Land cover 2018 Lozère

The OCS GE (large-scale land cover) repository is a vector database describing land cover and land use for the entire metropolitan area and the overseas departments and regions (DROM). Its model has two dimensions: it separates land use from land use (see precise nomenclature). The geometric accuracy of the OCSGE is metric and is based on the RGE®. Its information comes mainly from aerial photographs updated every three years, and it therefore has a temporal consistency with them. Successive vintages make it possible to quantify and qualify changes in the soil surface. By 2025, the new generation GE SCO – financed by the Directorate-General for Planning, Housing and Nature (DGALN) of the Ministry of Ecological Transition and Territorial Cohesion – will offer complete coverage of the national territory in at least two vintages. It is a core data layer, which can be enriched if necessary at refined thematic levels to take into account local specificities and respond to specific needs. As part of the artificialization observatory, IGN is carrying out work that optimizes the current production chain in order to achieve the greatest possible automation. The aim is to meet two objectives: • a significant reduction in costs, minimising the share of human photo-interpretation, • and a significant reduction in production times making it possible to produce 1/3 of France every year under cruising conditions. This is done by using artificial intelligence (AI) processes such as ‘deep learning’. The GE SCO production chain is based on an infrastructure with significant computing capacities and storage space to host and process large data. This database will be crucial for monitoring artificialisation and achieving net zero artificialisation by 2050, as set out in the ‘Climate and Resilience’ law of 22 August 2021. Further information is available on the Artificialisation Portal. The BD OCS GE N-G is based on the national nomenclature recommended by the National Geographical Information Council (CNIG), developed by the Centre d’études et d’expertise sur les risques, l’environnement, la mobilité et l’aménagement (CEREMA), under the supervision of the Ministry for Ecology, Sustainable Development and Energy (MEDDE.DGALN). The BD OCS GE complies with the national production recommendations that accompany the national nomenclature. It is based on an intermediate data layer, the national reference system for the main networks constituting the ‘National Ossature’. It has four main functions: • ensure geographical continuity between territories; • ensure a reference geometry; • partition territories homogeneously; • ensure spatial cohesion between territorial scales. OPenIG makes available in shapefile format the OCS GE comic for Lozère and the associated documentation. In addition, the IGN provides a user guide designed to facilitate the understanding and use of GE SCO data, presented here at the level of the national pillar. The first section provides a detailed description of the GE OCS and its characteristics, the second presents how these data can be exploited by geomaticians using QGIS software. Each party may be consulted independently. Here is the link to access this guide: https://storymaps.arcgis.com/stories/193550c4e4af4f92845201d74ca8a002

OCS GE（大规模土地覆盖）是一款面向全都会区以及海外省与海外大区（DROM）的矢量数据库（vector database），用于描述该区域的土地覆盖（land cover）与土地利用（land use）情况。其模型包含两个维度：区分土地覆盖与土地利用（详见精准命名规则）。OCS GE的几何精度为米级，基于RGE®地理参考框架构建。其数据主要源自每三年更新一次的航空影像，因此与影像的时间一致性良好。不同年份的数据集版本可实现对地表变化的量化与定性分析。
至2025年，由法国生态转型与国土协调部规划、住房与自然总局（DGALN）资助的新一代GE SCO数据集，将至少覆盖两个年份批次的法国全域国土。该数据集属于核心数据图层，可根据需求细化专题层级以适配地方特异性，并响应特定应用需求。
作为地表人工化观测站的组成部分，法国国家地理研究院（IGN）正开展优化现有生产链的工作，以实现尽可能高的自动化程度。该工作旨在实现两大目标：一是大幅降低成本，减少人工影像解译的占比；二是显著缩短生产周期，在常规产能下可实现每年完成法国三分之一国土的数据集生产。此项优化将借助深度学习等人工智能（AI）技术实现。
GE SCO的生产链依托具备强大计算能力与存储空间的基础设施，用于承载并处理大规模数据。如2021年8月22日颁布的《气候与韧性法案》所规定，该数据库对于监测地表人工化进程、实现2050年人工化净零目标至关重要。更多信息可登录地表人工化门户网站查询。
BD OCS GE N-G数据集基于法国国家地理信息委员会（CNIG）推荐的国家命名规则，由风险、环境、交通与规划研究与专家中心（CEREMA）制定，并由生态、可持续发展与能源部（MEDDE.DGALN）监管。BD OCS GE数据集符合配套国家命名规则的国家级生产规范。该数据集依托名为“国家骨干（National Ossature）”的核心网络国家级参考系统这一中间数据图层构建，具备四项核心功能：一是保障辖区间的地理连续性；二是提供基准几何框架；三是实现辖区的均匀分区；四是维系不同国土尺度间的空间衔接性。
OPenIG平台提供洛泽尔省OCS GE数据集的Shapefile格式文件及配套文档。此外，法国国家地理研究院（IGN）还提供了一份用户指南，旨在帮助用户理解并使用GE SCO数据集，本指南以国家级支柱层面的视角呈现。指南第一部分详细介绍了GE OCS数据集及其特性，第二部分则讲解了测绘人员如何借助QGIS软件对该数据进行开发利用，两部分内容可独立查阅。该指南的访问链接如下：https://storymaps.arcgis.com/stories/193550c4e4af4f92845201d74ca8a002