Data associated with 'Processes at the margins of supraglacial debris cover: quantifying dirty ice ablation and debris redistribution'

Data associated with Fyffe, C. L., Woodget, A. S., Kirkbride, M. P., Deline, P., Westoby, M. J. and Brock, B. W. (2020) Processes at the margins of supraglacial debris cover: quantifying dirty ice ablation and debris redistribution, Earth Surface Processes and Landforms, doi:10.1002/esp.4879. The file All_quadrat_data_Z contains the data associated within each of the quadrats which were positioned on the ice surface. Some of the values are extracted from the UAV derived data within the area of the quadrat, while other data is based on measurements from the ground truth images (taken at ground level). The main data types are given below. The data sub-types and units are given in the file header. Quadrat: Quadrat name Elevation: Elevation from the UAV DEM Aspect: Aspect from the UAV DEM Ablation: Ablation derived from the UAV products (see the paper for details) Albedo: Measured albedo Rock_stats_image: Statistics on the clasts sampled from the ground truth image of the quadrat Debris_cover: Percentage debris cover derived from both the ground truth image (point) and UAV derived orthophotos Rock_stats_meas: Statistics on the clasts measured in the field The file Feature_Tracking_Data_Z contains data on clast movement, derived by locating the same clasts in the July and August orthophotos. The August orthophoto location was corrected for ice flow. The main data types are given below. The data sub-types and units are given in the file header. Coordinates: Locations of the points on the clasts in the July and August orthophotos Elevation: Elevation from the UAV derived DEMs Slope_from_slope_map: Slope from the UAV derived DEMs Surface: Either dirty ice (partial debris cover, or debris (continuous cover) Clast_length: A-axis length of the tracked clast Track_lines_stats: Characteristics of the line joining the clast locations Clast_velocity: Velocity of the tracked clast. Note the velocities derived from the distance measured over the surface were used for the analysis in the paper. The file Profiles_Data_Z contains the elevation and ablation data extracted following four cross-profiles which crossed the study area. Tables are also included giving the calculated moraine slope gradients and their change over time. The main data types are: Distance: The distance along the cross-section Elevation: The elevation from either the July or August DEM Ablation: The ablation value from the map of spatially continuous ablation. The folder GIS_Data_Z contains a range of GIS data associated with the paper. Included in the Zip file is an ArcMap document 'GIS_Data_Dirty_Ice' which includes all the data, along with a Word document ('Metadata for GIS data') which describes each of the files included within the ArcMap document. Briefly, the included data covers ground truth data (georeferenced ground truth photos, sample points and their classification, clast sizes, quadrat georeferencing information), clast track data (over the study area and the small scale clast tracks), stake data (measured and modelled ablation, calculated horizontal velocities and combined slope and emergence values), mapped ablation, percentage debris cover (and the difference in percentage cover), orthophotos, elevation data (and the cross-sections used to extract this) and the boundaries between the dirty and debris-covered ice. All data sets are in the WGS 1984 UTM Zone 32N coordinate system. The folder Percent_Debris_Analysis_H_Z contains the data used to derive Figure 5 (ablation and percentage debris cover data) in Matlab format (.mat file). It also includes the code used to make the figure. More details on file names will not be given here as the code documents the analysis steps. If any further information is required about the data then please get in contact with Catriona Fyffe.

本数据集关联于Fyffe, C. L.、Woodget, A. S.、Kirkbride, M. P.、Deline, P.、Westoby, M. J. 与 Brock, B. W. 于2020年发表在《Earth Surface Processes and Landforms》（《地表过程与地形》）的研究论文：《冰川表面碎屑覆盖层边缘过程：量化污化冰消融与碎屑再分配》，DOI:10.1002/esp.4879。

文件All_quadrat_data_Z包含布设于冰面的每个样方（quadrat）关联的数据集。部分数据值提取自样方区域内无人机（Unmanned Aerial Vehicle, UAV）生成的数据，其余数据则基于地面实况图像（地面拍摄）的测量结果。主要数据类型如下，数据子类型与单位详见文件头部注释：
- 样方：样方名称
- 高程：来自无人机数字高程模型（Digital Elevation Model, DEM）的高程值
- 坡向：来自无人机DEM的坡向
- 消融量：基于无人机衍生产品计算的消融量（详细说明参见论文）
- 反照率：实测反照率
- 图像岩石统计量：从样方的地面实况图像中采样的砾石（clast）统计参数
- 碎屑覆盖率：同时基于地面实况图像（点数据）与无人机正射影像（orthophoto）计算的碎屑覆盖百分比
- 实测岩石统计量：野外实测的砾石统计参数

文件Feature_Tracking_Data_Z包含砾石运动相关数据，通过在7月与8月的正射影像中定位同一砾石得到。8月正射影像的坐标已针对冰流进行校正。主要数据类型如下，数据子类型与单位详见文件头部注释：
- 坐标：7月与8月正射影像中砾石点的位置
- 高程：来自无人机DEM的高程值
- 坡度图坡度：基于无人机DEM计算的坡度
- 地表类型：分为污化冰（部分碎屑覆盖）与碎屑覆盖冰（连续碎屑覆盖）
- 砾石长度：追踪砾石的A轴长度
- 追踪线统计量：连接砾石位置的线段的特征参数
- 砾石运动速度：追踪砾石的运动速度。请注意，本文分析中使用的是基于地表测量距离计算得到的速度值。

文件Profiles_Data_Z包含沿研究区布设的4条横剖面提取的高程与消融量数据。文件同时包含计算得到的冰碛物坡度梯度及其随时间变化的表格。主要数据类型如下，数据子类型与单位详见文件头部注释：
- 距离：沿剖面的测量距离
- 高程：来自7月或8月DEM的高程值
- 消融量：基于空间连续消融图得到的消融量数值

文件夹GIS_Data_Z包含本研究相关的一系列地理信息系统（Geographic Information System, GIS）数据。压缩包内包含ArcMap文档《GIS_Data_Dirty_Ice》，整合了全部数据集，同时附带一份Word文档《GIS数据元数据》，用于说明ArcMap文档内各文件的详细信息。简言之，包含的数据涵盖：地面实况数据（地理配准的地面实况照片、采样点及其分类信息、砾石尺寸、样方地理配准信息）、砾石追踪数据（研究区全域及小尺度砾石追踪数据）、测杆数据（实测与模拟消融量、计算得到的水平运动速度及坡度与抬升综合参数）、制图消融量数据、碎屑覆盖率（及覆盖率差值）数据、正射影像、高程数据（及用于提取数据的横剖面）以及污化冰与碎屑覆盖冰的边界数据。所有数据集均采用WGS 1984 UTM分区32N坐标系。

文件夹Percent_Debris_Analysis_H_Z包含用于生成图5（消融量与碎屑覆盖率数据）的Matlab格式（.mat文件）数据集，同时附带用于绘制该图的代码。由于代码已记录了分析步骤，此处不再赘述各文件名的详细信息。如需获取该数据集的更多信息，请联系Catriona Fyffe。