Hydrologic Soil Groups (HSG) of NSW

This map provides an estimation of Hydrologic Groups of soils in NSW according to the four class system (A-D)\r\n\r\n* A — soils having __high infiltration__ rates, even when thoroughly wetted and consisting chiefly of deep, well to excessively-drained sands or gravels. These soils have a high rate of water transmission and have low water run-off potential.\r\n\r\n* B — soils having __moderate infiltration__ rates when thoroughly wetted and consisting chiefly of moderately deep to deep, moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission.\r\n\r\n* C — soils having __slow infiltration__ rates when thoroughly wetted and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately fine to fine texture. These soils have a slow rate of water transmission.\r\n\r\n* D — soils having __very slow infiltration__ rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a claypan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission.\r\n\r\nThe map uses the best available soils mapping coverage and was derived from a lookup table system linking a Hydrologic Group class to a particular soil type using the Great Soil Group (GSG) classification. Each dominant GSG has been assigned a Hydrologic Soil Group.\r\n\r\nThe classification is based on the United State's Hydrologic Soil Group system published within the National Engineering Handbook (2007).\r\n\r\n__Online Maps:__ This dataset can be viewed using eSPADE (NSW’s soil spatial viewer), which contains a suite of soil and landscape information including soil profile data. Many of these datasets have hot-linked soil reports. An alternative viewer is the SEED Map ; an ideal way to see what other natural resources datasets (e.g. vegetation) are available for this map area.\r\n\r\n__Reference:__ Department of Planning, Industry and Environment, 2021, _Hydrologic Soil Groups of NSW_, Version 4.5, NSW Department of Planning, Industry and Environment, Parramatta.

本地图基于四级分类体系（A-D），对新南威尔士州（New South Wales，NSW）的土壤水文组别（Hydrologic Soil Group）进行了估算。

* A类：**高入渗率**土壤，即便完全浸湿后仍维持高入渗特性，主要由深厚、排水良好至过度排水的砂土或砾石组成。此类土壤水分传输速率高，地表径流潜力低。

* B类：**中等入渗率**土壤，完全浸湿后入渗速率处于中等水平，主要为中深至深厚、质地中等偏粗至中等偏细的土壤。此类土壤水分传输速率中等。

* C类：**缓入渗率**土壤，完全浸湿后入渗速率较慢，主要包含存在阻碍水分向下运移层的土壤，或质地中等偏细至细粒的土壤。此类土壤水分传输速率缓慢。

* D类：**极缓入渗率**土壤，完全浸湿后入渗速率极慢，主要包括高膨胀性黏土、永久性高地下水位土壤、表层或近表层存在黏磐或黏土层的土壤，以及覆盖近乎不透水层的浅薄土壤。此类土壤水分传输速率极慢。

本地图采用当前可获取的最优土壤测绘覆盖数据，通过查找表系统将土壤水文组别与特定土壤类型进行关联，关联依据为**大土壤组（Great Soil Group, GSG）**分类体系，每个主导性大土壤组均已被分配对应的土壤水文组别。

该分类体系基于美国《国家工程手册（2007版）》中发布的土壤水文组别标准。

**在线地图**：本数据集可通过eSPADE（新南威尔士州土壤空间可视化工具）查看，该工具集成了包括土壤剖面数据在内的多套土壤与景观信息，多数数据集附带关联的土壤报告。替代可视化方案为SEED地图，该工具可便捷查看该地图区域内可获取的其他自然资源数据集（如植被数据）。

**参考文献**：新南威尔士州规划、产业与环境部，2021年，《新南威尔士州土壤水文组别》，版本4.5，新南威尔士州规划、产业与环境部，帕拉马塔。