Givi Gavardashvili

In the scientific paper, field-reconnaissance studies have been carried out at the Kobi-Gudauri section of the Georgian military road to develop a methodology for designing innovative avalanches.

Based on the joint field surveys of the main researchers of the grant project and the staff of the Hydrometeorology Department of the National Environment Agency of the Ministry of Environment and Agriculture of Georgia, the mountain slope of the project building was selected, the main parameters of which change within the following boundaries.3: GPS coordinates; Y = 4705596, length 800 m. Slope inclination 240, with absolute mark H = 2570 m.

Through the basic hydrodynamic parameters of the avalanche and the computer program - "Complex program for spatial framing of structures Lira-SAPR 2019 (license number # 1/7165)" innovative snow avalanche design is designed taking into account the dynamic and statistical loads of the avalanche.

 The Elastic Debris Flow-Regulating Barrage is a longitudinal structure placed across the bed of a debris flow channel. As the heights of the prisms are increasing, the structure has a springboard shape directed opposite the current, while damping of the debris flow energy is attained by means of pockets formed with elastic ropes between the upper faces of the prisms. With the purpose of designing an elastic debris flow -regulating

barrage, computational models were developed and a laboratory model was made based on them (with sizes: length – 0,60 m, width – 0,36 m and height – 0,25 m; the gradient of a springboard-type model is 0.25) to test it at the hydraulic laboratory. The methodology for calculating the design of Elastic Debris Flow-Regulating Barrage is presented.

Using theoretical and field studies, computer software programs (VOLNA-4, and MIKE-21, ) and GIS technology, and taking into account the possible accident (destruction) of the Earth Dam with a height of 102 meters, the contours of the riverbed of flooded territories in riverbeds for rivers Aragvi and Mtkvari have been defined in the given article considering the configuration of the water-catchment basins of rivers.

By means of basic differential equations of hydraulics, geometrical dimensions of Zhinvali Earth Dam, hydrological basic parameters of the reservoir, and computer software, the basic hydrodynamic parameters of the destructive wave at the Zhinvali Earth Dam are calculated taking into account the time of flow movement.

The paper provides empirical relationships with complex theoretical and field scientific studies, which are used to calculate the maximum discharges of turbulent and hyperconcentrated debris flows, taking into account the main hydrological and hydraulic characteristics of the Mtkvari River Basin. The proposed methodology allows to determine the volume of the debris mass transported by the debris flows, which allows to accurately predict the dead volume of sediment in the reservoirs at a later stage.

The problem of protecting territories from the harmful effects of water is very relevant for Ukraine, since 27% of its territory is more or less exposed to flooding. One of the most representative flood protection methods in Ukraine is the construction of flood-control dams. For today, the total length of protective dams in Ukraine is more than 4.0 thousand kilometers.

The technical condition of the dams of hydraulic structures was assessed based on the study materials. In the course of study some filtration losses and suffusion removal of clay soil particles were detected, which led to local damage of the dams. To reduce filtration losses and prevent the suffusion removal of clay soil particles in the area where the dams are adjacent to the slopes, a hydro-enclosure in the form of a groundwater cutoff was proposed. In general, for solving the problems of counteracting the harmful effects of water when assessing the technical conditions of protective structures, it should be included: conducting the study on natural and man-made risks; specifying the research methods for hydraulic and hydrogeological conditions of facilities; establishing a system area network for monitoring the condition of protective structures. The methodological approaches to assess the technical condition of protective hydraulic structures tested at Ukrainian facilities can be used in other countries, including Poland, Georgia, Azerbaijan and others.

