Topic: Irrigation without hosing temperature data

[LABob]

I can't figure out how to water the yard without screwing my temperature data. When it's really dry and I water the yard, it drops the temperature by about 6°. It's noticeable enough that WU kicks me off of the Wundermap. Just wondered if there's something obvious I haven't thought of. Since I'm wireless I'm tempted to carry the ISS somewhere else in the yard while I water.

[ValentineWeather]

Water night time, early morning just before sunrise may help with less temperature change because humidity is higher so you get less cooling evaporation.
 
If portable can you mount higher above grass where the cooling is less also. Last thought 
move unit to different area where watering won't bother.
 

[Felix1]

I can't figure out how to water the yard without screwing my temperature data. When it's really dry and I water the yard, it drops the temperature by about 6°. It's noticeable enough that WU kicks me off of the Wundermap. Just wondered if there's something obvious I haven't thought of. Since I'm wireless I'm tempted to carry the ISS somewhere else in the yard while I water.

Seems to me like you have to decide whether you are interested in knowing what the conditions are at *your* location or whether it's more important to just fit in with the 'average' of the nearby stations. I'm fortunate in that my siting is in an open field area which I keep mowed, but isn't artificially watered, so I don't have that dilemma. But I have a neighbor and friend with a cosmic setup of WeatherHawk, Young and Dynamax sensors which he calibrates yearly. He could care less about the nearby averages and how Gladstone's website rates him. He's interested in knowing what the microclime weather is on his five acres and those expensive Dynamax soil moisture probes regulate the lawn irrigation system and English garden drip system. He wants to know exactly what the actual conditions are on his acreage, the nearby averages be damned.

[LABob]

Seems to me like you have to decide whether you are interested in knowing what the conditions are at *your* location or whether it's more important to just fit in with the 'average' of the nearby stations.

I don't care about "fitting in," but I do care about sending data I know are false. Sending temperatures that are below ambient because of irrigation isn't any different to me than having a barbeque under the ISS and sending in the higher temps. Sure, it's the "real" temperature where the ISS is located, but it's not representative of the weather.

If it were 15 or 30 minutes, I wouldn't care. The problem is that since I'm not watering grass, but a drought-tolerant shrub landscape (our drought's bad enough that you have to water the drought tolerant plants this year). To simulate a typical seasonal rainfall event of 1" means watering for about 6 hours per zone. I don't want to send 6 hours of bogus data if I can help it.

[pfletch101]

Not only should drip irrigation distort your local temperature and (particularly) humidity readings less than sprinkling, but you will deliver a much greater percentage of the water to the plants which need it, and waste correspondingly less, so your total water consumption will be reduced. Even if your water is not metered, this is a good thing for the environment.

[dalecoy]

I don't want to send 6 hours of bogus data if I can help it.

Have your irrigation controller turn off your data feed.  [Exactly how depends on your network setup, of course]

[CW2274]

Since I'm wireless I'm tempted to carry the ISS somewhere else in the yard while I water.

If you were to do that daily, I'm thinking that'd get pretty old, pretty fast, especially the anchoring part. Could you possible send pics, maybe we all could brainstorm from there.

[LABob]

Not only should drip irrigation distort your local temperature and (particularly) humidity readings less than sprinkling, but you will deliver a much greater percentage of the water to the plants which need it, and waste correspondingly less, so your total water consumption will be reduced. Even if your water is not metered, this is a good thing for the environment.

Drip irrigation is really horrible for healthy plant development. It's great for annual crops, but for long-lived plants that have evolved to strategize for drought, it kills many of them within a few years, stunts others, or causes disease. Drought tolerant native plants have evolved huge surface root systems and symbiotic relationships with soil fungi to maximize moisture availability. Drip irrigation breaks all of that by encouraging vertical root development and disturbing the microbiology of the site. When the root systems and the hyphae of symbiotic fungi no longer mesh to maximize moisture uptake, it also give weeds a niche in which to establish themselves.

In California, watering established native plant landscapes should only take place during cool weather during the rainy season, and should come in the form of "rain". That keeps the whole ecology of the site moving along as it should.

If you were to do that daily, I'm thinking that'd get pretty old, pretty fast, especially the anchoring part. Could you possible send pics, maybe we all could brainstorm from there.

Watering takes place about once a month during the rainy season in bad drought years. It never happens during regular years.

[CW2274]

Not only should drip irrigation distort your local temperature and (particularly) humidity readings less than sprinkling, but you will deliver a much greater percentage of the water to the plants which need it, and waste correspondingly less, so your total water consumption will be reduced. Even if your water is not metered, this is a good thing for the environment.

