青海省西宁市区天然草地等级面积统计数据（1988，2012）

该数据集记录了1988年，2012年度青海省西宁市区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：西宁市区天然草地等级面积统计数据（2012）、西宁市区天然草地类型等级面积、载畜量统计数据（1988）。数据表结构相似。例如西宁市区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 statistics of natural grassland grade and area in the urban district of Xining, Qinghai Province in 1988 and 2012. The data is classified and counted based on the code of natural grassland grades. The classification of grassland quality grades takes grassland types as the basic unit, which is divided into five grades: excellent, good, medium, low and inferior. The classification standards for each grade are as follows:
- Grade Ⅰ (excellent) grassland: Forage of the excellent category accounts for more than 60% of the total weight;
- Grade Ⅱ (good) grassland: Forage of the good category and above accounts for more than 60% of the total weight, with the remaining 40% coming from other categories;
- Grade Ⅲ (medium) grassland: Forage of the medium category and above accounts for more than 60% of the total weight, with the remaining 40% coming from other categories;
- Grade Ⅳ (low) grassland: Forage of the low category and above accounts for more than 60% of the total weight, with the remaining 40% coming from other categories;
- Grade Ⅴ (inferior) grassland: Forage of the inferior category accounts for more than 40% of the total weight.

The classification of grassland yield grades also takes grassland types as the basic unit, and divides the grasslands of the province into 8 grades based on fresh grass yield. The standards for each grade are as follows:
1. Grade 1 grassland: Fresh grass yield per hectare is above 12,000 kg;
2. Grade 2 grassland: Fresh grass yield per hectare ranges from 9,000 kg to 12,000 kg;
3. Grade 3 grassland: Fresh grass yield per hectare ranges from 6,000 kg to 9,000 kg;
4. Grade 4 grassland: Fresh grass yield per hectare ranges from 4,500 kg to 6,000 kg;
5. Grade 5 grassland: Fresh grass yield per hectare ranges from 3,000 kg to 4,500 kg;
6. Grade 6 grassland: Fresh grass yield per hectare ranges from 1,500 kg to 3,000 kg;
7. Grade 7 grassland: Fresh grass yield per hectare ranges from 750 kg to 1,500 kg;
8. Grade 8 grassland: Fresh grass yield per hectare is below 750 kg.

This dataset is compiled from the *Statistical Book of Grassland Resources in Qinghai Province* released by the Qinghai Grassland Station in 1988 and 2012. It contains two data tables with similar structures: 1. Statistical Data of Natural Grassland Grade and Area in Xining Urban District (2012); 2. Statistical Data of Natural Grassland Type, Grade, Area and Carrying Capacity in Xining Urban District (1988). Take the 2012 table as an example, it has a total of 9 fields:
1. Field 1: Total
2. Field 2: Grade 1
3. Field 3: Grade 2
4. Field 4: Grade 3
5. Field 5: Grade 4
6. Field 6: Grade 5
7. Field 7: Grade 6
8. Field 8: Grade 7
9. Field 9: Grade 8