修改银行侵蚀危险指数（BEHI）协议的河岸侵蚀美国俄亥俄州东北部的快速评估
Summary
Streambank erosion potential can be evaluated and ranked using David Rosgen’s Bank Erosion Hazard Index (BEHI), however this protocol has significant limitations. Here we present protocol modifications to address time constraints, allow nonprofessionals to complete accurate assessments, and account for non-alluvial stream conditions in Northeast Ohio.
Abstract
Understanding the source of pollution in a stream is vital to preserving, restoring, and maintaining the stream’s function and habitat it provides. Sediments from highly eroding streambanks are a major source of pollution in a stream system and have the potential to jeopardize habitat, infrastructure, and stream function. Watershed management practices throughout the Cleveland Metroparks attempt to locate and inventory the source and rate the risk of potential streambank erosion to assist in formulating effect stream, riparian, and habitat management recommendations. The Bank Erosion Hazard Index (BEHI), developed by David Rosgen of Wildland Hydrology is a fluvial geomorphic assessment procedure used to evaluate the susceptibility of potential streambank erosion based on a combination of several variables that are sensitive to various processes of erosion. This protocol can be time consuming, difficult for non-professionals, and confined to specific geomorphic regions. To address these constraints and assist in maintaining consistency and reducing user bias, modifications to this protocol include a “Pre-Screening Questionnaire”, elimination of the Study Bank-Height Ratio metric including the bankfull determination, and an adjusted scoring system. This modified protocol was used to assess several high priority streams within the Cleveland Metroparks. The original BEHI protocol was also used to confirm the results of the modified BEHI protocol. After using the modified assessment in the field, and comparing it to the original BEHI method, the two were found to produce comparable BEHI ratings of the streambanks, while significantly reducing the amount of time and resources needed to complete the modified protocol.
Introduction
溪流的侵蚀是一个自然过程;然而，过度的侵蚀悬浮泥沙2的形式，有助于一个显著量的非点源污染。增加悬浮泥沙影响水质，物理和流3的生物学功能。人类的影响会大大影响河岸侵蚀，显著增加输沙量4，特别是在城市系统中有一个增加雨水径流量和不透水表面5。更高的泥沙量能水质和流6的生态系统产生负面影响。整个克利夫兰城市流域管理办法试图找到和库存的来源和潜在的评级侵蚀河岸的风险，以协助有效的管理策略，以及在河流，河岸和栖息地恢复。
大卫乐志勤，与荒地水文，开发银行侵蚀危险指数（BEHI），其计算上的流溪流的侵蚀的敏感性达到基于若干可蚀变量7的组合。 BEHI使用各种指标来排名的严重程度和溪流的侵蚀的可能性，包括银行材料，分层，根系深度和密度，坡度角，所述平滩高度银行高度比，而且表面保护的存在量。所述BEHI评估分配对应于整体BEHI评级（非常低，低，中，高，非常高，或极端），对于特定的河岸的数值。该协议已有效地评估潜在的河岸侵蚀和8-10可以与其他水质和栖息地评估结合使用。 Streambanks表现出高BEHI等级已经显示，以对应于较少多样化和稳定性较差底栖动物群落，为主机会种11。虽然原BEHI方法我兴利，它可以是非常耗时，很难对非专业人士，并限制在特定的地貌区，专为冲积流条件12量身定做。
是必要的，以解决这些限制修改本协议。 “预筛选问卷”（ 图1）的开发，以识别和消除streambanks有可能排名很低或低，从而专注于更高的水土流失面积的评估，并减少了时间和资源来进行BEHI所需的金额评估对整个流。问卷还涉及见于东北俄亥俄冲积和非冲积流条件之间的地质差异，如极度侵蚀基岩页岩13，这将不会被评定为在原有基础上BEHI协议的侵蚀的材料。消除包括平滩阶段研究银行高比度量，其可以是很难确定，允许更快的河岸的评估和对非专业人士来完成与入门培训的评估。这消除了研究银行高比例的是基于由乔拉思在环境质量14的密执安部门制定了修改BEHI程序。消除的必要性在现场额外的计算，所有其它度量表示为除了坡度百分比，以及分层和银行材料调整。根密度最初表达为土壤根，其中根部延伸的组成的百分比。此乘以根深度占整个银行高度;然而，我们换成这种有根在全行密度的简单估算。分数调整是为了解释为消除研究银行高度的比度量和估计的百分比的原始BEHI评分系统进行。如在原始BEHI描述协议所测量的度量被转换为1-10的风险等级（10为风险最高级别）。从1到10的风险评级对应风险非常低，低，中，高，非常高，而极端潜在侵蚀的评级。根据现场观察10的目录建立这些关系。在改性BEHI协议，分数为研究银行高比度量从原始BEHI评分系统中减去，以反映新的总分数和风险评分（ 图2）。这些修改涉及在美国俄亥俄州东北部原BEHI协议的局限性，并协助保持一致性，减少用户的偏见。
改性BEHI协议被用来评估内克利夫兰城市几个高优先级流。原来BEHI评估是由受过训练的克利夫兰景的人员进行，在流的长度，以确认identi修改的有效性fying streambanks与侵蚀率较高。修改后的BEHI协议所使用的专业人士，志愿者，工作人员和学生评价整个克利夫兰城市河岸侵蚀。
Protocol
Representative Results
Discussion
The most critical steps for accurate completion of the modified BEHI protocol are to: correctly identify a uniform section of streambank to assess, if the streambank length has too much variability it is best to separate and assess smaller segments to accurately capture the erodibility of the streambank; complete the Pre-Screening Questionnaire to confirm that a BEHI assessment should be completed on that streambank, if there is uncertainty in whether a bank passes the Pre-Screening Questionnaire, a BEHI assessment shoul…
Offenlegungen
The authors have nothing to disclose.
Acknowledgements
The authors would like to acknowledge the Cleveland Metroparks, including J. Grieser, J. Markowitz, B. Garman, and supporting staff; Case Western Reserve University, Dr. J. Burns; and GLISTEN, the Great Lakes Innovative Stewardship through Education Network.
Materials
| Name of Material/ Equipment | Company | Catalog Number | Comments/Description |
| 200' reel tape measure | Any | N/A | Tape measure can be used to measure bank length and height |
| Inclinometer | Any | N/A | Inclinometer may be used to measure bank angle. |
| GPS | Any | N/A | GPS is used to take points along the stream, make sure for mapping purposes to use a GPS that takes accurate readings. |
| Camera | Any | N/A | Camera is used to take photos of the banks under assessment and of any major stream features. |
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