Eno River Discharge and Flashiness Time Series (1964-2020)

Riverine flooding creates hazardous conditions for surrounding communities that can threaten lives and property. Flood inundation modeling for communities is limited due to the tremendous amount of time and money required to generate a hydraulic model. Therefore, decision-makers tend to rely on FEMA (Federal Emergency Management Agency) flood maps for information about flooding and related hydrological hazards. FEMA flood maps offer guidance about areas at risk of flooding based on historic stream gauge information; however, these maps are not regularly updated with recent changes to stream morphology, watershed land cover conditions, precipitation characteristics, or river discharge. The evaluation of the river flashiness can provide some awareness of how the modification of land cover within a watershed by removing vegetation, sediment, or the addition of impervious surfaces can impact a river flow. Increasing the rate of erosion and flashiness in a moving body of water can negatively impact downstream. Running an assessment on a watershed flashiness before any form of development involving removing vegetation and increased runoff could be beneficial to state and local regulators. By evaluating 57 years of United States Geological Survey discharge data for the Eno, the current study found an increasing trend in river flashiness for the Eno River. Additional evidence suggests this could be cause by slight changes in land cover and precipitation. Such outcomes are of concern for downstream communities where increased river flashiness serves as a proxy for increased flash floor potential. Furthermore, the outcome reported provide immortal hydrological information as decision makers plan for future development in the Eno River Watershed.

河流洪水对周边社区构成了危险的环境，可能威胁生命和财产安全。由于生成水力模型所需的时间和金钱巨大，社区层面的洪水淹没模拟受到限制。因此，决策者倾向于依赖联邦紧急事务管理局（FEMA）的洪水图来获取有关洪水及相关水文危害的信息。FEMA洪水图基于历史河流水位计信息提供洪水风险区域的指导；然而，这些地图并未定期更新以反映河流形态、流域土地覆盖条件、降水特征或河流径流的最新变化。对河流易发性进行评估，可以提供一些关于通过移除植被、沉积物或增加不透水表面等方式改变流域内土地覆盖对河流流量的影响的认识。增加流动水体中侵蚀速率和易发性的趋势可能对下游造成负面影响。在涉及移除植被和增加径流的任何形式的发展之前，对流域易发性进行评估可能对州和地方监管机构有益。通过对美国地质调查局57年的Eno河径流数据进行评估，本研究发现Eno河的河流易发性呈上升趋势。进一步的证据表明，这可能是由土地覆盖和降水的小幅变化引起的。这些结果对下游社区构成关注，因为河流易发性的增加被视为洪水位潜力增加的替代指标。此外，所报告的结果为决策者在规划未来Eno河流域发展提供了永恒的水文信息。