If you were to do that daily, I'm thinking that'd get pretty old, pretty fast, especially the anchoring part. Could you possible send pics, maybe we all could brainstorm from there.

Watering takes place about once a month during the rainy season in bad drought years. It never happens during regular years.

Well, kinda sounds like carting it around may be the way to go, obviously if you don't find something else permanent that's adequate for proper sitting.

[pfletch101]

Not only should drip irrigation distort your local temperature and (particularly) humidity readings less than sprinkling, but you will deliver a much greater percentage of the water to the plants which need it, and waste correspondingly less, so your total water consumption will be reduced. Even if your water is not metered, this is a good thing for the environment.

Drip irrigation is really horrible for healthy plant development. It's great for annual crops, but for long-lived plants that have evolved to strategize for drought, it kills many of them within a few years, stunts others, or causes disease. Drought tolerant native plants have evolved huge surface root systems and symbiotic relationships with soil fungi to maximize moisture availability. Drip irrigation breaks all of that by encouraging vertical root development and disturbing the microbiology of the site. When the root systems and the hyphae of symbiotic fungi no longer mesh to maximize moisture uptake, it also give weeds a niche in which to establish themselves.

I think that we may understand somewhat different things by 'drip irrigation'. The OP had said that his plantings were drought tolerant but were being negatively affected by excessive drought, and therefore needed occasional watering - 'to simulate a typical seasonal rainfall event of 1"'. The issue for me is and was how to deliver that necessary water with least waste and least interference with his weather station readings. I still believe that the solution is an appropriate layout of drip tubing and/or mini-sprayers, running on a one-off basis for the 6 hours for which he wishes it to 'rain'.

[dalecoy]

Since I'm wireless I'm tempted to carry the ISS somewhere else in the yard while I water.

Which, of course, would ruin the continuity of your data.  And consider the anemometer (unless you have an anemometer transmitter, of course).

Depending on where you're sending the data, and what software is in use - it might be practical to (for those 6 hours) pick up temperature and humidity data from some other source, and substitute that in your data feeds.  Of course, that would be fake data.

Or, is there another Davis station nearby that you could receive????

OK - what's your aspiration situation?  If forced, then turn off the fan.  Next, seal the shield with good insulation for the watering period (i.e., no aspiration at all) and an hour or so afterward.

[azchrisf]

I have the same problem. The humidity/dew point rises about 6-8 deg when I water in the summer, usually morning (7am) and it kills my Gladstone and MADIS ratings. I can't move the station anywhere else in the backyard (it's all grass, a pool, or blocked by the side of the house for the solar panel). Gable mounting I tried and it shows very odd resjults, and Roof is a no-no here in the Southwest epsicially here in AZ...so I have to deal with it.

Only thing I could do is raise the station to 15ft. Doesn't fix the issue but helps.

There really isn't a solution to the problem outside of moving the station. The ideas of turning it off when watering really won't matter, because when it turns back on the humidity/temp levels will still be the same - out of whack - from the water evaporating.

The night idea seems to be the only logical other thing that could be done IMHO.

[ValentineWeather]

Also being from Arizona it was something I dealt with for years. Watering only early morning and 10' mounted shield you see much less evaporation cooling, so 15' would even be better but then you are getting above the ideal surface height  6' and may see slightly warmer low temperatures.

I like the higher mounted shield 10' over 6' especially in yards with limited air flow it really helps reduce artificial heat pockets with better air flow and gives more accurate temps/humidity.  I was mounted 10' but had the detached rain gauge mounted about 3'.

[azchrisf]

Hmm...maybe I'll move mine back down to 10'. I raised it higher just for the hell of it, I see everyone else around here mounting them on side of roof gables on the 1 story houses, which is definitely 18-20 ft. Mine's 2 stories and an odd configuration so it's undoable.

BTW what do you mean "mounted shield"? Aspirated shield?

Thanks

[ValentineWeather]

I use aspirated shield. The non aspirated would benefit even more mounted higher for better air flow. I experimented with 2 stations one  6' and the other 10', overnight lows were the same but the 10' station was generally a degree or 2 cooler on high temps.
When I went with taller mount off roof the lows started suffering by several degrees especially low wind nights.

[azchrisf]

So based on all that would you say 10' is bad for an aspirated shield during the day?

[ValentineWeather]

So based on all that would you say 10' is bad for an aspirated shield during the day?

No I wasn't saying that at all. Just forget about aspirated vs non. 10' is a good compromise if you are watering lawn and concerned. It's not  so high you start having warmer low temperatures is all I was saying. For those with fenced backyards its a good compromise all the time for better airflow to sensors vs 5-6' standard height.

