Weather Bug - What data is available?

[JMC]

HI IndyMike,

 

To explain lava cap it's best I start by saying I live in the Sierra Nevada foothills. Auburn is about 35 miles NE of Sacramento on I-80 and I'm at just over 1,200' elevation. There is a dense, very low absorption and very rocky layer in the soil around here that is anywhere from on the surface to 12-18" below the surface that we call lava cap. That stuff is the main reason that a jack hammer is a standard gardening tool here. On my property it is very near the surface and the absorbent layer I mentioned is soil that I have put down. The lawn has varying amounts of slope (nothing is level around here) and as soon as water reaches the lava cap it begins to run off below the top soil. At least I'm assuming that's what happens when the soil is moist but not saturated and there is water collecting on the sidewalk that isn't coming from overspray. I use the 0.25" per cycle as a safety factor and run an extra cycle in the evening if called for to make sure the lawn gets enough water.

 

I use Hunter MP Rotator sprinkler heads, a mix of MP2000 and MP3000 and I'm using the factory provided data to determine how long to run the system to get 0.25" of water. Each irrigation cycle runs each zone in the system twice to get the 0.25".

 

I began collecting the data you suggested this morning. I'll try to remember to collect each morning for the next few days.

 

mike

[IndyMike]

Hello Mike,

 

I've been reading Engineering Manuals for the past couple of days. After educating myself a bit more, I am have to retract an earlier statement: The ISY is correct in not allowing a negative water requirement. This is accepted practice in the absence of a detailed site analysis and/or active soil moisture measurements.

 

From the US Dept of Agriculture Engineering Handbook:(FC is Field Capacity)

When rainfall or irrigation takes in excess of the amount needed to bring the soil back to FC, the extra amount is assumed to percolate below the root zone; the daily balance is recorded as the FC level. Should high intensity rains cause runoff before the soil is filled to FC, it will be necessary to either estimate or measure the effective rainfall percolating into the soil that is available for plant

use. This amount is added to achieve the daily balance.

 

What I view as important in the above is the phase "percolation below the root zone" - You have rock below the root zone. There is no percolation.

 

To explain lava cap it's best I start by saying I live in the Sierra Nevada foothills. Auburn is about 35 miles NE of Sacramento on I-80 and I'm at just over 1,200' elevation. There is a dense, very low absorption and very rocky layer in the soil around here that is anywhere from on the surface to 12-18" below the surface that we call lava cap. That stuff is the main reason that a jack hammer is a standard gardening tool here. On my property it is very near the surface and the absorbent layer I mentioned is soil that I have put down. The lawn has varying amounts of slope (nothing is level around here) and as soon as water reaches the lava cap it begins to run off below the top soil. At least I'm assuming that's what happens when the soil is moist but not saturated and there is water collecting on the sidewalk that isn't coming from overspray. I use the 0.25" per cycle as a safety factor and run an extra cycle in the evening if called for to make sure the lawn gets enough water.

 

From your previous description, you have 6 - 8" of topsoil above the Lava cap. Referring to the graphic below, when it rains (or you irrigate) a portion of the water will travel through the soil and hit the lava cap. As you noted above, the slope of your land will cause the water to travel downward until it hits an obstruction (curb, driveway, foundation). The soil near the obstruction will become saturated as a result.

 

As you probably already know, saturated soil is not a healthy environment for grass. Under watering grass will cause it to go dormant. Over watering can kill it (in a much shorter time).

 

I do not have a solution for heavy rainfall. The ISY calculation should accurately calculate the ETo for the upper end of your slopes. If the low end of the slopes are being dammed by an obstruction (saturated), you'll need to apply some "Kentucky Windage". From the looks of your weather history, heavy rainfall should be gone until November.

 

As far as irrigation is concerned, I think you have to correct approach in applying .25" per watering. I would not run the system twice in a day (.5") unless the ISY tells you that you lost over .5" the previous day. Based on your ET#'s, you're not there yet.

 

Most irrigation manuals promote "deep watering" of 0.5" to promote root growth. With only 8" of soil, your grass roots have little room to grow. In other words, daily watering of .25" will cause less drainage to the lower sections of the lawn whereas 0.5" watering every other day may saturate the area.

 

I use Hunter MP Rotator sprinkler heads, a mix of MP2000 and MP3000 and I'm using the factory provided data to determine how long to run the system to get 0.25" of water. Each irrigation cycle runs each zone in the system twice to get the 0.25".

 

I began collecting the data you suggested this morning. I'll try to remember to collect each morning for the next few days.

mike

 

The Rotator heads are nice. I wish they had them when I laid out my system. They are susceptible to wind (which you appear to have a lot of). Be careful watering in the evening when the winds may be high - your uniformity will go to the wind (pun intended).

