玛曲县天然草原资源及分布研究

Grassland Resources and Distribution in Maqu County

甘肃省玛曲县作为黄河源区重要的水涵养区和生态脆弱区,其天然草原对涵养水源、保护黄河源区生态安全、确保当地草地畜牧业生产的健康发展具有十分重要的意义。为摸清玛曲县草原资源现状,将遥感与地面调查相结合,选择决策树分类等方法对玛曲县天然草原的分布、分类和面积进行研究与评价。结果表明:玛曲县有低地草甸、高寒草甸、山地草甸和高寒草原4个草原类,总草原总面积93.13万hm2,其中高寒和低地草甸分别占全县草原面积的82.37%和11.62%,山地草甸和高寒草原仅占4.23%和1.78%;各乡镇分类草原面积均以高寒草甸所占比例最大,其中阿万仓镇、木西合乡、欧拉镇和欧拉秀玛乡高寒草甸所占比例均在90%以上,尼玛镇、阿孜站和西科河羊场占比在80%以上,仅齐哈玛镇占比在50%以下(47.02%);低地草甸占比较大的乡镇有曼日玛镇(40.68%)、齐哈玛镇(26.21%)、采日玛镇(24.30%)和河曲马场(30.84%)。

Maqu county as an important water conservation area and ecologically vulnerable area in the source area of the Yellow River,its natural grassland is of great significance to conserve water resources,protect the ecological security of the source area of the Yellow River and ensure the healthy development of local grassland animal husbandry production. To investigate the present situation of grassland resources in Maqu county,combining remote sensing with ground survey,the distribution,classification and area of natural grassland in Maqu county were studied and evaluated by using decision tree classification method. The result showed that Maqu county had four grassland types(lowland meadow,alpine meadow,mountain meadow,alpine grassland),with a total grassland area of 931 300 hm2,the alpine and lowland meadows accounted for 82.37% and 11.62% of the grassland area,mountain meadow and alpine grassland accounted for 4.23% and 1.78%. Alpine meadow accounted for the largest proportion of grassland area classified by towns and villages,the proportion of Awancang town,Muxihe township,Oula town and Oulaxiuma township alpine meadows was above 90%,Nima town,Azi and Xikehe sheep farm accounted for more than 80%,only the town of Qihama accounted for less than 50%(47.02%). Townships with a large proportion of lowland meadows were Manrima(40.68%),Qihama(26.21%),Cairima(24.30%)and Hequ horse farm(30.84%).