Geoecological aspects of the underground erosion development in loessial massifs of Uzbekistan

Abstract

The problem of the development of the underground erosion is considered ion the article. The most brightly the underground erosion is shown in the massifs of the loessial breeds, which are widely developed in Uzbekistan. This phenomenon of consequences of the underground erosion development is described in science as the term “loessial pseudo-karst”. The loessial pseudo-karst have received the greatest spread and development in places of an active technogenesis since the second half of the XX century. Besides the territories connected with civil, industrial and hydrotechnical engineering the loessial pseudo-karst develops actively in the connection with active irrigation of the massifs formed with the loessial breeds. In case of not dosed water supply for the irrigation of agricultural grounds and the subsequent uncivilized dumping of surplus of water there is an extremely fast development of a loessial pseudo-karst (a day and even several hours). The negative consequences of the development of the underground erosion in loessial massifs lead to the violation of fragile balance of the natural and technical geosystems (NTG) and their conclusion from the condition of metastable balance. When forming pseudo-karst sinkholes near settlements, their unreasoned elimination by filling happens generally at the expense of solid and liquid household waste that considerably accelerates process of destruction of the massif, due to the impact on the loessial breeds of aggressive infiltrate. In case of active development of the underground erosion there is a final fracture of the loessial massif and formation of so-called pseudo-karst “bedlend”, that is sites where any economic activity is impossible. There are considerable economic, ecological and quite often social damages. It is easier to prevent a loessial pseudo-karst, than to fight against after its development has begun. The lack of due consideration to this promptly developing process annually causes the necessity of recultivation of the soil massifs broken by an underground erosion (pseudo-karst) or to the conclusion from the crop rotation of the most valuable irrigation lands in arid areas. The qualitative recommendations about the prevention of the development of a loessial pseudo-karst and minimization of damage are made.