 

If you are interested, I've used the following site many times over the years as an irrigation reference:http://www.irrigationtutorials.com/reviews/rotor/mprotator.htm

 

I am still interested in the numbers that your ISY is providing. Let's give things a couple more days, then we can compare notes. I have some more suggestions, but want to see the numbers first.

[JMC]

IndyMike,

 

Thanks for the valuable info. Incidentally the only reason I started this particular thread is that I discovered my system applying water less than 48 hours after a heavy rain and when the soil was nearly saturated. It is this tendency to resume irrigation too soon after rainfall that I'm trying to prevent.

 

I always do my soil moisture test at the highest point on the slope, preferably near an edge where it is most susceptible to wind.

 

I agree on the 2nd watering. In fact, that scheduler not only looks at Irrigation Requirement (after the morning irrigation has been accounted for), it also limits the watering to days where the high temp exceeds 95 degrees F and when wind is not over 5 mph. Yes, MP Rotators are definitely very susceptible to wind.

 

I have data for 4/1, 4/2 and today. I couldn't get yesterday's because I'm not familiar with getting historical data and my system was down for a major HVAC control rebuild. When I get finished it will be completely Insteon (right now I have nothing).

 

mike

[IndyMike]

Hello Mike,

 

I'm still struggling with your soil system. Comments below -

 

IndyMike,

Thanks for the valuable info. Incidentally the only reason I started this particular thread is that I discovered my system applying water less than 48 hours after a heavy rain and when the soil was nearly saturated. It is this tendency to resume irrigation too soon after rainfall that I'm trying to prevent.

 

Normal soil structures have been characterized and assigned "Field Capacity" (FC) numbers base on the soils ability to hold water. You stated that you were using a "loamy sand" soil classification and had 6" - 8" of soil.

 

From the table below:

1) 8" of soil @0.07" per inch of root depth (8 x 0.07) = 0.56" in H20 Field Capacity. This is the maximum water that that classification of soil is assumed to be able to hold.

2) Assuming an 8" root depth, your Maximum Allowable Depletion (MAD%) is 60% (0.6*.56" = .34" water depleted).

 

Problems:

1) The table assumes a normal level of percolation - any irrigation above the Field Capacity of 0.56" is assumed to run-off (heavy soil) or be lost to percolation.

2) While a heavy rain in excess of the FC will saturate a "normal" soil, Evapotranspiration will be increased as will percolation. Normally, the FC will be re-established within 24 hours. In other words - the ISY is correct in re-starting irrigation after 48 hours. It is assuming a "normal system" that has re-established the FC due to run-off/percolation.

3) As I stated previously - your lava cap prevents Percolation. This effectively throws the concept of Field Capacity out the window. You effectively have a closed container that can be filled to saturation and is only subject to drainage due to elevation changes. I have not found a "residential" application that can account for the lack of Percolation. The alternative is active soil moisture measurement.

 

As I said in the lead in, I have not come up with a good solution for this. In the meantime:

 

1) Adjust your soil type to sand (100% absorption). This will help account for the lack of percolation.

2) Historically, your summer months will be marked by lower rainfall and higher ET. This should lesson the problem of Rain storage above the lava cap.

3) Your normal March ETc was 2.4" vs a rainfall of 2.2". Assuming your soil is retaining the rainfall, that's not enough difference to worry about. You might consider disabling the system from Jan through March.

 

 

I always do my soil moisture test at the highest point on the slope, preferably near an edge where it is most susceptible to wind.

 

That's a news item for me. I did not realize that you had a means of measuring the soil moisture. Could you post back the make/model of your tester and any measurements that you have performs?

 

I have data for 4/1, 4/2 and today. I couldn't get yesterday's because I'm not familiar with getting historical data and my system was down for a major HVAC control rebuild. When I get finished it will be completely Insteon (right now I have nothing).

 

I rolled up my data this morning. I'm rather disappointed:

 

1) I forgot about the time zone difference. I believe the ISY was pulling numbers for your site 3 hours early.

2) I had modem issues (1st time in over a year) on 4/3. I missed some rainfall on that date as a result.

3) Sampled the KAUR site at 5 minute intervals. Had 3 errors over the space of 5 days (seems reliable).

 

Other than the loss of data on 4/3 (Modem down), I don't see anything incorrect in the following. Please let me know how I can get your recorded data. PM me if you need an Email address.

 

[JMC]

IndyMike,

 

I've been up to my ears in getting my HVAC controls converted so I haven't been paying scrupulous attention to the irrigation.

My soil tester doesn't have a brand on it, other than Made In China of course. It's called 3-Way Meter and measures soil moisture, soil ph and ambient light. It measures moisture on a scale of 1 to 10 with 1 to 3 being dry, 4-7 being moist and 8-10 being wet. At a reading of 1 the soil is seriously parched and at 10 it is suitable for mud pies. I have a half dozen selected spots where I check moisture, 4 along the highest points of the lawn and 2 in the lowest.

