黄河上游1:100万土壤数据库（1995）

一、概述
黄河上游1:100万土壤数据库是以1:100万中国土壤数据库为数据源裁剪而成。1:100万中国土壤数据库根据全国土壤普查办公室1995年编制并出版的《1:100万中华人民共和国土壤图》编制而成。该数据库采用传统的“土壤发生学分类”系统，基本制图单位为亚类，共分12个土纲，61个土类，227个亚类，基本覆盖了全国各种类型的土壤及其主要属性数据。
二、数据处理说明
中国1:100万土壤数据库，是由中国科学院南京土壤研究所以史学正研究员为学术带头人的土壤资源与数字化管理创新科研小组，历经四年组建而成的。该数据库由两部分组成，即土壤空间数据库与土壤属性数据库。数据库的建立得到了中国科学院知识创新项目资助，并在刘纪远与庄大方研究员的领导下完成。
三、数据内容说明
土壤空间数据库，即全国1:100万数字化土壤图，是依据全国个普查办公室1995年编制并出版的《1:100万中华人民共和国土壤图》，经数字化处理、图幅接边和编辑后完成。该数字化土壤图如实地反映了原土壤图的面貌，继承了原土壤图编制时的制图单元，其基本制图单元大部分为土属，共分12个土纲，61个土类，235个亚类，是目前全国性唯一的，也是最为详细的数字化土壤图件。
土壤属性数据库，其属性数据引自《中国土种志》，该套土种志共分六卷，收集了近2540个土种。土壤属性数据可分为土壤物理性质、土壤化学性质和土壤养分等。土壤物理性质 土壤颗粒组成和土壤质地等，土壤化学性质如PH值、有机质等，土壤养分包括全N、全P、全K以及有效P和有效K等。
四、数据使用说明
土壤类型与土壤属性是自然地理学研究中的一项重要内容，借助黄河上游1:100万土壤数据库，可对黄河上游土壤资源的类型、数量和空间分布以及成土环境与特征进行了解与分析。该数据集对进行黄河上游大范围土壤侵蚀预警与自然灾害预报有着重要的意义。

1. Overview
The 1:1,000,000-scale Soil Database of the Upper Yellow River is cropped from the 1:1,000,000-scale Chinese Soil Database. The 1:1,000,000-scale Chinese Soil Database was compiled based on the *1:1,000,000-scale Soil Map of the People's Republic of China* compiled and published by the National Soil Survey Office in 1995. This database adopts the traditional genetic soil classification system, with subgroup as its basic mapping unit. It covers 12 soil orders, 61 soil great groups, and 227 soil subgroups, and basically includes all types of soils across the country and their main attribute data.

2. Data Processing Instructions
The 1:1,000,000-scale Chinese Soil Database was developed over four years by the Soil Resources and Digital Management Innovation Research Team led by Researcher Shi Xuezheng from the Institute of Soil Science, Chinese Academy of Sciences (Nanjing). This database consists of two parts: the soil spatial database and the soil attribute database. The development of this database was funded by the Knowledge Innovation Program of the Chinese Academy of Sciences, and was completed under the leadership of Researchers Liu Jiyuan and Zhuang Dafang.

3. Data Content Description
The soil spatial database, namely the national 1:1,000,000-scale digital soil map, was completed through digitization, sheet mosaicking and editing based on the *1:1,000,000-scale Soil Map of the People's Republic of China* compiled and published by the National Soil Survey Office in 1995. This digital soil map faithfully reflects the original soil map and inherits the mapping units used in the original compilation. Most of its basic mapping units are soil families, with 12 soil orders, 61 soil great groups, and 235 soil subgroups. It is currently the only and most detailed national-scale digital soil mapping product.
The soil attribute database derives its attribute data from *Chinese Soil Series*, which consists of six volumes and collects nearly 2,540 soil series. Soil attribute data can be divided into three categories: soil physical properties, soil chemical properties and soil nutrients. Soil physical properties include soil particle size distribution and soil texture, etc.; soil chemical properties include pH value, organic matter content, etc.; soil nutrients include total nitrogen (N), total phosphorus (P), total potassium (K), available phosphorus (P) and available potassium (K), etc.

4. Data Usage Instructions
Soil types and soil attributes are important contents in physical geography research. With the help of the 1:1,000,000-scale Soil Database of the Upper Yellow River, one can understand and analyze the types, quantities, spatial distribution, pedogenic environments and characteristics of soil resources in the Upper Yellow River region. This dataset is of great significance for large-scale soil erosion early warning and natural disaster forecasting in the Upper Yellow River region.