Downstream Geomorphic Impacts of Large Dams on American Rivers

亚利桑那州立大学 这项调查的目的是检查大坝对国家河流下游的影响。 特别是，PI希望开发新的知识，大坝的安装和运行如何影响河道和河岸环境的特点。 具体问题包括与大坝规模和工程特性以及运行规则有关的下游水流功率的时间和空间分布。此外，河流功率分布的地理影响将从渠道宽度，河漫滩尺寸，渠道模式和近渠道地貌，河岸生态系统的空间分布的角度进行评估。 该战略是比较目前的条件下，实验河段已受到大坝附近的类似控制河段，没有这样的结构，在该国最大的42个大坝的影响。 调查方法侧重于使用统计技术对径流数据进行水文分析，使用地理信息系统对航空摄影图像进行地理分析，以及进行实地调查以收集沉积物和植被数据。 该项目将推进目前蓄水河流的河流理论，因为这种理论尚处于起步阶段，不包括对大坝水文和地貌影响范围的概括。 从应用的角度来看，这项工作将提供有关河流对关键栖息地影响的新信息。

Arizona State University The objective of this investigation is to examine the downstream impacts of large dams on the nation's rivers. In particular the PI wishes to develop new knowledge about how dam installation and operation have affected the characteristics of river channels and riparian environments. Specific questions include the temporal and spatial distributions of stream power downstream in relation to scale and engineering characteristics of dams, as well as, operating rules. In addition the geographic effects of distributions of stream power will be assessed from the perspectives of channel width, flood plain dimensions, channel patterns and near channel landforms, and spatial distributions of riparian ecosystems. The strategy is to compare present conditions on experimental river reaches that have been impacted by dams with nearby similar control reaches that are without such structures for up to 42 of the largest dams in the country. Methods of investigation focus on hydrologic analyses of streamflow data using statistical techniques, geographic analyses of aerial photographic images using GIS, and field investigations to collect sediment and vegetation data. The project will advance present fluvial theory for impounded rivers for such theory is in its infancy and does not include generalizations about the range of hydrologic and geomorphic impacts of dams. From an applied perspective the work will provide new information on the effect of rivers on critical habitat.