Coastal wetlands, sea level, and the dimensions of geomorphic resilience
Coastal wetlands, sea level, and the dimensions of geomorphic resilience
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DOI：
10.1016/j.geomorph.2017.03.022
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发表时间：
2017-03
期刊：
影响因子：
3.9
通讯作者：
J. Phillips
中科院分区：
文献类型：
--
作者：
J. Phillips
地貌系统弹性通常被认为是系统结构和相互作用的内在属性，但也与特殊的地点和历史因素有关。地理和历史环境的重要性使得很难对地貌恢复力做出明确的陈述。然而，基于网络的系统结构分析可用于确定基于一般适用关系的动态稳定性（=弹性），并确定稳定或不稳定的情景。这些为评估复原力的地点和历史因素提供了指导方针。基于相对海平面、湿地表面高程、水期、植被和沉积的相互作用，分析了滨海湿地模型。系统通常（但不总是）动态不稳定且无弹性。由于环境因子的梯度以及微地形和植被的斑块分布，沿海湿地景观在稳定性/恢复力以及引发不稳定性的关键关系方面可能存在广泛的局部差异。一个案例研究说明了这一点，在北卡罗来纳州纽斯河河口的两个附近的沿海湿地——水獭溪口和安德森溪——发现了动态不稳定的破碎。两者都没有跟上相对海平面上升的步伐，并且在湿地系统内都表现出不稳定的状态转变；但湿地系统内部存在着局部稳定的关系。
Geomorphic system resilience is often perceived as an intrinsic property of system structure and interactions but is also related to idiosyncratic place and history factors. The importance of geographical and historical circumstances makes it difficult to generate categorical statements about geomorphic resilience. However, network-based analyses of system structure can be used to determine the dynamical stability (= resilience) based on generally applicable relationships and to determine scenarios of stability or instability. These provide guidelines for assessing place and history factors to assess resilience. A model of coastal wetlands is analyzed, based on interactions among relative sea level, wetland surface elevation, hydroperiod, vegetation, and sedimentation. The system is generally (but not always) dynamically unstable and non-resilient. Because of gradients of environmental factors and patchy distributions of microtopography and vegetation, a coastal wetland landscape may have extensive local variations in stability/resilience and in the key relationships that trigger instabilities. This is illustrated by a case study where dynamically unstable fragmentation is found in two nearby coastal wetlands in North Carolina's Neuse River estuary—Otter Creek Mouth and Anderson Creek. Neither is keeping pace with relative sea level rise, and both show unstable state transitions within the wetland system; but locally stable relationships exist within the wetland systems.