Water balance for a public park ( 7 acres )
Water balance for a public park ( 7 acres )
(OP)
Hi,
I am attempting to produce a water balance or budget for a park. Basic Equation: In (precipitation) - Out (Evapotransiration + Evaporation from 1100m2 marsh surface + infiltration (dependent on soil and density of plantings) + irrigation for season) = Change in Storage with time.
Now if I have monthly precipitation averages (20 year span) for my park area with the various plantings and soil types, would this be enought to perform a water balance for the park?
Thank you for your time in this as it is important to me.
I am attempting to produce a water balance or budget for a park. Basic Equation: In (precipitation) - Out (Evapotransiration + Evaporation from 1100m2 marsh surface + infiltration (dependent on soil and density of plantings) + irrigation for season) = Change in Storage with time.
Now if I have monthly precipitation averages (20 year span) for my park area with the various plantings and soil types, would this be enought to perform a water balance for the park?
Thank you for your time in this as it is important to me.





RE: Water balance for a public park ( 7 acres )
Evaporation is not steady state: temperature, wind speed, humidity and area of water surface all cause changes. Precipitation is an enormous variable. Average rainfall with standard deviation accounted for does not allow much accuracy in predictions.
The subgrade is another variable that is hard to quantify for water transport and storage. To model the layers of soil and the flow within is an entire field of study for hydrogeologists.
A simple model is a good tool for some uses but can not reflect reality for accurate predictions.
RE: Water balance for a public park ( 7 acres )
RE: Water balance for a public park ( 7 acres )
I would add a waste and management term. How active is water management. Will it have shutoff during rain events and for so long after significant events (e.g. 5 day shutoff after 0.5" rains) How good is the spread and how much runs off. This last one is typically just a percentage of applied water and rain. Also for parks a big factor can be if you system is zoned well. Hills and trees often have poorer soils making these areas dry quicker. This can lead to "over-watering" in other locations.
(As for your monthly average)You also have to be a little careful in rainfall analysis. Large events help less than lots of little so depending on you climate this can be a problem. Where is the site located. I am alway interested in the 20% worst case year for both sizing the system and budgetting in areas where swings to drought are common.
The easiest method might be to look at the rainfall data to see how often storms occur for each month and just delete those waterings.
I used to evaluate efficiencies and help for irrigation systems and at the end of the day showing someone how to feel the soil and use a shovel to get to the roots always saved the most water.
RE: Water balance for a public park ( 7 acres )
I obtained my rainfall data from http
Ok I dont know if I have gotten more confused or if I have resolved my issue. Thank your again!
RE: Water balance for a public park ( 7 acres )
RE: Water balance for a public park ( 7 acres )
RE: Water balance for a public park ( 7 acres )