Simulating regional groundwater transport to surface waters combining stream tube and ydrogeochemical approaches
Deltas are among the most densely populated areas in the world and often suffer from water quality problems due to intensive agricultural land use. Transport of nutrients, metals and pesticides by shallow groundwater adds significantly to surface water quality problems. Therefore, regional groundwater transport modelling is increasingly used, but these transport models often require fine grid resolution to adequately simulate groundwater-surface water interaction. The fine grid resolution, however, limits opportunities for a thorough uncertainty analysis because of excessive computation times. Stream tube modelling is an alternative which allows for uncertainty analysis because computation times are limited even with fine grids. We present a stream tube modelling approach which combines 3D flow path distributed modelling with 1D hydrogeochemical modelling and we compare the results with 3D transport modelling.. Model uncertainty was assessed by evaluating the grid resolution, and different weak sink options in particle tracking. The results indicate that using fine resolution models and a new weak sink option in MODPATH yield appropriate results. For example, the breakthrough of sulphate in the case study stream agrees well with an existing MT3D-model. The main advantage of the method, compared with regular 3D transport models, is the fast computation time which enables a spatial uncertainty analysis using Monte Carlo or random field approaches.
H.P.Broers R.Heerdink A.Visser
Deltares/TNO Geological Survey of the Netherlands, P.O.Box 80015, 3508 TA, Utrecht, The Netherlands
国际会议
武汉
英文
121-124
2009-09-20（万方平台首次上网日期，不代表论文的发表时间）