Bighorn Canyon National Recreation Area Landscape Context, Raster Data

This zip file contains 21 raster layers representing data from a variety of landscape metrics used to analyze the landscape context of Bighorn Canyon National Recreation Area (BICA). Their names, descriptions and categorization are as follows:

Housing
This raster dataset contains sixteen layers named in the format "bhc1950us," with the name of each layer containing a year representing the decades from 1950 through 2100 (ex. bh1960us, bhc1970us, bhc1980us, etc.). The layers depict housing density classes for the area around the 30 km buffer around and including BICA’s managed lands for each decade. These housing density estimates come from a Spatially Explicit Regional Growth Model (SERGoM, Theobald 2005) based on U.S. Census data from 2010 and depict the location and density of private land housing unit classes around BICA. SERGoM methods combined housing data with information on land ownership and density of major roads (interstates, state highways, and county roads) to provide a more accurate allocation of the location of housing units over the landscape. Details on how SERGoM was used for NPS data can be found in the NPScape Standard Operating Procedure (SOP): Housing Measure at https://irma.nps.gov/DataStore/Reference/Profile/2221576

The SERGoM used historical and current housing density patterns as data inputs to develop a simulation model to forecast future housing density patterns based on county-level population projections. Further details about the methodology of SERGoM can be found at https://www.jstor.org/stable/26267722?seq=2

SERGoM_bhc_metrics:

Value CLASSNAME
0 Private undeveloped
1 < 1.5 units / square km
2 1.5 - 3 units / square km
3 4 - 6 units / square km
4 7 - 12 units / square km
5 13 - 24 units / square km
6 25 - 49 units / square km
7 50 - 145 units / square km
8 146 - 494 units / square km
9 495 - 1,234 units / square km
10 1,235 - 2,470 units / square km
11 > 2,470 units / square km
12 Commercial/industrial

Land Cover
This raster dataset depicts land cover and contains four layers from the National Land Cover Database (NLCD). The names and descriptions of each layer are as follows:

- NLCD2001. The National Land Cover Database 2001 land cover layer for mapping was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. This is a single layer for 2001 landcover data at all levels. Level 2 data for 2001 can be derived from this layer by collapsing level 1 features into level 2 categories. This level 1 layer contains seventeen classes:

Value Land Cover
0 Unknown
11 Open Water
12 Perennial Snow/Ice
21 Developed, Open Space
22 Developed, Low Intensity
23 Developed, Medium Intensity
24 Developed, High Intensity
31 Barren Land
41 Deciduous Forest
42 Evergreen Forest
43 Mixed Forest
52 Shrub/Scrub
71 Herbaceous
81 Hay/Pasture
82 Cultivated Crops
90 Woody Wetlands
95 Emergent Herbaceous Wetlands

