Modelling

The steady-state model calibration was carried out to minimize difference between the simulated and observed water levels. Model has been calibrated by head and deuterium observation data. Head data were collected on the rivers Borjomula and Gujaretis-tskali, in Daba and Tba boreholes during 2 years. Together with head observation, isotope data (deuterium observation) were used. Deuterium data showed different values for Bakuriani and Boijomi regions, indicating possibility of using deuterium for improving calibration process. Deuterium samples from Borjomula river, Tba, Sadgeri, Borjomi park were added into model as concentration observation points. The concentration was added into model by using particles tracking package. Each particle represents mass of concentration, which is transported by groundwater flow.

As a final result, we got the path ways of possible pollution's movement. Here, we can say that movement along left path way is faster. Three flow path ways inside

Fig. 29.6 All data: 3H [TU] vs. TIME
Fig. 29.7 Vertical view of movement of adjective transport (a) Shows veridical direction of particles' movement from the left site of model; (b) Shows vertical direction of particles' movement from the right site of model

and under lava were determined by the model (Fig. 29.7). Movement of water streams in different directions takes different time. First stream flowing coincides with old river bed in breccia's rocks. This stream has direction on the western site of lava stream and passes area near Tba borehole and runs up to Sadgeri springs. For reaching from recharge area to the Tba borehole, approximately 80 days are necessary to reach Sadgeri springs. Second stream found path on the right eastern site of lava and takes about 70 days to run up to the central part of Lava body near Tba village (red-brown segment of path line). Flowing from recharge area to the central part of area, not along old riverbed, takes about 50 days. Twenty-six days of flowing is marked by blue colour of line. It means that contaminant could reach central area where Tba and other boreholes are located at least in 26 days.

0 0

Post a comment