Soil Use - Hydric Soils database

Hydric soils are defined as those soils that are sufficiently wet in the upper part to develop anaerobic conditions during the growing season. The Hydric Soils section presents the most current information about hydric soils. The lists of hydric soils were created by using National Soil Information System (NASIS) database selection criteria that were developed by the National Technical Committee for Hydric Soils. These criteria are selected soil properties that are documented in Soil Taxonomy (Soil Survey Staff, 1999) and were designed primarily to generate a list of potentially hydric soils from the National Soil Information System (NASIS) database. It updates information that was previously published in Hydric Soils of the United States and coordinates it with information that has been published in the Federal Register. It also includes the most recent set of field indicators of hydric soils. The database selection criteria are selected soil properties that are documented in Soil Taxonomy and were designed primarily to generate a list of potentially hydric soils from soil survey databases. Only criteria 1, 3, and 4 can be used in the field to determine hydric soils; however, proof of anaerobic conditions must also be obtained for criteria 1, 3, and 4 either through data or best professional judgment (from Tech Note 1). The primary purpose of these selection criteria is to generate a list of soil map unit components that are likely to meet the hydric soil definition. Caution must be used when comparing the list of hydric components to soil survey maps. Many of the soils on the list have ranges in water table depths that allow the soil component to range from hydric to nonhydric depending on the location of the soil within the landscape as described in the map unit. Lists of hydric soils along with soil survey maps are good off-site ancillary tools to assist in wetland determinations, but they are not a substitute for observations made during on-site investigations.
The list of field indicators of hydric soils — The field indicators are morphological properties known to be associated with soils that meet the definition of a hydric soil. Presence of one or more field indicators suggests that the processes associated with hydric soil formation have taken place on the site being observed. The field indicators are essential for hydric soil identification because once formed, they persist in the soil during both wet and dry seasonal periods.
The Hydric Soil Technical Notes — Contain National Technical Committee for Hydric Soils (NTCHS) updates, insights, standards, and clarifications.
Users can query the database by State or by Soil Survey Area.
Resources in this dataset:Resource Title: Website Pointer to Hydric Soils . File Name: Web Page, url: https://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/use/hydric/ Includes description of Criteria, Query by State or Soil Survey Area, national Technical Committee for Hydric Soils. Technical Notes, and Related Links.
Report Metadata:

* Area_Symbol: A symbol that uniquely identifies a single occurrence of a particular type of area (e.g. Dane Co., Wisconsin is WI025).
* Area_Name: The name given to the specified geographic area.
* mukey: A non-connotative string of characters used to uniquely identify a record in the Mapunit table.
* Mapunit_SYM: The symbol used to uniquely identify the soil mapunit in the soil survey.
* Mapunit_Name: Correlated name of the mapunit (recommended name or field name for surveys in progress).
* Comp_Name_phase: Component name - Name assigned to a component based on its range of properties. Local Phase - Phase criterion to be used at a local level, in conjunction with "component name" to help identify a soil component.
* muacres: The number of acres of a particular mapunit.
* Comp_RV_Pct: The percentage of the component of the mapunit.
* majcompflag: Indicates whether or not a component is a major component in the mapunit.
* Comp_Acres: The number of acres of a particular component in a mapunit. ((muacres*comppct_r)/100)
* Comp_Landform: A word or group of words used to name a feature on the earth's surface, expressed in the plural form. Column Physical
* Hydric_Rating: A yes/no field that indicates whether or not a map unit component is classified as a "hydric soil". If rated as hydric, the specific criteria met are listed in the Component Hydric Criteria table.
* Hydric_criteria: Criterion code for the soil characteristic(s) and/or feature(s) that cause the map unit component to be classified as a "hydric soil." These codes are the paragraph numbers in the hydric soil criteria publication.

Criteria:

1. All Histels except Folistels and Histosols except Folists; or
2. Map unit components in Aquic suborders, great groups, or subgroups, Albolls suborder, Historthels great group, Histoturbels great group, or Andic, Cumulic, Pachic, or Vitrandic subgroups that:
a. Based on the range of characteristics for the soil series, will at least in part meet one or more Field Indicators of Hydric Soils in the United States, or
b. Show evidence that the soil meets the definition of a hydric soil;
3. Map unit components that are frequently ponded for long duration or very long duration during the growing season that:
a. Based on the range of characteristics for the soil series, will at least in part meet one or more Field Indicators of Hydric Soils in the United States, or
b. Show evidence that the soil meets the definition of a hydric soil; or
4. Map unit components that are frequently flooded for long duration or very long duration during the growing season that:
a. Based on the range of characteristics for the soil series, will at least in part meet one or more Field Indicators of Hydric Soils in the United States, or
b. Show evidence that the soils meet the definition of a hydric soil.

