مورد إلكتروني
Network dynamics and origin of anastomosis, upper Columbia River, British Columbia, Canada.
| العنوان: | Network dynamics and origin of anastomosis, upper Columbia River, British Columbia, Canada. |
|---|---|
| المؤلفون: | Haas, T. de |
| بيانات النشر: | Utrecht University 2010 |
| تفاصيل مُضافة: | Kleinhans, M.G. (Thesis Advisor) |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | The upper Columbia River is an anastomosing river. Anastomosing rivers consist of a network of channels enclosing floodbasins. The factors that determine the configuration of river networks such as the upper Columbia River are unknown. Additionally the origin of anastomosing rivers is unclear. Two main theories exist on the origin of anastomosis; Nanson and Knighton (1996) state that it is hydraulically more efficient to transport flow and sediment in multiple channels instead of a single channel, for rivers that are unable to adjust their slope. Makaske (2001) states that frequent avulsion and/or slow abandonment of old channels leads to continuing coexistence of multiple channels. The Nanson and Knighton (1996) hypothesis on the origin of anastomosis implicates that anastomosis is an equilibrium channel pattern, whereas Makaske (2001) states that it is a disequilibrium channel pattern. The aim of this research was to explain the network dynamics and origin of anastomosis in the upper Columbia River. Field measurements were performed in the upper Columbia River to collect model input and to test model concepts. A river network model was developed to address the factors that determine the configuration of river networks, and to test the current hypotheses on the origin of anastomosis. The discharge distribution through a river network is mainly determined by the network topology. Additionally, the bifurcation (morpho)dynamics affect the discharge distribution through a river network. The bifurcation dynamics are determined by downstream slope differences between bifurcates, upstream bend effect and amount of downstream confluences and bifurcations. When a constant Chézy roughness is assumed to represent bed roughness, it is more efficient to transport flow and sediment in multiple channels than in a single channel. When a constant Nikuradse roughness length is assumed to represent bed roughness, it is more efficient to transport flow and sediment in a single channel |
| مصطلحات الفهرس: | Master Thesis, Student Thesis |
| URL: | |
| الإتاحة: | Open access content. Open access content CC-BY-NC-ND Open Access |
| ملاحظة: | English |
| أرقام أخرى: | QGJ oai:studenttheses.uu.nl:20.500.12932/6162 https://studenttheses.uu.nl/handle/20.500.12932/6162 1362664929 |
| المصدر المساهم: | UNIVERSITEIT UTRECHT From OAIster®, provided by the OCLC Cooperative. |
| رقم الأكسشن: | edsoai.on1362664929 |
| قاعدة البيانات: | OAIster |
| الوصف غير متاح. |