Purple soil is highly susceptible for overland flow and surface erosion, therefore understanding surface runoff and soil erosion processes in the purple soil region are important to mitigate flooding and erosion hazar...Purple soil is highly susceptible for overland flow and surface erosion, therefore understanding surface runoff and soil erosion processes in the purple soil region are important to mitigate flooding and erosion hazards. Slope angle is an important parameter that affects the magnitude of runoff and thus surface erosion in hilly landscapes or bare land area. However, the effect of slope on runoff generation remains unclear in many different soils including Chinese purple soil. The aim of this study was to investigate the relationship between different slope gradients and surface runoff for bare-fallow purple soil, using 5 m × 1.5 m experimental plots under natural rainfall conditions. Four experimental plots(10°, 16°, 20° and 26°) were established in theYanting Agro-ecological Experimental Station of Chinese Academy of Science in central Sichuan Basin. The plot was equipped with water storage tank to monitor water level change. Field monitoring from July 1 to October 31, 2012 observed 42 rainfall events which produced surface runoff from the experimental plots. These water level changes were converted to runoff. The representative eight rainfall events were selected for further analysis, the relationship between slope and runoff coefficient were determined using ANOVA, F-test, and z-score analysis. The results indicated a strong correlation between rainfall and runoff in cumulative amount basis. The mean value of the measured runoff coefficient for four experimental plots was around 0.1. However, no statistically significant relationship was found between slope and runoff coefficient. We reviewed the relationship between slope and runoff in many previous studiesand calculated z-score to compare with our experimental results. The results of z-score analysis indicated that both positive and negative effects of slope on runoff coefficient were obtained, however a moderate gradient(16°-20° in this study) could be a threshold of runoff generation for many different soils including the Chinese purple soil.展开更多
Vegetative filter strip (VFS) is a main kind of Best Management Practices for the control of non-point source pollution. The goal of this paper is to evaluate the effectiveness of VFS in Chinese northwest regions. Thr...Vegetative filter strip (VFS) is a main kind of Best Management Practices for the control of non-point source pollution. The goal of this paper is to evaluate the effectiveness of VFS in Chinese northwest regions. Three VFSs with natural grass and Hippophae rhamnoides/grass patterns have been constructed in the bank slope of Xiaohuashan reservoir, Huaxian County, Shannxi Province. The removal effects of VFS and influencing factors have been analyzed based on field experiment data. The result reveals a positive effect on reducing the transportation of suspended solids, phosphorus and nitrogen in surface runoff, and it is more efficient on suspended solids removal. The experiment also shows that most of the suspended particles and pollutants bound to them were entrapped in the first 10 m of VFS. The main factors influencing effectiveness of VFS include vegetation patterns and inflow rate. In addition, inflow pollutant concentration has a larger impact on reducing total nitrogen and total phosphorus by VFS, but the reduction effect on SS has no significant difference.展开更多
土壤侵蚀是导致水土流失、土地退化和生态系统脆弱等问题的重要因素,径流小区尺度的土壤侵蚀研究有助于深入理解侵蚀机制并制定防治策略。使用CiteSpace软件对1992—2023年间Web of Science数据库收录的径流小区土壤侵蚀研究文献进行了...土壤侵蚀是导致水土流失、土地退化和生态系统脆弱等问题的重要因素,径流小区尺度的土壤侵蚀研究有助于深入理解侵蚀机制并制定防治策略。使用CiteSpace软件对1992—2023年间Web of Science数据库收录的径流小区土壤侵蚀研究文献进行了文献计量分析。通过对4313篇文献的系统研究,分析了土壤侵蚀研究的主要研究机构及作者的合作与贡献情况、关键词共现以及研究热点的转移。结果显示:全球范围内该领域的发文量呈增长趋势,出现了“气候变化”“土地利用”和“黄土高原”等热点话题,美国和中国是发文量最大的国家,其中美国与欧洲国家和机构合作程度较高;研究热点从传统的侵蚀机理和监测预防转向气候变化、土地利用与遥感技术的综合应用;关键词共现与时区分析揭示了生态系统服务和可持续土地管理策略的重要性日益增加。未来关于跨尺度研究和技术应用,特别是在生态系统服务领域和遥感技术与GIS的应用方面将是研究的重点,同时也需要关注土壤侵蚀测量方法的准确性和实用性,以及全球合作在解决土壤侵蚀问题中的重要性。展开更多
