通过野外微型径流小区模拟降雨试验,对坡面小区尺度水力侵蚀过程中物理运移土壤有机碳的规律进行研究。结果表明:2 m×5 m径流小区持续降雨30 min后,大雨强(1.64 mm min-1)和小雨强(0.58 mm min-1)降雨条件下泥沙携带流失的有机碳...通过野外微型径流小区模拟降雨试验,对坡面小区尺度水力侵蚀过程中物理运移土壤有机碳的规律进行研究。结果表明:2 m×5 m径流小区持续降雨30 min后,大雨强(1.64 mm min-1)和小雨强(0.58 mm min-1)降雨条件下泥沙携带流失的有机碳总量分别为56.09 g和3.18 g,溶解于径流流失的有机碳总量分别为13.55 g和2.81 g。降雨强度和持续时间对有机碳流失的过程特征有显著影响。降雨强度越大,泥沙携带及溶解于径流的有机碳流失速率和总量也越大。大雨强泥沙有机碳富集比在产流发生后的18min内大于1,随后降至1以下。小雨强泥沙有机碳富集比始终小于1。大雨强径流有机碳浓度与径流量呈立方关系,小雨强有机碳流失量随径流量增加呈线性递增趋势;大雨强泥沙有机碳含量与泥沙量之间具有明显的立方关系。展开更多
Batch and soil column experiments were conducted to evaluate the influence of KH2PO4, （NH4）H2PO4and Ca（H2PO4）2on the adsorption and leaching characteristics of Cu and Zn in red soil. The results show that all the ...Batch and soil column experiments were conducted to evaluate the influence of KH2PO4, （NH4）H2PO4and Ca（H2PO4）2on the adsorption and leaching characteristics of Cu and Zn in red soil. The results show that all the three phosphates can greatly improve the adsorption capacity of red soil for Cu and Zn, and the effect of different phosphates on Cu and Zn adsorption follows the order of Ca（H2PO4）2〉KH2PO4〉（NH4）H2PO4. The addition of phosphate has little effect on the mobility of Cu. Ca（H2PO4）2and （NH4）H2PO4 show a strong ability in immobilizing Zn while the immobilization ability of KH2PO4 is much weaker. All the three phosphates are helpful for modifying the partitioning of Cu and Zn from the non-residual phase to the residual phase; however, they could also enhance the contents of Cu and Zn associated with exchangeable and carbonates fractions.展开更多
淮河流域位于我国南北气候过渡带,其复杂多变的降水过程及水汽来源是导致流域洪旱灾害易发、多发的重要因素。以全球降水同位素监测网络(Global Network of Isotope in Precipitation,GNIP)监测的多年降水氢氧稳定同位素数据为基础,探...淮河流域位于我国南北气候过渡带,其复杂多变的降水过程及水汽来源是导致流域洪旱灾害易发、多发的重要因素。以全球降水同位素监测网络(Global Network of Isotope in Precipitation,GNIP)监测的多年降水氢氧稳定同位素数据为基础,探讨了淮河流域大气降水氢氧稳定同位素组成时空变化的驱动因素及其气候指示意义;通过分析氢氧稳定同位素组成(δ^(18)O、δ^(2)H、氘盈余)、大气降水线特征与流域气温、降水量的响应关系,解析流域不同季节大气降水水汽来源及气团移动路径。结果表明:①淮河流域大气降水氢氧稳定同位素组成能够指示南北气候过渡带特征;②同位素时空变化及异常低的大气降水线斜率、截距与局地降水环境关系不大,主要是由水汽来源差异及降水气团在移动过程中同位素分馏造成的。氘盈余示踪和HYSPLIT模型模拟结果进一步表明流域降水水汽来源及变化受季风活动的控制,冬季风和夏季风的交替进退使得淮河流域的降水氘盈余变化具有明显的“V”型特征。研究成果可为水资源调度管理、极端气候应对决策等提供科学依据。展开更多
基金Project(41271294)supported by the National Natural Science Foundation of ChinaProject(NCET-09-330)supported by Program for New Century Excellent Talents in University,China
文摘Batch and soil column experiments were conducted to evaluate the influence of KH2PO4, （NH4）H2PO4and Ca（H2PO4）2on the adsorption and leaching characteristics of Cu and Zn in red soil. The results show that all the three phosphates can greatly improve the adsorption capacity of red soil for Cu and Zn, and the effect of different phosphates on Cu and Zn adsorption follows the order of Ca（H2PO4）2〉KH2PO4〉（NH4）H2PO4. The addition of phosphate has little effect on the mobility of Cu. Ca（H2PO4）2and （NH4）H2PO4 show a strong ability in immobilizing Zn while the immobilization ability of KH2PO4 is much weaker. All the three phosphates are helpful for modifying the partitioning of Cu and Zn from the non-residual phase to the residual phase; however, they could also enhance the contents of Cu and Zn associated with exchangeable and carbonates fractions.
文摘淮河流域位于我国南北气候过渡带,其复杂多变的降水过程及水汽来源是导致流域洪旱灾害易发、多发的重要因素。以全球降水同位素监测网络(Global Network of Isotope in Precipitation,GNIP)监测的多年降水氢氧稳定同位素数据为基础,探讨了淮河流域大气降水氢氧稳定同位素组成时空变化的驱动因素及其气候指示意义;通过分析氢氧稳定同位素组成(δ^(18)O、δ^(2)H、氘盈余)、大气降水线特征与流域气温、降水量的响应关系,解析流域不同季节大气降水水汽来源及气团移动路径。结果表明:①淮河流域大气降水氢氧稳定同位素组成能够指示南北气候过渡带特征;②同位素时空变化及异常低的大气降水线斜率、截距与局地降水环境关系不大,主要是由水汽来源差异及降水气团在移动过程中同位素分馏造成的。氘盈余示踪和HYSPLIT模型模拟结果进一步表明流域降水水汽来源及变化受季风活动的控制,冬季风和夏季风的交替进退使得淮河流域的降水氘盈余变化具有明显的“V”型特征。研究成果可为水资源调度管理、极端气候应对决策等提供科学依据。
