mercoledì 29 dicembre 2010

We'll have 100 lakes of Salento Lecce?

We'll have 100 lakes of Salento Lecce?

Antonio Bruno *

Today I write of Salento Lecce, its 97 municipalities, the forest of olive trees, but if I do not think there was none of that 130 million years ago, I can not help but intrigue and curiosity. Yeah! And what was there 130 million years ago?

All what we now call Lecce Salento, a peninsula that extends into the great salt lake, a bridge towards the coasts of Africa and Asia, happily settled with my antenati130 million years ago was .... "Under water". And in those waters lived molluscs which were protected by shells. And you know what happened to these shell when shellfish were dying? Are you scratching your head? Look, the answer is simple, and so they were fell to the bottom sediment. For long 65 million years those shells have fallen on the bottom and formed a layer of sediment than 3 thousand meters! Yes! You understand very well! We have a layer of sediments with shells of mollusks that lived 130 million years ago to 65 million years ago right where I live now, with a thickness of 3 km! But in the long run without bringing the water of Salento in Lecce is almost entirely in the deep aquifer that it is the rock formed by those shells!

The deep aquifer groundwater is also known as the main or "karst" because its sequence is represented by the limestone aquifer - permeable Cretaceous dolomite karst as well as cracking. Do not pass out please! All these words are used to describe those shells of molluscs lived 130 million years ago to 65 million years ago that has been accumulated to form a layer of 3 km! Quiet, it's all under control!

But this water that feeds this ground that we understand to be a cracked rock, where it comes from? This water is of meteoric origin! But no have nothing to do meteorites, galaxies and stars of the Universe infinite! Storm water means rain water, which quickly infiltrate into the ground through the numerous structural breaks and calcarenitic gathering of calcium deposits, deep, into a single body of water that floats, because of lower density, sea water invasion of the second continental a pattern common to all the Salento peninsula.

The movement is mostly free hair, according to a piezometric surface placed just above sea level.

The condition of flotation, as above, the lens of fresh water on the underlying salt water, can be explained by the law of GHYBEN-Herzberg for determining the thickness (h) depending on the density and load piezometric:

h = (df / (df-dm)) x t

where dm is the density of sea water (1,028 grams / cubic centimeter) and df is the density of fresh groundwater (1.0028 gram / cubic centimeter) and where t is the piezometric load.

So to recap, the rain water to be fed into the deep aquifer in the territory that lies at a depth ranging from a minimum of 74 meters to a maximum of 98 meters and for this reason that our fathers have had to Salento Lecce all their ingenuity to create systems for the supply of water: springs, wells, reservoirs and underground tunnels.

In September and October 1885 in Lecce was held the international competition of the mechanisms of water trucks and engines in the wind that was held in the Botanic Garden of Lecce on the ground which is now the Chamber of Commerce made davati to that temple of 'Agriculture, which was the Agrarian and Land Registry offices or the Ute. The Competition of Lecce was announced by the Ministry of Agriculture which bore all the costs. In 1883 the competition was held in Cagliari where, however, competed only the mechanisms of water trucks instead in what was held in Lecce two years after the engines were added to the wind. Of this competition are the notes of Cosimo De Giorgi, the extraterrestrial who lived in those years that he wrote about almost everything, what was observed in the Salento Lecce and not just in this area. The choice of Lecce was determined by lack of water recorded since the time of Horace who went even to the lack of drinking water, the productive potential of the land of Salento, Lecce for the climate and the prevalence of the winds as there is presence of mountains that prevent the unfolding.

Annotations love of De Giorgi concerning the lack of wind excluding the engines made by a young mechanic at Gallipoli, although some exhibitors sent to Lecce drawings and photographs.

However, for machines that drilled these "idrofore" there were 107 schemes exposed as detected by the official catalog.

Long ago, in 1885 in Lecce through a competition organized by the Ministry of Agriculture, has solved the problem of how to bring water from the aquifer that is at a depth ranging from a minimum of 74 meters to a maximum of 98 meters since the surface to quench the people and the public health, but also for agriculture.

Let's think together, today we got the water we need through the work of the Aqueduct of Puglia, this water is treated after it was used and as it were "thrown" or in the river system or in the fields of spread and the proportion of it does not evaporate that arrives in the ground, and we motor through the uncovered and used, but this water may not be as it were "kept" somewhere as in the case of the lakes?

The Province of Lecce with a population of about 800,000 inhabitants and a per capita water consumption of 120 liters per day, producing about 35 million cubic meters of wastewater per year.

Assuming an average depth of 5 meters of abandoned quarries we would have an area of about 700 hectares of lakes, divided by one hundred municipalities in the Province of Lecce would mean 7 acres of the quarry into a lake! Imagine a seven-acre lake near your home, in every municipality, it is not beautiful?

To give you an idea Alimini Great Lake which is located in Otranto Lecce and Salento that everyone knows has a major axis of 2600 meters, the lowest figure between 300 and 800 meters, reaching the seabed as the maximum depth of 4 m and the total area is 130 hectares.

Have you thought about how many acres could be irrigated? By providing a consumer with a thousand cubic meters per hectare could irrigate 35 thousand of 200 thousand hectares, ie about 20% of the total area! And above all we could avoid the deep aquifer to subtract that amount of water!

The Region of Puglia December 28, 2010 with the approval of the Budget has provided for the allocation of a fund of 500 thousand euro aimed at preparing the final design of constructed wetlands and the final delivery of waste water from abandoned quarries in Gallipoli "Gratiae Mater.

It 'the only possible solution? I wonder and ask why not imitate what the Cav. Prof. Cosimo De Giorgi did 125 years ago doing a competition funded by the Ministry of Agriculture? Why not make a contest of projects to keep the water from the waste water on the surface of Salento Lecce?

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


Antonio Bruno, The use of treated wastewater for irrigation could help entire agricultural land

Antonio Bruno, Model Giammatteo: To protect the countryside and promote the area of Lecce

Antonio Bruno, the rain water and waste water exhausted quarries and sinkholes collapse from pure, fresh and sweet waters of 97 lakes of Salento Lecce



Antonio Bruno, raining on the Salento Lecce: feel like coming down!

Antonio Bruno, Climate del Salento Lecce

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