世界杯2022是哪个国家_国足世界杯出线 - dtfyjq.com

摘要:

水土流失已经和正在蚕食着人们赖以生存的宝贵的水土资源，如何有效地控制水土流失日益受到社会各界和科学家们的广泛关注。中国在水土保持方面创造了许多颇具特色的水土保持措施，如：生物林草措施、耕作措施和水土保持工程措施。该文总结了目前所采用的主要水土保持措施类型。采用坡度、坡长校正公式将数据转化为具有可比性的量值(标准小区)，定量分析了各种水土保持措施对于减少径流和土壤侵蚀产沙的效果，即治理措施的减水减沙效益，为小流域土壤侵蚀预报、水土保持措施的优化及合理配置、优化土地利用结构等提供参考依据。

Abstract:

Soil and water loss have been and are degrading the precious soil and water resources on which we have to rely. How to control over them has been being paid increasingly great attentions by the societies and scientists all over the world. Chinese people have got a long history of soil and water conservation practices and invented many sound measures for soil and water conservation, such as biological methods, tillage measures and engineering technologies. The main measures presently used are briefly discussed in the paper. Equations for modifications of slope gradient factor and slope length factor are used to convert the raw data of soil and water losses into those from standardized runoff plots for the purposes of calculating the runoff and sedimentation reduction percentages under different conservation practices. The data could be useful for watershed soil erosion prediction, rational implementation of soil and water conservation measures, as well as optimal utilization of lands.