密云水库上游水土保持重点防治取得初步成效

<正> 密云水库是首都的重要水源工程,控制海河流域潮、白河水系15351km~2的面积,包括河北省的赤城、丰宁、滦平、兴隆、沽源和北京市的密云、延庆、怀柔等12个县的大部或部分地区。密云水库以上多为土石山区和丘陵区,水土流失较为严重。据卫星遥感解译成果,现有水土流失面积8397km~2,占总面积的54.7％,其中中度和强度流失面积4622km~2,

Preliminary Benefits Have Been Made in the Key Prevention Work for Soil and Water Conservation in the Upper Reaches of Miyun Reservior

Miyun Reservior is an important project of water supply for Beijing,capital of our country. The upland of Miyun Reservior was listed as a national key prevention area in 1989,since then,the prevention and supervision work was carried out actively to prevent new soil loss and water pollution according to the policies of " incorporating prevention with harnessment by taking the prevention work as priority ; carrying out integral harnessment according to local conditions and advancing actively by breaking through the focal points". In the first stage,projects for key harnessment were conducted in 65 small watersheds and the area of soil loss under control in past two years was 464. 8 km2 with an average annual rate of harnessment of 8. 7%. The siltation of sediment in reservior has slowed down by the extensive harnessment and the prevention projects built in past years and the water quality came up to the second grade of drinking water according to our national standard. The two years' work of key prevention had provided some experiences in prevention measures and organization ect. for the further protection of water resources in upland of a reservior.