ENGINEERING GEOMORPHOLOGICAL SURVEYING

A standard methodological approach to investigations performed by the Geo­

graphical Research Institute Hungarian Academy of Sciences has been thematic map­

ping of the components of the geographical environment (relief, hydrography etc.) ac­

companied by explanatory notes presenting general syntheses (Pécsi, M. 1963). This way environmental geomorphological maps and maps on settlements' environmental features were compiled primarily, serving for the purposes of environmental geology, settlement development and for decision making in order to create large-scale construc­

tions. For this reason topographical suitability with regard to forest management and agriculture was investigated and these studies also included engineering geological sur­

vey at Budapest, Pécs, Eger and Paks. Mass movement hazard was mapped in further towns and on the high bluffs along the Danube and Lake Balaton. Extended cellar sys­

tems were surveyed (Eger, Szekszárd) and areas unsuitable for construction singled out.

A complex investigation into the physical and social geographical environment has been considered indispensable for decision making as to large projects, among oth­

ers in site selection for hazardous and communal waste disposal. A recent trend of re­

search was the mapping of landforms to predict distribution and migration of radionu- clids in the immediate vicinity of the Paks Nuclear Power Plant. In the wider environ­

ment of the power plant geomorphological features were mapped those presumably affecting deposition from the atmosphere and concentration in the soil of pollutants of radioactive origin. Thematic map series can be instrumental in the identification of land- form units with different extent o‘f liability to contamination (Marosi, S. 1980; Borsy, Z.

1990; Rétvári, L. and Sóvágó, Gy. 1994; Tardy, J. 1994).

INVESTIGATIONS ON LANDSLIDING

The mapping of areas affected by landsliding is also of great importance before decision making. In the course of the last decade geomorphological research in Hungary - in keeping up with the demands of engineering practice - has been aimed increasingly at solving tasks to promote economic and technical planning of large constructions (Fo­

dor, T.-né and Kleb, B. 1986, Pécsi, M. 1993).

Until now, investigation or rather the surveying and assessment of areas and forms affected by mass movement came up mostly during the solution of actual planning or restoration tasks. Up to the present no comprehensive landslide and landscape quali­

fication map has been drawn about Hungary indicating all mass movement processes and forms. The trends and tasks of geomorphological research work on the subject have been defined by both engineering practice and scientific demand.

During the investigations conducted under the guidance of M. Pécsi in the Geographical Research Institute Hungarian Academy of Sciences a survey of the areas affected by landslides in Hungary was prepared. The principles and methodological aspects of mapping have already been described in previous publications (Pécsi, M.

1963; Pécsi, M., Scheuer, Gy. and Schweitzer, F. 1979).

Research objectives and mapping tasks have been the followings:

1. The compilation of a scientific, comprehensive material suitable for practical purposes about Hungary's landslide areas, providing information about the geomor­

phological characteristics and dynamic components of these areas.

2. Identification of natural and human factors responsible for landslide proc­

esses, and revealing cause and effect relations, while relying upon the knowledge of the dynamic geomorphological condition of the areas concerned.

3. Typifying groups of forms and processes in areas affected by landslides and mass movements with the separation of the individual and general movement and proc­

ess types, and categorization of them.

4. In the course of mapping of landslide areas it is aimed to collect information about the areas affected by landslides for the whole country, and to compile a compre­

hensive register.

Our investigations were summarized at different scales and in detailed dynamic geomorphological maps. On these maps, especially on the general geomorphological maps, mass movement phenomena are defined according to types. The detailed maps comprise the smaller individual forms created by the movements, e.g. slumps and scarps as well. Register forms were compiled about the forms and types of movement occurring in areas affected by landslides currently, about active slopes and those temporarily inac­

tive, and finally about terrains affected by fossil landslides.

These maps are of high scientific and technical as well as practical value for registering areas of mass movements. Registers have been prepared on almost one thou­

sand sites affected by mass movement phenomena in Hungary. Beside a sketch map, each register form provides information about the most important soil mechanical pa­

rameters as well.

On the basis of investigations it has been found that the future of mass move­

ment areas depends - apart from natural processes - on the consequences o f socio­

economic development, that man-induced relief forming factors are closely related to natural processes.

This is the reason why it cannot be indifferent for us, how and to what an extent has human activity been remodelling form types and altering the various states of equi­

librium, where stabilised fossil landslides and slumps, temporarily inactive slopes and active mobile slopes threatened by landslide, are found.

On the basis of the natural endowments of the areas affected by landslides, and as a result of a knowledge of present-day natural and man-induced processes and their impact, in some areas we have real possibilities for outlining the direction and rate of mass movements and surface development to be expected.

As to the future transformation of areas affected by landsliding from a practical point of view great attention has to be paid to this factor outlined above, as knowledge of future relief formation is a fundamental precondition of restoring damaged areas.

During detailed mapping work, the velocity of the widening and deepening of valleys was recorded and typical characteristics of the various valleys and the valley heads of different genesis under the present climatic conditions and under human impact were registered. In the course of mapping of landslide affected areas some special prob­

lems of deep mining regions were confronted with.

Rock movement and their crumbling-collapsing forms cause surface deforma­

tions which are due to large-scale exploitation and the growth of mining fields. These affect more and more areas in the Hungarian mining districts.

In the towns of coal mining regions affected by surface deformation and those assigned for or built up by the new housing estates often coincide, producing thereby heavy damage of the built environment. In the course of completing detailed maps it has turned out, for instance, that in the surroundings of Komló areas affected by surface collapse induced by undermining, stretch over three square kilometres.

The importance of this fact should be stressed, because the future selection of areas to be built up, must reckon with expectable changes in the morphological condi­

tions of the area. It has to be acknowledged that human activity, landscape modification, waters leaking from public utilities etc. have been speeding up movement processes despite the most careful planning.

There is a hope that relying on the results of engineering geomorphology, and having had some threatening warnings before, in the future, knowledge of expectable changes in the morphology of areas to be built in, and a more careful consideration of these aspects, will greatly contribute to the optimal site selection for large-scale indus­

trial or other constructions.

ENVIRONMENTAL IMPACT ASSESSMENT, GEOECOLOGICAL MAPPING