Vegetation - Tijuana River [ds3033]

In 2016, Debbie Waldecker from California State Parks (CSP) led a team in a strongly field-based update of the Western San Diego County Vegetation dataset for Border Field State Park, located in the southern portion of the mapping area. This mapping effort was conducted to support decisions regarding a road renovation project within the state park. The MMU was 0.4 ha for the majority of the park, with smaller polygons present in the area along the road. Dr. Kellie Uyeda of the Tijuana River National Estuarine Research Reserve and Dr. John Boland of Boland Ecological Services combined the maps produced by SFEI and CSP and assessed each polygon individually to ensure that a MMU of 0.1 ha was applied consistently across the mapping area. We made exceptions to the MMU for polygons that were part of our original field-based rapid assessment plots. Image interpretation was based on a combination of sources, including four-band (red, green, blue, NIR) orthoimagery collected in 2016 by Near Earth Observation Systems, LTD (15 cm spatial resolution), 2016 National Aerial Imagery Program four-band orthoimagery (60 cm spatial resolution), 2014 U.S. Geological Survey (USGS) four-band orthoimagery (10 cm spatial resolution), and 2014 USGS lidar point clouds (11 pts/m2). The lidar point clouds were processed to produce a digital elevation model and a canopy height layer. In addition, we conducted extensive ground reference surveys from 2016 - 2018, collecting over 3,700 geotagged photos across the mapping area. We mostly mapped to the association level, although in some highly disturbed sites where the exact species composition could not be clearly determined, we mapped only to the group level (Mediterranean California Naturalized Annual and Perennial Grassland Semi-Natural Stands and Naturalized Warm-Temperate Riparian and Wetland Semi-Natural Stands). Group and alliance level classes are noted in the association field with an asterisk. The vegetated habitats were based on the Western San Diego County Vegetation dataset, produced in 2012 by San Diego Association of Governments (SANDAG) with a minimum mapping unit (MMU) of 1 hectare (ha) for terrestrial systems and 0.5 ha for wetlands. Developed areas were mapped using the National Land Cover Dataset of 2011 with a MMU of 0.09 ha. Tidal channels and mudflats were based on the Southern California Wetlands Mapping Project from 2005 with a MMU of 0.2 ha. SFEI also conducted supplemental mapping based on aerial imagery from 2008 – 2010 to provide full coverage of the study area.2016年，来自加州公园管理局（California State Parks, CSP）的黛比·瓦尔德克（Debbie Waldecker）带领团队，针对位于测绘区域南部的边境菲尔德州立公园，开展了一项高度依托野外工作的西圣迭戈县植被数据集更新工作。本次测绘工作旨在为该州立公园内的道路翻新项目决策提供支撑。该公园绝大多数区域的最小制图单元（Minimum Mapping Unit, MMU）设定为0.4公顷，道路沿线区域则存在更小的多边形要素。 蒂华纳河国家河口研究保护区的凯莉·上田博士与博兰德生态服务公司的约翰·博兰德博士，将旧金山河口研究所（San Francisco Estuary Institute, SFEI）与CSP生成的测绘图进行整合，并对每个多边形逐一审核，确保整个测绘区域统一采用0.1公顷的最小制图单元。对于原始野外快速评估样地中的多边形，我们放宽了最小制图单元的限制。 图像解译工作依托多源数据开展，包括：由近地观测系统有限公司（Near Earth Observation Systems, LTD）于2016年采集的四波段（红、绿、蓝、近红外）正射影像（空间分辨率15厘米）；2016年美国国家航空影像计划的四波段正射影像（空间分辨率60厘米）；2014年美国地质调查局（United States Geological Survey, USGS）四波段正射影像（空间分辨率10厘米），以及2014年USGS的激光雷达点云数据（11个点/平方米）。 研究团队对激光雷达点云进行处理，生成了数字高程模型与冠层高度图层。此外，我们于2016年至2018年间开展了大量地面参考调查，在测绘区域内采集了超过3700张带有地理标签的照片。 本次植被制图主要划分至群丛级别，但在部分受干扰程度较高、无法明确确定物种组成的区域，仅划分至群系组级别，具体包括“地中海加州归化一年生与多年生草原半自然林分”以及“归化暖温带河岸与湿地半自然林分”。群系组与群系级别的分类将在群丛字段中以星号标注。 植被生境的底本采用2012年由圣迭戈政府协会（San Diego Association of Governments, SANDAG）生成的《西圣迭戈县植被数据集》，该数据集陆地系统的最小制图单元为1公顷，湿地系统为0.5公顷。建成区域的制图参考2011年全国土地覆盖数据集，其最小制图单元为0.09公顷。潮汐水道与潮滩的底本采用2005年《南加州湿地测绘项目》成果，最小制图单元为0.2公顷。SFEI还基于2008年至2010年的航空影像开展了补充测绘，以实现研究区域的全覆盖。