城市栖息地减少了沿海洪水的影响

随着气候变化的持续, some storm models are predicting an increase in hurricane intensity and an increase in precipitation, 造成洪水和毁灭性的沿海社区, 水质与日常生活.

A new study by re博彩平台ers at UNC-Chapel Hill assessed water quality regulation by flooded landscapes in the upper Neuse River Estuary along the North Carolina coast. They found urban estuarine habitats to be effective at permanently removing nitrogen through denitrification — a natural process that improves water quality.

“Urban landscapes 比如草坪和雨水池 are becoming more common as coastlines develop, so understanding the role they play in maintaining water quality is increasingly important,安妮·斯迈利说, lead re博彩平台er and doctoral student in the 文理学院’ 地球、海洋和环境科学系. Smiley也属于 圣实验室.

“沿海景观是自然栖息地的拼凑, 比如沼泽和森林, 以及城市栖息地. Denitrification capacity and distributions of these landscapes within a floodplain can influence water quality regulation capacity at the watershed scale. 随着沿海发展的继续, it is important to understand the beneficial functions of urban landscapes, 比如草坪和雨水池, 以及自然栖息地的功能, 像沼泽, 在建筑环境的背景下,斯迈利说.

Previous studies have documented effective denitrification in wetlands and oyster reefs, 但本研究侧重于城市和自然景观元素, 比如雨水池, 未开发休憩用地, 森林湿地和潮下沉积物. It also accounted for different storm characteristics such as high-speed sustained winds or high amounts of rainfall, 它们对水化学的影响不同. The team used data from 37 hurricanes that affected the study region ranging from 1996 to 2019.

这项研究的结果发表在 自然灾害与地球系统科学, an EGUsphere 杂志, show that both urban landscapes and natural habitats play an important role in regulating water quality during flooding events, although nitrogen is processed differently due to storm characteristics.

风暴的特点, habitat type and habitat coverage within a storm’s floodplain influence overall contribution to nitrogen removal. Flooded landscapes were less effective at removing nitrogen during high-wind, high-precipitation博彩平台. 在一般情况下, natural habitats 像沼泽 and swamp forests were more effective at removing nitrogen than urban habitats 比如草坪和雨水池.

Although the importance of these urban habitats cannot be discounted, the stormwater pond sampled in this study was part of a restored wetland and likely removes a considerable amount of nitrogen during low-precipitation and low-wind storm events. 沼泽森林, 丰富的洪泛区栖息地, made the largest contribution to removing nitrogen from the water during every type of storm, 使它们成为维持水质的宝贵栖息地.

“These differences in processing suggest that abundance and spatial distributions of these habitats within a floodplain can influence overall nitrogen removal capacity at the watershed scale,斯迈利说. “Understanding nitrogen removal capabilities and limitations of flooded natural coastal habitats as well as those urban landscapes that will become more and more prevalent, will enable us to make informed management decisions to benefit the integrity of our coastal waters.”

“Anne’s work has advanced our understanding of the value of natural systems 像沼泽 in urbanized areas,” 迈克圣, 合著者和教授, director of the UNC Institute for the Environment and chief sustainability officer at Carolina. “This information is already informing land use decisions in North Carolina’s coastal communities and has broad application beyond our state. I am so excited for Anne to have this great paper from her dissertation published in an excellent journal.”

阅读全文 自然灾害与地球系统科学.