NLCD2001 land cover class descriptions:
Open Water - All areas of open water, generally with less than 25% cover or vegetation or soil.
Perennial Ice/Snow - All areas characterized by a perennial cover of ice and/or snow, generally greater than 25% of total cover.
Developed, Open Space - Includes areas with a mixture of some constructed materials, but mostly vegetation in the form of lawn grasses. Impervious surfaces account for less than 20 percent of total cover. These areas most commonly include large-lot single-family housing units, parks, golf courses, and vegetation planted in developed settings for recreation, erosion control, or aesthetic purposes.
Developed, Low Intensity - Includes areas with a mixture of constructed materials and vegetation. Impervious surfaces account for 20-49 percent of total cover. These areas most commonly include single-family housing units.
Developed, Medium Intensity - Includes areas with a mixture of constructed materials and vegetation. Impervious surfaces account for 50-79 percent of the total cover. These areas most commonly include single-family housing units.
Developed, High Intensity - Includes highly developed areas where people reside or work in high numbers. Examples include apartment complexes, row houses and commercial/industrial. Impervious surfaces account for 80 to100 percent of the total cover.
Barren Land - Rock/Sand/Clay; Barren areas of bedrock, desert pavement, scarps, talus, slides, volcanic material, glacial debris, sand dunes, strip mines, gravel pits and other accumulations of earthen material. Generally, vegetation accounts for less than 15% of total cover.
Deciduous Forest - Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75 percent of the tree species shed foliage simultaneously in response to seasonal change.
Evergreen Forest - Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75 percent of the tree species maintain their leaves all year. Canopy is never without green foliage.
Mixed Forest - Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. Neither deciduous nor evergreen species are greater than 75 percent of total tree cover.
Shrub/Scrub - Areas dominated by shrubs; less than 5 meters tall with shrub canopy typically greater than 20% of total vegetation. This class includes true shrubs, young trees in an early successional stage or trees stunted from environmental conditions.
Herbaceous - Areas dominated by graminoid or herbaceous vegetation, generally greater than 80% of total vegetation. These areas are not subject to intensive management such as tilling but can be utilized for grazing.
Hay/Pasture - Areas of grasses, legumes, or grass-legume mixtures planted for livestock grazing or the production of seed or hay crops, typically on a perennial cycle. Pasture/hay vegetation accounts for greater than 20 percent of total vegetation.
Cultivated Crops - Areas used for the production of annual crops, such as corn, soybeans, vegetables, tobacco, and cotton, and also perennial woody crops such as orchards and vineyards. Crop vegetation accounts for greater than 20 percent of total vegetation. This class also includes all land being actively tilled.
Woody Wetlands - Areas where forest or shrub land vegetation accounts for greater than 20 percent of vegetative cover and the soil or substrate is periodically saturated with or covered with water.
Emergent Herbaceous Wetlands - Areas where perennial herbaceous vegetation accounts for greater than 80 percent of vegetative cover and the soil or substrate is periodically saturated with or covered with water.

- Landcover_NaturalConverted_NLCD2011. This layer depicts natural vs. converted land cover circa 2011 and was extracted from the map package NLCD2011_LNC.mpk. This layer contains two classes:

Value Class Name
1 Converted
2 Natural

Natural vs. Converted class descriptions:
Converted - Developed areas, cultivated crops, and hay/pasture lands.
Natural - All other major cover types.

- Landcover_Level1_NLCD2011. This layer was extracted from the map package NLCD2011_Level1.mpk and contains nine classes:

Value Class Name
1 Open Water
2 Developed
3 Barren/Quarries/Transitional
4 Forest
5 Scrubs/Shrub
6 Perennial Ice/Snow
7 Grassland/Herbaceous
8 Agriculture
9 Wetlands

- Landcover_Level2_NLCD2011. This layer was extracted from the map package NLCD2011_Level2.mpk and contains fifteen classes:

Value Class Name
11 Open Water
12 Perennial Ice/Snow
21 Developed, Open Space
22 Developed, Low Intensity
23 Developed, Medium Intensity
24 Developed, High Intensity
31 Barren Land
41 Deciduous Forest
42 Evergreen Forest
43 Mixed Forest
52 Shrub/Scrub
71 Herbaceous
81 Hay/Pasture
82 Cultivated Crops
90 Woody Wetlands
95 Emergent Herbaceous Wetlands

Road Density
- Road_Density. This raster layer depicts road density (km/km2) calculated for all roads in and around the study area (30 km buffer around BICA) as of 2005. This layer was extracted from the map package AllRoads_rdd.mpk.

The map packages mentioned above can be found in the DataStore reference:
Bighorn Canyon National Recreation Area Landscape Context, Map Packages. National Park Service.
https://irma.nps.gov/DataStore/Reference/Profile/2306146>https://irma.nps.gov/DataStore/Reference/Profile/2306146

本压缩包包含21个栅格图层，涵盖用于分析大角峡谷国家游乐区（Bighorn Canyon National Recreation Area, BICA）景观背景的多种景观指数数据。各图层的名称、描述与分类如下：

