河北坝上地区脆弱生态环境特征

坝上地区为典型的脆弱生态环境地带，这种地带易发生环境退化，但也存在着逆转的可能性。由于全球气候变化和人类活动的影响，近几十年来生态环境严重退化。土地风蚀沙化调查研究表明，影响风蚀沙化的因素很多，尤其是外部环境因素相互关系更为复杂，如大风和尘暴日、风速、降水、植被生长状况、土地封冻与融冻、土地耕翻等。但重要因素仍是风日、风速和地表物质。由于气候干旱，降水少等原因，本区最大的湖淖──安固里淖，在不断萎缩，该湖历史上比现在大十几倍，并且萎缩一直是自东向西进行，可能与新构造运动有关。坝上地区生态环境的退化是可以逆转的，近几年，一系列生态建设工程的实施，已初步收到了较好的效果。

FRAGILE ECO-ENVIRONMENT CHARACTERISTICS IN BASHANG REGION,HEBEI PROVINCE

Bashang region in Hebei Province is a typical zone of fragile eclolgical environment.Owing to global climatic changes and human activity influence the ecological environment in the regionhas severely degraded in the past several decades. The Anguli Lake,and largest lake in the region,hasshrinked tenfold or more in water area,Observations on land wind erosion and desertification showedthat many factors,such as gale,dust-storm,wind velocity,precipitation,vegetation cover and landtillage etc, affected the wind ercoion and descrtification,However,the eco-environment degradationin the region can be reversed as long as some ecological projects have been adopted.