National soil hydrologic groups map of Hungary

The national soil hydrologic groups map of Hungary aggregates the information available from the 100 m resolution 3D soil hydraulic maps of Hungary. The map was derived using k-means clustering combined with expert-based rules. Source data included the national 3D soil hydraulic maps (HU-SoilHydroGrids), maps of basic soil properties (DOSoReMI.hu), maps of salt affected soils, and the Hungarian Detailed Soil Hydrophysical Database (MARTHA). The derived 68 groups are defined by distinct hydraulic properties, including van Genuchten parameters - describing water retention - and saturated hydraulic conductivity. This national map simplifies the representation of complex soil properties to support computationally intensive national-scale models and land management planning. The dataset has a resolution of 100 m and provides full coverage of Hungary. The data is stored in soil_hydrologic_groups.tif, a GeoTIFF file using the Hungarian Unified National Projection System (EOV/HD72 – EPSG:23700; see https://epsg.io/23700). A supplementary CSV file (map_code_cluster_VG_KS.csv) provides definitions of the map codes, including the cluster numbers and their corresponding soil hydraulic parameters. Column descriptions: map_code: map codes map_code_depth: map code with depth interval (e.g., 1_0_5 refers to the 0–5 cm depth of map code 1) cluster_number: cluster number of the soil hydrologic groups thr_VG, ths_VG, alp_VG, n_VG: van Genuchten parameters thr (cm³/cm³), ths (cm³/cm³), alp (1/cm), n (–) KS: saturated hydraulic conductivity (cm/day) The thr parameter was set to 0. The m parameter is equal to 1 - 1/n. The statistics_based_clustering.R file contains the code for the k-means analysis. The code for the expert-based rules is stored in the expert_based_clustering.R file.匈牙利国家土壤水文组地图整合了源自分辨率为100米的匈牙利三维土壤水力地图的可用信息。该地图经k-means聚类（k-means clustering）结合专家经验规则推导生成。源数据涵盖国家三维土壤水力地图（HU-SoilHydroGrids）、基础土壤属性地图（DOSoReMI.hu）、盐渍化土壤分布图，以及匈牙利详细土壤水理数据库（MARTHA）。 本次生成的68个土壤水文组以差异化的水力属性作为划分依据，包括表征土壤持水性能的范·盖嫩参数（van Genuchten parameters）以及饱和导水率。该国家地图简化了复杂土壤属性的表征形式，可为计算量需求极高的全国尺度模型构建与土地管理规划工作提供支撑。 本数据集分辨率为100米，实现了匈牙利全境全覆盖。数据以GeoTIFF格式存储于soil_hydrologic_groups.tif文件，采用匈牙利统一国家投影坐标系（EOV/HD72 – EPSG:23700；详见https://epsg.io/23700）。 配套的CSV文件map_code_cluster_VG_KS.csv提供了地图编码的定义信息，涵盖聚类编号及其对应的土壤水力参数。 字段说明如下： map_code：地图编码 map_code_depth：带深度区间的地图编码（例如1_0_5代表地图编码1对应的0–5厘米土层） cluster_number：土壤水文组的聚类编号 thr_VG、ths_VG、alp_VG、n_VG：范·盖嫩参数 其中： thr（cm³/cm³）， ths（cm³/cm³）， alp（1/cm）， n（无量纲） KS：饱和导水率（cm/天） thr参数已被设置为0，m参数等于1 - 1/n。 用于k-means聚类分析的代码存储于statistics_based_clustering.R文件，专家经验规则的实现代码则存储于expert_based_clustering.R文件。