2025 New Hampshire Shoreline Structure Inventory

The 2025 NH Shoreline Inventory Project is an effort to update an important baseline dataset to inform coastal shoreline management decisions. This integrated dataset would be used to gain a better quantitative understanding of the state of the NH coastal shoreline, including the proportion of the shoreline that is subject to manmade hardened structures. New Hampshire Shoreline Inventory Project provides baseline information about existing engineered shoreline structures, including total spatial extent and coarse level information about type of structure. It also integrates information about key coastal habitats, including salt marshes, sandy beaches, and rocky shores. NHDES Wetlands Bureau Permits were thoroughly examined via the Land Resource Management Database application (LRM) using project-related keywords for each community. Applicable permits were determined by an examination of a permits project description (i.e., construction of a living shoreline, repair existing rip rap). Following permit examination, an aerial review of the tidal shoreline was conducted using the Google Earth Pro application. This review verified permitted shoreline structure construction. Additionally, structures missing from the 2016 project and unpermitted structures from 2016-2025 could be located with this review. The historical imagery slider tool in Google Earth Pro was utilized to determine the approximate date of a structure’s construction. Any structure that was established before 2016 was deemed as a pre-existing structure and was cross referenced with 2016 shoreline inventory GIS layer. Any structure that did not have a corresponding polyline in the GIS layer was recorded in a separate excel spreadsheet dedicated for future field verification. Any structure found that was constructed from 2016-2025 and did not have a corresponding permit was also recorded in the future field verification excel spreadsheet. Following aerial review, field verifications were conducted by driving to each site and verifying if the observations of the aerial review were accurate. It serves as an information source for decision-makers as they consider development of a Comprehensive NH Shoreline Management Plan and involves key experts in the Coastal Zone in order to ensure that the product is useful and usable.2025年新罕布什尔州（New Hampshire, NH）海岸线清查项目旨在更新一套核心基准数据集，为沿海海岸线管理决策提供科学支撑。本整合数据集将用于更精准地量化评估新罕布什尔州沿海海岸线的现状，包括受人工硬质构筑物影响的岸线占比。新罕布什尔州海岸线清查项目可提供现有工程化岸线构筑物的基准信息，涵盖总空间范围以及构筑物类型的粗粒度分类信息，同时还整合了盐沼、沙滩与岩质岸线等关键沿海生境的相关数据。项目组通过土地资源管理数据库（Land Resource Management Database, LRM），针对各社区使用项目相关关键词，对新罕布什尔州环境服务部（New Hampshire Department of Environmental Services, NHDES）湿地局的许可文件开展了全面核查，并通过核查许可项目的描述内容（即生态岸线建设、现有抛石护岸修缮等）确定适用的许可文件。完成许可文件核查后，项目组借助谷歌地球专业版（Google Earth Pro）对潮汐岸线开展航空目视解译，以核验获批岸线构筑物的建设情况；通过本次解译，还可定位2016年海岸线清查项目遗漏的构筑物，以及2016至2025年间未获批的岸线构筑物。项目组使用谷歌地球专业版的历史影像滑动工具，以确定各构筑物的大致建设时间。2016年前建成的构筑物将被归类为既有构筑物，并与2016年海岸线清查地理信息系统（Geographic Information System, GIS）图层进行交叉比对；若GIS图层中无对应折线要素的构筑物，则将其记录在专门的Excel表格中，用于后续野外核查。2016至2025年间建成且无对应许可文件的构筑物，也将被录入上述野外核查专用Excel表格。完成航空目视解译后，项目组前往各点位开展野外核查，以验证航空解译结果的准确性。本项目成果可为决策者制定《新罕布什尔州全面海岸线管理计划》提供信息支撑；同时项目邀请了沿海地带的核心专家参与，以确保成果具备实用性与易用性。