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Erodibility of claypan soils: Identifying erosion mechanisms for sustainable reduction of sediment loss

粘土土壤的侵蚀性：确定可持续减少泥沙流失的侵蚀机制

基本信息

批准号：
1705823
负责人：
Gretchen Sassenrath
金额：
$ 11.41万
依托单位：
Kansas State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2019-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705823&HistoricalAwards=false
关键词：
Erodibility claypan soils Identifying erosion

项目摘要

1705823 (Sassenrath). Claypan soils cover approximately 4 million hectares in the US and are characterized by a highly impermeable layer below the topsoil. This impermeable layer may create lateral flow within the soil matrix that increases the rate of erosion of the topsoil. Surface vegetation increases the erosion resistance at the surface of claypan soils; however, the limited topsoil continues to diminish annually. This research addresses the need to identify the mechanisms that are causing this sediment loss and restore the ecological function of soil and water ecosystems before the topsoil is irretrievably lost.The objective is to test the hypothesis that the impermeable claypan layer is increasing soil erosion by undermining topsoil. This will be achieved by measuring the erodibility and strength of soil samples from areas where soil management practices are identical yet soil loss is variable. The variability has been identified by aerial imagery, terrain analysis, yield maps and surface conductivity measurements. Geotechnical delineation of erodibility will be measured using a variety of geotechnical methodologies, including an Erosion Function Apparatus in the laboratory and a Jet Erosion Test in the field. The primary hypothesis of this research is that topsoil is undergoing undermining erosion within the soil core which is further reducing its shear strength and thus increasing the erodibility. Measured strength and erosion parameters will be used to better predict sediment loss. The research plan has been developed in close collaboration with local landowners. The understanding of the fundamental mechanisms that are resulting in the claypan erodibility phenomena will be shared with landowners so appropriate land use management practices can be developed and implemented. The multidisciplinary leadership team of an agronomist, a geotechnical engineer, and a mass communications specialist will work closely with Extension personnel, conservationists and landowners to address this multifaceted problem and implement change.

1705823（萨森拉特）。在美国，粘土岩土壤覆盖了大约400万公顷，其特征是表层土下面有一层高度不透水的土层。这种不透水层可能会在土壤基质中产生横向流动，从而增加表土的侵蚀速度。地表植被增加了粘土层土壤表面的抗侵蚀能力;然而，有限的表土每年继续减少。这项研究旨在确定导致沉积物流失的机制，并在表土不可挽回地流失之前恢复土壤和水生态系统的生态功能。目的是检验不透水的粘土层通过破坏表土而加剧土壤侵蚀的假设。这将通过测量土壤管理做法相同但土壤流失不同的地区土壤样本的可蚀性和强度来实现。通过航空图像、地形分析、产量图和地表电导率测量确定了变异性。可侵蚀性的岩土工程划定将使用各种岩土工程方法进行测量，包括实验室的侵蚀功能装置和现场的喷射侵蚀试验。本研究的主要假设是，表层土壤正在经历破坏性侵蚀的土壤核心，这是进一步降低其抗剪强度，从而增加可蚀性。测得的强度和侵蚀参数将用于更好地预测泥沙流失。该研究计划是与当地土地所有者密切合作制定的。将与土地所有者分享对导致粘土层可蚀性现象的基本机制的理解，以便制定和实施适当的土地使用管理做法。由一名农学家、一名岩土工程师和一名大众传播专家组成的多学科领导团队将与推广人员、自然资源保护者和土地所有者密切合作，解决这一多方面的问题并实施变革。