Data for: Barnegat Bay (NJ) salt marsh extent 1995 and 2015

We provide salt marsh delineations for Barnegat Bay, New Jersey, by means of object-based image analysis of high-resolution aerial imagery and digital elevation models. We performed trends analyses of salt marsh extent from 1995 to 2015 and estimated drivers of marsh area change. We found that in 1995, 8,830 ± 390 ha were covered with marsh vegetation, while in 2015 only 8,180 ± 380 ha of salt marsh habitat remained., Data for the classification of coastal land-cover of Barnegat Bay were downloaded from the USGS Earth Resources Observation and Science (EROS) Center via the USGS Earth Explorer website. The spatial data comprised high-resolution orthoimages acquired in April 1995 (color-infrared, 3 bands, 1 m resolution) and April 2015 (4 bands, red, green, blue, near-infrared, 0.3 m resolution), as well as a bathymetric model from 2000 (10 m resolution) and a digital elevation model (DEM) from 2015 (1 m resolution). Digital elevation models were clipped to the area of interest and resampled to 1-m cell size in ArcMap 10.2.2 (Esri, West Redlands, CA, USA). Aerial imagery orthomosaics were clipped to the same extent and fused with the DEMs to generate a five-band raster file for 2015 (red, green, blue, near-infrared, elevation; 1-m cell size) and a four-band raster file for 1995 (red and near-infrared combined in band 1, 1-m cell size). These raster files were imported into eCognition Developer 9 (Trimb..., Files are provided as raster in .tiff format (8 bit).
Classes are defined as follows:
1995.tif, 2015.tif: 1-Open Water; 2-Upland; 3-Salt Marsh; 4-Unvegetated
Trend.tif: 1-Stable non-marsh; 2-Stable marsh; 3-Marsh gain; 4-Marsh loss
 
Ground-control points are provided in .csv format.
Classes are defined as follows:
Control_points.csv: M-Marsh; U-Unvegetated

本数据集提供了新泽西州巴内加特湾的盐沼划定成果，基于高分辨率航空影像与数字高程模型（Digital Elevation Model, DEM）的面向对象影像分析（object-based image analysis）方法完成。随后开展了1995至2015年盐沼分布范围的趋势分析，并估算了盐沼面积变化的驱动因子。研究结果显示，1995年该区域盐沼植被覆盖面积为8830±390公顷，而到2015年仅剩余8180±380公顷的盐沼生境。

巴内加特湾海岸土地覆盖分类数据通过美国地质调查局（USGS）地球资源观测与科学中心（Earth Resources Observation and Science, EROS），经由USGS地球探索者网站下载获取。空间数据包含：1995年4月采集的高分辨率正射影像（彩色红外波段，共3个波段，分辨率1米）、2015年4月采集的4波段正射影像（红、绿、蓝、近红外波段，分辨率0.3米）；此外还有2000年的水深模型（分辨率10米）以及2015年的数字高程模型（DEM，分辨率1米）。

数字高程模型已裁剪至研究区域范围，并在ArcMap 10.2.2（Esri，美国加利福尼亚州西米德兰兹）中重采样至1米像元尺寸。航空影像正射镶嵌图同样裁剪至相同研究范围，并与数字高程模型融合，分别生成2015年的五波段栅格文件（红、绿、蓝、近红外、高程波段，像元尺寸1米），以及1995年的四波段栅格文件（波段1为红与近红外波段合并，像元尺寸1米）。上述栅格文件已导入eCognition Developer 9（Trimb...）。

数据集以8位.tiff格式的栅格文件提供。

类别定义如下：
1995.tif与2015.tif的类别规则为：1-开阔水域；2-高地；3-盐沼；4-无植被区域
Trend.tif的类别规则为：1-稳定非沼泽生境；2-稳定盐沼；3-盐沼扩张；4-盐沼退化

地面控制点以.csv格式提供，类别定义如下：
Control_points.csv：M-盐沼；U-无植被区域