Given paper has the objective for modelling of Emergency Warning System for monitoring and managing earthen dams-break due to natural and human-caused hazards in Kura-Basin in Georgia and Azerbaijan. Monitoring systems set in Azerbaijan and Georgia will consist the water level and discharge measurement stations and the geodetic-geotechnical system to control dam physical stability. By the quantity of large dams (height of a dam > 60 m and power of HPS > 100 MW) the Kura River basin takes 14th place in the world. There are 8 large dams on Kura River basin. Last of them is Mingecevir earthen dam, which was put into operation in 1953 (The height of dam is 80 m, length 1,550 m and total capacity of soil 15.6 mln m3 and reservoir with water capacity 16 km3 ). Heavy flooding and/or break one of dams in Georgia is enough for catastrophic "domino" destruction of all downstream dams. Only, in case of Mingecevir dam failure, the flash flood hazards area of downstream valleys, are 8,000 km2 with around 3.5 mln of inhabitants. The dams on rivers belong to the critical infrastructure of countries. That is, they form part of functionally related objects, including building objects, devices, installations, crucial for the security of the country and its citizens, and serving to ensure efficient functioning of administration. Therefore, they must be subject to crisis management of countries. The creation of the dam management system on the Kura River should use the world experience of other countries. The latest equipment should be used to test the flow and monitor the technical condition of dams. In assessing the condition of dams and the changes that have occurred in them, as well as sediments at the bottom of dams, 3D scanning technology should be used. To carry out a very large scope, various research and create a monitoring system for dams on the Kura River, it would be advisable to use funds from foreign organizations financing activities aimed at improving the security of such facilities.

Given paper has the objective for modelling of Emergency Warning System for monitoring and managing earthen dams-break due to natural and human-caused hazards in Kura-Basin in Georgia and Azerbaijan. Monitoring systems set in Azerbaijan and Georgia will consist the water level and discharge measurement stations and the geodetic-geotechnical system to control dam physical stability. By the quantity of large dams (height of a dam > 60 m and power of HPS > 100 MW) the Kura River basin takes 14th place in the world. There are 8 large dams on Kura River basin. Last of them is Mingecevir earthen dam, which was put into operation in 1953 (The height of dam is 80 m, length 1,550 m and total capacity of soil 15.6 mln m3 and reservoir with water capacity 16 km3 ). Heavy flooding and/or break one of dams in Georgia is enough for catastrophic "domino" destruction of all downstream dams. Only, in case of Mingecevir dam failure, the flash flood hazards area of downstream valleys, are 8,000 km2 with around 3.5 mln of inhabitants. The dams on rivers belong to the critical infrastructure of countries. That is, they form part of functionally related objects, including building objects, devices, installations, crucial for the security of the country and its citizens, and serving to ensure efficient functioning of administration. Therefore, they must be subject to crisis management of countries. The creation of the dam management system on the Kura River should use the world experience of other countries. The latest equipment should be used to test the flow and monitor the technical condition of dams. In assessing the condition of dams and the changes that have occurred in them, as well as sediments at the bottom of dams, 3D scanning technology should be used. To carry out a very large scope, various research and create a monitoring system for dams on the Kura River, it would be advisable to use funds from foreign organizations financing activities aimed at improving the security of such facilities.

 The climate change drew a wide response in the field of environmental protection, particularly, in the mountain-type countries of the world with predominantly floods, erosive-landslide and debris flow processes formed in their mountain landscapes. Their activation causes great damage to many countries of the world, destruction of various structures and unfortunately, many human and animal victims.

Following the above-mentioned, an elastic debris flow-regulating barrage was designed, which is made of the sections of triangular prisms of the same height connected to one another with their bases forming a springboard.

The barrage is a longitudinal structure placed across the bed of a debris flow channel. As the heights of the prisms are increasing, the structure has a springboard shape directed opposite the current, while damping of the debris flow energy is attained by means of pockets formed with elastic ropes between the upper faces of the prisms.

With the purpose of designing an elastic debris flow-regulating barrage, computational models were developed and a laboratory model was made based on them (with sizes: length – 0,60 m, width – 0,36 m and height – 0,25 m; the gradient of a springboard-type model is 0.25) to test it at the hydraulic laboratory.

Based on the analysis of theoretical and field studies, the methodology for calculating the basic hydrodynamic parameters of the tsunami wave formed in the event of a possible accident of the Zhinvali earth dam is discussed. The contours of the flooded area in the event of a possible accident at the Zhinvali Dam have been established and the population at high risk is estimated.

