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：河流整治对陆水耦合系统中横向和纵向物质和能量转移的影响河流与浅层地下水相互连通并不断交换水分，河水在河床和河岸之间暂时循环。岸边的侧向交换区（LEZ）影响瞬时水质，因为LEZ中的微生物群落消耗水载营养物质和溶质。我们对当地LEZ过程如何整合影响大型河流的瞬时水质知之甚少。在全球范围内，60%的主要河流由大坝调节，一些大坝调节的河流会定期（每天）发生洪水。这项研究将检查和了解如何在受管制的河流流量和动态生态地球化学制度的影响养分和热能转移通过河流走廊。它将导致人类影响的地表-地下水文系统的地球化学过程的理解。通过沿着德克萨斯州6级下科罗拉多河90 km段的实地观测，并通过对洪水和LEZ过程的耦合数值模拟，我们将确定在洪水/衰退期间LEZ的动态膨胀/收缩如何控制LEZ内的化学反应速率和热传递，以及这反过来如何影响瞬时水质和下游溶质和能量的输送。这项研究将产生对大坝调节河流管理有用的知识。德克萨斯州拥有所有州中最多的水坝，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，计划建造更多的水坝。关键是要了解河流治理对低排放区过程、地下水和非恒定水质以及河流生态的权衡和潜在影响。这很少被研究，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-地下水相互作用重要性的认识，特别是在受管制河流的情况下。学生从K-12，BS，MA/MS，到博士水平，和K-12教师将参与研究。将为K-12学生组织实地考察。将向公众举办外联讲座。

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.