沼泽土壤被界定为在生长季节上层土壤湿度充足，从而形成厌氧环境的土壤。本节沼泽土壤部分展示了关于沼泽土壤的最新信息。沼泽土壤清单系基于国家土壤信息系统（NASIS）数据库的筛选标准编制而成，该标准由国家沼泽土壤技术委员会制定。这些标准是《土壤分类学》（Soil Survey Staff, 1999）中记载的土壤属性，旨在主要从国家土壤信息系统（NASIS）数据库中生成潜在沼泽土壤清单。本清单更新了先前在《美国沼泽土壤》中发布的信息，并与《联邦登记》中发布的信息相协调。此外，还包括了最新的沼泽土壤现场指标。数据库筛选标准是《土壤分类学》中记载的土壤属性，旨在主要从土壤调查数据库中生成潜在沼泽土壤清单。在现场确定沼泽土壤时，仅可使用标准1、3和4；然而，对于标准1、3和4，还必须通过数据或最佳专业判断（根据技术笔记1）来获取厌氧条件的证明。这些选择标准的主要目的是生成一组可能符合沼泽土壤定义的土壤图单元成分清单。在将沼泽成分清单与土壤调查图进行比较时，必须谨慎行事。清单中的许多土壤在地下水位深度范围内，土壤成分可能从沼泽土壤到非沼泽土壤变化，具体取决于土壤在图单元中的位置。沼泽土壤清单以及土壤调查图是良好的现场辅助工具，有助于湿地确定，但不能替代现场调查时的观察结果。

沼泽土壤现场指标清单——现场指标是已知与符合沼泽土壤定义的土壤相关的形态学属性。一个或多个现场指标的存在表明，与沼泽土壤形成相关的过程已在该观察地点发生。现场指标对于沼泽土壤识别至关重要，因为一旦形成，它们在湿季和干季期间都会在土壤中持续存在。

沼泽土壤技术笔记——包含国家沼泽土壤技术委员会（NTCHS）的更新、见解、标准和阐明。

用户可以通过州或土壤调查区域查询数据库。

本数据集包含的资源：
资源标题：沼泽土壤网站指针
文件名：网页，url：https://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/use/hydric/
包含标准描述、按州或土壤调查区域查询、国家沼泽土壤技术委员会技术笔记和相关链接。
报告元数据：
* 地区符号：唯一标识特定类型区域单个发生的符号（例如，威斯康星州的达内县为WI025）。
* 地区名称：指定地理区域的名称。
* mukey：用于唯一标识Mapunit表中记录的非含蓄字符串。
* Mapunit_SYM：用于唯一标识土壤调查中土壤图单元的符号。
* Mapunit_Name：与图单元相关的名称（推荐名称或正在进行调查的现场名称）。
* Comp_Name_phase：成分名称——基于其属性范围分配给成分的名称。本地阶段——在“成分名称”的基础上用于本地级别的阶段标准，以帮助识别土壤成分。
* muacres：特定图单元的英亩数。
* Comp_RV_Pct：图单元成分的百分比。
* majcompflag：指示成分是否是图单元中的主要成分。
* Comp_Acres：图单元中特定成分的英亩数。（（muacres*comppct_r）/100）
* Comp_Landform：用于命名地球表面特征的单词或单词组，以复数形式表达。
* Hydric_Rating：是/否字段，指示图单元成分是否被归类为“沼泽土壤”。如果被评定为沼泽土壤，则满足的具体标准列在“成分沼泽土壤标准”表中。
* Hydric_criteria：导致图单元成分被归类为“沼泽土壤”的土壤特征（和/或特征）的标准代码。这些代码是沼泽土壤标准出版物中的段落编号。

标准：
1. 所有Histels除Folistels和Histosols除Folists；或
2. 在Aquic亚序、大组或亚组、Albolls亚序、Historthels大组、Histoturbels大组或Andic、Cumulic、Pachic或Vitrandic亚组中的图单元成分：
a. 根据土壤系列的特性范围，至少部分符合美国沼泽土壤的至少一个现场指标，或
b. 显示土壤符合沼泽土壤定义的证据；
3. 在生长季节期间频繁积水或长时间积水的图单元成分：
a. 根据土壤系列的特性范围，至少部分符合美国沼泽土壤的至少一个现场指标，或
b. 显示土壤符合沼泽土壤定义的证据；或
4. 在生长季节期间频繁洪水或长时间洪水的图单元成分：
a. 根据土壤系列的特性范围，至少部分符合美国沼泽土壤的至少一个现场指标，或
b. 显示土壤符合沼泽土壤定义的证据。