In the article are considered rules for population living in the flood risk zone in the emergency, their readiness for disaster relief and providing first aid to victims in line with modern requirements are discussed and provide first aid of victim according to modern requirement.

It has been presented mathematical model in case overflow of wave on the dam, in order to hydrodynamic characteristics of wave generated by debris flow, various types landslides, also terrorists attract at the land dam. In the mathematical model has been considered differential equation system of cohesive debris flow uncontrollable movement considering the hydraulic friction and airborne impedance in the flow of the flow variable. The numerical method of solving the

equation is used to diagnose the system of differential equations, in particular the "fracture of the vector". In the realization of the problem is considered the main hydrological hydraulic properties of the Zhinvali land dam and reservoir, as well as the debris flow wave overflow on the dam and geological-topographical

characteristics of river Aragvi in the GIS system.

The article gives the physical-mechanical properties of coherent (hyper-concentrated) mudflows and evaluates the wave nature of their movement. Based on the theoretical and experimental calculations, force of a dynamic impact of a coherent mudflow during its influence on a structure is identified and is used to calculate the reliability of the anti-mudflow structure at the following stage. The hydraulic calculations demonstrate that the wave velocity during the coherent mudflow motion is 3 times more the average velocity of current in the effective cross section what must be taken into account during the dynamic impact of a current on an anti-mudflow structure. 

In the mathematical model of debris flow formed as a result of water wave outstretched on the land dam of Zhinvali the coefficient of complete resistance K of flow movement is represented as the sum of the resistance caused by the internal friction coefficient (K ) and the flow of air resistance against the flow front (K '). By using of Shvedov-Bingam modified equation and considering of hydrological and hydraulically parameters of water flow outstretched on the land dam of Zhinvali has been developed mathematical model, using which is calculated the dynamic parameters of debris flow motion. 

Georgia is one of the most vulnerable countries to natural disasters within South Caucasus Region. In recent years, the disaster risk has increased due to faulty land-using. Outstanding building codes lead to inadequate building construction. There is a lack of real data on natural disasters and the impact of mudflows, floods, debris flows etc. on land-use planning and prompt actions after above mentioned catastrophes.

Therefore it is important task to carry out assessments of critical structures sensitive to natural threats such as dams and reservoirs. In order to be able to improve the resistance of hydraulic engineering structures it is necessary to utilize a formal risk analysis framework, such as the Critical Asset and Portfolio Risk Analysis (CAPRA) method. The scientific article examined the

creation of a framework for the condition of the earth dam and risk management using the analysis of the critical state and the risk portfolio, which was developed by Professor Billal Ayyub who represents Maryland University in USA, to examine human caused threats, such as terrorism events, and natural hazards, such as flooding due to dam failures, with focus on potential failure modes due to deterioration. For this purpose, based on the field and theoretical studies, the regulation of hydrological (floods, debris-flows, snow avalanches), geological (erosion, mudflows), and seismic (earthquake), as well as those natural disasters formed in the water area of Zhinvali Reservoir, which determines the stability and reliability of the Zhinvali Earth Dam, is estimated using existing statistical data and theory of reliability and risk.

Special attention is paid to the safety of the population living in the risk zone, as well as the development and evaluation of methods and principles of the impact of expected disasters.

Prediction of the water erosion of agricultural lands in Georgia under the climate change consideration is given in the paper. Based on the implemented scientific researches in Georgia, the main challenges that are appeared against the agriculture, are revealed, particularly: for the East Georgia – in means drought, hail, degradation and erosion of lands, and for the West Georgia – distribution of crop diseases, degradation and water erosion of soils. Taking into consideration the climate change, the average indicator of Water erosion risk at the agricultural lands in Georgia, which reaches 0,55 ha and quantitative indicators of soil water erosion along regions of Georgia for the two predictive periods incl. 2021-20-50 and 2071-2010 have been evaluated.

In order to assess the ecological condition of Zhinvali reservoir, the results of theoretical and field surveys are presented in the paper. The current situation of the main junctions of Zhinvali earth-fill dam is considered and its operational conditions are estimated. According to the theoretical and field studies, the erosion rate of the active erosion-mudflow type Mletis Khevi, which is tributary of river Aragvi is calculated, the value of which is equal to: E=1,13, with the intensity 10-50 (t/ha per year) corresponding to the fourth erosion class.

