Evaluation of drainage enhancement for vegetation recovery in New ENgland satl marshes using public domain, high-resolution aerail imagery (Dataset, R Code, and Tidal Watershed Boundary Shapefiles)

EVALUATION OF DRAINAGE ENHANCEMENT FOR VEGETATION RECOVERY IN SALT MARSHES IN NEW ENGLAND USING PUBLIC AERIAL IMAGERYAuthors: J Grant McKown*, David M Burdick, Gregg E Moore, Jennifer L Gibson, and Wenley FergusonContact Information: Grant McKown ([e-mail], [e-mail])Institution: Jackson Estuarine Laboratory, University of New HampshireProject Description:
Paired stressors of sea level rise and abandoned ditches and embankments from historic farming practices has exacerbated waterlogging and accelerated replacement of valuable interior high marsh with large pools throughout the United States Atlantic seaboard. High marsh loss has contributed to substantial population declines and the threat of future extinction of the Saltmarsh Sparrow (Ammodramus caudacutus), an endemic species of coastal wetlands. Creation of runnels and selective ditch maintenance has been promoted as a short- and medium-term solution to conserve and restore high marsh habitat and restore natural single-channel hydrology. A comprehensive monitoring program was launched in 2020 to evaluate the impact of runnels and maintenance of selective ditches on the hydrology, vegetation, and elevation of interior marshes across 19 sites of Maine, Massachusetts, and Rhode Island with the explicit goal of habitat conservation for the Saltmarsh Sparrow. The marsh surface was classified from 2010 – 2021 with public aerial imagery to document the change in aerial extent of the vegetated marsh surface and unvegetated – vegetated ratio (UVVR) of tidal watersheds (mean size = 2.12 + 0.18 ha) associated with specific management actions: runnelling, reference healthy marshes, and no action pannes and pools. Runnels reversed the expansion of pools and pannes with annual declines of -0.037 UVVR and gains of 1.55 % vegetated area. Tidal watersheds gained an overall net 2.08 ha vegetated surface post-restoration, despite continued losses in reference and no action tidal watersheds. Re-establishing hydrologic paths to allow regular tidal flooding and drainage promotes revegetation of shallow waterlogged pools – a first step toward rebuilding marsh elevation and conserving habitat for saltmarsh sparrows.

Dataset Description:
Please note that each folder as a README file that should be reviewed beforehand. All columns in excel and CSV files are explained in the README file.
Drainage Enhancement Dataset and Metadata - The master dataset of calculated unvegetated - vegetated ratio (UVVR) and vegetated marsh surface (hectares) of image classification of salt marshes across New England of 2010 - 2021. The dataset additionally includes the background information and metadata about drainage enhancement construction, salt marsh site characteristics, tidal watershed descriptions, and experimental design. Spatial accuracy assessments for each image classification of individual sites and years is provided as well.
Drainage Enhancement Tidesheds File Geodatabase - The tidal watershed boundaries in polygon shapefiles for each salt marsh site in the study. Each shapefile has the size (acres and hectares) for each tidal watershed and UVVR scores and vegetated marsh surface (hectares) from 2010 - 2021.
Drainage Enhancement Analysis and R Code - Input data analysis CSV file (also found in the Drainage Enhancement Dataset) and the R code for post-image classification analysis. R code is well-annotated with details and explanations for each step. R code formats the dataset, computes statistics, creates figures, and calculates change metrics found in the publication.

# 新英格兰盐沼植被恢复的排水增强效果评估——基于公开航空影像
作者：J Grant McKown*、David M Burdick、Gregg E Moore、Jennifer L Gibson、Wenley Ferguson
联系方式：Grant McKown ([e-mail], [e-mail])
机构：新罕布什尔大学杰克逊河口实验室

## 项目概况
海平面上升与历史农业活动遗留的沟渠及堤岸双重胁迫，加剧了美国大西洋沿岸盐沼的积水问题，并加速了珍贵的内陆高潮沼被大型积水塘替代的进程。高潮沼的流失导致了盐沼麻雀（Ammodramus caudacutus）——一种沿海湿地特有物种——的种群数量大幅下降，并使其面临未来灭绝的威胁。开挖径流沟（runnels）并开展选择性沟渠维护，被推广为保护与恢复高潮沼生境、重塑天然单沟水文系统的中短期解决方案。

2020年，研究团队启动了一项全面监测计划，旨在评估缅因州、马萨诸塞州与罗德岛州共19个研究点的径流沟与选择性沟渠维护措施对内陆盐沼水文、植被及高程的影响，核心目标为保护盐沼麻雀的栖息生境。研究团队利用公开航空影像对2010-2021年的盐沼地表进行分类，以记录不同管理措施下潮汐流域（平均面积=2.12±0.18公顷）的植被盐沼地表面积变化，以及无植被-植被比（unvegetated-vegetated ratio, UVVR）的动态。所涉及的管理措施包括：径流沟开挖、健康盐沼对照组，以及无干预的浅洼与积水塘组。

研究结果显示，径流沟开挖逆转了积水塘与浅洼的扩张趋势，UVVR年均下降0.037，植被覆盖面积年均增长1.55%。尽管对照组与无干预组的潮汐流域植被覆盖面积仍在持续减少，但修复后的潮汐流域整体净增植被覆盖面积达2.08公顷。重建水文通路以实现规律性潮汐淹没与排水，可促进积水浅洼的植被恢复——这是提升盐沼高程、保护盐沼麻雀栖息生境的第一步。

## 数据集说明
请注意，每个文件夹均附带自述文件（README），请提前查阅。Excel与CSV文件中的所有列均在自述文件中附有详细解释。

### 排水增强数据集与元数据
该数据集为2010-2021年新英格兰地区盐沼影像分类结果的核心数据集，包含计算得到的无植被-植被比（UVVR）以及植被盐沼地表面积（单位：公顷）。此外，数据集还涵盖排水增强工程的背景信息与元数据、盐沼研究点特征、潮汐流域描述以及实验设计。同时提供了各研究点每年影像分类的空间精度评估结果。

### 排水增强潮汐流域文件地理数据库
该数据库包含本研究中各盐沼研究点的潮汐流域边界多边形形状文件（shapefile）。每个形状文件均包含对应潮汐流域的面积（单位：英亩与公顷），以及2010-2021年的UVVR值与植被盐沼地表面积（单位：公顷）。

### 排水增强分析与R代码
包含用于数据分析的输入CSV文件（同样收录于排水增强数据集），以及用于影像分类后分析的R代码。该R代码附有详细的逐步骤注释与说明，可完成数据集格式化、统计量计算、图表生成以及论文中提及的变化指标计算。