With the abundant natural grassland resources,Maqu County becomes the important stockbreeding base in the upper reaches of Yellow River.Eco environment problems,such as grassland degeneration,land desertification,wate...With the abundant natural grassland resources,Maqu County becomes the important stockbreeding base in the upper reaches of Yellow River.Eco environment problems,such as grassland degeneration,land desertification,water and soil loss,and water resource decrease were incurred by population increase and stockbreeding development.Under the trend of global warming,human factors,for example,over loading and grazing,irrational dieforestation,and low input,etc., were the direct and radical reasons to deteriorate the vulnerable ecoenvironment.Technological,legal,administrative and economic measures,such as afforestation,artificial grass planting,grassland water saving irrigation and fertilization,industrial structure,adjustment scientific and technical education,high efficient management and so on,should be taken to control eco environment synthetically in order to realize the favorable circulation of eco system and the sustainable development of regional stockbreeding.展开更多
文摘With the abundant natural grassland resources,Maqu County becomes the important stockbreeding base in the upper reaches of Yellow River.Eco environment problems,such as grassland degeneration,land desertification,water and soil loss,and water resource decrease were incurred by population increase and stockbreeding development.Under the trend of global warming,human factors,for example,over loading and grazing,irrational dieforestation,and low input,etc., were the direct and radical reasons to deteriorate the vulnerable ecoenvironment.Technological,legal,administrative and economic measures,such as afforestation,artificial grass planting,grassland water saving irrigation and fertilization,industrial structure,adjustment scientific and technical education,high efficient management and so on,should be taken to control eco environment synthetically in order to realize the favorable circulation of eco system and the sustainable development of regional stockbreeding.
文摘利用1982年至2003年NASAGIMMS逐月归一化植被指数（NDVI）数据集和玛曲县气温、降水资料,对玛曲县近22年来NDVI变化和气候变化特征及其相互关系进行分析,以揭示黄河上游地区植被对全球变暖的区域响应.结果表明：（1）玛曲县植被变化在不同时段表现出较大差异,NDVI年际变化略有增加.（2）夏季是NDVI增长最快的季节,春季NDVI在20世纪90年代后期到本世纪初呈下降趋势,秋、冬季NDVI呈下降趋势.（3）返青期和NDVI值在春季达到同一水平值的时间及夏季达到峰值的时间逐年提前,说明生长季提前是该地区植被对全球变暖的主要响应表现.（4）玛曲县近22年来植被的NDVI变化在中等盖度水平（0.3～0.5）呈增加趋势,高盖度水平（≥0.7）的植被呈下降趋势,而在年代间变化水平上,气温和降水对植被生长都有影响,其中气温要比降水更显著;玛曲县降水和气温在季节尺度上对NDVI的影响不明显,除夏季气温与夏季NDVI关系密切之外,其他季节的关系均不明显.（5）按植被变化特点,将NDVI变化斜率最大值0.005定义为返青期指标,发现该地区牧草返青期的变化主要受温度条件影响,随气候变暖,返青期提前,其变化规律为4～5月份平均气温每10年升高0.6℃,返青期每10年提前3 d.
