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| 1 | Application of Bayesian model and discriminant function analysis to the estimation of sediment source contributions显示文摘Bayesian and discriminant function analysis(DFA)models have recently been used as tools to estimate sediment source contributions.Unlike existing multivariate mixing models,the accuracy of these two models remains unclear.In the current study,four well-distinguished source samples were used to create artificial mixtures to test the performance of Bayesian and DFA models.These models were tested against the Walling-Collins model,a credible model used in estimation of sediment source contributions estimation,as a reference.The artificial mixtures were divided into five groups,with each group consisting of five samples with known source percentages.The relative contributions of the sediment sources to the individual and grouped samples were calculated using each of the models.The mean absolute error(MAE)and standard error of(SE)MAE were used to test the accuracy of each model and the robustness of the optimized solutions.For the individual sediment samples,the calculated source contributions obtained with the Bayesian(MAE?7.4%,SE?0.6%)and Walling-Collins(MAE?7.5%,SE?0.7%)models produced results which were closest to the actual percentages of the source contributions to the sediment mixtures.The DFA model produced the worst estimates(MAE?18.4%,SE?1.4%).For the grouped sediment samples,the Walling-Collins model(MAE?5.4%)was the best predictor,closely followed by the Bayesian model(MAE?5.9%).The results obtained with the DFA model were similar to the values for the individual sediment samples,with the accuracy of the source contribution value being the poorest obtained with any of the models(MAE?18.5%).An increase in sample size improved the accuracies of the Walling-Collins and Bayesian models,but the DFA model produced similarly inaccurate results for both the individual and grouped sediment samples.Generally,the accuracy of the Walling-Collins and Bayesian models was similar(p>0.01),while there were significant differences(p<0.01)between the DFA model and the other models.This study demonstrated that the Bayesian model could provide a credible estimation of sediment source contributions and has great practical potential,while the accuracy of the DFA model still requires considerable improvement. | Pengfei Du Donghao Huang Duihu Ning Yuehong Chen Bing Liu Jian Wang Jingjing Xu | 2019 | International Journal of Sediment Research2019，34，6： | 2 |
| 2 | Regions and Their Typical Paradigms for Soil and Water Conservation in China显示文摘China is experiencing conflicts between its large population and scarce arable land,and between a demand for high productivity and the severe soil erosion of arable land.Since 1949,China has committed to soil and water conservation(SWC),for which eight regions and 41 subregions have been developed to improve the environment and increase land productivity.To obtain information from the regional planning and strategies for SWC and to explore whether SWC practices simultaneously contribute to soil conservation,ecosystem functioning,and the livelihoods of local farmers,and to summarize the successful experiences of various SWC paradigms with distinct characteristics and mechanisms of soil erosion,this paper systematically presents seven SWC regions(excluding the Tibetan Plateau region)and 14 typical SWC paradigms,focusing on erosion mechanisms and the key challenges or issues in the seven regions as well as on the core problems,main objectives,key technologies,and the performance of the 14 typical paradigms.In summary,the 14 typical SWC paradigms successfully prevent and control local soil erosion,and have largely enhanced,or at least do not harm,the livelihoods of local farmers.However,there remain many challenges and issues on SWC and socioeconomic development that need to be addressed in the seven SWC regions.China,thus,still has a long way to go in successfully gaining the win-win objective of SWC and human aspects of development. | DANG Xiaohu SUI Boyang GAO Siwen LIU Guobin WANG Tao WANG Bing NING Duihu BI Wei | 2020 | Chinese Geographical Science2020，30，4： | 1 |
| 3 | Estimation of wind erosion from construction of a railway in arid Northwest China显示文摘A state-of-the-art wind erosion simulation model,the Wind Erosion Prediction System and the United States Environmental Protection Agency's AP 42 emission factors formula,were combined together to evaluate wind-blown dust emissions from various construction units from a railway construction project in the dry Gobi land in Northwest China.The influence of the climatic factors:temperature,precipitation,wind speed and direction,soil condition,protective measures,and construction disturbance were taken into account.Driven by daily and sub-daily climate data and using specific detailed management fles,the process-based WEPS model was able to express the beginning,active,and ending phases of construction,as well as the degree of disturbance for the entire scope of a construction project.The Lanzhou-Xinjiang High-speed Railway was selected as a representative study because of the diversities of different cli-mates,soil,and working schedule conditions that could be analyzed.Wind erosion from different working units included the building of roadbeds,bridges,plants,temporary houses,earth spoil and barrow pit areas,and vehicle transportation were calculated.The total wind erosion emissions,7406 t,for the first construction area of section LXS-15 with a 14.877 km length was obtained for quantitative analysis.The method used is applicable for evaluating wind erosion from other complex surface dis-turbance projects. | Benli Liu Larry E.Wagner Duihu Ning Jianjun Qu | 2017 | International Soil and Water Conservation Research2017，5，2： | 0 |
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