本数据集采用美国地质调查局（USGS）的全球可视化浏览器（Glovis）（http://glovis.usgs.gov） 网站公布的1972-2020年73幅Landsat5、7、8影像作为遥感数据源，基于NDWI指数提取巴尔喀什湖湖面矢量面状数据，只有27年的数据，数据时间不连续，共缺少22年的数据，主要缺少1973-1974年、1978-1990年、2003-2005年、2018年等年份的数据。
", "ds_source": "原始影像数据来源于美国地质调查局（USGS）的全球可视化浏览器网站（http://glovis.usgs.gov）， 包括1972-2020年Landsat TM/ETM+/OLI数据，选取的数据满足以下要求：①云覆盖少（云覆盖率<30%）；②阴影较少、色调层次分明；③无噪声。
", "ds_process_way": "基于1972—2020年间的Landsat影像，采用全域-局部自适应迭代的阈值分割方法提取湖泊面积信息。
", "ds_quality": "自动解译的矢量数据在结合目视修正工作后，取得了较高的精度，能够满足研究需求。\n本数据中存在一个年度内有多个月份的矢量数据，共有73期数据；按照年份统计，本数据有27年的数据，数据时间不连续，共缺少22年的数据，主要缺少1973-1974年、1978-1990年、2003-2005年、2018年等年份的数据。
", "ds_acq_start_time": null, "ds_acq_end_time": null, "ds_acq_place": "巴尔喀什湖", "ds_acq_lon_east": null, "ds_acq_lat_south": null, "ds_acq_lon_west": null, "ds_acq_lat_north": null, "ds_acq_alt_low": null, "ds_acq_alt_high": null, "ds_share_type": "apply-access", "ds_total_size": 13166343, "ds_files_count": 1, "ds_format": ".shp", "ds_space_res": "无", "ds_time_res": "年", "ds_coordinate": "WGS84", "ds_projection": "WGS84", "ds_thumbnail": "1f742979-6af4-464f-b145-459b05d76120.png", "ds_thumb_from": 2, "ds_ref_way": "", "paper_ref_way": "", "ds_ref_instruction": "", "ds_from_station": null, "organization_id": "a5877b42-96ea-4f13-af7e-246f355413d6", "doi_value": "", "subject_codes": [ "170.45" ], "quality_level": 1, "publish_time": "2025-04-09 11:27:26", "first_publish_time": null, "last_updated": "2025-05-28 17:03:02", "protected": false, "protected_to": null, "lang": "zh", "cstr": "33110.11.ariddc.00330", "license": null, "extra": null, "files_shape": [ { "name": "1972-2020_Balkash_Lake_vector.rar", "size": 13166343, "is_dir": false } ], "features": null, "data_level": 0, "i18n": { "en": { "title": "1972-2020 Area change data of Balkhash Lake in Kazakhstan", "ds_abstract": "This dataset uses 73 Landsat5, 7, and 8 images from 1972 to 2020 published on the U.S. Geological Survey's (http://glovis.usgs.gov) website as remote sensing data sources. Vector surface data of Balkhash Lake is extracted based on the NDWI index. There are only 27 years of data, and the data time is discontinuous. There is a total of 22 years of data, mainly missing data from 1973-1974, 1978-1990, 2003-2005, 2018 and other years.
", "ds_source": "The raw image data comes from the U.S. Geological Survey's (USGS) global visualization browser website (http://glovis.usgs.gov), including Landsat TM/ETM+/OLI data from 1972 to 2020. The selected data meets the following requirements: ① Less cloud coverage (cloud coverage rate of 30%);② Less shadows and clear tone levels;③ No noise.
", "ds_process_way": "Based on Landsat images from 1972 to 2020, a whole-local adaptive iterative threshold segmentation method is used to extract lake area information.
", "ds_quality": "After combined with visual correction, the automatically interpreted vector data achieves high accuracy and can meet research needs.\nThere are vector data for multiple months in a year, with a total of 73 periods of data; according to year statistics, this data has 27 years of data, and the data time is discontinuous, and a total of 22 years of data are missing, mainly missing data for the years 1973-1974, 1978-1990, 2003-2005, 2018 and other years.
", "ds_acq_place": "Balkhash Lake", "ds_format": ".shp", "ds_projection": "WGS84", "ds_space_res": "no", "ds_time_res": "years" } }, "license_type": null, "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": [ "湖泊", "水体", "面积" ], "ds_subject_tags": [ "地理学" ], "ds_class_tags": [], "ds_locus_tags": [ "巴尔喀什湖" ], "ds_time_tags": [ 1972, 1975, 1977, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2006, 2007, 2008, 2009, 2010, 2011, 2013, 2014, 2015, 2016, 2017, 2019, 2020 ], "ds_contributors": [ "黄粤", "刘铁" ], "ds_meta_authors": [ "黄粤" ], "ds_managers": [ "黄粤", "刘铁" ], "category": "水文" }