该数据集为中国西北地区甘肃省1990年的1:70万土地覆被数据。本数据采用一个分层的土地覆被分类系统，分类系统的一级类与IPCC系统保持一致共6类（林地、草地、湿地、耕地、人工表面、其他），二级类采用了由FAO的LCCS生成的具有全球统一代码的38个类型。
", "ds_source": "主要数据源有：1．1990年代土地利用数据 2．与土地利用数据同期陆地卫星精纠正分县假彩色合成影像 3．辅助数据包括1:50万草地资源图（矢量）、1:100万土壤类型图（矢量）、1:100万植被类型图（扫描）等。
", "ds_process_way": "基于eCognition软件平台，采用面向对象分类方法
", "ds_quality": "数据质量良好
", "ds_acq_start_time": "1990-01-01 00:00:00", "ds_acq_end_time": "1990-12-31 00:00:00", "ds_acq_place": "甘肃省", "ds_acq_lon_east": 109.0, "ds_acq_lat_south": 32.0, "ds_acq_lon_west": 92.0, "ds_acq_lat_north": 42.0, "ds_acq_alt_low": null, "ds_acq_alt_high": null, "ds_share_type": "login-access", "ds_total_size": 27396759, "ds_files_count": 3, "ds_format": "SHP", "ds_space_res": null, "ds_time_res": "", "ds_coordinate": "WGS84", "ds_projection": "", "ds_thumbnail": "e0048812-1fc4-4ce6-8500-240be4770a3e.jpg", "ds_thumb_from": 2, "ds_ref_way": "颜长珍, 谢家丽，1990年甘肃省1:70万土地覆被数据集，国家冰川冻土沙漠科学数据中心(www.ncdc.ac.cn)，2019，doi：10.12072/ncdc.NIEER.db0075.2020", "paper_ref_way": "", "ds_ref_instruction": null, "ds_from_station": null, "organization_id": "52b7b79b-860c-49a5-9083-9a70cf8bed5a", "ds_serv_man": "敏玉芳", "ds_serv_phone": "0931-4967596", "ds_serv_mail": "ncdc@lzb.ac.cn", "doi_value": "", "subject_codes": null, "quality_level": 3, "publish_time": "2021-01-05 10:24:35", "last_updated": "2021-01-05 10:24:35", "protected": false, "protected_to": null, "lang": "zh", "cstr": "11738.11.ncdc.nieer.2020.1478", "i18n": { "en": { "title": "1:700000 land cover data set of Gansu Province in 1990", "ds_format": "", "ds_source": "The main data sources are as follows: 1. Land use data in 1990's; 2. False color synthetic images of counties accurately corrected by Landsat at the same period of land use data; 3. Auxiliary data include 1:500000 grassland resource map (vector), 1:1000000 soil type map (vector), 1:1000000 vegetation type map (scan), etc.
", "ds_quality": "Good data quality
", "ds_ref_way": "Yan Changzhen, Xie Jiali, 1990 1:700000 land cover data set of Gansu Province, national glacial and frozen soil desert scientific data center（ www.ncdc.ac.cn )，2019，doi：10.12072/ ncdc.NIEER.db0075 .2020", "ds_abstract": "The data set is 1:700000 land cover data of Gansu Province in Northwest China in 1990. This data adopts a hierarchical land cover classification system. The first class of the classification system is consistent with the IPCC system, with a total of 6 categories (woodland, grassland, wetland, cultivated land, artificial surface, others), and the second class uses 38 types with global unified code generated by the LCCs of FAO.
", "ds_time_res": "", "ds_acq_place": "Gansu Province", "ds_space_res": "", "ds_projection": "", "ds_process_way": "Based on ecognition software platform, object-oriented classification method is adopted
", "ds_ref_instruction": " \nNone" } }, "submit_center_id": "ncdc", "data_level": 0, "license_type": "CC BY 4.0", "doi_reg_from": "reg_local", "cstr_reg_from": "reg_local", "doi_not_reg_reason": null, "cstr_not_reg_reason": null, "ds_topic_tags": [ "土地覆被", "土地利用", "基础地理" ], "ds_subject_tags": [ "自然地理学" ], "ds_class_tags": [], "ds_locus_tags": [ "西北地区", "甘肃省" ], "ds_time_tags": [ 1990 ], "ds_contributors": [ { "true_name": "颜长珍", "email": "yancz@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" }, { "true_name": "谢家丽", "email": "xiejl@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": "谢家丽", "email": "xiejl@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": "颜长珍", "email": "yancz@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": "生态" }