The proposed site for the construction of a new dam(Laleni Dam)on the Tsitsa River in the Eastern Cape,South Africa falls within a high soil erosion zone,which is expected to affect the lifespan of the dam.Estimating ...The proposed site for the construction of a new dam(Laleni Dam)on the Tsitsa River in the Eastern Cape,South Africa falls within a high soil erosion zone,which is expected to affect the lifespan of the dam.Estimating the sediment yield of the catchment is important from a management perspective,and thus we designed this study to assess the applicability of the Modified Universal Soil Loss Equation(MUSLE).The original MUSLE was applied to the Inxu River sub catchment,upstream of a proposed dam,over a summer rainfall period extending from October 2016 to April 2017.A modified version of the MUSLE,incorporating a storage module,was later applied over the same period.Model calibration of the MUSLE with and without a storage model was tested against 7 months of recorded daily suspended sediment discharge data.With a storage model,we achieved a percentage bias,coefficient of efficiency and R2 of 2%,0.83 and 0.83,respectively,while without storage the performance statistics were markedly lower.These results suggest that a calibrated MUSLE can provide estimates of sediment yield that are valuable for regional planning,and that the inclusion of a storage component further improves the MUSLE application.Given the complexity of sediment generation and transport processes,a relatively simple empirical MUSLE model is a useful tool for initial sediment yield estimation for planning purposes.展开更多
当前大多数Linux发行版使用功能强大的glibc(GNU C library)作为C标准库(简称C库),但glibc的LGPL协议存在商用不友好条款,制约了商业Linux发行版的推广.一种可行的解决方案是选择某个与glibc相比尚有功能缺陷但适宜商用的C库加以补全,...当前大多数Linux发行版使用功能强大的glibc(GNU C library)作为C标准库(简称C库),但glibc的LGPL协议存在商用不友好条款,制约了商业Linux发行版的推广.一种可行的解决方案是选择某个与glibc相比尚有功能缺陷但适宜商用的C库加以补全,从而制成新的C库以替代glibc.开源欧拉(openEuler)操作系统社区以MIT协议的musl libc作为新的C库选型.新C库对已有应用软件的兼容是成功替换的关键,而精确的兼容性分析算法不仅可以定位缺失API,还可以量化计算兼容性和API补全的优先级.为此,提出兼容性分析算法来研究openEuler的4种主要软件生态中的musl libc兼容性和缺失API优先级.基于应用软件包之间的依赖关系和谷歌PageRank算法的思想,提出了PackageRank算法和APIRank算法,分别用于软件包兼容性度量和优先级计算.这2种算法提供了系统个性化兼容分析的方法,所需信息易于获取,适用于缺乏用户数据统计的、尚不完整而仍有开发需求的系统及构件.这2种算法在musl libc上的分析结果清晰准确,与软件生态的特点和现状相符,与musl libc的国际社区开发者的观点接近,为openEuler的新C库补全工作提供了有效指导.展开更多
水沙模型是计算和评估水土流失和泥沙侵蚀的重要工具。黄土高原是我国土壤侵蚀最严重的地区之一,针对黄土高原地区水沙特点,耦合降雨径流模块、土壤侵蚀模块和泥沙输移模块,构建了基于物理机制的水沙模型,其中降雨径流模块采用水箱模型...水沙模型是计算和评估水土流失和泥沙侵蚀的重要工具。黄土高原是我国土壤侵蚀最严重的地区之一,针对黄土高原地区水沙特点,耦合降雨径流模块、土壤侵蚀模块和泥沙输移模块,构建了基于物理机制的水沙模型,其中降雨径流模块采用水箱模型,土壤侵蚀模块包括降雨溅蚀、梁峁坡侵蚀、沟谷坡侵蚀、沟道侵蚀,泥沙输移模块采用泥沙平衡方程与蓄泄方程联合方法。以黄河支流无定河的西南部黄土丘陵沟壑区岔巴沟流域作为典型代表进行水沙模拟,并将模拟结果与MUSLE(Modified Universal Soil Loss Equation)模型进行对比,探究不同的水沙模型对于模拟结果的影响。模拟结果表明:(1)构建的水沙模型详细考虑黄土高原侵蚀过程特点,物理机制更明确,侵蚀计算更加全面。(2)构建的水沙模型具有更高的精度和可靠性,优于基于经验公式MUSLE模型,其模型平均纳什效率系数NSE为0.722,平均沙量相对误差绝对值为21.3%;基于MUSLE的模型平均NSE为0.576,平均沙量相对误差绝对值为32.8%。该研究成果为黄土高原地区泥沙侵蚀过程研究和水沙防治提供一定的科学依据。展开更多
