本数据集基于冰川编目数据(RGI 6.0)和消融期末（每年7月20日-9月20日）Landsat TM/ETM+/OLI影像，结合ArcGIS和ENVI软件和Google Earth影像，基于积雪和裸冰反照率值差异显著的特性以及遥感反演的整条冰川范围的反照率结果。提取了阿尔泰山地区17条冰川2000-2019年消融期末的雪线高度数据。并通过目视解译的方法对提取结果进行了验证，误差在8-67米之间。2000-2019年间阿尔泰山平均雪线高度为3135米，呈现轻微的上升趋势，速率约为2.5 米/每年。本数据集为阿尔泰山冰川响应气候变化的定量研究奠定数据基础。\n
数据格式为Excel，时间为2000-2019年。由于消融期末降雪以及云的影响，个别年份数据缺失。本数据集选择了缺失小于10年的17条冰川。数据单位为米（m）。", "ds_source": "
1.Landsat陆地卫星影像数据：从美国地质调查局网站(https://www.usgs.gov/) 和地理空间数据云 (http://www.gscloud.cn/)下载。\n
2.冰川编目数据：中国第二次冰川编目数据(http://westdc.westgis.ac.cn) 和RGI 6.0 (https://www.glims.org/RGI/rgi60_dl.html)。\n
3.ASTER GDEM V3数据：空间分辨率为30米，下载地址 https://lpdaac.usgs.gov/products/astgtmv003/。", "ds_process_way": "
1.遥感数据预处理：通过辐射定标，大气校正、地形校正、BRDF校正以及窄-宽波段转换的方法反演获得冰川表面反照率。\n
2.雪线高度识别：利用冰川区DEM和遥感反演反照率结果，以50m等高线间隔计算冰川中流线（中流线附近7个像元，约210m范围）附近各海拔带的反照率值、标准差，得到中流线上反照率随海拔的变化曲线。曲线上标准差最大点表明该海拔带内冰面类型差异最大，为积雪区与裸冰区的过渡带，其反照率值记为α0。随着海拔的升高，自该海拔带以上的区域为积雪区，以下为裸冰区。因此，将α0作为雪线提取的阈值，将冰川表面划分为积雪区和裸冰区，积雪区下界即为雪线。但是，冰川雪线高度不一定沿等高线规则分布，很可能穿越几条等高线。在此，根据5m间隔提取的等高线，取该线最邻近的等高线或者最邻近等高线的平均值作为最终雪线高度。", "ds_quality": "
人工目视解译划定雪线高度与本研究提取的雪线高度差值在8-67米之间。", "ds_acq_start_time": "2000-08-07 00:00:00", "ds_acq_end_time": "2019-08-04 00:00:00", "ds_acq_place": "阿尔泰山冰川", "ds_acq_lon_east": 88.5, "ds_acq_lat_south": 48.5, "ds_acq_lon_west": 87.0, "ds_acq_lat_north": 49.5, "ds_acq_alt_low": 2371.0, "ds_acq_alt_high": 4319.0, "ds_share_type": "apply-access", "ds_total_size": 10809, "ds_files_count": 2, "ds_format": "excel", "ds_space_res": "30m", "ds_time_res": "年", "ds_coordinate": "无", "ds_projection": "", "ds_thumbnail": "783e3191-8983-4206-bd67-9072d3940985.png", "ds_thumb_from": 2, "ds_ref_way": "岳晓英，阿尔泰山冰川消融期末雪线高度数据集（2000-2019年），国家冰川冻土沙漠科学数据中心(www.ncdc.ac.cn)，2023，doi：10.12072/ncdc.nieer.db2878.2023", "paper_ref_way": "", "ds_ref_instruction": "", "ds_from_station": null, "organization_id": "c6ac5c3c-eb4f-4119-86fb-c4534a9bd7fb", "ds_serv_man": "敏玉芳", "ds_serv_phone": "0931-4967596", "ds_serv_mail": "ncdc@lzb.ac.cn", "doi_value": "10.12072/ncdc.nieer.db2878.2023", "subject_codes": [ "170.4510" ], "quality_level": 3, "publish_time": "2023-06-19 10:16:26", "last_updated": "2023-06-21 11:54:24", "protected": false, "protected_to": null, "lang": "zh", "cstr": "11738.11.NCDC.NIEER.DB2878.2023", "i18n": { "en": { "title": "Data set of snow line altitude at the end of ablation season in Altai Mountains from 2000 to 2019", "ds_format": "", "ds_source": "
1. Landsat Land Satellite Image Data: From the US Geological Survey website（ https://www.usgs.gov/ ）And Geospatial Data Cloud（ http://www.gscloud.cn/ ）Download.\n
2. Glacier Cataloging Data: China's Second Glacier Cataloging Data（ http://westdc.westgis.ac.cn ）And RGI 6.0（ https://www.glims.org/RGI/rgi60_dl.html )。\n
3. ASTER GDEM V3 data: spatial resolution of 30 meters, download address https://lpdaac.usgs.gov/products/astgtmv003/ 。", "ds_quality": "
The difference between the height of the snow line defined by manual visual interpretation and the height of the snow line extracted in this study is between 8-67 meters.", "ds_ref_way": "", "ds_abstract": "
