Defense of the dissertation of Toxanbayeva Sabina Týrsynovna for the degree of Doctor of Philosophy (PhD) in the specialty «8D05211 - Search geography and geographic information systems»
L.N. Gumilyov Eurasian National University, a dissertation defense for the degree of Doctor of Philosophy (PhD) by Toxanbayeva Sabina Týrsynovna on the topic «Modeling of flood forecasting in the Nura river basin and analyse of geographical factors» in the field of «8D05211 – Search geography and geographic information systems».
The dissertation was completed at the department «Physical and Economic Geography» NJSC «Eurasian National University named after L.N. Gumilyov».
The language of defense is Russian.
Official reviewers:
Alimkulov Sayat Kurbanbaevich - Candidate of Geographical Sciences, Associate Professor, Deputy Chairman of the Board of JSC «Institute of Geography and Water Security» (Almaty c., Republic of Kazakhstan), specialty: 00.25.27 – «Terrestrial hydrology, water resources and hydrochemistry».
Moldakhmetov Marat Moldabekovich - Candidate of Geographical Sciences, Director of the Agrobiological Research Institute, International Taraz Innovation Institute named after Sh. Murtaza (Taraz c., Republic of Kazakhstan), specialty: 11.00.07 – «Land hydrology, water resources, hydrochemistry».
Temporary members of the Dissertation Committee:
Yegemberdiyeva Kamshat Baratovna - Candidate of Geographical Sciences, head of the laboratory «Geotourism and Geomorphology», JSC «Institute of Geography and Water Security» (Almaty c., Republic of Kazakhstan), specialty: 25.00.23 – «Physical geography and biogeography, soil geography and landscape geochemistry».
Nysanbaeva Aiman Sagynbaevna - Candidate of Geographical Sciences, Associate Professor, Head of the Department of «Meteorology and Hydrology», al-Farabi Kazakh National University (Almaty c., Republic of Kazakhstan), specialty: 25.00.30 – «Meteorology, agrometeorology, climatology».
Kurepina Nadezhda Yuryevna - Candidate of Geographical Sciences, Senior Researcher, Institute of Water and Environmental Problems of the Siberian Branch of the Russian Academy of Sciences (Barnaul c., Russian Federation), specialty: 25.00.33 – «Cartography».
Popova Natalya Borisovna – Doctor of Geographical Sciences, Professor of the Department «Transport Economics», Siberian State Transport University (SGUPS), (Novosibirsk с,, Russian Federation), specialty: 25.00.36 – «Geoecology».
Academic Advisors:
Ramazanova Nurgul Esenovna - PhD, acting Professor, Head of the Department of Physical and Economic Geography, NJSC «ENU named after L.N. Gumilyov», specialty: 6D060800 – «Ecology» (Astana c., Republic of Kazakhstan).
Tusupbekov Zhanbolat Ashikovich – Candidate of Geographical Sciences, Associate Professor, Omsk State Agrarian University named after P.A. Stolypin, (Omsk c., Russian Federation), specialty: 25.00.27 – «Land hydrology, water resources, hydrochemistry».
The defense will take place on February 29, 2024, at 11:00 AM in the Dissertation Council for the training direction «8D052 – %!s(*string=0xc001ece1a0)» in the specialty «8D05211 – Search geography and geographic information systems» of L.N. Gumilyov Eurasian National University. The defense meeting is planned to be held online.
Address: Astana, st. Kazhymukan, 13, educational building No. 3, meeting room (room No. 333).
