small- and large-scale structures of drainage networks using field studies and computer analysis of 30-m digital elevation model. Topologic variables were derived from a composite 30-m DEM, which included 14 order 6 watersheds within the Pikes Peak batholith. Both topologic and hydraulic variables were measured in the field in two smaller burned watersheds (3.7 and 7.0 hectares) located within one of the order 6 watersheds burned by the 1996 Buffalo Creek Fire in Central Colorado. Horton ratios of topologic variables (stream number, drainage area, stream length, and stream slope) for small-scale and large-scale watersheds are shown to scale geometrically with stream order (i.e., to be scale invariant). However, the ratios derived for the large-scale drainage networks could not be used to predict the rill and gully drainage network structure. Hydraulic variables (width, depth, cross-sectional area, and bed roughness) for small-scale drainage networks were found to be scale invariant across 3 to 4 stream orders. The relation between hydraulic radius and cross-sectional area is similar for rills and gullies, suggesting that their geometry can be treated similarly in hydraulic modeling. Additionally, the rills and gullies have relatively small width-to-depth ratios, implying sidewall friction may be important to the erosion and evolutionary process relative to main stem channels.

作 者： D. A. KINNER J. A. MOODY   作者單位： U.S. Geological Survey, Box 25046 DFC Mail Stop 966, Denver CO 80225, USA  刊 名： 國(guó)際泥沙研究（英文版）  SCI 英文刊名： INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH  年，卷(期)： 2005 20(3)  分類(lèi)號(hào)： P3  關(guān)鍵詞： Channel network   Steep hillslope drainage network   Wildfire   Gullies   Hydraulic geometry  

【DRAINAGE NETWORKS AFTER WILDFIRE】相關(guān)文章：

Pollen transport in the Shiyang River drainage, arid China04-27

After Work 下班以后05-04

Combined Method of Chaotic Theory and Neural Networks for Water Quality Prediction04-26

畢業(yè)計(jì)劃 Plan After Graduation02-27

A Modified Earthquake Model of Self-Organized Criticality on Small World Networks04-27

「相似詞語(yǔ)辨析「7」after和behind」05-04

Sediment transferring function of the lower reaches of the Yellow River influenced by drainage basin factors and human a04-27

Spurs edge Mavericks, Lakers beat Jazz after overtime05-04

牛津小學(xué)英語(yǔ)5A Unit 7 After school Part A教案04-25

What did you do after university?你畢業(yè)后做了什么05-04