摘要
利用近10a宁夏8大类土地详查资料和沙尘暴实况及风速资料,结合亚洲环流指数和NCEP(1990—2002年)全球再分析资料,对宁夏沙尘暴多发区生态环境年际变迁与沙尘暴演变规律特征进行了综合对比分析。结果表明:近10a来,宁夏生态环境状况整体呈逐年退化趋势,尤其是中部干旱带地区,由于牧草地和耕地面积明显减少,草场品质及载畜量下降,恶化趋势更为严重;在同等气象条件下,多发区沙尘暴发生前后的风速为逐渐减小趋势,这与宁夏地区生态特征量有显著的相关关系,且近10a沙尘暴多发的4月,其发生次数在20世纪90年代后期有所增多。即生态环境的退化,导致宁夏中部干旱带地区沙尘暴起暴阈值明显下降,发生机率在显著提高。
A comprehensive analysis on sandstorm evolvement and annual ecological variance was conducted in the area where sandstorms occurred frequently in Ningxia by making use of the detailed survey data of the main eight land types, sandstorm and wind regimes in Ningxia in past 10 years, and integrating the Asia circulation index and reanalyzed data of NCEP in 1990\_2002. Result shows that the ecological environment in Ningxia was degraded, especially in the drought strip in middle Ningxia. Because of the decreasing of pasture and plough field apparently, the descending of grass quality and capacity of feeding livestock, the deterioration of ecological environment is much more serious; meanwhile under same meteorological circumstance, in recent 10 years, the wind speed before and after sandstorms reduced, which has close correlation with the ecological features of this region. Sandstorms were likely to happen in April, and the occurrence increased in later 1990s. The above means that the deterioration of ecological environment resulted in the descent of sandstorm threshold wind and the obvious increase of occurrence possibility.
出处
《中国沙漠》
CSCD
北大核心
2005年第1期45-49,共5页
Journal of Desert Research
基金
国家自然科学基金项目(40065002)
宁夏自然科学基金项目(AD001 2004)共同资助