Abstract (English): Relevance of the research. A pressing problem both for Kazakhstan and for the whole world is the occurrence of natural disasters or natural disasters. The study of hazardous natural phenomena for the purpose of predicting them is the scientific basis for the activities of government agencies to ensure the safety of human life. Among natural disasters, floods are the most destructive, causing enormous damage to human life, infrastructure, agriculture and the socio-economic system. This puts pressure on governments to develop robust methods to protect flood-prone areas and plan for future sustainable flood risk management, with a focus on prevention, protection and preparedness. Flood forecasting models are of great importance for hazard assessment and management of extreme events. A reliable and accurate forecast greatly contributes to the development of water resource management strategies, situation analysis and proposals for effective protection methods, as well as timely evacuation of the population and other national economic facilities. Thus, the importance of advanced short- and long-term forecasting systems for floods and other hydrological events to reduce damage is emphasized. However, predicting the lead time of a flood and the location of its occurrence is fundamentally difficult due to the dynamic nature of climate conditions. Therefore, the reliability of the results in modern flood forecasting models is mainly related to the quality and representativeness of the source data and includes various simplified assumptions about the development of events. As a consequence, to simulate complex mathematical expressions of the physical processes and behavior of the basin, such models use special methods, for example, event-driven, empirical black box, lumped and distributed, stochastic, deterministic, continuous and hybrid. Flooding of areas used for socio-economic activities causes various negative consequences. The magnitude of adverse impacts depends on the vulnerability of the activity and population, as well as the frequency, intensity and extent of floods. Natural disasters and floods are part of natural phenomena. They have always existed and will always exist. With the exception of some floods caused by dam failures or landslides, floods are climatological phenomena influenced by geology, geomorphology, topography, soil and vegetation conditions. Meteorological and hydrological processes can be fast or slow and can result in flash floods or the more predictable slow-moving floods, also called river floods. Society has become more vulnerable to natural disasters. Although floods are natural phenomena, human activities and their interference with natural processes, such as changes in drainage patterns through urbanization, agricultural practices and deforestation, have significantly changed the situation in all river basins. At the same time, exposure and vulnerability in flood-prone areas are constantly increasing. Flood risk increases where risk is defined as the probability of occurrence multiplied by its impact. The likelihood of flooding is expected to increase as the earth's climate is changing rapidly. Since the warm period in the Middle Ages and after the Little Boulder, the earth is undoubtedly becoming warmer again. Currently, the world is experiencing global changes in climatic and natural factors; there is a need for research into catastrophic phenomena. In the current situation, modeling the forecast of floods caused by spring floods is one of the components of ensuring life safety in settlements located in river valleys, and an important scientific task. Timely forecasting and warning of emergency services and the population about an impending threat is a necessary prerequisite for preserving the life and health of people and minimizing economic damage. Since river floods are one of the natural phenomena and lead in the number of deaths, in the number of victims, in the amount of damage caused among other natural disasters. In this regard, there is a need to analyze the geographical factors influencing the processes of flood forecast modeling. The purpose of the dissertation research is to model and forecast floods in the Nura River basin and analyze geographical factors to create an adaptive forecast model for rivers in Kazakhstan. To achieve this goal, the following tasks are identified: 1. Study and analysis of the theoretical and methodological foundations of flood modeling and short-term forecasting of flood-hazardous situations; 2. Determination of the main geographical, hydrological, geomorphological features of the formation of the Nura River basin runoff based on the study of natural-climatic, geographical, cartographic, and statistical data over a long period of time for the study area; 3. Analysis of geographical factors in the formation of runoff in the Nura River basin, affecting the flood situation in the Karaganda region; 4. Modeling and forecasting of floods for the research object in the presence and absence of observational data for the Nura River basin; 5. Recommendations for the prevention of catastrophic floods, as well as for flood control measures in order to prevent the risk of floods and mitigate their consequences. Protected provisions: 1. A comprehensive analysis of the flood-hazardous situation in the central part of the Kazakh small hills based on consideration of the physical and geographical features of the drainage basin and the conditions for the formation of runoff in