Im simulating a ditch beside a farm. In the ditch the water level is at 70 cm for a week and then it reduces linearly. The initial condition is that ditch level 70cm (bottom of the ditch 90cm) and initial groundwater is -200cm. but as soon as Hydrus starts simulating it brings the groundwater level high to the level of ditch (the second day of simulation suddenly groundwater increases), which is not the case we observe in the field. We observe the water from the ditch goes slowly.
Im wondering where im making mistake or how should I approach this simulation. The file is attached.
Thanks
Ditch Farm interaction
Re: Ditch Farm interaction
If you have a sandy loam with Ks of about 1 m/d, 70 cm ponding at the surface, and groundwater 200 cm below the surface, the infiltrating waterfront reaches groundwater in less than 6 hours. You would need to specify different soil hydraulic properties to have a slower movement of the waterfront. Change Ks to 10 cm/d (or less) and you will see how quickly the moisture front moves. J.