How the precipitation is effected by Water Year Method ?

kind regards
Aumran Nazar

The Water Year Method is only used if you select Water Year Method as the method for calculating a river's headflow or a groundwater's recharge. It is not used for catchments. Therefore, catchment precipitation is NOT affected by the Water Year Method.

Jack

Dear Mr. jack

Thank you for quick responding , how can i enter the effect of climate change on the run off from catchment .

Aumran

There are several different catchment methods, each of which have different climate parameters that affect runoff. Please see the User Guide for more information:

http://www.weap21.org/WebHelp/index.html#Overview_of_Catchment_Calculation_Methods.htm

Jack

Yes Mr. jack I us Rainfall Runoff Method (Simplified Coefficient Method) and I want to enter the future predicted monthly precipitation on the catchment for several year and see how the runoff affected by it

In this case, it is your responsibility to define how preciptation will change in the future.

If you wanted to forecast future precipitation using a method like the Water Year Method, you could do it with a simple expression. Here is an example of a scenario expression that will multiply the Current Acounts monthly values (presumably an average water year) by a value representing the Water Year -- less than 1 for a dry year, greater than 1 for a wet year:

CurrentAccountsValue * Interp(2011, 1.2, 2012, 0.7, 2013, 0.5, 2014, 1, 2015, 1.5, ...)

This says that 2011 was wet (120% of average), 2012 was dry (70% of average), 2013 was very dry (50% of average), etc.

Jack

Yes Mr. Jack it became clear for me now thank you very much

best regards Mr. Jack

Aumran