Speeding Up QGIS Rendering - a Workaround (sort of)

It is known that QGIS is painfully slow in redrawing canvas when at least one of the vector layers contains a lot of features. The obvious way to speed up the process is to forbid to render layer (or some of the features) at certain scale(s). Yes, it works, but what do we have to do, when we want to see the whole picture? To disable scale rendering and wait couple of minuets until the several hundreds of thousands features will be redrawn? Bo-o-oring!

The workaround that I use is not that elegant (as a rule based feature scaling for example), but it can be used in certain situations. When your vector layer is large but it is necessary to see all the features - start a WMS-server for this particular layer. Raster renders a way more quickly and will be generated by different software. Taking into account that the layer is on the same machine or in the local network the speed increase will be magnificent.

So you produce WMS-layer from the needed layer (lets call it parent-layer) by WMS-sever of choice (I use GeoServer because it has a straightforward GUI that allows you to set up server and WMS-layer in minuets), add it in QGIS and place it under the parent-layer. Then set visibility of the parent-layer to the larger scale (that is suitable for editing). Now you will be able to see the whole picture at the small scale, and rendering still will be fast. And because WMS-layer is produced from the same layer all of the committed changes to the parent-layer will appear at WMS-layer immediately.

And you will have another thing to decide: whether to create the same [complicated] style for WMS-layer as for parent layer or not. Well, I do not bother)))

Small Scale

Large scale

About Environmental Risk Assessment

There was a scientific seminar dedicated to environmental risks assessment in the scientific-research centre where I work. A speaker was awfully ignorant in subject unfortunately. As a person who is experienced in environmental risk assessment (see my posts about risks and a particular methodology) I was afraid that I will be the one to ask the speaker (quite an old man) some inconvenient question about formulas he used, but luckily he was ashamed by someone else.

During the discussion the question of monetary aspect of the risk and damage to environment was raised: whether it is possible to use money as the measure of risks that only applicable to environment itself. In other words: is it rational to use money when assessing possible damage to solely ecosystem (there are no money in ecosystem by itself), and how to perform such assessment?

What do YOU think? I wasn't able to find an appropriate answer at that moment, but now I believe I have a point. My answer is YES, we can use money to assess risks and damage dealt to ecosystem only.

Firstly the assessment is made by humans and for humans. And humans understand monetised value more easily. The approach that I want to propose is about assessment of money that have to be spent to recover ecosystem to exact the same state it was prior to caused or possible damage. Just imagine how much money one have to spent for recreating and reintroduction of just one extinguished species (a tasmanian wolf for example). Here you are a monetised damage to environment.

Another approach I have in mind is about evaluation of risks via relative live value of species (which can be easily monetised too). Lets use this formula for evaluation of life of individual of a given species: V=(1/N)*P, where V - relative value, N - population of the given species (or given areal of species), P - total population of the human beings. We will have a relative value as 1 for humans and 1*(P/N) for a given species. For example for a tiger we will have its relative individual value about 1 076 900! Literally, if we have a choice whether to save 1 million people or a single tiger, the tiger must be saved - not a million of people!!!

And we can monetise this value by multiplication on the average value of the single human life (you can play a bit with numbers given here).

So the damage to ecosystem may be assessed via loss of number of individuals of species that live in a given ecosystem and we are able to easily evaluate a relative value of the individuals of the each species, and it can be easyly monetised.

Legal and Illegal Dumps in Voronezhskaya Region, Russia

I couldn't believe my eyes when I saw that map! The true situation with waste management uncovered at the official geoportal of Voronezhskaya region.

The geoportal itself is quite good especially for Russia and thare are a lot of information. It is even possible to download some of the data and almost all metadata. And because of their kindness we can see the ugly face of true Russian environmental ignorance and corruption:

Dumps in Voronezhskaya region: Red circles - illegal dumps; Green circles - officially allowed, unlicensed dumps; Squares with circles inside - landfills

First of all - you may see how many red circles out there. These are my "favourite" illegal dumps... terrible indeed. 

But look at all these green circles and don't let them trick you: green here does not stand for "green". These are the same as illegal dumps, but... legal! Yes, these are dumps and their owners have no license for waste treatment and will never have because the soil and ground waters are not protected there.

So we have 9 landfills there. But not all of them have licence too... And finally there are no waste treatment plant at all.

Here you are an ugly inconvenient truth about dumps in Russia. Thanks to administration for shearing with us, but too bad they paint the same shit in different colours.

2011 - An Apple Year

(Photo by net_efekt - CC-BY)

Just for the record, 2011 was remarkably plentiful of apples in European part of Russia. So I ate a lot of apple jam this winter and even tasted a home made apple wine.

Maybe there will be another apple year in future and it will be possible at least to try to estimate an interval for this phenomenon.