The forecasts of suspended solid sediment transported in the headrace of Enguri reinforced concrete high arch dam (with the height of 271.5 m) is based on the results of the field and laboratory studies accomplished from 2013 to 2015.The goal of the study was to fix the lateral profile in the river in the construction section of Khudoni dam across the river Enguri with an echometer, fix the relevant coordinates by using a GPS and sampling the river water by using a bathometer.It was established that the discharge of the suspended solid sediment transported by the water current in the construction section of Khudoni dam in the river Enguri bed changes by 1.14-1.30 kg/m3 a second, with respective coordinates: X=0267983, Y=4757922 and X=0268019, Y=4757911, while the discharge of the suspended solid sediment from the river Enguri to the confluence of the river Nenskra changes by 1.46 kg/m3 a second with respective coordinates: X=0271289 and Y=4760149.In the low-water period of the river Enguri (in summer) when the average current discharge was 261,0 m3 /s, with average velocity of 3.25 m/s, the measurements demonstrated that the average discharge of the suspended solid sediment was 297.54 kg/s.

The paper considers the methods of qualitative-criteria evaluation and prediction of the degree of water pollution of the rivers of the Black Sea basin and gives a flow chart of the ecological-ingredient system of the Black Sea with decision-making and regulatory functions. The methods given in the work consider the damage inflicted to the environment and public health for different levels of hazard of the environmental pollution risk: when d Є [0,20-0,37] - the Catastrophic, or “Situation of Ecological Disaster” or d Є [0,37-0,63] - the Critical, or “Critical Ecological State”. The qualitative-criteria evaluation of the degree of water pollution of the rivers of the Black Sea basin can be identified by means of recommended methods given in complex, in line with the values of ingredients characterizing the pollution, based on the probability and descriptive modeling.

The aim of the study was to assess the current situation of natural hazards in the village of Nakra in the Nakra River Basin and to take appropriate preventive measures. Periodic activation of catastrophic floods and extreme landslide-gravitational processes is due to the hyper-sensitive properties of the geological environment and the process is synergistic with provocative climatic-meteorological factors. Therefore, it is necessary to have complete information on the types of geological processes, the regularity of their development and the trends and factors of changes that directly or indirectly determine the nature and scale of their occurrence and reactivation. Moreover, at the same time the Nakra and Nenskra basins are real objects of hydrotechnical properties.

In Stephantsminda (Kazbegi) district, debris flows pose a special danger, and we can see almost all of them in the mentioned area. Based on the research conducted, the assessment of flood events and their causes was carried out. The causal factors were identified, on the basis of which the main direction of recommendation for the regulation of debris flows in the catchment area was established. In addition, innovative reliable copyrighted structures are proposed for debris flow regulation. In case of their use, the calculation equations for defining parameters of the structural elements of the structures, in particular, flow, average velocity, wave velocity, critical depth, impact force, as well as the defining criteria for the regulation of bed processes are given.

Prediction of the water erosion of agricultural lands in Georgia under the climate change consideration is given in the paper. Based on the implemented scientific researches in Georgia, the main challenges that are appeared against the agriculture, are revealed, particularly: for the East Georgia – in means drought, hail, degradation and erosion of lands, and for the West Georgia – distribution of crop diseases, degradation and water erosion of soils. Taking into consideration the climate change, the average indicator of Water erosion risk at the agricultural lands in Georgia, which reaches 0,55 ha and quantitative indicators of soil water erosion along regions of Georgia for the two predictive periods incl. 2021-20-50 and 2071-2010 have been evaluated.

The work is devoted to the question of the influence of waves in slope shallow streams on the intensity of soil erosion, which was not considered by anyone before. Methods are proposed for predicting the occurrence of waves on the free surface of a slope runoff both in water and in sediment-carrying flows. Theoretical studies have established that the effect of wave formation on the process of erosion intensity should be taken into account in the existing calculated dependencies using the correction factor Vb = 1.5V for the average flow velocity in the open section.

