Doc. of geography sciences Ivlieva O.V., junior researcher Ivliev P.P.,

doc. of geography sciences Bespalova L.A., senior teacher Sknarina I.I.

Southern Federal University, Rostov-on-Don

Geo-ecological Assessment of the Sea Coast in Rostov Region

The coast of the Taganrog Gulf has got an exceptionally favorable geographical position and tremendous potential of natural resources, which promotes the development of various economic activities and causes a profound transformation of the natural complex of the coastal zone.

For the last few decades the shores of the Taganrog Gulf have been extensively damaged both by natural and by anthropogenic factors. Erosion has sharply intensified; landslides and debris have been widely developed. As for Rostov Region more than 50 % of the coast of the Taganrog Gulf in the Azov Sea is in the area of high geo-ecological risk (because of the wave destruction, devastating landslides, flooding and flood inundation and surge waters).

This area differs from the others, because it is the most densely populated in Rostov Region: 12% of the population live on 1% of the territory.

The main reasons of the sea coast destruction in Rostov Region are of natural and technogenic origin. These include: changes of climatic conditions and the related strengthening of the cyclonic activity, increased frequency of western storms and surges, and an increase level of the Taganrog Gulf caused. Unfavorable geological conditions ( i.e. widespread easily eroded clay deposits in the cliffs, little capacity of sands, deficiency of beach-forming material, multidirectional character of neotectonic processes in the coastal zone, broad development of gully- dean network) promote the development of active exogenous processes.

A number of major technogenic factors include: inefficiency and alarm status of significant part

of existing protection structures. Also intensive development of the coast is one of these factors: more than 60% of the shore line on the northern coast has been developed; 18% of that - on the southern coast, being densely populated in the region (613 people per square km in the north and more than 120 people per square km in the south that is10 times higher than the average index of the region)

Taganrog city and 56 towns lie on the coast, which can be characterized by high percentage of industrial production (15 % of the regional indices), concentrated mainly on the northern sea coast, and it resulted in a high degree of the beach pollution. (Average amount of technogenic material on the beaches of the northern zone is 10%; the one of the southern coast is about 4%).

Land use is carried out without taking into account the natural features of the coastal zone (intensive plowing, cutting down forests, irrigated agriculture) that leads to more damage of the sea coast (Taganrog city, Chumburka village).

The deterioration of water quality and reduction of biological components of the beach formation;

removal of sand and shell material from the beaches and spits, regulation of small rivers resulted in decreasing beach forming material and reducing their width. Compared to the 80-s of the twentieth century, the width and shell material of the beaches cut, practically, in half, from 30 % till average15%. Reduction of solid effluent of the Don River compared to conventionally natural screen more than 10 times, led to erosion of the modern sea edge of the delta of the Don River to 0.6 m per year.

The research done for many years has established that on the coast average speed of coastal retreat reaches 1.0-1.5 m / year, maximum of 4.0-6.0 m / year. In general, in the Taganrog Gulf area the coast of strong abrasion and landslides activity stenches 60,0 km or 28% of the gulf coastline that have abrasion processes along 42 km, and landslides happen in the 18-km-zone.

Large-scale development of dangerous exogenous processes is a problem of increasing importance due to the extensive settling and development of the coastlines that requires advanced assessment of the hazardous effects and adopting urgent measures to protect the banks from collapsing.

To specify the priority of environmental actions, the task of ranking of the coast geo-ecological risk due to its degree is very urgent. To differentiate the coast according to risk four intervals have been singled out; the methods proposed in an integrated environmental assessment of Rostov Region have been used.(Ecological Atlas , 2000) In this case, it must be assumed that the greater the intensity of the symptoms of adverse processes and population density on the coast is, the greater the risk to human habitation can be.

The intensity of adverse processes have been evaluated according to assessment of the ecological and geological conditions (by Trofimov V.T., Ziling D.G., 2002). Assessment of environmental conditions and the following natural hazard and technogenic processes have been made: gullying, pollution of beaches, building-up the areas, the necessity of coastal protection and abrasion- landslides processes.

Within the coast of the Rostov Region the areas corresponding to four levels of geo-environmental risk have been specified- low, average, high and very high.

Most of the coast (52 %), mainly the northern coast, belongs to the zone of high and very high risk that characterizes extremely unfavorable conditions for humans and in a number of cases it is direct threat to life.

Very high geo-ecological risk is mainly observed within the northern coast of the Taganrog Gulf, an average one is typical for central part of the gulf, and the south-eastern part is characterized by the lowest risk.

Extremely high levels are observed in the northern coast of the Gulf of Taganrog, where Taganrog city and adjacent zone of the village Petrushina from the west lie.

The population density here is the highest in Rostov region (3663, 3 p per km) combining with “very high” level of anthropogenic impact, development and pollution of the beaches. These factors show the highest level of geo-ecological risk for human living.

Very high geo-ecological risk can be found mainly on the northern coast of the Taganrog Gulf in such zones as: Veselovoznesensky, Beglitsky, Novobessergenovsky, Mikhailovsky, Merzhanovsky. Margaritovsky and Port-Katonovsky areas can be also noted for a very high geo-ecological risk on the southern coast. First of all, it is due to very intensive abrasive landslides, very poor bank protection structures or their absence though there is a great need in their availability, and high degree of built-up areas. The average level of risk is typical for the central parts of the Gulf. In the northern sector of the Gulf such zones are Bokovsky, Rozhkovsky, Novolakemodovsky, Primorsky; as for the southern sector the typical area is Pavlo-Ochakosky. These zones are characterized by average degree of abrasive landslides. There are no big towns or settlements in these zones; the territory hasn’t been built much and the beaches are less polluted here. The south-east of the coast is characterized by the lowest degree of geo-ecological risk. This area differs from the others in the least number of intensive abrasive landslides, in territory which is less built up and less densely –populated and the beaches here are not polluted much.

Thus, the results of geo-ecological assessment of the coast in Rostov region obtained conclusively indicate that it needs urgent developing and implementing some coast protection measures, which must be carried out in nine emergency areas of the 59 km- coastline in Rostov region: Taganrog city, Veselo-Voznesenskaya village, Rozhok village, Novozolotovka village, Primorka village, Ochakovskaya spit, Chumbur-Kosa village, Novomargaritovo village and Port-Koton village. The immediate object of coastal protection on the coast of Rostov region unquestionably should be the coastal zone of Taganrog city.