首页 >> 学术报告
Revealing the hydrological controls on nutrient fluxes at the groundwater-surface water interface

发布日期:2017-06-16访问次数:字号:[ ]

 

     人:Andrew M.  Binley (教授)
 
        间:2017616(周五)下午4:30
 
        点:东校区水院楼101
 
主办单位:中国农业水问题研究中心、水利与土木工程学院

 

人:毛晓敏  (010-62738498)

 

Binley教授简历:

 
        Binley
教授,是英国兰卡斯特大学教授,水文地球物理领域的知名科学家。他是Water Resources ResearchWater Resources Research and  Vadose Zone JournalJournal of Hydrology and Quarterly Journal of  Engineering Geology and Hydrogeology等学术期刊副主编,AGU水文地球物理委员会主席(2003-2008 Fellow2013年当选)。 

学术报告摘要:
 In groundwater-fed catchments, there is widespread  recognition of the threat to surface water quality caused by rising  concentrations of nitrate in groundwater.   At the interface of groundwater and surface water, biogeochemical  conditions may exist to alleviate the threat of emerging nutrient rich  groundwater, however, the spatial and temporal controls of such conditions  remains an active area of research.     We report here on the results of two large UK-based projects examining  the key drivers of nutrient transport to lowland rivers.   In a study reach of the River Leith in  Cumbria, detailed experimental investigations has led to a conceptualisation  of the spatial patterns of water fluxes and their influence on biogeochemical  conditions.  Under baseflow, the  quantification of vertical and horizontal water fluxes, was achieved through  a series of Darcian flow estimates coupled with in-stream piezometer tracer  dilution tests.  These data, enhanced  by multi-level measurements of chloride concentration in river bed pore water  and water-borne geophysical surveying, reveal a localized connectivity to  regional groundwater that appears to suppress the hyporheic zone. Multi-level  samples of nitrate in shallow ground/hyporheic water, coupled with results from  push-pull tracer tests demonstrate the linkage between hydrological setting  and biogeochemical conditions.   Investigations of groundwater-surface water exchange under storm  events reveal the dynamic nature of hydrological pathways and the occurrence  of flow path reversal in the hyporheic zone.    In a second study area – the Hampshire Avon – we investigated the  hydrogeological controls on nutrient transport to a number of study  reaches.  Using baseflow index (BFI) as  a simple measure of regional groundwater contribution we analysed the effect  of stream ‘flashiness’ on in-stream concentrations of nitrate and dissolved  organic carbon (DOC). Using data from 6 study reaches, covering 3 contrasting  hydrogeological settings, our results show a non-linear negative correlation  between DOC: nitrate molar ratio and BFI, suggesting low potential for  in-stream uptake of inorganic forms of nitrogen in baseflow dominated  catchments. Our analysis also reveals significant seasonal variations in DOC:  nitrate transport and highlights critical periods of nitrate export. Future  work should determine whether the results reported here are transferable to other  agricultural, lowland catchments.

 

 

 

 





打印本页 关闭窗口