Aerial photographic analysis of channel narrowing and vegetation expansion in Canyon De Chelly National Monument, Arizona, USA, 1935–2004
Aerial photographic analysis of channel narrowing and vegetation expansion in Canyon De Chelly National Monument, Arizona, USA, 1935–2004
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1935-2004 年美国亚利桑那州谢伊峡谷国家纪念碑河道变窄和植被扩张的航空摄影分析
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发表时间：
2011
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影响因子：
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通讯作者：
D. Cooper
中科院分区：
文献类型：
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作者：
D. Cadol;S. Rathburn;D. Cooper
过去70年的航拍照片显示，Canyon de Chelly国家纪念碑的航道变窄，这与木本植物河岸植被的建立和扩张相吻合，主要是非原生的罗望鱼(Tamarix SSP.)和俄罗斯橄榄(Elaagnus Angustifolia)和本土白杨(Pillius spp.)。使用校正后的航空照片集绘制了6年的峡谷底部木质河岸植被覆盖范围和海峡平面几何形状：1935、1964、1975、1981、1989和2004年。1935年，植被覆盖了不到1%的峡谷底部，海峡呈辫状，平均宽度为91 m。到2004年，峡谷上部75%的河道已经缩小到平均6.5 米宽的一条线，并被河岸植被覆盖，在一些河段，植被覆盖了峡谷底部的45%。开发了一个相对时序指数，该指数将河道和植被面积扩大或缩小的信息合并到一个单一变量中。在峡谷上游，植被建设滞后于河道变窄，而在中下游，植被建设与缩窄同时发生。随着时间的推移，下游河段的面积逐渐缩小，2006年，最下游的河段仍然编织在一起，没有被切割。我们解释这些模式是为了表明河岸植被是对切利峡谷航道形态变化的反应和相互作用，而不是驱动航道变化。版权所有©2010 John Wiley&Sons，Ltd.
Aerial photographs from the past 70 years show narrowing of channels in Canyon de Chelly National Monument, which coincided with the establishment and expansion of woody riparian vegetation, primarily non‐native tamarisk (Tamarix ssp.) and Russian olive (Elaeagnus angustifolia) and native cottonwood (Populus spp.). Rectified air photo sets were used to map the extent of woody riparian vegetation cover in the canyon bottom as well as the channel planform geometry for 6 years: 1935, 1964, 1975, 1981, 1989 and 2004. In 1935, vegetation covered less than 1 per cent of the canyon bottom and the channel was braided and 91 m wide on average. By 2004, the channel in the upper 75% of the canyon had narrowed to a single thread an average of 6.5 m wide and was lined by riparian vegetation, with vegetation covering up to 45% of the canyon bottom in some reaches. A relative timing index was developed that incorporates information from both channel and vegetation area expansion or contraction into a single variable. Vegetation establishment lagged channel narrowing in the upper reaches of the canyons, but narrowing and vegetation establishment occurred simultaneously in the middle and lower reaches. Narrowing progressed downstream through time, and the lowermost reaches remained braided and unincised in 2006. We interpret these patterns to suggest that riparian vegetation is responding to and interacting with changes in the channel morphology of Canyon de Chelly rather than driving channel change. Copyright © 2010 John Wiley & Sons, Ltd.