Supplementary data for "Less extreme and earlier outbursts of ice-dammed lakes since 1900"

This respository contains supplementary and source data for the study for Less extreme and earlier outbursts of ice-dammed lakes since 1900 by Georg Veh and co-authors. We investigate trends in the peak discharge Qp, flood volume V0, timing doy (day of year) and elevation Z of glacier lake outburst floods (GLOFs), and focus on ice-dammed lakes. We use Bayesian hierarchical models, implemented in the package brms in in the statistical programming software R. More information on these data, including detailed scripts to process them, are available at available at https://github.com/geveh/IceDamFailures, and archived at 10.5281/zenodo.7326865. We provide the following data: 1 The GLOF database glofdatabase_2022_05_30.ods: OpenOffice table with all reported GLOFs. Compiliation as of May 30, 2022 Parameter_Readme.ods: Readme file describing all parameters (i.e. columns) in glofdatabase_2022_05_30.ods 2 Data on glacier elevation changes dh_pergla_cut.7z: zipped csv tables of cumulative elevation change (in m) for glaciers with repeat GLOFs between 2000 and 2019 3 Preprocessed GLOF data as R objects all_glofs_tibble.RDS: R-object with a preprocessed table of all reported GLOFs all_glofs_qp_tibble.RDS: R-object in table format of lakes with repeat GLOFs and reported peak discharge Qp all_glofs_V0_tibble.RDS: R-object in table format of lakes with repeat GLOFs and reported flood volume V0 glofs_ice_with_z.RDS: R-object of first reported GLOF from a given lake and its elevation Z 4 Output from Bayesian hierarchial models a) Regional models qp_models.RDS: R-object with regional quantile regression models of Qp versus time for the 50th and 90th for 4 time periods V0_models.RDS: R-object with regional quantile regression models of V0 versus time for the 50th and 90th for 4 time periods doy_trends_per_region.RDS: R-object with regression models of doy versus time for all dated GLOFs in the six regions Z_trends_per_region.RDS: R-object with a hierarchical regression models of elevation Z versus time for dated GLOFs in the six regions between 1900 and 2021 Regional_glacier_and_melt_volumes.rds: R-object containing the total volume of glacier volume and volume change between 2000 and 2019 in 100-m elevation bins b) Local models V0_model_median_local.RDS: R-object with regional quantile regression models of median V0 versus time qp_model_median_local.RDS: R-object with local quantile regression models of median Qp versus time doy_trends_per_glacier.RDS: R-object with regression models of doy versus time for lakes with repeat GLOFs local_Qp_vs_dhdt_model.RDS: R-Object containing a hierarchical model of local changes in Qp versus glacier elevation change local_V0_vs_dhdt_model.RDS: R-Object containing a hierarchical model of local changes in V0 versus glacier elevation change 4 GIS Data Ice_dammed_lakes_Zenodo.7z: zipped folder containing manually mapped outlines of ice-dammed lakes. Region_extents.7z: zipped folder containing the outlines of the study regions. 5 Figures Qp_local.pdf: PDF figure showing temporal trends of median Qp for individual glacier lakes V0_local.pdf: PDF figure showing temporal trends of median V0 for individual glacier lakes doy_local.pdf: PDF figure showing temporal trends in GLOF timing for individual glacier lakes

本仓库包含Georg Veh及其合作者题为《1900年以来冰碛湖溃决强度降低且发生时间提前》的研究的补充数据与源数据。本研究聚焦冰碛湖，探讨了冰川湖溃决洪水（Glacier Lake Outburst Floods, GLOFs）的峰值流量Qp、洪水体积V0、溃决时间（以一年中第几日即doy表示）及高程Z的变化趋势。我们采用贝叶斯分层模型，该模型通过统计编程软件R中的brms包实现。更多相关数据信息（包括数据处理的详细脚本）可访问https://github.com/geveh/IceDamFailures获取，数据存档于10.5281/zenodo.7326865。

本次公开的数据包括：
1. 冰川湖溃决洪水数据库
- `glofdatabase_2022_05_30.ods`：收录所有已报道冰川湖溃决洪水的OpenOffice表格，汇编截至2022年5月30日。
- `Parameter_Readme.ods`：用于说明`glofdatabase_2022_05_30.ods`中所有参数（即表格列项）的说明文档。
2. 冰川高程变化数据：`dh_pergla_cut.7z`：包含2000至2019年间发生过多次溃决的冰川的累积高程变化（单位：米）的压缩CSV表格集。
3. 预处理后的冰川湖溃决洪水R数据对象
- `all_glofs_tibble.RDS`：收录所有已报道冰川湖溃决洪水的预处理表格R对象。
- `all_glofs_qp_tibble.RDS`：收录发生过多次溃决且报告了峰值流量Qp的湖泊的表格格式R对象。
- `all_glofs_V0_tibble.RDS`：收录发生过多次溃决且报告了洪水体积V0的湖泊的表格格式R对象。
- `glofs_ice_with_z.RDS`：收录各湖泊首次报道的溃决洪水及其对应高程Z的R对象。
4. 贝叶斯分层模型输出结果
a. 区域模型
- `qp_models.RDS`：针对4个时间段的50th与90th分位数，构建Qp随时间变化的区域分位数回归模型的R对象。
- `V0_models.RDS`：针对4个时间段的50th与90th分位数，构建V0随时间变化的区域分位数回归模型的R对象。
- `doy_trends_per_region.RDS`：针对6个区域内所有有年代记录的冰川湖溃决洪水，构建doy随时间变化的回归模型的R对象。
- `Z_trends_per_region.RDS`：针对1900至2021年间6个区域内有年代记录的冰川湖溃决洪水，构建高程Z随时间变化的分层回归模型的R对象。
- `Regional_glacier_and_melt_volumes.rds`：收录2000至2019年间以100米高程分箱统计的冰川总体积及体积变化量的R对象。
b. 局地模型
- `V0_model_median_local.RDS`：构建中位数V0随时间变化的区域分位数回归模型的R对象。
- `qp_model_median_local.RDS`：构建中位数Qp随时间变化的局部分位数回归模型的R对象。
- `doy_trends_per_glacier.RDS`：针对发生过多次溃决的湖泊，构建doy随时间变化的回归模型的R对象。
- `local_Qp_vs_dhdt_model.RDS`：包含局地Qp变化量与冰川高程变化量之间关系的分层模型的R对象。
- `local_V0_vs_dhdt_model.RDS`：包含局地V0变化量与冰川高程变化量之间关系的分层模型的R对象。
5. GIS数据
- `Ice_dammed_lakes_Zenodo.7z`：包含人工绘制的冰碛湖轮廓的压缩文件夹。
- `Region_extents.7z`：包含研究区域轮廓的压缩文件夹。
6. 可视化图表
- `Qp_local.pdf`：展示单个冰川湖中位数Qp时间变化趋势的PDF图。
- `V0_local.pdf`：展示单个冰川湖中位数V0时间变化趋势的PDF图。
- `doy_local.pdf`：展示单个冰川湖溃决洪水发生时间变化趋势的PDF图。