Subject: Calculation of Discharge and Rainfall in WEAP Posted: 4/15/2022 Viewed: 4729 times
Dear Anne
First of all thanks for your guidance. My question is related to discharge calculation. For example, we have a mean monthly discharge data (i.e) of 40 (cubic meters per second) in the month of January in a canal (model as a diversion that takes water from a river and supplies water to an agricultural field). When WEAP converted this Flow rate(m3/sec) data into Volume (m3). It becomes a too large value that covers all the water requirements of the demand site.
For Example:
40x31x24x60x60= 107136000 cubic meter. this Supply of water covers all the needs of the demand site. (100% Coverage) Could you Please Clarify what can I do but the reality is the opposite In Pakistan, almost 50-60 % of Crop water requirement is fulfilled by pumping water from groundwater?
Similarly, in the case of Precipitation (i.e) 10mm/month.
For Example:
10(mm)/1000=0.010meterx100 hectares= 0.01x100x10,000m2=10000m3 which also becomes avery large value.
Ms. Anne Hereford
Subject: Re: Calculation of Discharge and Rainfall in WEAP Posted: 4/28/2022 Viewed: 4592 times
Dear Nalain,
Thank you for posting your question here.
These conversions all look correct to me, so perhaps there is a problem in the data. If the water in the canal is meeting 100% of demand and this is not representative of reality, then either your monthly discharge data is erroneously high or the demand you have entered in your model is lower than the true demand. The other option (and in some cases this can be significant) is that there is one or more elements of loss in your system--basically leaky pipes. This can be entered in the Data view for the diversion under Losses.
Could you tell me how you have the agricultural field connected to the diversion? Where does the diversion end?
Anne
Mr. Nalain E Muhammad
Subject: Re: Calculation of Discharge and Rainfall in WEAP Posted: 5/10/2022 Viewed: 4426 times
Thanks, Dear Madam for your reply.
Description of my model:
A diversion that takes supply from a river and delivers water to the agricultural field (Catchment node) through a transmission link.Because in Pakistan Agricultural fields don't take supply from the river directly. First, take water into the manmade channel (networks of canals), then watercourse/Field channels, and then fed into the agricultural field.
To make the demand close to true demand I added 20 crops to the agricultural Catchment node.
Ms. Anne Hereford
Subject: Re: Calculation of Discharge and Rainfall in WEAP Posted: 6/22/2022 Viewed: 4220 times
Dear Nalain,
I think my previous answer still stands as to the likely reasons that your modeled agricultural area is receiving more water than expected--either the Flow Rates you are inputting for the canal are too high, and/or you need to add data on losses from the system.
Best,
Anne
Topic "Calculation of Discharge and Rainfall in WEAP"