The free surface flow of high concentration non-Newtonian suspensions is becoming more prevalent in modern industry. The mining industry in particular is considering innovative tailings dewatering technologies such as high density thickeners, paste thickeners, and filtration to higher density. High concentration thickened tailings promotes both water recovery, and helps reduce embankment construction costs and reduce environmental risks. Dewatered tailings often travels some distance to the disposal site and are normally transported through pipe or open-top flumes or launders. But with increase in density, the tailings exhibits significant non-Newtonian behaviour and flow prediction of such material presents considerable challenges, when compared to that for Newtonian fluids. Where the terrain permits, an open channel is an economical alternative to a pipeline. However, unlike pipe flow, the open channel flow of non-Newtonian fluids such as thickened tailings has not received much attention and only limited investigations have been conducted to study open channel flow. However, in many studies, the pipe flow paradigm is adopted to hydraulically design open channel. The objective of this paper is to present a set of models as a basis to design open channel flow of thickened tailings material in the laminar and turbulent regimes. In particular, a Reynolds number approach to transition prediction is based upon true wall shear – rather then bulk shear as is more often the case. It is shown that for yield stress materials this change in approach has a significant effect. The design approach is validated using previously published flume data. Furthermore, a criterion to discriminate the onset of transitional flow in open channels is developed and compared with the experimental data.

The free surface flow of high concentration non-Newtonian suspensions is becoming more prevalent in modern industry. The mining industry in particular is considering innovative tailings dewatering technologies such as high density thickeners, paste thickeners, and filtration to higher density. High concentration thickened tailings promotes both water recovery, and helps reduce embankment construction costs and reduce environmental risks. Dewatered tailings often travels some distance to the disposal site and are normally transported through pipe or open-top flumes or launders. But with increase in density, the tailings exhibits significant non-Newtonian behaviour and flow prediction of such material presents considerable challenges, when compared to that for Newtonian fluids. Where the terrain permits, an open channel is an economical alternative to a pipeline. However, unlike pipe flow, the open channel flow of non-Newtonian fluids such as thickened tailings has not received much attention and only limited investigations have been conducted to study open channel flow. However, in many studies, the pipe flow paradigm is adopted to hydraulically design open channel. The objective of this paper is to present a set of models as a basis to design open channel flow of thickened tailings material in the laminar and turbulent regimes. In particular, a Reynolds number approach to transition prediction is based upon true wall shear – rather then bulk shear as is more often the case. It is shown that for yield stress materials this change in approach has a significant effect. The design approach is validated using previously published flume data. Furthermore, a criterion to discriminate the onset of transitional flow in open channels is developed and compared with the experimental data.

The environmental project in Erekle II Street in the city of Sighnaghi envisages developing the storm-water and anti-landslide measures. For this purpose, the landslide section in Erekle II Street in the city of Sighnaghi was subject to the topographic survey. With the purpose of the engineering-geological evaluation of the object, 3 boreholes with the total length of 20 m were made. Ground and water samples were taken from the boreholes and were subject to the laboratory analysis. In addition, the hydrogeological and hydrological evaluation and hydraulic calculations of the area were done.

In order to ensure the stability of the landslide slope in Erekle II Street in the city of Sighnaghi, a drainage system to discharge the ground waters was designed, and a ditch by considering the calculations of the relevant hydrological and hydraulic properties was also designed.

The article gives the evaluation of the ecological processes in the catch basins of the rivers Inguri (Georgia) and Yangtze (China) and new environmental protection measures to regulate the natural disasters (erosion, mudflow) with these rivers.

It is established that the ecological problems in the catch basins of the rivers Inguri and Yangtze, in the upstream wall of their dams, at their estuaries with the Black and Yellow Seas are almost similar and differ with their scales only.

The evaluation of the ecological problems in the catch basins of the rivers Inguri and Yangtze is proposed to do with the methods for carrying out the field and laboratory experiments in Georgia and China. These methods allow accurately predicting the erosive-mudflow and landslide processes.

