分水梁小流域水土保持项目调查分析

准格尔旗布尔陶亥苏木分水梁小流域被选定为京津风沙源治理二期工程项目区,2015年开始实施,2016年底全部完成;该项目治理面积11km2,采用植物措施和水利工程措施相结合;项目实施后,水土流失治理程度达到95.84%,植被覆盖度达到59.31%,实现年保水14.9万t,保土2.5万t;发展节水灌溉工程23处,灌溉面积共72.67hm2,文章对此作了介绍。

双碟圆盘夹分水梁造林整地技术

介绍了一种"双碟圆盘夹分水梁"造林整地技术,从土壤含水量、水分入渗深度、改善局部生态环境、造林质量等方面比较分析其优势,为半干旱地区改进造林整地方式提供技术参考。

镇坪县概况

【位置】镇坪县位于安康地区东南部。东与湖北省竹溪县接壤。南与四川省巫溪、城口县毗邻。县城距安康城公路里程210公里。【面积】总面.1,503平方公里。耕地12.2万亩,有林地面积162.8万亩,草地28.2万亩。【地势】地处大巴山北缘,以山地为主,地势南高北低。鸡心岭、杉树坪、分水梁、火石梁横亘县境南部,形成了川、陕屏障;化龙山和大界梁两大山系由南向北延伸,南江河纵贯其中,将全县切割为东西两半,构成了"两山夹一谷"的地貌。境内最高点化龙山主峰,海拔2,917米,最低点江家垭子,

Dynamic analysis of dam-reservoir-foundation interaction using finite difference technique

Time domain dynamic analysis of inclined dam-reservoir-foundation interaction was conducted using finite difference method （FDM）. The Timoshenko beam theory and the Euler-Bemoulli beam theory were implemented to draw out governing equation of beam. The interactions between the dam and the soil were modeled by using a translational spring and a rotational spring. A Sommerfeld＇s radiation condition at the infinity boundary of the fluid domain was adopted. The effects of the reservoir bottom absorption and surface waves on the dam-reservoir-foundation interaction due to the earthquake were studied. To avoid the instability of solution, a semi-implicit scheme was used for the discretization of the governing equation of dam and an explicit scheme was used for the discretization of the governing equation of fluid. The results show that as the slope of upstream dam increases, the hydrodynamic pressure on the dam is reduced. Moreover, when the Timoshenko beam theory is used, the system response increases.

匙吻鲟池塘养殖技术

<正>陕西省黄陵县,介于108033′20″~108054′13″E、35035′29″~35043′14″N之间,处于世界最大的黄土高原腹地,独特的区位使该区具有重要的调节气候、涵养水源、保持水土的特殊生态功能。向北森林极少,再向北则为毛乌素沙地,无森林存在,它已成为陕北地区生态安全的'桥头堡',区位优势独特;该区西靠子午岭主脊,南北为次一级的分水梁环绕,形成起伏不大的低山丘陵,上有风成黄土覆盖。