the drainage area of the Nura River; 2. Adapted methodology for predictive computer modeling of flood-hazardous situations and floods for the territory of the Republic of Kazakhstan based on advanced flood modeling methods widely used in foreign practice, combining both mathematical and field research methods, and data from remote sensing (RS) and geographic information systems (GIS); 3. Science-based and practice-oriented recommendations for flood control measures to prevent flood risks. The object of the study is the unregulated section of the Nura River basin from the source of the river to the Samarkand reservoir and the regulated section of the river from the Samarkand to Intumak reservoirs, including the Koktal Lake basin. The subject of the study is the patterns of occurrence of flood situations and predictive modeling of floods. The scientific novelty of the dissertation research lies in the fact that for the study area of the Nura River basin: an analysis of geographical factors influencing the flood situation was carried out; computer programs for predictive modeling, widely used in foreign practice, have been adapted for the territory of Kazakhstan; scientifically based and practice-oriented recommendations on flood control measures were proposed in order to prevent the risk of floods. Source materials of the study. Materials of scientific and literary review, materials of review of scientific periodical publications of domestic, Russian and foreign publications, overview and topographic maps of areas, various thematic maps, satellite images, experimental research data, hydrometeorological data. Research methods. Comparative-descriptive method (study of geographical factors of the formation of the Nura River basin, influencing the flood situation in the Karaganda region), retrospective analysis (study of world and domestic experience in modeling and forecasting), general theoretical methods (analysis, synthesis, induction, deduction, abstraction and modeling, generalization, classification and systematization of data, drawing up general findings and conclusions), statistical method and methods of hydrological calculations (processing of quantitative parameters), graphical methods (graphical reflection of data in the form of tables, charts, graphs), cartographic method (compilation of a series of maps), geoinformation methods of data processing and calculation (tools and utilities of ArcGIS 10.5 software). Approbation of the research results is confirmed by an act of implementation into production and the educational process from the ALE «Association of Water Users, Water Consumers and Water Transport "KAZWATER», where the results of scientific research were tested and applied in the development and implementation of tasks within the framework of the project "Purchase of scientific internship materials for teaching assessment methods state of riverbed processes as one of the causes of floods (algorithm for calculating spectral indices and determining places of siltation and overgrowth of flood-prone sections of rivers). Personal contribution of the author. The author collected and analyzed methods for modeling and forecasting floods, scientific works on the topic of the dissertation research. A detailed examination of the physical and geographical features of the drainage basin and the conditions for the formation of runoff in the drainage area of the Nura River was carried out for the purpose of a comprehensive analysis of the flood hazard situation of the research object, an adapted methodology for predictive computer modeling of flood-hazardous situations and floods for the territory of the Republic of Kazakhstan was developed based on advanced flood modeling methods widely used in foreign practice, a series of maps were compiled for the object of study for the historical year 2014 and the modern period according to geographical factors, scientifically based and practical oriented recommendations on flood control measures to prevent flood risks. Publication of research results. The research results obtained were published in scientific journals and proceedings of international conferences (8 articles in total): 2 articles in scientific journals included in the Scopus database; 3 articles in scientific journals recommended by the ССFES of the Republic of Kazakhstan; 3 articles in materials of international scientific and practical conferences. Structure and content of the dissertation. The dissertation includes an introduction, a main part consisting of 4 sections, a conclusion, a list of sources used and applications. The illustrated material is represented by 56 figures, 14 tables and 15 formulas. The first chapter of the dissertation is devoted to the theoretical and methodological foundations of the study, which gave us an understanding of the theoretical foundations of the study of flood forecast modeling, including the history of modeling and forecasting research, the essence and content of the concepts of modeling and its types, the main flood forecast models and geographical factors influencing floods. At the moment, to study modeling the forecast of any process, including floods, you need knowledge of modeling physical processes, analytics of large amounts of data, and mathematical calculations. Hydrological modeling is used in river basin management, water supply management, hydropower, agriculture, and also for short-term forecasting of water flows and providing flood warnings. Hydrological modeling represents the process