Geostatistics and rainfall with R

With the rainy winter season behind us, it’s time to summarize how much precipitation we got this year. The southern Negev desert enjoyed above average annual rainfall (in stark contrast to the rest of the country, where we saw only 60% of the multi-year average)

I wrote about creating isohyetal contours some years ago. This time I’ll try to improve my interpolation by using the powerful, open source R statistics program.
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Acacia Progress

This past winter left above average rainfall in the southern desert regions (50 mm, where the annual average is about 40 mm). As a result, trees and annual plants are all smiling.

Here’s the updated measurements of my acacia seedling:

Acacia Seedling data

Physiological measurements of this tree
located at: Longitude 35d10'18.533"E and Latitude 30d47'33.321"N
Elevation -40 m
Date visitedcanopy width (cm.)height (max)trunk diameter (cm.)
2/4/201158220.14
28/1/201268300.8
0.7
0.63
23/8/201272350.8
0.76
0.57
17/11/201280380.91
0.75
0.58
16/8/201382510.96
0.88
0.67
18/4/201493541.22
0.95
0.69
11/10/2014112701.40
0.98
0.72

 

Acacia seedling April 19, 2014 at 11:00 AM
Acacia seedling – April 19, 2014 at 11:00 AM

My Acacia Seedling 2013

A bike trip out to the wadi where a few small acacia seedlings are struggling to survive showed, not surprisingly, that they were pretty dried up. We’ve learned to expect that in our 40+ degree temperatures thru the summer. But I took measurements of the seedling that I’m following, and the results reinforced my optimism:

Acacia Seedling data

Physiological measurements of this tree
located at: Longitude 35d10'18.533"E and Latitude 30d47'33.321"N
Elevation -40 m
Date visitedcanopy width (cm.)height (max)trunk diameter (cm.)
2/4/201158220.14
28/1/201268300.8
0.7
0.63
23/8/201272350.8
0.76
0.57
17/11/201280380.91
0.75
0.58
16/8/201382510.96
0.88
0.67
18/4/201493541.22
0.95
0.69
11/10/2014112701.40
0.98
0.72

I’ll look forward to another visit thru the winter – hopefully after some rainfall – when I expect to see even more growth.

Ancient stones and new bills

Last week the Bank of Israel published drafts of the set of new currency to be put into circulation soon. For this print cycle it was decided to showcase Israeli poets, instead of the usual political figures. What’s more, a stanza from each poet’s work will be printed on the new bills. The four writers that will appear on the 20, 50, 100, and 200 shekel bills include Rachel (Bluwstein) the poet, Shaul Tchernehovsky, Leah Goldberg, and Natan Alterman. Nice touch bringing a wiff of culture into the markets and fast food stands.

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Creating Depth-Volume curves with GRASS-GIS

Our regional Drainage Authority prepared a reservoir at the mouth of a small dry riverbed to catch and regulate flood water coming from a mountain canyon. This reservoir was to act as a buffer to prevent flooding of agricultural fields and residential areas further down the valley. After a sudden rainstorm last week, the reservoir bravely fulfilled (pun intended ;-) ) it’s duty. Now we want to know how much water was actually captured, and to create a depth volume curve for the small “lake” that was formed. Here’s how I did this using GRASS.
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New Labeling in Quantum GIS

The new labeling setup in QGIS has been around for over a year now, and in the upcoming version it will become the default, replacing the old labeling. This new engine brings some advanced options that are quite worth learning, such as bulding labels from expressions, and conditional labeling. I’ll expand on some of these tricks that have already appeared in other QGIS blogs
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