CAREER: STOCHASTIC MODELING AND UNCERTAINTY ANALYSIS OF SEDIMENT TRANSPORT IN REGULAR AND EXTREME SURFACE FLOW ENVIRONMENTS

职业：常规和极端地表流环境中泥沙输运的随机建模和不确定性分析

• 批准号: 0748787
• 负责人: Christina Tsai
• 金额: $ 40.79万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0748787&HistoricalAwards=false
• 关键词: CAREER; STOCHASTIC; MODELING; UNCERTAINTY; ANALYSIS

The primary research goals of this CAREER proposal are to characterize the stochastic movement of sediment particles and to scientifically quantify the variation and uncertainty of flow and sediment concentration and transport rate predictions in both regular and extreme flows. The proposed work focuses on examining the applicability of an innovative idea inspired by the 1997 Nobel Prize work on Option Pricing Theory to better describe the stochastic particle jump diffusion process of particles during extreme events. We hypothesize that the displacement of a sediment particle in natural rivers follows a stochastic jump diffusion process consisting of a mean drift term, a driving Wiener process due to flow turbulence, and a jump Poisson process in response to extreme flow events. A physically based 3-D stochastic partial differential equation (SPDE) based model for suspended sediment transport will be developed, which is composed of an innovative stochastic jump diffusion based particle tracking model, a hydrodynamic model using large eddy simulations (LES), and a mass transport equation. The proposed model will be validated against laboratory measurements and existing data. The modified Rosenblueth method will be used to quantify the risk of sedimentation in both regular and extreme event flows. This research project aims to address the following critical issues: (1) How can the spatial and temporal variability of the contributing flow and sediment variables and the uncertainty of the model parameters be effectively quantified in sediment transport modeling? (2) How can statistical characteristics of flow and sediment properties assist in providing a more scientifically based risk assessment and safety factors needed for sedimentation and water quality control? (3) Most of the sedimentation processes occur during the extreme flow events such as floods. How can we incorporate the probability of extreme event occurrences into sediment transport modeling? How can one distinguish the uncertainty sources of sedimentation processes or water pollution during regular flow periods from the extreme flow events?The education goals in this CAREER proposal are three-fold: to stimulate students? learning interest and improve their quantitative skills, to engage students in research and to guide students, particularly women and minority students, in their career development. The PI will improve the quality of education through creative pedagogy changes to teaching and mentorship as a faculty advisor, career consultant and role model. Major educational activities include the use of the ?cognitive discovery teaching and learning? paradigm and the ?simplicity solves complexity? teaching philosophy in quantitative courses, creative and innovative implementation of technology, incorporation of research into teaching, longer-standing recruitment and retention efforts and outreach activities of female and minority students, and student involvement in research.

该CAREER提案的主要研究目标是描述泥沙颗粒的随机运动，并科学地量化常规和极端水流中水流和泥沙浓度以及输沙率预测的变化和不确定性。 建议的工作重点是研究的适用性的创新思想的启发，1997年诺贝尔奖的工作期权定价理论，以更好地描述随机粒子跳跃扩散过程中的粒子在极端事件。我们假设，在天然河流中的泥沙颗粒的位移如下随机跳跃扩散过程组成的平均漂移项，驱动维纳过程，由于流动湍流，和跳跃泊松过程响应于极端流量事件。建立了一个基于物理的三维随机偏微分方程（SPDE）的悬沙输运模型，该模型由基于随机跳跃扩散的颗粒跟踪模型、基于大涡模拟（LES）的水动力模型和质量输运方程组成。将根据实验室测量结果和现有数据验证所提出的模型。 将使用改进的Rosenblueth方法来量化常规和极端事件流中的沉积风险。 本研究旨在解决以下关键问题：（1）如何有效地量化泥沙输移模型中水流和泥沙变量的时空变异性以及模型参数的不确定性？(2)水流和沉积物特性的统计特征如何有助于提供更科学的风险评估和沉积和水质控制所需的安全系数？(3)大多数沉积过程发生在洪水等极端流动事件期间。 我们如何将极端事件发生的概率纳入泥沙输运模型？ 如何区分沉积过程或水污染的不确定性来源在正常流量期间的极端流量事件？这个职业建议的教育目标有三个方面：激励学生？该项目旨在培养学生的学习兴趣，提高他们的量化技能，让学生参与研究，并指导学生，特别是妇女和少数民族学生的职业发展。PI将通过创造性的教学法变化来提高教育质量，并作为教师顾问，职业顾问和榜样进行指导。 主要的教育活动包括使用？认知发现教学和学习？范式和？简单解决复杂？在定量课程中教授哲学，创造性和创新性地实施技术，将研究纳入教学，长期招聘和留住女生和少数民族学生的努力和外联活动，以及学生参与研究。