 

I'll try attaching the saved files with the climate data from KAUN. I haven't tried attaching a file before so it should be interesting.

 

mike

20130401 Sample.xml

20130402 Sample.xml

20130404 Sample.xml

[arw01]

That sounds like the Harbor freight model I used for a couple of years before one of the tips got lost.

 

There are a couple of devices out there that measure actual soil moisture level and can be data logged.

 

The vegitronix http://www.vegetronix.com/Products/VG400/ sensor comes to mind, and I think a CAI board would handle it.

 

Also, for the more inclined the Davis Weather people make a commercial quality sensor. NOT cheap.

 

There was a fellow on misterhouse that used a Toro wireless sensor that just put out a it's wet, it's dry type signal and averaged that daily.

 

Sometime in my project of projects I am going the vegitronix route with a pi or something along those lines in my greenhouse.

[IndyMike]

Mike,

 

I looked over your XML files. Hard to tell whether the calculations are correct since the data isn't continuous.

 

I did notice that your April 2 data included a 121' elevation. Elevation is reported directly from Weatherbug. This is either a corrupt transmission, or an example of Weatherbug switching stations automatically (really annoys me). If this was a station switch, it was obviously a rather distant station.

 

[JMC]

IndyMike,

 

Not all that distant. That elevation would have been the WB station in Lincoln, CA. I'm about 15 miles from Lincoln and 8 miles from KAUN so distance isn't a great factor. The elevation difference is the main problem, especially for rain. Incidentally, I just retrieved a sample and it showed an elevation of 30 feet, which would be Sacramento Int'l Airport. That is about 35 miles from me and can have radically different climate. At least it isn't as bad as using KTRK, which has happened once that I know of.

 

mike

[rossarmstrong]

Mr. Armstrong,

 

Here's what I got back from Davis Instruments:

Hello Michel,

 

Good suggestion but unfortunately nothing is in the works currently.

 

I’ll forward this to our developer group.

 

________________________________

Brett Lane

Technical Support Manager

Davis Instruments

brettl@davisnet.com 510-732-9229

 

With kind regards,

Michel

 

 

Seeing another post about integrating Davis Weather Stations support into the ISY reminded me of our attempts last year (see above quote from Aug 2012 earlier in this thread) to contact Davis Weather directly.

 

Any chance U-D has gotten any updates or sees any benefit in continuing to try to work with Davis to implement some type of integration?

 

Regards,

 

Ross Armstrong

[Michel Kohanim]

Hello Mr. Armstrong,

 

We have not gotten any closer. The main issues we are grappling with are:

1. The number of customers who would actually buy a weather station is very low

2. There's no ROI for us to implement this solution

 

So, what we are doing instead is making integration with ISY even easier such that other devices can publish their events into ISY for processing. In this case, then, you can have any weather station feeding ISY.

 

With kind regards,

Michel

[rossarmstrong]

Michel,

 

Thank you for your usual prompt and informative reply.

 

I have already been using my personal weather station ID in the Irrigation Module. Are you hinting to additional features like interaction between incoming weather data and things like thermostats or attic fans, etc. ??!!

 

Always looking forward to your product improvements!

 

Regards,

 

Ross Armstrong

[Michel Kohanim]

Hello again,

 

My pleasure.

 

Those are already included in programs. I am hinting at bi-directional communications with external devices.

 

With kind regards,

Michel

[MWareman]

Hello again,

 

My pleasure.

 

Those are already included in programs. I am hinting at bi-directional communications with external devices.

 

With kind regards,

Michel

 

Possibly a sensor that directly measures soil moisture to optionally feed the irrigation module? Maybe several sensors - one per zone? Hoping....

 

I know.. Future plans etc...

 

I'm just getting into irrigation now - getting my sprinkler heads, rpz and valves installed in a couple of weeks once my permit comes thru. Planning my programming now - seems there is more to this that I thought.

 

Michael.

[Michel Kohanim]

Hi Michael,

 

Yes, quite possible.

 

Now, how's the RFC fix working for you?

 

With kind regards,

Michel

[JMC]

Michel:

Accommodating soil moisture sensors sounds like the perfect solution for me. Tell me more.

 

Michael:

What kind of soil moisture sensor do you have in mind?

 

mike

[Michel Kohanim]

Hi Mike,

 

Patience my son! Patience ....

 

With kind regards,

Michel

[MWareman]

Yes, quite possible./quote]

 

Awesome - thanks!

 

Now, how's the RFC fix working for you?/quote]

 

To be honest, I hadn't noticed it on the 4.0.3 fix list and was still at 3.3.10. Oops..

 

I posted back in the original thread on this issue so I don't pollute this one.

 

As always - awesome help. I do very much appreciate it.

