ENGINEERING GEOLOGY AND THE ENVIRONMENT

Paulo Teixeira da Cruz'

ABSTRACT: The paper tries to separate the activities of an engineering geologist that works for a civil engineering project, from the work of an engineering geologist that works for the same project but in the environmental aspects. The paper is divided in 3 themes: An overall view of the problem; Geology and Engineering Geology; and An attitude towards Engineering Geology and the Enviroimient.

RÉSUMÉ: Cet article veut distinguer les activités d'un ingénieur géologue qui travaille dans un projet de ringénierie Civile de celles d'un autre ingénieur géologue qui s'occupe des aspects de Tenvirormement dans le même projet. L'article est partagé en trois thèmes: Une vision génerale du problème; la Géologie et la Géologie de Tlngénieur; et Une attitude vers la Géologie de ringénieur et de TEnvironnement. AN OVERALL VIEW OF THE PROBLEM

"Ancestors of the first humans appeared just 300000 years ago. Like many other animais, they are plants, but over time they have found countless other uses for plant products - for shelter, fuel, tools and containers, for clothing transport, Communications and medicines.

In the relatively, short time since they emerged, people have had an enormous effect on the Earth's plant life. They have caused major environmental changes and brought about, directly and indirectly, a more rapid extinction of plants than has ever taken place before.

Now people have realized that plants are vital for the survival of life on Earth. They are beginning to conserve the plant biodiversity that is the result of 3500 raillion years of evolution".

This message is written on the wall of the Evolution House in the Kew Gardens in London. Similar messages related to the ocean and fishes are exhibited in the "Oceanário" of Lisbon, calling

clearly the responsibility for preserving life in the ocean as a permanent source of nourishment for the human race.

José Goldenberg (a Brazilian physics), in the joumal "O Estado de São Paulo" (July 24*, 2001) reports that among the various gazes that contribute for the greenhouse effect the Carbon Dioxide (CO2) that comes from the buming of fossils (coal, petrol and natural gas) is the most important, and that 80% of the energy consumed in the world, comes from this source.

As a consequence any attitude to avoid or to reduce the Earth waming, means a reduction of the emissions of CO2, and so by the reduction of the consume of fóssil combustion. The scientific evidence is so clear that more than 150 countries have signed and ratify the Weather Convention approved in 1992 in Rio de Janeiro. Beyond that in 1997 they approved the Kyoto Protocol that determine the reduction in the emission of each one of the industrialized countries up to the year 2010. A few countries have signed the last Protocol but Pres. Bush said clearly that he won't sign. There are indications, however, that the European Union, Japan and developing countries will rectify the Protocol, independently of the U.S.A. This has been confírmed recently.

This September, the Conference on Sustainable Development called Rio + 10, will take place in Joharmesburg to which Brazil has prepared a "Rio Letter" emphasize 7 points.

Prof. Escola Politécnica, Universidade de São Paulo, Brasil

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The first calls for the necessity of an efficient environmental policy that establish mechanisms able to prevent the destruction of the environment. The second point consider access to the water as a basic human right. The third deals with the access to genetic resources, in which emphasis is given to the free access to biotechnology. , j • Í- •

The fourth and the fífth points proposes basic requisites related to the city and reduction ot waste. And the last two discuss the problem of the forests and the necessity of regional legislation to prevent

environmental degradation. . • u- u An International Fórum took place in Porto Alegre in the South of Brazil (February 2 , 2002), in which

Environmental was one of the main issues. Non govemmental organizations ali over the World are discussing the problems on Environmental m

many aspects, including Indians, forests, animais, firesh water, agriculture, desertification, rains, v/eather, atmosphere, among others.

On the govemmental side, codes, protocols, agendas, resolutions, federal and state laws, have been issued since the 70', but only on the 80' and even 90' these laws have imposed severe penalties for water contamination, air pollution, improper land use, and forest devastation.

Historically the first codes seem to have appear in relation to fi-esh water, already in the 30' (the Brasília code is from 1934), when man had the conscious of the limitations of fresh water sources in the world. New codes appear disciplining forest preservation.

An historical mark was the Stockolm Conference in 1971. This Panorama is known, and has been knovm for the last decades and not to be repetitious and mostly

boring I want to discuss more specific the role of geology in this whole process. GEOLOGY AND ENGINEERING GEOLOGY

Geologists deals with the process of evolution related to the physical aspects of the earth. Natural hazards as earth and ocean quakes, volcano's activities, tomado, slope instabilities and debris-

flows, have sometimes more destractive power than any human means of destmction of the environment, but they have to be consider in a separate category.

Stmctural geologists have been able to reconstmct with the actual knowledge the past, and from the most remote past explain the present.

And more than explain the present they can predict the fiiture. Earth and sea quakes and volcano activities can be predicted with some accuracy, because they follow mechanisms that are careíully observed and registered.

Man is not capable of preventing or avoiding natural hazards of great magnitude but the understanding of the physical laws that cause such phenomena, have been incorporated in the design and constmction of engineering works at least in order to redtice the consequences of such hazards to human life.