基金supported by the Water Research Commission of South Africa under project K5/2448,which also provided partial support for the post-graduate bursary for the first authorAdditional post-graduate financial support was provided by the Carnegie Corporation of New York under the Regional Initiative for Science Education(RISE)programme of the Carnegie Corporation of New York and the Oppenheimer Memorial Trust(OMT)+1 种基金The Department of Environment,Forestry and Fisheries(DEFF),Chief Directorate:Natural Resource Management Programmes(NRM)Directorate:Operational Support and Planning provided financial support to conduct the sediment sampling programme and post-graduate funding for the second author.
文摘The proposed site for the construction of a new dam(Laleni Dam)on the Tsitsa River in the Eastern Cape,South Africa falls within a high soil erosion zone,which is expected to affect the lifespan of the dam.Estimating the sediment yield of the catchment is important from a management perspective,and thus we designed this study to assess the applicability of the Modified Universal Soil Loss Equation(MUSLE).The original MUSLE was applied to the Inxu River sub catchment,upstream of a proposed dam,over a summer rainfall period extending from October 2016 to April 2017.A modified version of the MUSLE,incorporating a storage module,was later applied over the same period.Model calibration of the MUSLE with and without a storage model was tested against 7 months of recorded daily suspended sediment discharge data.With a storage model,we achieved a percentage bias,coefficient of efficiency and R2 of 2%,0.83 and 0.83,respectively,while without storage the performance statistics were markedly lower.These results suggest that a calibrated MUSLE can provide estimates of sediment yield that are valuable for regional planning,and that the inclusion of a storage component further improves the MUSLE application.Given the complexity of sediment generation and transport processes,a relatively simple empirical MUSLE model is a useful tool for initial sediment yield estimation for planning purposes.
文摘水沙模型是计算和评估水土流失和泥沙侵蚀的重要工具。黄土高原是我国土壤侵蚀最严重的地区之一,针对黄土高原地区水沙特点,耦合降雨径流模块、土壤侵蚀模块和泥沙输移模块,构建了基于物理机制的水沙模型,其中降雨径流模块采用水箱模型,土壤侵蚀模块包括降雨溅蚀、梁峁坡侵蚀、沟谷坡侵蚀、沟道侵蚀,泥沙输移模块采用泥沙平衡方程与蓄泄方程联合方法。以黄河支流无定河的西南部黄土丘陵沟壑区岔巴沟流域作为典型代表进行水沙模拟,并将模拟结果与MUSLE(Modified Universal Soil Loss Equation)模型进行对比,探究不同的水沙模型对于模拟结果的影响。模拟结果表明:(1)构建的水沙模型详细考虑黄土高原侵蚀过程特点,物理机制更明确,侵蚀计算更加全面。(2)构建的水沙模型具有更高的精度和可靠性,优于基于经验公式MUSLE模型,其模型平均纳什效率系数NSE为0.722,平均沙量相对误差绝对值为21.3%;基于MUSLE的模型平均NSE为0.576,平均沙量相对误差绝对值为32.8%。该研究成果为黄土高原地区泥沙侵蚀过程研究和水沙防治提供一定的科学依据。
