2 resultados para West Asia and North Africa

em University of Washington


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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.

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The potential of online learning has long afforded the hope of providing quality education to anyone, anywhere in the world. The recent development of Massive Open Online Courses (MOOCs) heralded an exciting new breakthrough by providing free academic instruction and professional skills development from the world’s leading universities to anyone with the sufficient resources to access the internet. The research in Advancing MOOCs for Development Initiative study was designed to analyze the MOOC landscape in developing countries and to better understand the motivations of MOOC users and afford insights on the advantages and limitations of MOOCs for workforce development outcomes. The key findings of this study challenge commonly held beliefs about MOOC usage in developing countries, defying typical characterizations of how people in resource constrained settings use technology for learning and employment. In fact, some of the findings are so contrary to what has been reported in the U.S. and other developed environments that they raise new questions for further investigation.