## 住房
本栅格数据集包含16个以"bhc1950us"为格式命名的图层，每个图层名称中包含代表1950年至2100年各十年的年份（例如bh1960us、bhc1970us、bhc1980us等）。这些图层描绘了BICA管理用地及其周边30公里缓冲区范围内，各十年的住房密度分级。
此类住房密度估算结果源自空间显式区域增长模型（Spatially Explicit Regional Growth Model, SERGoM, Theobald 2005），其数据基础为2010年美国人口普查数据，用于刻画BICA周边私人住房单元的分布与密度。SERGoM方法将住房数据与土地所有权信息、主要道路（州际公路、州道及县道）密度相结合，以更精准地匹配景观中住房单元的分布位置。关于SERGoM应用于美国国家公园管理局（National Park Service, NPS）数据的详细说明，可查阅NPScape标准操作流程（Standard Operating Procedure, SOP）：《住房测度》，链接为https://irma.nps.gov/DataStore/Reference/Profile/2221576。
SERGoM以历史与当前住房密度格局作为输入数据，构建模拟模型以基于县级人口预测数据对未来住房密度格局进行预测。关于SERGoM方法论的更多细节，可访问https://www.jstor.org/stable/26267722?seq=2查阅。

SERGoM_bhc_metrics分级如下：
| 数值 | 类别名称 |
| ---- | ---- |
| 0 | 未开发私人用地 |
| 1 | ＜1.5 单元/平方公里 |
| 2 | 1.5 - 3 单元/平方公里 |
| 3 | 4 - 6 单元/平方公里 |
| 4 | 7 - 12 单元/平方公里 |
| 5 | 13 - 24 单元/平方公里 |
| 6 | 25 - 49 单元/平方公里 |
| 7 | 50 - 145 单元/平方公里 |
| 8 | 146 - 494 单元/平方公里 |
| 9 | 495 - 1,234 单元/平方公里 |
| 10 | 1,235 - 2,470 单元/平方公里 |
| 11 | ＞2,470 单元/平方公里 |
| 12 | 商业/工业用地 |

## 土地覆盖
本栅格数据集包含来自美国国家土地覆盖数据库（National Land Cover Database, NLCD）的4个图层，各图层名称与描述如下：
1. NLCD2001：该2001年土地覆盖制图图层由多分辨率土地特征（Multi-Resolution Land Characteristics, MRLC）联盟开展的合作项目制作，为涵盖全类别的2001年土地覆盖单图层。通过将一级类别合并为二级类别，可由此图层导出2001年二级数据。该一级图层包含17个类别：
| 数值 | 土地覆盖类型 |
| ---- | ---- |
| 0 | 未知 |
| 11 | 开阔水域 |
| 12 | 常年冰雪 |
| 21 | 开发开放空间 |
| 22 | 开发低密度区域 |
| 23 | 开发中密度区域 |
| 24 | 开发高密度区域 |
| 31 | 裸地 |
| 41 | 落叶林 |
| 42 | 常绿林 |
| 43 | 混合林 |
| 52 | 灌丛/灌草地 |
| 71 | 草本植被 |
| 81 | 干草/牧场 |
| 82 | 耕作作物地 |
| 90 | 木本湿地 |
| 95 | 挺水草本湿地 |