[azchrisf]

Gotcha. Thanks

[LABob]

I still believe that the solution is an appropriate layout of drip tubing and/or mini-sprayers, running on a one-off basis for the 6 hours for which he wishes it to 'rain'.

100% coverage of 1/2 acre would be cost and labor prohibitive that way, but I see what you're saying. The watering is so infrequent that I just use portable sprinklers attached to a hose. In bad years (like this one), I water about a half dozen times a year. Normal years I won't water at all. The plants would survive bad years without water too since they're species native to my location anyway, but they would look pretty bad.

This problem is even rarer than the infrequent watering, as it only happens when we have a local condition called offshore flow. The very dry, warm desert air flows from the Great Basin towards the coast. I was just hoping I wasn't missing any obvious way to avoid the very local spike in humidity and drop in temperature that happens sometimes when conditions are right.

[pfletch101]

I still believe that the solution is an appropriate layout of drip tubing and/or mini-sprayers, running on a one-off basis for the 6 hours for which he wishes it to 'rain'.

100% coverage of 1/2 acre would be cost and labor prohibitive that way, but I see what you're saying. The watering is so infrequent that I just use portable sprinklers attached to a hose. In bad years (like this one), I water about a half dozen times a year. Normal years I won't water at all. The plants would survive bad years without water too since they're species native to my location anyway, but they would look pretty bad.

You're probably right, unless the half acre only contained a finite and relatively small number of individual 'shrubs', each of which could have one or two drip outlets. The cost (money and/or labor) of those and the necessary distribution piping would not necessarily be prohibitive, though it would be significant.

[LABob]

You're probably right, unless the half acre only contained a finite and relatively small number of individual 'shrubs', each of which could have one or two drip outlets. The cost (money and/or labor) of those and the necessary distribution piping would not necessarily be prohibitive, though it would be significant.

Have to evenly wet about 8' radius around each shrub to encompass the entire root system and avoid the aforementioned problems. In my soil it seems like drip emitters only wet about 6" radius. It would take 200+ emitters per shrub. I could go microspray, but spray is difficult with shrubs because the shrub gets in the way. That's why I do overhead watering. Oh well. Life is always a series of compromises given a set of objectives and available choices.

[LABob]

That's the intent, but the practicality requires watering from above. It's not practical for me to install 20,000+ emitters on the property.

[SpartanWX]

If your concern is data accuracy I'd just quit watering and let the lawn go to hell.  That way the data will reflect the negative externalities of the decisions we make on a regular basis (such as needing to have a nice lawn).  We can't have our cake and eat it too.

[LABob]

If your concern is data accuracy I'd just quit watering and let the lawn go to hell.  That way the data will reflect the negative externalities of the decisions we make on a regular basis (such as needing to have a nice lawn).  We can't have our cake and eat it too.

I don't have a lawn. My water use is less than 30% of the average use in my area. I will not cut back further to subsidize my neighbor's lack of conservation.

[SpartanWX]

If your concern is data accuracy I'd just quit watering and let the lawn go to hell.  That way the data will reflect the negative externalities of the decisions we make on a regular basis (such as needing to have a nice lawn).  We can't have our cake and eat it too.

I don't have a lawn. My water use is less than 30% of the average use in my area. I will not cut back further to subsidize my neighbor's lack of conservation.

Lawn, yard, whatever.  That's semantics.  It's a half acre of whatever.  You're trying to get 13,000+ gallons of crystal clear potable water onto it (and further wasting a ton in the process through evaporation as evident by the significant temperature drop).  All because you want your shrubs to look nice and climate change is going to make that a non-starter. I guess you want a pat on the back for doing 30% better than horrible people.  Congrats?

You are right.  Life is a series of compromises.  All too often we (myself included) choose ignorance over action because action requires selflessness and we have been programmed against that.  Just saw some irony there in the concern over your precious data, which wouldn't accurately reflect the changing climate, which is directly related to waste, which is directly related to the choices and compromises we do or don't make. 

In any event.  If you don't want to xeriscape (too a greater extent than maybe you are), consider spending a whole Saturday that month you need to water walking around with your hose and flood irrigating (no nozzle), applying the water directly to the soil in lieu of applying it in the least efficient way possible (spraying it willy-nilly through the air).  It will be good exercise, and you will have plenty of time to commune with each endangered native shrub and ponder the nature of life's decisions.  There will still be a perceptible change in your data, but maybe it won't be so severe that you get dumped off of the website for the day.

Sorry for the preaching.