S.D.ISAYEVA

The All-Russian Research Institute for Hydraulic

Engineering and Land Reclamation,

Moscow, Russia

 

Some ecological and ethical problems caused by LAND RECLAMATION

 

      Land reclamation is a powerful factor of the human impact on environment in Russia. Some ecological and ethical problems caused by land reclamation are arising in different regions. These problems deal with water table rise, damage to the water resources, salinization, bogging etc. For a long time they were not so important because the main aim was the yield receiving. Nowadays as the result we have unfavorable ecological situation on irrigation land in Volga basin as well as in other basins. Very often ecological crises are connected with economic and social crises.

 

     Practice shows that rough forms of regulation of natural medium (the big irrigation and drainage systems, cascades of the water storage etc.) are often antagonistic to tendencies of natural systems evolution. In such cases the reclamation methods are ineffective. Irrigation and drainage systems destroy and agriculture lands would be deteriorated.

 

     So there is a problem of how to regulate human impact on natural geological systems (geosystems) and this problem must be solved. Analysis of the ecological risk serves as a basis of land reclamation and hydrotechnic designs are oriented to increase an adequacy of the designed measures with natural conditions.

 

     For agricultural success and effective development of water and land resources the appropriate relation must be found between the designed man-made influence and the potential sustainability and stability of geosystem conditions.

 

     The ecological stability of a geosystem is understood as the possibility to resist against various fluctuations (both natural and anthropogenic) for a determined period and also as the possibility to guard the structural and functional unity that would be favorable to the man.

 

     Ecological risk is a probability of some losses resulting from the ecologically unfavorable processes or disorders caused by the land reclamation or by water-building practice.

 

     In case of a synchronized development of several unfavorable processes occurring in boundaries of a geosystem the risk calculation takes into account that they all will take part in deteriorating the area, i.e. it will be equal to the sum of risks of each unfavorable process (soil, hydrogeological, engineering-geologic etc.) for all geosystem components and risks, initiated by rejections of technical systems and structures. We use data of actual observation or polyvariant simulation of hydraulic engineering measures etc.

 

      The allowable risk is determined under the condition of preserving the geosystem index in the field of sustainable states.

 

      The geosystem stability to the impact of both land reclamation and hydraulic engineering measures must be estimated on the base of comparing alternative designs of the proper impact and agricultural activities.

 

      The estimation of geosystems ecological stability should be based on the natural and genetic approach taking into consideration ecological and ethical problems. Mathematical simulation of various types of loads of land reclamation and hydraulic engineering is used and probability for designed variants is computed.

 

      Probabilities of system escaping beyond allowable limits have to be predicted for various loads. These variants of stability destruction risks for the geosystem as well as the probable size of ecological, social and economic damages must be estimated. Predicted results should be followed by suggesting measures for increasing stability in the agricultural production and also by determining reasonable limitations for impacts of both water building and land reclamation. Ecological stability of the region development should be ensured.

 

      The problem of regulating human impact on geosystem is being solved. A strategy should be determined which would allow accomplishing a designed aim without any destruction of development process of natural system caused by human activity.

 

      For realizing the mathematical model the simulation is used in a complex with probabilistic methods allowing - together with estimations of the consulting experts - to choose the optimum strategy. Recommending rational influences on natural systems must follow the choice of an allowable variant - based on problem solution and expert estimations -.

 

      In the course of realizing recommendations for regulating the influence the risk analyses complex includes:

-         control of conditions for a geosystem

-         complex estimating (for every geosystem component) the prediction reliability

-         continual estimation of geosystem conditions

-         realization of corrections for predicted conditions based on risk analyses methodology (after receiving results of system diagnostic and estimating the prediction reliability)

-         determining the regulation influences for regime function ensuring stability of the ecologically favorable geosystem.