长江中游典型稻田-沟-塘系统中磷浓度时空变化特征  

Spatiotemporal variations of phosphorus concentration in a typical paddy fieldditch-pond system in the middle reaches of the Yangtze River

作　　者：刘连华 欧阳威[2] 龚静仪 白艳 郝芳华 LIU Lianhua;OUYANG Wei;GONG Jingyi;BAI Yan;HAO Fanghua(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081;School of Environment,Beijing Normal University,Beijing 100875;School of Urban and Environmental Sciences,Central China Normal University,Wuhan 430079)

机构地区：[1]中国农业科学院农业环境与可持续发展研究所,北京100081 [2]北京师范大学环境学院,北京100875 [3]华中师范大学城市与环境科学学院,武汉430079

出　　处：《环境科学学报》2024年第11期176-183,共8页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.U21A2039);中央级公益性科研院所基本科研业务费专项(No.BSRF202309)。

摘　　要：长江中游稻田周围常常分布着沟渠和水塘,形成了稻田-沟-塘系统景观.本文以长江中游典型稻田-沟-塘系统为研究对象,通过对水稻全生育期和稻田排水过程中磷浓度进行监测,研究稻田-沟-塘系统磷浓度时空变化规律.结果表明,整个水稻生长季,稻田田面水中磷以颗粒态磷(PP)为主,占总磷(TP)的68.83%.稻田排水过程中,随着水流从一级沟渠、二级沟渠到水塘的传输,磷浓度逐级递减;沟塘系统对TP的平均削减率为48.88%,并且以PP的截留为主.全生育期内稻田-沟-塘系统磷浓度时空动态变化表明,田面水中TP浓度在施肥第1 d达到浓度峰值,随后趋于稳定并保持在较低水平;沟塘系统的存在可以降低磷峰值浓度和峰值出现时间,沟渠和水塘的磷浓度峰值分别出现在施肥后第3~4 d和第7 d.沟塘系统的截留净化效果存在尺度效应,田间尺度的TP削减率显著高于流域尺度的削减率.综上所述,应充分利用稻田周边沟渠和水塘对面源污染流失的时空滞后效应和污染截留作用,提升稻作区面源污染防治能力.Ditches and ponds are often distributed around paddy fields in the middle reaches of the Yangtze River Basin,forming the landscape characteristics of the paddy field-ditch-pond system.In this paper,a typical paddy field-ditch-pond system in the middle reaches of the Yangtze River was selected as the research object.By monitoring the phosphorus concentrations during the entire rice growing season and the drainage process of paddy fields,the spatiotemporal variations of phosphorus concentrations in the paddy field-ditch-pond system were investigated.The results showed that phosphorus in the surface water of paddy fields was mainly in the form of particulate phosphorus(PP),accounting for 68.83%of total phosphorus(TP)during the rice growing season.During the drainage process of paddy fields,phosphorus concentrations gradually decreased as water flowed from primary and secondary ditches to ponds.The average reduction rate of TP by the ditch-pond system was 48.88%,with the main interception form being PP.The spatiotemporal variations of phosphorus concentrations in the paddy field-ditch-pond system during the entire growth period indicated that the TP concentrations in the surface water reached their peak value on the first day of fertilization,and then tended to stabilize and maintained at a low level.The existence of a ditch-pond system could reduce the peak concentrations and occurrence time of phosphorus concentrations.The peak concentrations of phosphorus in ditches and ponds occurred at 3~4 days and 7 days after fertilization,respectively.The interception and purification effect of the ditch-pond system exhibited a scale effect,with the TP reduction rate at the field scale being significantly higher than that at the watershed scale.In summary,it is necessary to fully utilize the spatiotemporal lag effect and pollution interception effect of ditches and ponds to enhance the ability to prevent and control non-point source pollution in rice growing areas.

关 键 词：面源污染 稻田 沟渠 水塘 磷削减 

分 类 号：X52[环境科学与工程—环境工程]