论文部分内容阅读
1、保持水土:巴中县五十年代初,森林复盖率30.2％。1985年后森林复被率降为16.4％据巴河七里沱水文站六十年代测定、巴河输沙量年平均达455.8万吨,比五十年代末期年输沙量增加了六倍。六十年代中期在植树造林的同时采用封山育林,森林复被率上升到22.58％。七十年代测定,巴河的输沙量,年平均减为276.86万吨,比六十年代的输沙量降低39.27％。八十年代初全县森林复被率上升到24.81％,其中白岩河流域通过造林护林治理,经测定现在的年输沙量,比1665年前输沙量减少64.7％。
1, to maintain soil and water: Bazhong County in the early 1950s, the forest coverage rate of 30.2%. After 1985, the rate of forest rehabitation was reduced to 16.4%. According to the analysis conducted in the 1960s by the Ba Litang Hydrographic Station, the annual sediment discharge of the Ba River reached an average of 4,558,000 tons, an increase of six times that of the sedimentation rate in the late 1950s. In the mid-1960s, afforestation and afforestation were carried out in closed hillsides for afforestation. The rate of forest reforestation increased to 22.58%. Seventies determination, Ba River sediment transport, the average annual reduction of 2.7686 million tons, less than the sediment transport in the sixties 39.27%. In the early 1980s, the entire county’s forest recovery rate has risen to 24.81%. Among them, the management of afforestation and forest protection in the Baiyanhe River basin has determined that the current annual sediment discharge is reduced by 64.7% compared with that before 1665.