Saturday, January 2, 2016

Interaction of Coastal aquifer and Lake Urmia

Hey guys.

As I discussed previously, I am a true believer of  existence of interaction between coastal aquifer and Lake Urmia water level. Many authorities and politicians refuse to accept the theory and there are some research articles based on rejection of existence of such an interaction.
Recently I used to publish a conference paper (ASCE, EWRI 2015) about the interaction of water level in some random coastal aquifers in West coast of the Lake Urmia basin and water level in the Lake itself. I used a soft computational method named "Decision Tree" to manipulate my model. It is based on Entropy and probability. Evidence and results of this model are in agreement with a theory of existence of such interaction in Coastal aquifer.
Fig. 1 shows the schematic relation between lake and coastal aquifer which I believe that exist in the hydrological process. In general in closed basin lakes, such interaction is one of the main hydrological variables that should be considered and studied carefully.

Fig. 1. Schematic of interaction of coastal aquifer and Lake Urmia in balance

So I used to select some random wells just near to the west coast of the lake. You can find the position of this wells in Fig. 2. Data in east coast is not ready for use for now and I will try to manipulate them a.s.a.p. Followingly, a Pearson correlation coefficient test between Lake water level and water level in wells is done and interesting results are shown in Fig. 3 with a radar chart including the direction of such relations.
Fig. 3. Correlaogram radar chart

Fig. 2. Position of wells in west coast of the Lake


It is obvious that, there is strong linear relationship specially in North and South of the basin all with negative values. Same analysis on probability distribution function of lake water and water level in wells showed strong similarities in shape and moments of distribution. I have done some investigations on the structure of cross-correlations in time and space between lake and coastal aquifer. Two samples of such investigation are shown in Fig. 4. You can see seasonality and strong interaction between lake and coastal aquifer. As shown in Fig. 3 and 4,  these two stations (Station 1 and 6) have the most impact on the interaction.
Fig. 4. Cross-correlation between lake water level and water level in wells of station 1 and 6

I though a model may reveal more detailed structure of the relation, so I used to select a probabilistic one. As entropy concept is very popular now a days I used DT for manipulation of data and calibrated my tree. Here is the scatter plot of my model in Fig. 5. As you can see these are strong estimation result and I personally satisfied with the results.

Fig. 5. Scatter lot of DT model
That is all I was eager to share for now!
So I think I proved my theory at least to some extent. You may find out my paper's abstract in Related page in my weblog and/or download the whole article from ASCE library.

Please share your points of view with me.
Thank you

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