Geomorphic Impacts of the 2013 Colorado Front Range Flood on Black Canyon Creek and North Fork Big Thompson River

In September 2013, the Colorado Front Range experienced a five-day storm that brought record-breaking precipitation to the region. As a consequence, many Front Range streams experienced flooding, leading to erosion, debris flows, bank failures and channel incision. I compare the effects that debris flows and flooding have on the channel bar frequency, frequency and location of wood accumulation, and on the shape and size of the channel along two flood impacted reaches located near Estes Park and Glen Haven, Colorado within Rocky Mountain National Park and Arapaho-Roosevelt National Forest: Black Canyon Creek (BCC) and North Fork Big Thompson River (NFBT). The primary difference between the two study areas is that BCC was inundated by multiple debris flows, whereas NFBT only experienced flooding. Fieldwork consisted of recording location and size of large wood and channel bars and surveying reaches to produce cross-sections. Additional observations were made on bank failures in NFBT and the presence of boulders in channel bars in BCC to determine sediment source. The debris flow acted to scour and incise BCC causing long-term alteration. The post-flood channel cross-sectional area is as much as 7 to 23 times larger than the pre-flood channel, caused by the erosion of the channel bed to bedrock and the elimination of riparian vegetation. Large wood was forced out of the stream channel and deposited outside of the bankfull channel. Flooding in NFBT caused bank erosion and widening that contributed sediment to channel bars, but accomplished little stream-bed scour. As a result, there was relatively little damage to mid-channel and riparian vegetation, and most large wood remained within the wetted channel.

Negotiating proximity:expert testimony and collective memory in the trials of environmental activists in France and the United Kingdom

This article analyzes the role of expert witness testimony in the trials of social movement actors, discussing the trial of the "Kingsnorth Six" in Britain and the trials of activists currently mobilising against airport construction at Notre Dame des Landes in western France. Though the study of expert testimony has so far overwhelmingly concentrated on fact-finding and admissibility, the cases here reveal the importance of expert testimony not simply in terms of legal argument, but in "moral" or political terms, as it reflects and constitutes movement cognitive praxis. In the so-called climate change defence presented by the Kingsnorth Six, I argue that expert testimony attained a "negotiation of proximity," connecting different types of contributory expertise to link the scales and registers of climate science with those of everyday understanding and meaning. Expert testimony in the trials of activists in France, however, whilst ostensibly able to develop similar bridging narratives, has instead been used to construct resistance to the airport siting as already proximate, material, and embedded. To explain this, I argue that attention to the symbolic, as well as instrumental, functions of expert testimony reveals the crucial role that collective memory plays in the construction of both knowledge and grievance in these cases. Collective memory is both a constraint on and catalyst for mobilisation, defining the boundaries of the sayable. Testimony in trials both reflects and reproduces these elements and is a vital explanatory tool for understanding the narrativisation and communication of movement identities and objectives. © 2013 The Author. Law & Policy © 2013 The University of Denver/Colorado Seminary.