Wetland shear strength with emphasis on the impact of nutrients, sediments, and sea level rise's
Wetland shear strength with emphasis on the impact of nutrients, sediments, and sea level rise's
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DOI：
10.1016/j.ecss.2019.106394
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发表时间：
2019-11-30
影响因子：
2.8
通讯作者：
Lane, Robert R.
中科院分区：
文献类型：
--
作者：
Jafari, Navid H.;Harris, Brian D.;Lane, Robert R.
本文介绍了湿地土壤抗剪强度的测量，它可以用来推断营养物质和沉积物对湿地健康的影响进行了全面的审查。整个墨西哥湾和其他沿海系统的生态系统恢复正在增加，与土壤强度相关的管理问题是恢复计划可持续性的最关键问题之一。岩土工程原理的概述作为理解应力、有效应力、孔隙水压力、单位重量和抗剪强度的基本土力学概念的起点。综述了湿地土壤抗剪强度的测定方法，主要介绍了手持式十字板剪切仪、托氏剪切仪、锥形剪切仪和湿地土壤强度测试仪。结果表明，十字板剪切试验可以反映湿地土壤强度在水平和垂直方向上的变化趋势，可以作为湿地土壤强度的一个指标。然而，叶片剪切测量的显著不确定性可能会妨碍在没有进一步测试和校准设备的情况下得出关于剪切强度值的结论。torvane结果显示出相当大的分散性，因此不推荐用于定量剪切强度测量。锥形流量计代表了一种独立于操作员的技术，并提供了高密度的深度测量。它标志着湿地剪切强度测试的实践状态，是测量土壤强度和其他岩土性质（例如，孔隙水压力、土壤湿度、电阻率和温度）。湿地土壤强度测试仪提供了对前15厘米湿地土壤阻力的深入了解，这是地下生物量最多的区域。建议未来的研究包括评估所有原位土壤强度测试方法的不确定性，发展不同的现场仪器之间的关系，并建立一致的统计方法和现场测试程序进行推断和评估。
This paper presents a comprehensive review of shear strength measurements in wetland soils, which can be used to make inferences of the influence of nutrients and sediments on wetland health. Ecosystem restoration is increasing across the Gulf of Mexico and in other coastal systems, with management questions related to soil strength among the most critical to address for the sustainability of restoration programs. An overview of geotechnical engineering principles is provided as a starting point to understand basic soil mechanics concepts of stress, effective stress, pore-water pressure, unit weight, and shear strength. The review of wetland shear strength measurements focuses on the hand-held vane shear, torvane, cone penetrometer, and wetland soil strength tester. This synthesis shows that vane shear measurements can identify the shear strength trend in horizontal and vertical spaces and may be an indicator of wetland soil strength. However, the significant uncertainty of the vane shear measurements may preclude making conclusions about shear strength values without further testing and calibration of the devices. The torvane results show considerable scatter such that it is not recommended for quantitative shear strength measurements. The cone penetrometer represents a technique that is independent of operators and provides a high density of measurements with depth. It signifies the state-of-practice of wetland shear strength testing and is a reasonable tool to measure spatial and temporal variations in soil strength and other geotechnical properties (e.g., pore-water pressure, soil moisture, resistivity, and temperature) in wetlands. The wetland soil strength tester provides insight into the wetland soil resistance in the first 15 cm, which is the zone where most belowground biomass is present. Recommended future research includes evaluating the uncertainty in all in-situ soil strength testing methods, developing relationships between different field instruments, and establishing consistent statistical methods and field-testing procedures to make inferences and assessments.