The lack of rainfall puts under scrutiny again one of the most important resources of men: water. Last autumn and this spring have been the driest seasons in the last fifty years and inevitably the usual questions arise again: Are we witnessing the first consequences of the climatic change? Is a new drought cycle starting? Could we have taken measures to avoid this situation? The experts try to answer these questions on the basis of the experience of past situations to check that drought usually appears cyclically in periods of 11 and 18 years whereas the European Union announces a policy establishing that in 2010 every user must pay all the costs caused by the water used.
To what extent are the irrational use of water and the greenhouse effect provoked by man responsible for drought? The professor of External Geodynamics and ex-principal of the Institute of Water of the University of Granada, Javier Cruz San Julián, answers this question lately delivered by a large sector of society explaining that we must not be alarmist as, although the action of man can actually take part in these natural processes, the drought is mainly a normal consequence of the meteorological variability that characterized the Mediterranean climate.
In this sense, he remembers the situation lived in Spain in the 90´s: “Granada suffered for 15 years, from 1980 to 1995, under-average rainfall, to such an extent that the severe drought reduced to a critical limit the availability of water resources. The alarm also raised then, they started to talk about the climatic change and my answer was the same again, besides the fact our climate is very irregular droughts usually occur after a eleven year-period, so if the last one was in 1995 it was not strange that we were witnessing the start of a dry cycle that could remain for the next years”.
The periodicity of these cycles is due, according to Cruz San Julián, first of all, to fluctuations in the activity of the solar surface, that are apparent in the periodical increase of the intensity of solar spots “something we are not indifferent to, as they destabilize the atmosphere”. Droughts can also occur after periods of 18 years, produced by a change in the position of the axe of the lunar orbit with regards the equator of the sun.
Despite the data that point to natural phenomenon as the cause of the drought, the ex –head of the Institute of Water insists that we must worry and take measures because the action of man can influence to make a dry period catastrophic or not and he adds that there are certain things we must always do, regardless whether there are drought problems or not, such as “the rational use of water, avoiding water wastes and designing strategies to make an optimum use of the resources”.
Measures in agriculture
He also refers to one of the main harmed by the lack of water: agriculture, the main consumer of this resource, is in fact the responsible for 80% of consumption in Spain. “Therefore, and although saving measures must also be taken in the domestic and urban use, the most important are those referred to the main consumption, the agricultural: we must implement economic trickle irrigation systems and plan the type of products we must cultivate to avoid those which require a high consumption.
As for desalination as a measure to deal with the problem of drought, the geologist says that it is evident that desalination is another system for a responsible use of resources. But it is also evident that it can not be considered as the only solution, although it has become an ideal answer in certain areas like the Canaries. “Desalination is not a panacea, among other reasons, because it consumes energy and I think we can not afford to suggest, in this moment, a solution based on a system with a high energetic consumption, regardless of the fact that the abuse of this measure can affect the marine ecological richness”.
On the other hand, Cruz San Julián, who nest July will supervise the course of the Centro Mediterráneo in Lanjarón, referred to the measure announced by the European Union in the 90´s with regard to collection of all the costs caused by the water used, from construction and maintenance of infrastructures to sewage purification and treatment, and he pointed out that, if they finally put it into practice, the result of this policy “will be more than positive, as users will become aware, once and for all, that we must rationalize in an intelligent way a scarce good as water”.
Reference
Prof Javier Cruz San Julián
Institute of Water.
Phone numbers: 958 24 80 20 / 958 24 33 56
E-mail. jjcruz@ugr.es