As Y. Hasui (1992 - Geologia Estmtural Aplicada) explains "the basic purpose of the stmctural investigations is to determine the spatial distribution of the rock masses and reconstmct the phenomena and the process that produce such rock masses. They are initially conducted through the inductive method that starts from the characteristics of local stmctures, to define the framework of the whole mass. So the work starts from the detail, to reach the general".

The capacity of understanding the mechanism that affects mountains, valleys, rivers, prairies and oceans is a basic requirement to develop a consciousness about environment in a large and overall scale.

A man that is concera with nature, can contribute to evaluate the real danger in which the humanity is living today.

In the X ICSMFE in Stockholm (1981), P. Sembenelli and K. Ueshita in their state of the Art report on Environmental Geotechnics relate works in which Geotechnic has contributed to improve the Environment.

A.mong others tbey are: Slides due to raising the water levei near reservoirs; subsidence due to gas extraction; damage due to

surface accumulation of phosphate mining waste; sanitary fills to handle urban garbage; geotechnical maps contributing to risk analysis; loss of territory produced by enhanced surface etosion; ecoconsistent retaining stmctures for slope stability; tbe Vajon slide and the Venice engulfed by the sea.

In a more restrict sense geologists are called to contribute with their knowledge to the design and constmction of engineering works. More specifically they are called to describe the ground in which dams. roads, buildings, tunnels, cavems, cuts, etc. are to be built.

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This activity has been called engineering geology within the last decades, for which the International Association on Engineering Geology (lAEG) has made the most important contributions.

Recently, the lAEG has added to its name the word Environment, as many other national or International societies of a very large branch of activities.

It is obvious that a geologist as any other professional that has a clear consciousness of environment, wlien exercising his professional activity will consider the impact of such work in the environment. But the questions is - Is he prepared to do so? In many recently published papers the words "Sustainable development" and "environment" appear in the title of such publications, but going through the papers, only the traditional knowledge of rock and soil mechanics applied to excavations, mining, or foundation are encountered. In these cases it seems that environment is confiised with safety.

I do not disagree that scientific societies include in their names the word environment, because it is not only necessary but urgent to develop a consciousness of the impact of any activity in the environment, but that consciousness must be formed with the interaction of a far large participation of experts of other Sciences in the evaluation of such impact.

But even if environment is properly understood, the global economy that is ruling the economical activities of the majority of the coimtries, has in many cases serve as a barrier to the effectiveness of a sustainable development, as discussed by Ermio Candotti (1992 - Revista de Estudos Avançados, n°15 Maio/Junho - vol. 6 - Universidade de São Paulo) Ennio wrote:

"The dynamic of the world economical markets, determines a competition of prices and quality, that sacrifíces the costs of the preservation of the environment.

The relation of power among the nations, are based on military arsenais, industrial and agriculture productivity and rentability of the financial investments. Factors that do not consider the reason for the preservation of the environment.

The recent changes of the global politicai situation, have redefined the priorities and reoriented the investments of the rich countries. Resources that could have been given to environmental programs of the southem countries were reoriented to the recuperation of the economies of the coimtries in East Europe".

Within the last few years (1992 - 2002) in spite of the efforts of many people, organizations and the many intemational meetings and protocols, the situation described by Candotti has not changed too much, and in some aspects is even worse.

In terms of laws, codes, agendas, intemational recognition of problems related to environment some progress has been made. The Kyoto Protocol of 1977 is a good sign.

So there is hope. Many engineering geologists are now merging into the broad legislation on environment :id are developing a deep consciousness of urban geology, dealing with risk analysis, transmission lines,

. jntamination of water sources, industrial pollution. Geochemistry and Hydrogeologists have contribute to evaluate underground water and other fluid pollution. A \E TOWARDS ENGINEERING GEOLOGY AND THE ENVIRONMENT

Two brief stories can be included here to introduce the theme: A young student of agronomy, a friend of my son, told me that he wanted to do his post graduate studies

" organic agronomy, that uses natural predators instead of fertilizers and pesticides. The project was to go to - igland and work in farms where these principies are used with success. He had a clear notion of the

iisequences to the environment of the modem large scale agricultural techniques. If he had finished his graduate courses some 25 or 30 years ago, he probably would be more interested in

e modem technologies to increase production. The second story is personal. When I started working in dam design and constmction 40 years ago, every

me that a dam was finished, there was a party in the near cities, and the dam was considered as an element : progress to everybody. A first sign of protest happened some 25 years ago when the so president of CESP, ent to inaugurate the Capivara dam, and was received by a group of the local farmers, that were requiring nipensation for the last crop, that CESP had already paid for, but they have consider not enough. From the 70* to today the situation has changed very fast. In the more than a hundred dam in which I

-.'.e been involved within these 40 years, I have seen the change. But one attitude that concems me is that iny engineers and geologists are still convinced that a dam cannot have negative environmental impacts, . ;ause it only creates a lake as so many natural lakes in nature, and that the water that goes through the r-^mes is clear, and restituted clear to the natural river course.