of runoff formation on the scale of river basins. Modeling methods include different types. The second chapter contains an analysis of the system of natural factors in the formation and development of the Nura River basin, which showed us a detailed description of the physical-geographical position of the study area and the history of the study of the natural environment of the Nura River basin, the geomorphological and geological-lithological structure of the river basin, the climatic conditions of the formation of the basin, and biotic factors and recreational resources, hydrological knowledge of the basin and hydrographic features. The third chapter is devoted to the methodological foundations of flood modeling and short-term forecasting of flood situations, which gave us an understanding of mathematical modeling research methods, field research methods and modern methods of geographic information research in flood modeling. This methodological knowledge from the third chapter is shown in order to understand the issue of flood modeling and forecasting in more detail and in order to apply certain methods and flood models in the future fourth chapter. The fourth chapter contains specific results of research work on modeling and forecasting of floods with the characteristics of the digital relief model of the Nura River basin using the ArcGIS 10.5 program, with modeling and forecasting of melt runoff in the WIN SRM and HBV-light programs, with a forecast in the absence of observational data, with an analysis of geographical factors influencing the flood situation with the influence of hydrometeorological, soil and relief factors. Since the basin of the river under study is located in a flat area and is characterized by an uneven intra-annual distribution of flow, as a result, 90% of the river flow occurs during the spring flood, it should be noted that a distinctive characteristic feature of the river basin of the Nura River is that the flood flow is formed during account of snow melt runoff. The location in the center of the Kazakh small hills, also called the Kazakh folded country, and in the center of Eurasia affects the climate and describes it as a sharply continental and extremely arid place with insufficient moisture and low air humidity with a predominance of arctic, polar and tropical air masses. These factors show that the Nura belongs to the lowland type of river and has a sharply continental climate. As a result of the work carried out, the following conclusions were obtained: 1. Coordinating the literary sources of such scientists as A.V. Shnitnikov, Zh.A. Aitaliev, A.V. Egorin, who deal with general physical geography; I.V. Seversky, A.R. Medeu, F.J. Akiyanova, A.P. Gorbunov, engaged in geomorphology; A.S. Uteshev, who studies climatology and meteorology; A.A. Tursunov, V.M. Boldyrev, R.I. Galperin, Zh.D. Dostai, I.M. Malkovsky, I.S. Sosedov, engaged in research in hydrology, and K.M. Dzhanaleeva, G.V. Geldiyeva, M.Sh. Ishankulov, A.V. Chigarkin, V.M. Chupakhin, I.B. Skornitseva, who are engaged in landscape science; for the historical 2014 and modern period of research from 2021 to 2023, having analyzed the geographical factors influencing the flood situation, we identified changes in air temperature in spring by 0.71 degrees and in winter by 0.23 degrees from the norm based on hydrometeorological factors, which indicates about gradual global warming and climate change not only in the Karaganda region, but throughout Kazakhstan; Further considering the precipitation in the Nura River basin, we can say that every year it becomes significantly less, considering the period from 2021 to 2023, precipitation indicators become less intense. Considering soil moisture, we can say that every year the soil becomes less wet. These factors show that currently there are significantly fewer flood situations compared to the historical year of 2014. Filtration of the soil in the Nura River basin also has its own characteristics; most of the study area consists of loamy, sandy loam and clayey types of soil, which indicates weak permeability and impermeability of the soil according to the scale of average filtration coefficients for some soils. In the study area, snow accumulation occurs gradually, reaching a maximum in March. The snow supply by area coverage in the period from November 1, 2013 to April 1, 2014 was characterized by an increase in snow cover by mid-November and stability until mid-February with a gradual decrease until the end of March 2014. The modern period is characterized by less snow cover, which indicates a gradual decrease in solid precipitation. Considering the territory of the research object, we can say that in the territory of the dissertation research, congestions and jams do not occur, but they occur in Kazakhstan in the territory of the Irtysh River basin. As a result of the analysis of soil factor data on atmospheric precipitation, the annual amount of precipitation averages 280 mm, the maximum is observed in the summer in the form of downpours and heavy rains. Precipitation falls unevenly; it happens that 3-4 rains immediately give the summer norm. Evaporation approaches 1000 mm, and the humidification coefficient drops to 0.5-0.3. Winter is cold with strong south-west winds and frequent snowstorms, beginning in mid-November and lasting about 5 months, and in the south of the reserve it is 1-2 months shorter. The distribution of snow cover over the surface is uneven. Snow accumulates in depressions of the relief, while