In order to map a zone of contaminated groundwater, various aquifer assessment models have been developed such as DRASTIC, GOD, EPIK and so on. I want to know how to proceed with this. I will appreciate if anyone could recommend me some software. Kindly suggest me some fundamental books to learn it in great detail.
Use SWS (schulumberger water service) Visual Modflow., if you have problems in using SWS Modflow and want to try and open source alternative, you could probably have a look at this link. PMWIN8 (processing Modflow for windows)
http://www.simcore.com/pm8
Dear Prashant Kumar, You can proceed with single ion contamination first. Also Fuzzy logic may be used.The following links may be useful to you. Regards
http://www.sciencedirect.com/science/article/pii/S0022169499001304
http://link.springer.com/article/10.1007/s00254-005-0104-1
See this link for the answer: www.who.int/water_sanitation.../groundwater8.pdf. Also books.google.co.ke/books?isbn=1420032895
Hello Prashant,
You are right, GOD and DRASTIC are basically destined to tell you if the aquifer is vulnerable to be contaminated, mostly based on its hidrogeology (regardless of any actual contamination really happening, that's the other side of the equation). We had the opportunity to apply both of them using "model builder in ArcGIS" and again a similar model with the same software for landslide vulnerability. In my experience this is enough to apply and run both DRASTIC and GOD, of course you must elaborate on the model yourself which is not at all complicated. You will find DRASTIC to be much more data demanding. I recommend you have information from wells (profiles) to obtain most of the information, however still some data will have to be calculated or obtained from other works. Some cannot be derived alone from data of wells, for example Net recharge, Hydraulic conductivity, while other can be obtained or estimated from wells, for example, Depth to water, Impact of vadose zone.
Best regards and hope this works!
P. S. I have now stopped using ArcGIS and hope to find a model builder equivalent for QGIS.
Thesis "Assessing integrated watershed management and spatial groun...
Hi, One consideration to be aware of that can lead to confusion in reviewing the literature is that different terms have been used to describe two relevant, related concepts: 1) the first refers to the intrinsic ease with which a groundwater system could be contaminated, independent of whether or not a source is actually present, and in the US this has been called "groundwater sensitivity"; 2) the second combines that idea with the presence of of actual contamination sources, which in the US has been called "groundwater vulnerability." I believe that in Europe the term "intrinsic vulnerability' and "risk" have been used. In any case in any paper a first thing is to understand how the authors are using terminology.
Much of the progress in developing such mapping schemes has been made in Europe due to the importance of karst aquifers as drinking water sources in many countries there, and a very useful publication on the web summarizing a good bit of that work up through the early 2000's is the final report of the COST Action 620 "Vulnerability and Risk Mapping for the Protection of Carbonate (Karst) Aquifers” . The appendix summarizes the methods that had been developed by that time, and the five year period of the COST action was a very fruitful time for research and development of relevant methodologies.
Dear Prashant,
To my sense you should first chose (as Christopher said above) which kind of vulnerability you wish to derive (intrinsic or specific), and then based on your available data and the physiographic conditions of the area chose the appropriate method. It is evident that different methods for the same area may result in totally diverse results, so the fundamental step is to chose the most appropriate as said. The only tool to apply index and overlay methods like EPIK, DRASTIC, PI etc, is a GIS software. There is a huge amount of papers dealing with this issue, but if you are a novice you better advise the final report of COST 620 for kartsic aquifers or the original report of DRASTIC for sedimentary ones, which are more detailed.
Dear Prashant, If I understand your question which is...... In order to map a zone of contaminated groundwater ....this means.... is the zone already contaminated? if so, you need to define the different possible contaminants entering into the area and try to understand their chemical and physical behaviour. You did not indicate if you expect the contaminant to come from above or from below the intake area of the extraction wells, for which a bit more hydrogeological data is required.
Please note that If you have grounds to think that contamination is reaching your wells. possibly it might come from below the intake zone of your wells. If so they are much at risk as the contamination is expected to get effectively to a much more number of wells. This case is often observed .in volcanic regions.
If you are worried for any possible future contamination, then I would recommend you to try to understand the expected processes to be occurring; a simple involved factor, also forgotten and often misunderstood is the depth to the water-table. If the water-table is close to the surface, this means that the groundwater is flowing with an important vertically-upwards component. The opposite case is when the water table is very deep, there the water could have a downwards vertical component. In the first case (flow upwards) the contaminant is kind of controlled especially if it is less or equally dense than water. In the second case you will need to define where the contaminant is expected to travel to..... Groundwater contamination requires to understand the processes behind the expected contaminant distribution this could aid to anticipate its movement and in defining its possible controls....
