National Land Cover Database 2001 (NLCD01) Tree Canopy Layer Tile 2, Northeast United States: CNPY01_2

This 30-meter resolution data set represents the tree canopy layer for the conterminous United States for the 2001 time period. The data have been arranged into four tiles to facilitate timely display and manipulation within a Geographic Information System, browse graphic: nlcd01-partition.jpg

The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). One of the primary goals of the project is to generate a current, consistent, seamless, and accurate National Land Cover Database (NLCD) circa 2001 for the United States at medium spatial resolution. For a detailed definition and discussion on MRLC and the NLCD 2001 products, refer to Homer and others (2004) and http://www.mrlc.gov/mrlc2k.asp.

The NLCD 2001 was created by partitioning the United States into mapping-zones. A total of 68 mapping-zones browse graphic: nlcd01-mappingzones.jpg were delineated within the conterminous United States based on ecoregion and geographical characteristics, edge-matching features, and the size requirement of Landsat mosaics. Mapping-zones encompass the whole or parts of several states. Questions about the NLCD mapping zones can be directed to the NLCD 2001 Land Cover Mapping Team at the USGS/EROS, Sioux Falls, SD [phone] or [e-mail].

本数据集空间分辨率为30米，代表2001年时段美国本土48州的树冠覆盖图层。为便于在地理信息系统中高效显示与处理，该数据已被划分为四个分幅，配套浏览图为nlcd01-partition.jpg。

2001年全国土地覆盖数据集由多分辨率土地特征（Multi-Resolution Land Characteristics, MRLC）联盟合作实施的项目制作完成。该联盟为联邦机构间的合作伙伴联合体（官网：www.mrlc.gov），成员包括美国地质调查局（U.S. Geological Survey, USGS）、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）、美国环境保护署（U.S. Environmental Protection Agency, USEPA）、美国农业部（U.S. Department of Agriculture, USDA）、美国林务局（U.S. Forest Service, USFS）、美国国家公园管理局（National Park Service, NPS）、美国鱼类及野生动物管理局（U.S. Fish and Wildlife Service, USFWS）、土地管理局（Bureau of Land Management, BLM）以及美国农业部自然资源保护服务局（USDA Natural Resources Conservation Service, NRCS）。本项目的核心目标之一，是生成一套现势性良好、一致性统一、无缝衔接且精度可靠的2001年前后美国中等空间分辨率全国土地覆盖数据库（National Land Cover Database, NLCD）。如需获取MRLC及NLCD 2001产品的详细定义与讨论内容，请参阅Homer等人（2004）的研究成果，或访问网址http://www.mrlc.gov/mrlc2k.asp。

NLCD 2001通过将美国划分为制图分区的方式制作完成。基于生态区域与地理特征、边缘匹配要求以及Landsat镶嵌图的尺寸限制，美国本土48州范围内共划定68个制图分区，配套浏览图为nlcd01-mappingzones.jpg。单个制图分区可覆盖一个或多个州的全部或部分区域。若对NLCD制图分区存在疑问，可联系位于南达科他州苏福尔斯市USGS/EROS的NLCD 2001土地覆盖制图团队，联系电话：[phone]，或发送邮件至[e-mail]。