By using the data gained through the experiments, the calculation methods to design the new environmental protective structures will be developed

The presented method is based on processing of “fuzzy”-type analysis-and-a priori information which enables, on the basis of expert knowledge, to solve engineering problem   intractable from mathematical viewpoint: from the considered variety of buildings complex to evaluate, in conditions of stochastic ambiguity in “negative ecological factors sphere”, the separately taken quality of the complex functioning under the action of single dominating negative factors, as well as in integrated form - in “negative ecological factors sphere” - when simulating short, medium and long waves formed at sea.

the field-expeditionary investigations were carried out at the length of 110 km, within the boundaries of Georgia in the Black Sea coastal zone in 2010-2011. From the border between Georgia and Turkey (Sarphi) to the village of Ganmukhuri water samples were taken from the territories adjoining the estuaries of the main rivers of the Black Sea basin – at 35 points in all. The temperatures pH and TDS were measured. At a point fixed on the territory of Poti port the water and air temperature, wind speed, values of sea level and characteristics of sea roughness are measured systematically and the obtained values are estimated.

Within the boundaries of Georgia, in the Black Sea water area (minus the 200 km long Abkhazian water area that is annexed by Russia), field-expeditionary studies were carried out at the length of 110 km, in spring 2011. From the border between Georgia and Turkey (Sarpi) to the village of Ganmukhuri water samples were taken from the territories adjoining the estuaries of the main rivers of the Black Sea basin – at 35 points in all. The temperatures pH and TDS were measured.

At a point fixed on the territory of Poti port the water and air temperature, wind speed, values of sea level and characteristics of sea roughness are measured systematically and the obtained values are estimated.

On the basis of field explorations carried out in 2000-2010 in the river Mletis-khevi (along the Georgian Military Road) the principal morph metric, hydrological and hydraulic parameters of the debris flow formed in the river-bed have been studied. Using these parameters, the hydro morph metric and dynamic values of the debris flow formed in the catchments area of the river and the debris flow mass at the river debris cone have been determined.

Taking into consideration the above basic parameters, the volume of sediments transported by the debris flow formed in May 2010 has been determined, with account of the configuration of stone inclusions.

The main objective of the work refers to protection of water resources of the transboundary Mtkvari(Kura) River located in the South Caucasus Region (Georgia, Azerbaijan, Armenia) from mechanical pollution using modern methods and technologies. To protect water resources from mechanical pollution in the South Caucasus Region the Mtkvari River watershed will be studied, assessed and forecasted from the environmental point of view. The results expected from the implementation of a work will have the following impacts in the ecological, economical and social dimension, especially: Ecological - Qualitative pollution indices of water resources in the Mtkvari River will be fully investigated for the transboundary regions of the South Caucasus; Economical - Adoption of new scientific researches will have a great economical impact taking into account that profitable complex activities implemented in the watersheds of the rivers mentioned above will decrease potential expenditures on drinking water purification; Social - Work implementation will be of a great social importance because of new ecological engineering activities, which will be implemented to provide safety of population living in ecologically unstable sections within the watershed of the Mtkvari River.

For the effective protection of the population of the City of Kvareli in Georgia from debris flow formed on the river Duruji, the critical places on the river-bed of Duruji, where overflow of debris flow is possible, were identified. Erosion coefficients of mountain slopes with debris flowing into the basin of river Duruji, which establishes links between the class of erosion and degree of damage of a slope, were explored. Maximum charges on debris flow of river Duruji in different provisions were established, through which, at a following stage of an ongoing project, anti-debris flow structures are planned and designed.

Using the theories of reliability and risk, probability distributions of the maximum charges of debris flow formed on river Duruji were examined including the suitability of using the Weibull probability distribution.

The reliability of new spring-board type debris flow protection structures and associated risk profiles in the case of joint and separate dynamic and statistic influences of debris flow on the structures were assessed.

Results from this investigation enabled us to predict effectively erosive-debris flow processes in the river-bed of Duruji, and introduce new ecological measures engineered to ensure the effective protection of the population of the City of Kvareli in Georgia and contiguous territory of the Duruji River from debris-flow.