[MWareman]

Michael:

What kind of soil moisture sensor do you have in mind?

 

I don't know what's available, but I would think that as far as irrigation goes a program could be along the lines of "if soil is dryer than xx, then begin irrigation cycle" - subject to time of day and day of week restrictions. Basically, a way of suppressing the irrigation cycle if a soil sensor reports that the soil is damp above a certain level.

 

Likewise, if VERY dry, have the ability to extend the irrigation cycle maybe.

 

It would allow for the dependency on the weather module to be dropped. In my case, the nearest weather station does not provide rain fall data - so I have to go further away. I get rain data, but its very wrong for my rain fall. So, my irrigation requirements are necessarily very wrong when calculated just from the climate module. The system needs the feedback to close the loop.

 

It would be *awesome* if there was, say, a Z-wave or wifi enabled weather sensor package that would pipe weather data directly to the ISY... Not sure if a) something like that exists or if the ISY could use such data....

I do know, I could get one and run software on a separate system to send my data to Weatherbug, then set the ISY to use *my* station, but that a lot of stuff in the loop if a sensor package can just send directly to the ISY.

 

Lots of other 'enhancements' I'd like to see regarding irrigation if we are on it.. (Forgive me - just spent the last couple of days learning about this function...)

 

My local ordinances require irrigation to only happen on odd or even days, depending on the address. I've managed to setup a variable and program set to do this, but its a heck of a kludge. I would think the calendar functions in the ISY should be extended to provide as many of the common timing possibilities to the system. Odd days, even days, every second Tuesday, third tuesday of each month etc etc.

[MWareman]

Patience my son! Patience ....

 

I can't wait... Looking forward to seeing what you have in mind.

[arw01]

There is a wiki entry for a series of programs that provide a lot of calendar functions, holidays, every third week, every other day, every third day, etc..

 

An hour or so setting them up and you are good to go once the variables are set correctly.

 

I've been looking at a Pi or a CAI board with some of the Vegetronix moisture sensors. They start at $35 each and go up to $50 or so if you get a really long cable.

 

I saw a Toro device that was wireless that you just stepped on to place in your lawn, but their system only handled one of those.

 

Ideally would be a vegetronix sensor, a robust case, solar, some sort of storage battery or caps, and zwave or zigbee radio. Use some dip switches or let it have a little setup function in the ISY to assign it to a zone.

 

Mwareman, check out the MP Rotator heads for the sprinklers. They are fabulous, put out the water very slowly, extremely little affect from the wind, and since they put the water out slow, you don't have big run off. I can walk along my sidewalk on a windy day and stay dry with them on, seriously. We are not talking 25 mile per hour gusts here, but a breezy day is not an issue for them.

 

Also since they are so frugal, the amount of water you loose into the air as mist is extremely minimal.

 

Alan

[JMC]

I'll second the MP Rotator heads, they have dramatically reduced runoff which with my soil is a really big deal.

 

I've looked at the Vegetronix sensors a couple of times but I would need at least 4 of them and getting their output into the ISY seems to be the major stumbling point. It sure would be nice to learn that someone has already solved that problem.

 

mike

[mountainman3520]

My apologies for not reading the full thread to try to find the current answer to this question.

I'd like to add future based decision making into my thermostat programs. The idea is to adjust the current temp programs based on how hot or cold the next day is predicted to be.

Is there a good way to get local weather forecast of the next few days into the isy? Does the weather module do that? If not, it should. Please add that feature. I'd like to know high and low temp for night and day, plus rain probability. This would factor into irrigation programs too, as well as hvac.

[Mike Ippolito]

I'm using station KCEF to get my weather info from the plugin. Tonight we were discussing whether to actually turn off the A/C and open the windows.. finally! When I looked at the weatherbug rss feed in my ISY it showed:

 

 

However when I went to the Weatherbug website it showed:

 

 

While not that different, the low temp for tonight is different, in fact different enough to be a factor in opening the windows... Anyone know why there' s a difference?

 

- Yes it's the same station, Yes I re-pulled data at the same exact time....

[Michel Kohanim]

Hi Mike,

 

That's quite odd. I suspect that it might have to do with caching in RSS vs. Real time in the commercial APIs. But, then again, pure speculation!

 

With kind regards,

Michel

[Stik]

I noticed today when using the java tool that the My Weather page from the Weather Module shows the sky's cloud cover in graphical form, both present and forecast for the day - Clear, Partly Cloudy, Mostly Cloudy, Overcast, etc. I do not seem to find this information (as a variable) in the Weather Module to use to program. I would prefer this over the light and light rate variables for programming shades based on cloud cover since the light and light rate numbers are difficult and unreliable to use for this purpose in the morning and afternoon.

 

Am I missing something or is this data not available for use as a variable for programming? Thanks for the help,

 

Andy