Land Use Strata - Selected States

The United States Department of Agriculture (USDA), National Agricultural Statistics Service (NASS) area sampling frame is a delineation of all parcels of land for the purpose of later sampling the parcels. The area frame is constructed by visually interpreting satellite imagery to divide a state into homogenous land use areas (strata) based on percent cultivated. The strata are typically defined as low, medium or high percent cultivated, non-agricultural land, urban use, agri-urban, or water. The boundaries of the strata usually follow identifiable features such as roads, railroads and waterways. The strata boundaries do not coincide with any political boundaries, with the exception of state boundaries. This site provides links to download ESRI shape and symbology layer files, as well as low resolution JPEG or higher resolution PDF images for each state. Also included in the FAQ are how to cite the data set, time period, how geographic features are represented and described, originators and contributors, contacts to address questions about the data, how the data set was created (previous works, e.g. USGS topographic quadrangles, US Census Bureau, space imagery, etc.), data generation-, processing-, and modification methods, and similar or related data. Applicable legal restrictions on access or use of the data and disclaimers are provided. Resources in this dataset:Resource Title: Land Use Strata - Selected States. File Name: Web Page, url: https://www.nass.usda.gov/Research_and_Science/stratafront2b.php This site provides links to download ESRI shape and symbology layer files, as well as low resolution JPEG or higher resolution PDF images for each state.

美国农业部（USDA）国家农业统计服务局（NASS）的区域抽样框架是对所有地块的划分，旨在随后对这些地块进行抽样。该区域框架通过视觉解读卫星影像，根据耕作百分比将各州划分为同质化的土地利用区域（层），通常包括低、中、高耕作百分比的非农业用地、城市用途、农业城市以及水域。这些层的边界通常遵循可识别的特征，如道路、铁路和水道。层的边界通常不与任何政治边界重合，州界除外。本网站提供下载ESRI形状和符号层文件的链接，以及每个州的低分辨率JPEG或高分辨率PDF图像。常见问题解答（FAQ）部分还包括如何引用数据集、时间范围、地理特征的表示和描述、原作者和贡献者、联系信息以解答关于数据的问题、数据集的创建方法（如美国地质调查局的地形四边形、美国人口普查局、空间影像等）、数据生成、处理和修改方法，以及类似或相关的数据。此外，还提供了数据访问或使用方面的适用法律限制和免责声明。本数据集中包含的资源：资源标题：土地利用层 - 选择州。文件名：网页，URL：https://www.nass.usda.gov/Research_and_Science/stratafront2b.php。本网站提供下载ESRI形状和符号层文件的链接，以及每个州的低分辨率JPEG或高分辨率PDF图像。