This data set is based on glacier cataloguing data (RGI 6.0) and Landsat TM/ETM+/OLI images at the end of ablation period (July 20 to September 20 each year), combined with ArcGIS, ENVI software and Google Earth images, based on the characteristics of significant differences in snow cover and bare ice albedo values, and the albedo results of the entire glacier range retrieved by remote sensing. The snow line height data of 17 glaciers in the Altay Mount Taishan region at the end of the ablation period from 2000 to 2019 were extracted. And the extraction results were verified through visual interpretation, with an error of between 8-67 meters. From 2000 to 2019, the average snow line height of Mount Mount Taishan was 3135m, showing a slight upward trend, with a rate of about 2.5m/year. This data set lays a data foundation for quantitative research on the response of glaciers in the Altay Mount Taishan Mountains to climate change.\n
The data format is Excel, covering the period from 2000 to 2019. Due to the impact of snowfall and clouds at the end of the ablation period, some years' data are missing. This dataset selected 17 glaciers that were missing for less than 10 years. The data unit is meters (m).
", "ds_time_res": "年", "ds_acq_place": "Mount Taishan Glacier", "ds_space_res": "30m", "ds_projection": "", "ds_process_way": "1. Remote sensing data pre-processing: the glacier surface albedo is retrieved by radiometric calibration, atmospheric correction, topographic correction, BRDF correction and narrow to wide band conversion.\n
2. Snow line height recognition: using the results of albedo retrieved from the DEM and remote sensing in the glacier area, calculate the albedo values and standard deviations of each altitude zone near the glacier midstream line (7 pixels near the midstream line, about 210m range) at 50m contour interval, and obtain the change curve of albedo along the midstream line with altitude. The point with the maximum standard deviation on the curve indicates that the difference of ice surface types in this altitude zone is the largest, which is the transition zone between snow covered area and bare ice area, and its albedo value is recorded as α 0 As the altitude increases, the area above this altitude zone becomes a snow covered area, while the area below is a bare ice area. Therefore, the α As the threshold for snow line extraction, 0 divides the glacier surface into snow covered areas and bare ice areas, with the lower boundary of the snow covered area being the snow line. However, the height of glacier snow lines may not necessarily be distributed regularly along contour lines, and it is likely to cross several contour lines. Here, based on contour lines extracted at 5m intervals, the nearest contour line or the average of the nearest contour lines is taken as the final snowline height.", "ds_ref_instruction": "" } }, "submit_center_id": "ncdc", "data_level": 0, "recommendation_value": 0, "license_type": "https://creativecommons.org/licenses/by/4.0/", "doi_reg_from": "reg_local", "cstr_reg_from": "reg_local", "doi_not_reg_reason": null, "cstr_not_reg_reason": null, "is_paper_in_submitting": false, "ds_topic_tags": [ "冰川", "消融期", "雪线高度" ], "ds_subject_tags": [ "自然地理学" ], "ds_class_tags": [], "ds_locus_tags": [ "阿尔泰山" ], "ds_time_tags": [ 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 ], "ds_contributors": [ { "true_name": "岳晓英", "email": "yuexiaoying@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "ds_meta_authors": [ { "true_name": "岳晓英", "email": "yuexiaoying@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "ds_managers": [ { "true_name": "岳晓英", "email": "yuexiaoying@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "category": "冰川" }