Doctoral Dissertation Research: Thermal, Hydraulic, and Geomorphological Dynamics at Stream Confluences

溪流汇流是两条溪流的汇合，既代表着独特的栖息地斑块，也代表着河流景观中的关键运动走廊。尽管特定汇流的水力和热学性质会影响生物群通过它的能力或可能性，但在恢复工作中，汇流通常被忽视，因为它们是水力学和地貌上的复杂和动态系统。博士论文研究项目将寻求促进对河流汇合处存在的热、地貌和水力条件的基本了解，目的是为这些独特重要的河流特征的保护、管理和恢复提供信息。这位博士生将探索以下问题的答案：支流汇流动态如何影响主河道的热生境格局？学生将在配对汇流取样设计中使用尖端分布式温度传感光纤阵列和声学多普勒流剖面仪。本项目将有助于基本理解不同水文条件下河道形态影响汇流处水力和热生境变异性的过程。它将整合溪流汇合处的水力、地貌和热观测，以形成对汇流处影响热生境动态的复杂相互作用的整体理解。所产生的知识将通过以下方式改变对溪流汇流的基本理解：调查小汇流(小支流与大河汇合)、大平原沙层河流的汇流，以及小汇流和大汇流中的热混合模式和相关的热避热栖息地动态。该项目将为政策制定者和公众利益攸关方提供更多的知识，促进关于汇流恢复的基于科学的合作决定。作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立研究生涯。

Stream confluences, the joining of two streams, represent both unique habitat patches and critical movement corridors within a riverscape. Although the hydraulic and thermal nature of a particular confluence influences the ability or likelihood of biota to travel through it, confluences generally have been ignored in restoration efforts because they are hydraulically and geomorphologically complex and dynamic systems. The doctoral dissertation research project will seek to advance basic understanding of the thermal, geomorphological, and hydraulic conditions present at stream confluences with the intention of informing conservation, management and restoration of these uniquely important river features. The doctoral student will explore answers to the question: How do tributary confluence dynamics influence thermal habitat patterns in the main channel? The student will employ cutting-edge distributed temperature sensing fiber optic arrays coupled with acoustic Doppler current profilers in a paired confluence sampling design.This project will contribute to basic understanding of the processes through which channel morphology influences hydraulic and thermal habitat variability at confluences under different hydrologic conditions. It will integrate hydraulic, geomorphic, and thermal observations at stream confluences to form a holistic understanding of the complex interactions the influence thermal habitat dynamics in confluences. The knowledge generated will transform basic understanding of stream confluences by: investigating small confluences (small tributaries joining a large river), confluences on a Great Plains sand-bedded river, and thermal mixing patterns and associated thermal refuge habitat dynamics within both small and large confluences. The project will provide policy makers and public stakeholders with the greater knowledge that will facilitate scientifically based, cooperative decisions regarding confluence restoration. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.