青海湖流域草地退化时空分布特征

发布时间：2018-05-08 17:50

本文选题：青海湖流域 + 草地退化　；参考：《生态与农村环境学报》2017年05期

【摘要】：青海湖地区是我国青藏高原的生态脆弱区,草地退化状况是反映该流域生态环境状况的有效指标。在对青海湖流域退化草地进行分类的基础上,利用遥感手段获得流域退化草地的空间分布和空间动态。在草地退化重点区域选取8个样地来反映流域不同区域、不同类型草地的退化情况。结果表明,1977—2000年青海湖流域草地退化情况十分严重,流域内草地共减少206.68 km~2,其中,大部分草地转变为耕地和沙地。草地退化主要集中在湖区南岸、共和县的黑马河乡及布哈河口的鸟岛3个区域。2000年以后,流域内草地退化情况得到明显改善,草地总面积开始有所增加,主要原因是2000年之后温度升高和降水增加为草地的生长和改善提供了有利的自然条件,以及政府和相关部门在流域内实行了一系列草地保护政策。2004年是青海湖流域气候转折年,流域气温明显升高,降水明显增加,青海湖水位下降趋势有所缓解,流域草地退化现象明显好转。青海湖流域草地是该流域生态系统的重要指示植被,利用归一化植被指数(NDVI)可准确监测流域植被变化情况。
[Abstract]:Qinghai Lake region is a fragile ecological region of Qinghai-Tibet Plateau in China, and grassland degradation is an effective index to reflect the ecological environment of the basin. Based on the classification of degraded grassland in Qinghai Lake basin, the spatial distribution and spatial dynamics of degraded grassland in the basin were obtained by remote sensing. Eight plots were selected to reflect the degradation of grassland in different regions and different types of grassland. The results showed that grassland degradation was very serious in Qinghai Lake basin from 1977 to 2000, and the grassland in the basin was reduced by 206.68 km2, most of which were transformed into cultivated land and sandy land. Grassland degradation is mainly concentrated on the southern shore of the lake region, the three regions of Heima River Township and Bird Island of Buha Estuary in Republican County. After 2000, the degradation of grassland in the basin has been obviously improved, and the total area of grassland has begun to increase. The main reasons are that the increase in temperature and precipitation after 2000 has provided favorable natural conditions for the growth and improvement of grassland, as well as a series of grassland protection policies implemented by the government and relevant departments in the basin. The temperature and precipitation increased obviously, the water level of Qinghai Lake was alleviated, and the degradation of grassland in the basin was improved obviously. Grassland in Qinghai Lake basin is an important indicator vegetation in the basin ecosystem. The normalized vegetation index (NDVI) can be used to accurately monitor the vegetation change in the basin.
【作者单位】：环境保护部南京环境科学研究所/生态保护与气候变化研究中心;盐城师范学院江苏省盐土生物资源研究重点实验室;
【基金】：中央级公益性科研院所基本科研业务费专项
【分类号】：S812.6

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