higher areas are bare. The soil freezes at a depth of up to 1 meter. A dry, cool spring is characterized by rapid snow melting and lasts 20-30 days. During the winter period, an average of 30-35 mm evaporates. The total annual evaporation from moistened soil or water surface reaches 1200 mm, evaporation from land 200-300 mm. The average layer of evaporation from the water surface is 680-1000 mm. As a result of a study on the relief factor, it was revealed that the Nura River basin is located mainly in a dry-steppe and semi-desert zone, characterized by a variety of relief, soil-forming rocks, depth and degree of mineralization of groundwater, which is reflected in the diversity of soil cover. This heterogeneity is especially evident as you move from north to south. The soil cover is represented by southern chernozems, dark chestnut soils, chestnut soils, light chestnut soils, meadow soils, meadow soil soils, solonetzes, solonchak soils, and mountain chestnut soils. It is also possible for temporary high water to appear on the roof of loams, which are a natural aquifer during seasonal spring floods and heavy precipitation. The river catchment area is characterized by a dissected, large-hilly topography in the upper part, typical of a group of low hills separated by river valleys - small hills in the middle part and a flat topography with rare hills and a weakly defined watershed with the neighboring rivers Yesil, Kulanutpes - in the lower part of the Nura River basin. 2. Thanks to the analysis of foreign experience in flood forecasting and modeling and the study of computer programs, two models were adapted for the doctoral dissertation - the HBV model and the WIN SRM melt runoff model. The HBV model is a semi-distributed hydrological model for simulating watershed flow. The HBV model consists of three main components: a snow accumulation and melting routine, a soil moisture metering routine, and a river response and routing routine. The WIN-SRM snowmelt runoff model is designed to simulate and predict daily runoff in basins where snowmelt is the main driver of runoff. 3. A methodology for forecasting and modeling flood hazards and floods using remote sensing data and geographic information technologies has been adapted, combining both mathematical research methods and remote sensing and GIS. European computer programs for predictive modeling have been adapted for the territory of Kazakhstan on the section of the Nura River from the source to the Samarkand reservoir and between the Samarkand and Intumak reservoirs. Using an automated method for computer processing of DEM data for the drainage basin, it was possible to create a digital relief model of the Nura River basin using the ArcGis 10.5 program. To work in the WIN SRM program, the general initial data on the research object were initially analyzed, and the parameters for the WIN SRM program model were additionally calculated. The observation period for 2013-2014 was selected for the study, since this period was characterized as one of the high-water years in comparison between 1938 and 2023, this period was also selected due to the fact that the data were representative and reliable, all parameters for this observation period. When working in the WIN SRM program, the result of the modeling was a computer calculated volume of melt runoff and water consumption for the specified period. In the study, two key areas with two forecasts for a certain period of time were taken to work in the WIN SRM program. As a result, the accuracy of calculating the volume of melt runoff in the WIN SRM program for 1 key section from the source to the Samarkand reservoir was 86%. The accuracy of calculating the volume of melt runoff in the WIN SRM program for the 2nd key section for the Nura River bed between the Samarkand and Intumak reservoirs was 83%. The forecast model for the volume of melt runoff in the HBV program showed a model accuracy of 98.72% for 1 key section from the source to the Samarkand reservoir and 61.87% for 2 key sections along the Nura River bed between the Samarkand and Intumak reservoirs. When making a forecast in the absence of observational data using the example of calculations for Lake Koktal, a simplified method for calculating meltwater runoff in the absence of observational data using the Sokolovsky formula was used; as a result of mathematical calculations, the estimated volumes of meltwater runoff from Lake Koktal of various levels were obtained, because this territory is a unique lake and channel with a natural regulator, part of the group of Sholakshalkar lakes in the Nura River basin, located in the Korgalzhyn district of the Akmola region of Kazakhstan. 4. Scientifically based recommendations for flood control measures are proposed in order to prevent the risk of floods, including cleaning irrigation ditch networks and storm sewer systems, pumping melt water from city streets; Implementation of advanced flood prevention devices to increase the time to prepare and respond to flash floods and flash flood situations in order to save more lives and reduce socio-economic damage; constructing future buildings more than one meter from the ground foundation to prevent damage from floods and flood situations, restoring rivers and clearing drainage to prevent floods and flood situations; adding flood and flood barriers for monitoring; application of technological innovations and advances that will make it possible to detect floods before they actually occur for immediate prevention.