@Nagesh: I strongly endorse Dilip's warning. And I would add another question: One needs to be clear what one is trying to find out (question comes before tool) and whether the answer is already approximately known before hitting it with a tool that has all the limitations Dilip mentions. So what is the question?
For instance, we already know that the installed STPs don't operate at full capacity and that the problem is largely to do with clogged UGDs, broken UGDs and incomplete UGDs. E.g., Vrishabhavathy Valley STP has installed capacity of 180 MLD. One of the units does not work, so effectively 120 MLD. But even this 120 MLD consists of only 20-25 MLD of raw sewage coming from the UGD, rest is diluted sewage being picked up from the river. We have a published paper on V-Valley STP (mal)functioning. We also know that even as K&C valley STP capacity is being upgraded, it gets some of its sewage (60MLD) by pumping from the Agara side and will get another 100 MLD pumped from Ejipura drain (pickup point several km before drain reaches Bellandur). So any simple terrain-based analysis is pointless when on the one hand gravity-based movement is blocked by clogged UGDs and on the other hand pumping moves sewage around. Sharad On Thursday, March 23, 2017 at 9:04:21 PM UTC+5:30, Dilip Damle wrote: > > I would add that if anyone anywhere is even thinking of interpolating > ground levels then it is the biggest Blunder that can be done. > Unfortunately these days of software we have distanced ourselves from > ground realities and fundamentals and even such ideas are offered as > innovation/smartness and sold to ignorant management. > > On Thursday, March 23, 2017 at 8:33:17 PM UTC+5:30, Dilip Damle wrote: >> >> HI, >> >> I do not know your project nor whom you are working for. >> >> However I have worked professionally as a consultant On Many Water >> Supply, a few Sewerage projects and to a lesser extent on Stormwater >> projects. I also had my own water supply network software (before >> commercial software were easily available) with which I have done network >> planning for many large projects in different parts of the country. >> >> With that background I would say For a large city these kinds of projects >> involve a large PAID team with expertise in their own areas. Say my area >> was design and Hydraulics analysis but I can not work without another >> member without a GOOD site experience. So trying to look at these things >> just a s a software problems and getting help online may not really work. >> >> The most important part to start with is a real land survey to get actual >> ground levels. There is no way they can be estimated from anywhere. >> Unfortunately newer people do not understand the complexity of the >> issues. Also we try to fudge everywhere including survey. >> >> Your exercise will also involve analyzing the entire network existing and >> proposed. >> >> So any help from someone other than without a domain experience and >> responsibility against payment will be much less than a milligram of >> lipstick. >> >> If you think you can put together things from here and there, you cannot. >> If you could then you would not have asked here. >> >> >> >> *Availabee Digital elevation model is useless (inadequate) for this >> project.* >> >> Knowing Bangalore as the city where I will shift in near future and I >> live there (ALSO). I would say the following specifically about the city. >> >> Since it is highly undulated city there are advantages that you will get >> a good gravity assist in the network. But at the same time you will have >> many points from which sewage will have to be collected and pumped to the >> STP. This complexity and planning is HUGE. >> >> I just hope (for the sake of the city) that nonone is working with a >> shoestring budget on this one. Or the shoestrings are controlled by some >> other strings. >> >> Apologies for being forthright and clear on the issue. >> >> On Thursday, March 23, 2017 at 3:52:21 PM UTC+5:30, Nagesh Aras wrote: >>> >>> Hi >>> >>> >>> I would like help from users or QGIS (or ArcGIS) in analyzing the sewage >>> scenario in Bangalore. >>> >>> The rough idea is as follows: >>> >>> 1. We have the BWSSB STP locations and their capacity. >>> 2. We have the rain precipitation figures >>> 3. By analyzing the terrain (e.g. Digital Elevation Model from ISRO), >>> can we find the watersheds (catchment areas) for each STP? >>> 4. Can we estimate how much sewage and rainwater each STPwill get on a >>> day-to-day (or month-to-month) basis? >>> >>> Thanks in advance! >>> >>> Regards, >>> Nagesh >>> 9448239985 >> >> -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