NLCD2001土地覆盖类别详细说明：
- 开阔水域：所有开阔水体区域，通常植被或土壤覆盖率低于25%。
- 常年冰雪：以常年冰/雪覆盖为特征的区域，通常总覆盖率超过25%。
- 开发开放空间：包含混合了部分人工构筑物但以植被（如草坪）为主的区域，不透水面占总覆盖率的比例低于20%。此类区域通常包括大面积独栋住宅、公园、高尔夫球场，以及为休闲、水土保持或景观美化目的在开发区域种植的植被。
- 开发低密度区域：包含混合人工构筑物与植被的区域，不透水面占总覆盖率的20%-49%，此类区域通常以独栋住宅为主。
- 开发中密度区域：包含混合人工构筑物与植被的区域，不透水面占总覆盖率的50%-79%，此类区域通常以独栋住宅为主。
- 开发高密度区域：人口或就业高度密集的高度开发区域，例如公寓楼、联排住宅及商业/工业用地，不透水面占总覆盖率的80%-100%。
- 裸地：岩石/沙/黏土；无植被覆盖的基岩、荒漠砾石层、陡崖、塌积物、滑坡体、火山物质、冰碛物、沙丘、露天矿、砂砾坑及其他地表堆积物，通常植被覆盖率低于15%。
- 落叶林：以高度通常超过5米、总植被覆盖率超过20%的树木为主的区域，且超过75%的树种会随季节变化同步落叶。
- 常绿林：以高度通常超过5米、总植被覆盖率超过20%的树木为主的区域，且超过75%的树种全年保留叶片，冠层始终有绿色植被覆盖。
- 混合林：以高度通常超过5米、总植被覆盖率超过20%的树木为主的区域，落叶树种与常绿树种占比均未超过总树木覆盖的75%。
- 灌丛/灌草地：以高度低于5米的灌木为主的区域，灌木冠层通常占总植被覆盖率的20%以上，此类类别包括真正的灌丛、处于早期演替阶段的幼树或因环境条件而矮化的树木。
- 草本植被：以草本或禾本科植被为主的区域，通常占总植被覆盖率的80%以上，此类区域无需翻耕等高强度管理，但可用于放牧。
- 干草/牧场：为家畜放牧或生产种子/干草作物而种植的禾本科、豆科或禾豆混播区域，通常为多年生循环种植，牧草/干草植被占总植被覆盖率的20%以上。
- 耕作作物地：用于生产一年生作物（如玉米、大豆、蔬菜、烟草、棉花）及多年生木本作物（如果园、葡萄园）的区域，作物植被占总植被覆盖率的20%以上，此类类别也包括所有正在进行翻耕的土地。
- 木本湿地：森林或灌丛植被占总植被覆盖率20%以上，且土壤或基质周期性被水饱和或淹没的区域。
- 挺水草本湿地：多年生草本植被占总植被覆盖率80%以上，且土壤或基质周期性被水饱和或淹没的区域。

2. Landcover_NaturalConverted_NLCD2011：该图层刻画2011年左右的自然与人工转换土地覆盖类型，从地图包NLCD2011_LNC.mpk中提取，包含2个类别：
| 数值 | 类别名称 |
| ---- | ---- |
| 1 | 人工转换用地 |
| 2 | 自然用地 |
自然与人工转换类别说明：
- 人工转换用地：已开发区域、耕作作物地及干草/牧场用地。
- 自然用地：其余所有主要覆盖类型。

3. Landcover_Level1_NLCD2011：该图层从地图包NLCD2011_Level1.mpk中提取，包含9个类别：
| 数值 | 类别名称 |
| ---- | ---- |
| 1 | 开阔水域 |
| 2 | 开发用地 |
| 3 | 裸地/采石场/过渡地带 |
| 4 | 森林 |
| 5 | 灌丛 |
| 6 | 常年冰雪 |
| 7 | 草地/草本植被 |
| 8 | 农业用地 |
| 9 | 湿地 |

4. Landcover_Level2_NLCD2011：该图层从地图包NLCD2011_Level2.mpk中提取，包含15个类别：
| 数值 | 类别名称 |
| ---- | ---- |
| 11 | 开阔水域 |
| 12 | 常年冰雪 |
| 21 | 开发开放空间 |
| 22 | 开发低密度区域 |
| 23 | 开发中密度区域 |
| 24 | 开发高密度区域 |
| 31 | 裸地 |
| 41 | 落叶林 |
| 42 | 常绿林 |
| 43 | 混合林 |
| 52 | 灌丛 |
| 71 | 草本植被 |
| 81 | 干草/牧场 |
| 82 | 耕作作物地 |
| 90 | 木本湿地 |
| 95 | 挺水草本湿地 |

## 道路密度
Road_Density：该栅格图层刻画2005年研究区域（BICA周边30公里缓冲区）内及周边所有道路的道路密度（公里/平方公里），从地图包AllRoads_rdd.mpk中提取。

上述提及的地图包可在国家公园管理局数据仓库的参考条目《大角峡谷国家游乐区景观背景、地图包》中获取，链接为https://irma.nps.gov/DataStore/Reference/Profile/2306146。