To provide forecasting of erosion and debris flow processes for the energy supply and transport corridors of Georgia using the theory of reliability and risk, we have developeda methodology on basis of the theoretical analysis and long-term field surveys (1980–2010) regarding the intensity of rains and solar radiation. At the following stage this methodology will allow us to design new safe measures against erosion and debris flow processes. To provide study of development dynamics concerning the geometrical dimensions of ditches and gullies — characterizing values of erosion processes in the power supply corridors of oil pipelines (Baku-Tbilisi-Supsa, Baku-Tbilisi-Erzurum) and gas pipelines (Baku-Tbilisi-Shakdeniz), we have determined density distribution law on the basis of the intensity of rains and slope gradients for the case of separate and simultaneous events. For the forecasting of erosion and debris flow processes in the transport corridors (Transport Corridor Europe-Caucasus —Asia (TRACECA) and Georgian Military Road), we have studied the types of density distribution function for the erosive and accumulating areas of the slopes and debris-flow riverbeds, which will provide safe operation of the energy supply and transport corridors.

Forecasting techniques for estimating the movement of eroded soil, that accumulates in erosional river gullies at high waters and is transported by river flow or debris cone, require specific approaches and assumptions owing to the non-stationary nature of the process. This paper describes various theoretical models that have been developed to represent the movement of mudflows in erosional gullies. By means of a theoretical study, a forecast has been made of the change in time of the flow depth, discharge and erosion rate. Values are determined of the indices of the degree of concentration of cohesive mudflow, being a function of the physico-mechanical characteristics of mudflow mass.

With a view to effectively protecting Tbilisi, the capital of Georgia, from flooding and mudflows in the case of terrorist acts or an accident at the Zhinvali earth dam owing to obsolescence of its structure, a methodology is proposed for calculating the principal indices of the mechanics of the flood wave and associated cohesive mudflow. Using topographic, hydro-morphometric and other basic indices, as well as computer programs, the main hydrological and hydraulic time-varying characteristics of the flood are calculated, for prescribed dam failure scenarios. Using a flow vector splitting scheme, the St Venant differential equations, including the hydraulic friction of the mudflow and air resistance force, are solved numerically to predict principal dynamic indices of a cohesive mudflow wave at the sectors of the Aragvi and Mtkvari rivers where the destructive action of the flow is greatest.

An assessment of natural disasters in Georgia is given, including the issues of mitigating the risk and consequences of debris flow events based on the analysis of international basic documents. It is noted that by the beginning of the 20th century, debris flows in Georgia were recorded in drains and ravines (up to 3000), mainly of the first and second order, in the risk area of ​​which there are 2 million hectares of the country's area. A significant part of the population of the mountains and foothills is under the risk of debris flows. An assessment was made of the total data of human casualties and material damage for 1995-2009 as a result of the impact of debris-flows in Georgia. New designs of various types of debris flow control structures have been developed, the priority of scientific and technical novelty of which is protected by 14 copyright and patent certificates. Based on the analysis of long-term (1981–2011) field and laboratory studies, a methodology has been developed that can be used to design the above structures, taking into account the reliability of the operation of the relevant structures and the risk of their failure.

Georgian Technical University

Doctoral Thesis Referee

Master Theses Supervisor

Doctoral Thesis Supervisor/Co-supervisor

Scientific editor of monographs in foreign languages

Scientific editor of a monograph in Georgian

Editor-in-Chief of a peer-reviewed or professional journal / proceedings

Review of a scientific professional journal / proceedings

Member of the editorial board of a peer-reviewed scientific or professional journal / proceedings

Participation in a project / grant funded by an international organization

Participation in a project / grant funded from the state budget

Patent authorship

Membership of the Georgian National Academy of Science or Georgian Academy of Agricultural Sciences

Membership of an international professional organization

Membership of the Conference Organizing / Program Committee

National Award / Sectoral Award, Order, Medal, etc.

Honorary title

Monograph

Handbook

Research articles in high impact factor and local Scientific Journals

Publication in Scientific Conference Proceedings Indexed in Web of Science and Scopus