Resilience and Adaptation to the Effects of Permafrost Degradation-Induced Coastal Erosion – Orthomosaic Images and Digital Surface Models for Point Lay, Alaska, United States 2023-2025

This project is part of Navigating the New Arctic (NNA) which addresses converging scientific challenges in the rapidly changing Arctic. Specifically, the goal of this project is to better understand ice-rich permafrost at local, regional, and circumpolar scales. Orthomosaic images and digital surface models (DSM) were processed from unoccupied aerial vehicle (UAV) data for an area of study of the community of Point Lay and its southern coastline in northwestern Alaska, USA. This dataset provides a record of coastal change due to permafrost thaw and degradation as well as spatial data useful for validation of land surface deformation models. The first initial survey in 2023 was flown using a DJI Phantom 4 RTK (P4RTK) and a DJI D-RTK 2 Mobile Base Station for real-time kinematic (RTK) positioning. For the 2024 and 2025 survey, we used a DJI Matrice M300 RTK (M300RTK) drone equipped with a DJI Zenmuse P1 camera and a 35mm (millimeter) lens (45MP (megapixels)). An Emlid RS3 GNSS base station was used for RTK positioning. All images were processed using Agisoft Metashape (v.2.2.0) following a standard three-dimensional mapping processing workflow utilizing ground control points measured in the field for horizontal and vertical corrections and reliable reproduction from year to year. All DSM and orthomosaic files are projected using NAD83 State Plane 4 and ellipsoidal heights in meters. The community of Point Lay (Kali) is located on the coastal plain of the North Slope along the Chukchi Sea in Alaska, USA. It is separated from the open ocean by a barrier island and Kasugaluk Lagoon. Landcover units include dwarf shrubs, graminoid-moss tundra, and moss tundra (wet and moist non-acidic). The land surface is characterized by lake systems, polygonal tundra, and relatively flat topography.

本项目隶属于新北极航行（Navigating the New Arctic，NNA）计划，该计划旨在应对快速变化的北极地区日益汇聚的多重科学挑战。本项目的核心目标为在局地、区域乃至环极尺度上，更深入地认知富冰多年冻土。研究团队针对美国阿拉斯加州西北部波因特莱（Point Lay）社区及其南部海岸线区域，基于无人飞行器（Unoccupied Aerial Vehicle，UAV）采集的数据，处理得到了正射影像图与数字表面模型（Digital Surface Model，DSM）。本数据集记录了由多年冻土融化与退化引发的海岸变化，同时提供了可用于地表形变模型验证的空间数据。2023年的首次野外调研采用DJI Phantom 4 RTK（P4RTK）无人机与DJI D-RTK 2移动基准站，通过实时动态差分（Real-time Kinematic，RTK）技术实现定位。2024年与2025年的调研则使用搭载DJI Zenmuse P1相机与35mm（毫米）镜头（4500万像素（megapixels，MP））的DJI Matrice M300 RTK（M300RTK）无人机，并采用Emlid RS3 GNSS基准站进行RTK定位。所有影像均采用Agisoft Metashape（v.2.2.0）进行处理，遵循标准三维测绘处理流程，利用野外实测的地面控制点完成水平与垂直校正，确保不同年度的数据可实现可靠复现。所有DSM与正射影像文件均采用NAD83州平面坐标系4进行投影，高程采用以米为单位的椭球高。波因特莱（Kali）位于美国阿拉斯加州楚科奇海沿岸的北坡沿海平原，通过障壁岛与卡斯加拉卢克泻湖（Kasugaluk Lagoon）与外海相隔。该区域的土地覆盖类型包括矮灌丛、禾草-苔藓苔原以及苔藓苔原（湿润与潮湿非酸性类型）；地表景观以湖泊系统、多边形苔原与平缓地形为主要特征。