Vegetation - Modoc Plateau Applegate Areas - 2016 [ds2858]

The mapping study area was divided into two areas of Modoc and Lassen Counties. The Applegate area consists of approximately 84,574 acres, and work was performed on the project between 2017 and 2021. The Eagle Lake area, consists of approximately 66,402 acres in Lassen County, and Work was performed on the project between 2019 and 2021. The eastern portion of the Applegate area used the 2016 NAIP imagery as a base and the Eagle Lake and western portion of Applegate area were mapped using the 2018 NAIP imagery. The vegetation classification follows protocols compliant with the Federal Geographic Data Committee (FGDC) and National Vegetation Classification Standards (NVCS). The classification is based on new surveys and classification work conducted in collaboration with CDFW VegCAMP. The map was produced applying heads-up digitizing techniques using a base of one-meter National Agricultural Imagery Program (NAIP) imagery (true-color and color infrared), in conjunction with ancillary data and imagery sources. Map polygons are assessed for Vegetation Type, Percent Cover, Exotics, Development Disturbance, and other attributes. The minimum mapping unit (MMU) is 1 acre; exceptions are made for wetlands and riparian types, which were mapped to a 1/4 acre MMU. Field reconnaissance and accuracy assessment enhanced map quality. There were a total of 91 classes mapped in the Applegate area. The overall Fuzzy Accuracy Assessment ratings for the final vegetation map at the Alliance level were 92.2 percent at the 60-100% Correct or Acceptable level, and 86.4 percent at the 80-100% Correct or Acceptable level. At the Association level, the Fuzzy Accuracy Assessment ratings were was 88.1 percent at the 60-100% Correct or Acceptable level, and 79.1 percent at the 80-100% Correct or Acceptable level. For the Eagle Lake area, there were a total of 78 mapping classes. The overall Fuzzy Accuracy Assessment ratings for the final vegetation map at the Alliance level were 86.3 percent at the 60-100% Correct or Acceptable level, and 81.9 percent at the 80-100% Correct or Acceptable level. At the Association level, the Fuzzy Accuracy Assessment ratings were was 84.0 percent at the 60-100% Correct or Acceptable level, and 72.4 percent at the 80-100% Correct or Acceptable level. See the contingency tables (https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=192229) for more detailed information.本研究的制图研究区划分为莫多克县（Modoc）与拉森县（Lassen）两个区域。其中阿普尔顿区域面积约84574英亩，项目实施周期为2017年至2021年；鹰湖区域位于拉森县境内，面积约66402英亩，项目实施周期为2019年至2021年。阿普尔顿区域的东部片区以2016年美国农业部农业航空影像计划（National Agricultural Imagery Program, NAIP）影像作为基础底图，而鹰湖区域与阿普尔顿区域的西部片区则采用2018年NAIP影像完成制图工作。本次植被分类遵循联邦地理数据委员会（Federal Geographic Data Committee, FGDC）与国家植被分类标准（National Vegetation Classification Standards, NVCS）的相关规范，基于与加州鱼类与野生动物局植被分类与监测项目（CDFW VegCAMP）合作开展的全新野外调查与分类工作完成。本次制图采用目视数字化（heads-up digitizing）技术，以1米分辨率的NAIP真彩色与彩红外影像作为基础底图，结合辅助数据与其他影像数据源实现。对地图多边形的植被类型、覆盖百分比、外来物种占比、开发干扰情况及其他属性进行了系统评估。本次制图的最小制图单元（minimum mapping unit, MMU）为1英亩；湿地与河岸类型除外，其最小制图单元设定为0.25英亩。通过野外踏勘与精度评估，进一步提升了地图成果的质量。阿普尔顿区域共划分91个制图类群，其最终植被图在群丛联盟级（Alliance level）的模糊精度评估（Fuzzy Accuracy Assessment）结果显示：60%-100%正确或可接受等级的占比为92.2%，80%-100%正确或可接受等级的占比为86.4%；在群丛级（Association level），该评估结果为60%-100%正确或可接受等级的占比为88.1%，80%-100%正确或可接受等级的占比为79.1%。鹰湖区域共划分78个制图类群，其最终植被图在群丛联盟级的模糊精度评估结果为：60%-100%正确或可接受等级的占比为86.3%，80%-100%正确或可接受等级的占比为81.9%；在群丛级，该评估结果为60%-100%正确或可接受等级的占比为84.0%，80%-100%正确或可接受等级的占比为72.4%。详细信息请参阅列联表（https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=192229）。