QGIS fighting bugs

Real bugs, agricultural pests, cause damages to food production throughout the world. GIS techniques can help in monitoring pest infestation by collecting and mapping data from traps, baited with pheromone lures. QGIS when teamed up with Spatialite makes the ideal combination for pest control programs to maintain and display the distribution of different species of insects. Here’s how it’s done. Continue reading QGIS fighting bugs

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.
Continue reading Geostatistics and rainfall with R

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.

Spatialite helps creating an index of LIDAR tiles

We have a large set of LIDAR data, in separate *.las file, each covering a small rectangular area. I wanted to create a polygon shapefile of the coverage of each tile for reference so I know which files to choose when we need a subset of the whole region. Using a bash “one-liner” and a simple function in Spatialite I had my polygon layer.
Continue reading Spatialite helps creating an index of LIDAR tiles