青海省循化县天然草地等级面积统计数据（1988，2012）

该数据集记录了1988年，2012年度青海省循化县天然草地等级面积统计数据，数据按照天然草地等级代号分类统计，草地等的划分以草地型为基本单元，划分为优、良、中、低、劣五个等别。各等的划分标准如下：
Ⅰ等（优等）草地：优类牧草重量占60%以上；
Ⅱ等（良等）草地：良类以上牧草重量占60%以上，其他类占40%；
Ⅲ等（中等）草地：中类以上牧草重量占60%以上，其他类占40%；
Ⅳ等（低等）草地：低类以上牧草重量占60%以上，其他类占40%；
Ⅴ等（劣等）草地：劣类牧草重量占40%以上｡
草地级的划分以草地型为基本单元，按鲜草产量将全省草地划分为8级。各级标准如下：
1级草地：每公顷草地产鲜草12000k g 以上；2级草地：每公顷草地产鲜草9000kg ~ 12000kg；
3级草地：每公顷草地产鲜草6000kg~ 9000kg；4级草地：每公顷草地产鲜草4500kg ~ 6000kg；
5级草地：每公顷草地产鲜草30001kg~ 4500kg；6级草地：每公顷草地产鲜草1500kg~ 3000kg；
7级草地：毎公顷草地产鲜草750kg~ 1500kg；8级草地：每公顷草地产鲜草750kg以下。数据整理自青海省草原总站与1988年和2012年发布的《青海省草地资源统计册》。数据集包含2个数据表，分别为：循化县天然草地等级面积统计数据（2012）、循化县天然草地等级统计数据（1988）。数据表结构相似。例如循化县天然草地等级面积统计数据（2012）表共有9个字段：
字段1：合计
字段2：1级
字段3：2级
字段4：3级
字段5：4级
字段6：5级
字段7：6级
字段8：7级
字段9：8级

This dataset records the statistical data of natural grassland grade and area of Xunhua County, Qinghai Province, for the years 1988 and 2012. The data is classified and counted according to natural grassland grade codes. Grassland grading is based on grassland types, divided into five grades: excellent, good, medium, low, and poor. The grading standards for each grade are as follows:
Grade Ⅰ (excellent) grassland: the weight of excellent forage accounts for more than 60%;
Grade Ⅱ (good) grassland: the weight of good or higher-grade forage accounts for more than 60%, with other types accounting for 40%;
Grade Ⅲ (medium) grassland: the weight of medium or higher-grade forage accounts for more than 60%, with other types accounting for 40%;
Grade Ⅳ (low) grassland: the weight of low or higher-grade forage accounts for more than 60%, with other types accounting for 40%;
Grade Ⅴ (poor) grassland: the weight of poor forage accounts for more than 40%.

Grassland classification is also based on grassland types, and the grasslands of the whole province are divided into 8 grades based on fresh forage yield. The standards for each grade are as follows:
Grade 1 grassland: more than 12,000 kg of fresh forage per hectare;
Grade 2 grassland: 9,000 kg to 12,000 kg of fresh forage per hectare;
Grade 3 grassland: 6,000 kg to 9,000 kg of fresh forage per hectare;
Grade 4 grassland: 4,500 kg to 6,000 kg of fresh forage per hectare;
Grade 5 grassland: 3,000 kg to 4,500 kg of fresh forage per hectare;
Grade 6 grassland: 1,500 kg to 3,000 kg of fresh forage per hectare;
Grade 7 grassland: 750 kg to 1,500 kg of fresh forage per hectare;
Grade 8 grassland: less than 750 kg of fresh forage per hectare.

The data was compiled from the *Statistical Book of Qinghai Grassland Resources* published by the Qinghai Provincial Grassland Station in 1988 and 2012. This dataset contains two data tables, namely: Statistical Data of Natural Grassland Grade and Area of Xunhua County (2012), and Statistical Data of Natural Grassland Grades of Xunhua County (1988). The structures of the two data tables are similar. For example, the table *Statistical Data of Natural Grassland Grade and Area of Xunhua County (2012)* has a total of 9 fields:
Field 1: Total
Field 2: Grade 1
Field 3: Grade 2
Field 4: Grade 3
Field 5: Grade 4
Field 6: Grade 5
Field 7: Grade 6
Field 8: Grade 7
Field 9: Grade 8