giovedì 6 gennaio 2011

Measure the wind of Salento Lecce

Measure the wind of Salento Lecce


Antonio Bruno *



Salentu lu, lu sule, lu lu and sea jentu which translated means: The Salento, the sun, the sea and wind. Already the wind! But what? Did you ever wonder? And you who own a piece of environment and rural landscape of Salento Lecce that interest you to know what the wind?

The wind is the horizontal movement of air masses and is generated by the difference in atmospheric pressure in a horizontal direction. I know, you're lost, Aspe, do not change the page that I'll explain. We all speak the same language, but there is dottoreagronomichese which is a language that agronomists have been invented to understand each other and do not make themselves understood by others. But I, you know, you translate everything! Those words mean that the sun heats the earth's surface, which heats the air which is counted. Hot air rises because it is lighter, but the cold air descends and then create air currents ... or the Wind! Simple no? The wind makes, along with the movement of water masses, the rebalancing of the energy balance of the planet Earth! The various regions of the Earth are subjected to different atmospheric pressure: the more the air is heavy, the greater the atmospheric pressure. The pressure, in turn, depends on the temperature and humidity. If the temperature rises, the pressure decreases, if it goes down, the pressure increases. If the humidity increases the air gets lighter, but if it falls, the air gets heavy.

Air masses tend to move from areas of high pressure to low pressure ones. These air movements are precisely the winds, due to changes in humidity and temperature.

The winds are important for many aspects of agro climate are responsible for the movement of moisture and heat between the various points of the earth, accentuating the evaporation, which means that the cultures of Salento require more irrigation water, causing wind erosion which means that their mechanical force shaping the land and change the balance of radiation.

But we can measure the wind?

Sure you can! To rhyme you need to know what the wind speed that describes the average velocity of the air mass moving in a certain period of time. Then there is the wind SHOWS greatness that describes the movement of air mass during the day and finally the wind direction indicating the direction from which the air mass and thus indicates the main characteristics.

Wind is an important factor in Salento Lecce influence agricultural production. A small fan is always favorable to vegetation, while high winds and constants can cause serious damage.

In the presence of persistent wind-induced vegetation is to enhance some characters xeromorfici as the reduction of leaf area, harvest and compact habit, increased perspiration often not compensated by the absorption radical.

In this situation, in practice, is to create water stress.

Here it is convenient to take measurements of winds and currents of air that is

carried out with precision instruments called anemometers.

I propose you to make simple measurements useful in field research, and for this reason I suggest you use a simpler tools that you can easily make with your hands, and I assure you to be equally reliable for the values that allows for .

To make your wind meter you get a broom handle wood, 35 cm of wire, a wooden board of 30 x 20 cm x 2, three screws, a ping-pong, a lighter, a protractor, a line, a black marker, a car, a notebook, a compass.

With the help of a protractor and a line marked on the tablet by placing the zero degrees on the long side on the left and 90 ° or ninety degrees on the short side on the right.

Secure the screw at the top left above zero and 1 cm from the top.

Halve the ping pong ball, infilzatela with wire made incandescent with the lighter.

Attach the wire to the half-ball so that the concave look to the long side, right, of the tablet.

Secure the wire to the screw even in such a way that remains wide range of movement.

Screw the tablet to the broomstick with the two screws.

The wind speed is measured by placing the broomstick on the ground, vertically, so that the ball indicating the zero and turning the tool until you find the location where the half-ball record, whichever is greater, this value will

an indirect measure but is representative of wind speed.

If you want to scale the instrument in km / h uphill on a car and hold the anemometer out the window with a half-ball pointing in the direction of the machine, ask the driver to start moving very slowly and to declare the speed in km / h , marked in a notebook how many degrees you move the ball at speed

machine. In below the hourly rate also sull'anemometro. With this tool you can evaluate where the wind blows: just a compass based on cutting the tablet in order to identify the cardinal points of origin.

Here you just have to build your anemometer and measure wind!



* Agronomist (expert in urban and regional diagnostic entitled International University Master's Degree in Diagnostic IMD Urban and Regional Urban and Territorial Diagnostics).



Bibliography



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