文摘Purple soil is highly susceptible for overland flow and surface erosion, therefore understanding surface runoff and soil erosion processes in the purple soil region are important to mitigate flooding and erosion hazards. Slope angle is an important parameter that affects the magnitude of runoff and thus surface erosion in hilly landscapes or bare land area. However, the effect of slope on runoff generation remains unclear in many different soils including Chinese purple soil. The aim of this study was to investigate the relationship between different slope gradients and surface runoff for bare-fallow purple soil, using 5 m × 1.5 m experimental plots under natural rainfall conditions. Four experimental plots(10°, 16°, 20° and 26°) were established in theYanting Agro-ecological Experimental Station of Chinese Academy of Science in central Sichuan Basin. The plot was equipped with water storage tank to monitor water level change. Field monitoring from July 1 to October 31, 2012 observed 42 rainfall events which produced surface runoff from the experimental plots. These water level changes were converted to runoff. The representative eight rainfall events were selected for further analysis, the relationship between slope and runoff coefficient were determined using ANOVA, F-test, and z-score analysis. The results indicated a strong correlation between rainfall and runoff in cumulative amount basis. The mean value of the measured runoff coefficient for four experimental plots was around 0.1. However, no statistically significant relationship was found between slope and runoff coefficient. We reviewed the relationship between slope and runoff in many previous studiesand calculated z-score to compare with our experimental results. The results of z-score analysis indicated that both positive and negative effects of slope on runoff coefficient were obtained, however a moderate gradient(16°-20° in this study) could be a threshold of runoff generation for many different soils including the Chinese purple soil.
文摘Vegetative filter strip (VFS) is a main kind of Best Management Practices for the control of non-point source pollution. The goal of this paper is to evaluate the effectiveness of VFS in Chinese northwest regions. Three VFSs with natural grass and Hippophae rhamnoides/grass patterns have been constructed in the bank slope of Xiaohuashan reservoir, Huaxian County, Shannxi Province. The removal effects of VFS and influencing factors have been analyzed based on field experiment data. The result reveals a positive effect on reducing the transportation of suspended solids, phosphorus and nitrogen in surface runoff, and it is more efficient on suspended solids removal. The experiment also shows that most of the suspended particles and pollutants bound to them were entrapped in the first 10 m of VFS. The main factors influencing effectiveness of VFS include vegetation patterns and inflow rate. In addition, inflow pollutant concentration has a larger impact on reducing total nitrogen and total phosphorus by VFS, but the reduction effect on SS has no significant difference.
文摘土壤侵蚀是导致水土流失、土地退化和生态系统脆弱等问题的重要因素,径流小区尺度的土壤侵蚀研究有助于深入理解侵蚀机制并制定防治策略。使用CiteSpace软件对1992—2023年间Web of Science数据库收录的径流小区土壤侵蚀研究文献进行了文献计量分析。通过对4313篇文献的系统研究,分析了土壤侵蚀研究的主要研究机构及作者的合作与贡献情况、关键词共现以及研究热点的转移。结果显示:全球范围内该领域的发文量呈增长趋势,出现了“气候变化”“土地利用”和“黄土高原”等热点话题,美国和中国是发文量最大的国家,其中美国与欧洲国家和机构合作程度较高;研究热点从传统的侵蚀机理和监测预防转向气候变化、土地利用与遥感技术的综合应用;关键词共现与时区分析揭示了生态系统服务和可持续土地管理策略的重要性日益增加。未来关于跨尺度研究和技术应用,特别是在生态系统服务领域和遥感技术与GIS的应用方面将是研究的重点,同时也需要关注土壤侵蚀测量方法的准确性和实用性,以及全球合作在解决土壤侵蚀问题中的重要性。
