Collaborative Research: The effects of river regulation on lateral and integrated longitudinal mass and energy transfers in coupled terrestrial-aquatic systems

合作研究：河流治理对陆地-水生耦合系统中横向和整体纵向质量和能量传递的影响河流和浅层地下水相互连接并持续交换水；河流水暂时通过河床和河岸循环。岸边的横向交换带(LEZ)会影响河流的水质，因为LEZ中的微生物群落会消耗水中的营养物质和溶质。我们对当地LEZ过程如何整合以影响大河的InStream水质知之甚少。在全球范围内，60%的主要河流受到大坝的调节，一些受大坝调节的河流受到周期性(每日)洪水的影响。这项研究将检查和理解受管制河流中的水流和动态生物地球化学状况如何影响通过河流走廊的营养和热能转移。它将有助于理解人类影响的地表-地下水文系统中的生物地球化学过程。通过沿德克萨斯州6级下科罗拉多河90公里段的实地观测，以及通过对InStream和LEZ过程的耦合数值模拟，我们将确定LEZ在洪水/退缩过程中的动态膨胀/收缩如何控制LEZ内的化学反应速率和热传递，以及这如何反过来影响Inream水质和溶质和能量的下游输送。德克萨斯州拥有所有州中最多的水坝，更多的水坝计划作为最近一项为水利基础设施分配资源的州法案的一部分。重要的是要了解河流管理对LEZ过程、地下水和内河水质以及河流生态的权衡和潜在影响。很少有人研究这一点，这项调查将有助于填补这一知识空白。此外，这项研究将培训下一代水文工程师和科学家，并提高公众对河流-地下水相互作用的重要性的认识，特别是在受管制河流的背景下。从K-12、学士、MA/MS到博士水平的学生，以及K-12的教师都将参与研究。将为K-12的学生组织实地考察。将向公众举办外展讲座。

Collaborative Research: The effects of river regulation on lateral and integrated longitudinal mass and energy transfers in coupled terrestrial-aquatic systemsRivers and shallow groundwater are inter-connected and continuously exchange water; river water temporarily circulates through the beds and banks of rivers. The lateral exchange zone (LEZ) in the banks affects instream water quality since microbial communities in the LEZ consume water-borne nutrients and solutes. We know little about how local LEZ processes integrate to impact instream water quality for large rivers. Globally, 60% of major rivers are regulated by dams and some dam-regulated rivers are subject to periodic (daily) floods. This study will examine and understand how flow and dynamic biogeochemical regimes in regulated rivers impact nutrient and thermal energy transfers through the river corridor. It will lead to understanding of biogeochemical processes in human-impacted surface-subsurface hydrologic systems. Through field observations along a 90-km section of the 6-th order Lower Colorado River in Texas and through coupled numerical simulations of instream and LEZ processes, we will determine how the dynamic expansion/contraction of the LEZ during flooding/recession controls chemical reaction rates and heat transfer within the LEZ, and how this in turn impacts instream water quality and downstream delivery of solutes and energy.The study will generate knowledge that is useful for the management of dam-regulated rivers. Texas has the most dams amongst all states with many more planned as part of a recent state bill that allocates resources for water infrastructure. It is critical that the trade-offs and potential effects of river-regulation on LEZ processes, groundwater and instream water quality, and river ecology be understood. This has seldom been studied and this investigation will help fill this knowledge gap. Further, the study will train the next generation of hydrologic engineers and scientists and increase public awareness of the importance of river-groundwater interactions, particularly within the context of regulated rivers. Students from K-12, BS, MA/MS, to PhD level, and K-12 teachers will participate in the research. Field trips to the site will be organized for K-12 students. Outreach lectures will be presented to the public.