7 research outputs found
THE METHODOLOGY OF NATURAL HAZARDS MANAGEMENT IN KAZAKHSTAN
No full textOver the last 10 years, more than 4,000 natural disasters have been recorded around the world; they resulted in death of more than half a million people, which is 1.5 times greater than in the previous decade. Similarly, in the Republic of Kazakhstan, there has been an increase in occurrence of natural and technogenic disasters, leading to human casualties and substantial material loss. The paper demonstrates that risk management is one of the promising ways for providing safety of human activities. The methodology of risk management described in the paper is based on scientific and technological achievements and involves assessment of risks of natural and technogenic emergency situations (ES) emergence and associated damage. The paper provides systematization of natural hazards with isolation of geological, geomorphological, hydrological, climatic, and other processes. The characteristics of spatial distribution are identified; the level of hazard and risk of adverse impacts is shown; and a series of thematic maps at various scales, spatial coverage, and content is compiled for the Republic of Kazakhstan territory with consideration given to goals, objectives, and level of risk management.The paper demonstrates that natural and technogenic hazards are discrete in terms of emergence and their onset is of short duration. Risk management is broken into the following phases:1. Before the onset of ES;2. During the immediate threat of ES and their onset;3. After ES.The methodology suggests that all efforts of risk-management implementation should be directed towards achieving acceptable level and safety
Moraine-dammed glacial lakes and threat of glacial debris flows in South-East Kazakhstan
Get PDFGlacier retreat has caused the emergence of numerous moraine-dammed glacial lakes (MGL) over the last century which have become research foci in many mountain regions of the world. Outbursts of MGLs have caused destructive floods and debris flows, leading to numerous human casualties and significant material damage. The mountains of South-Eastern Kazakhstan have also become prone to lake outburst floods and related debris flows, specifically in the second half of the 20th century. This paper presents and reviews existing surveys and knowledge along with results of own investigations on the formation of MGLs and the characteristics of lake outburst floods and debris flows in the Kazakh part of Tien Shan. We suggest a workflow to identify the most dangerous types of lakes and provide information about their morphogenetic features and hazard criteria. The number of MGLs increased since the 1970s with more than 160 existing in 2018. Forty were identified as being dangerous. Forty-eight lake outbursts occurred since 1950 with all the documented events happened between end of June and end of August. The most dangerous outbursts were caused by ruptures in ice-cored moraine dams. Outbursts of nine MGLs caused disastrous debris flows, with some occurring repeatedly. The number of outbursts clearly decreased since the year 2000 compared to 1970–2000. However, due to ongoing glacier retreat new lakes are forming at higher altitudes. Their greater potential energy makes possible future outbursts more dangerous. Re-evaluation of existing methods to calculate the water volume and peak discharge based on bathymetric measurements and observed outbursts revealed that the applied equations provide suitable approximations and allow supporting mitigation and prevention measures. Finally, the presentation of implemented measures to lower the water level using siphons or artificial flow channels shows that they can reduce the lake outburst hazards. However, they are associated with risks and financial costs and it needs to be carefully considered whether protection measures of the endangered areas are more cost effective.Peer reviewe
Effects of glaciological and hydro-meteorological conditions on the glacial danger in Zailiyskiy Alatau
Get PDFA need to estimate a hazard of a mudflow stream appearance in the glacial-nival zone of the Northern slope of Zailiyskiy Alatau (Kasakhstan) is now one of the really urgent problems. The objective of this study was to inves‑ tigate influence of glacial and hydrometeorological factors on the condition of snow-glacial zone of Zailiyskiy Alatau and find out a mudflow-forming role of the mudflow centers arising due to climate warming and degra‑ dation of glaciation: periglacial lakes, intramoraine channels and reservoirs, and also talik massifs of morainic deposits. We analyzed glacial processes in the Zailiysky Alatau over a long period using meteorological data of the Almaty weather station and its close correlations with data from weather stations in the mountains. The area of glaciations was found out to be reduced after the maximum of the Little Ice Age. A combined diagram of occurrence of the mudflow manifestations and factors causing them had been constructed on the basis of sta‑ tistical data on the landslide phenomena. Glacial mudflows were the most frequent in 1960–1990, and later on activity of them became weaker. We believe, that in the next 10–20 years, the glacial mudflow hazard in Zailiys‑ kiy Alatau can sharply decrease, but at the same time, a probability of occurrence of the rainfall mudflows can increase in the mountainous zone of the ridge due the increase of areas with melted moraine and slope deposits
Гляциальные сели в Заилийском Алатау за последние 120 лет
Get PDFZailiyskiy Alatau is the most mudflow hazardous mountain region of the Republic of Kazakhstan. At the same time, this area is one of the most densely populated and economically developed one, so mudflows here cause the great damage. The paper presents results of our analysis of the glacial mudflow activity for the period from 1900 to 2019. Amount and total volume of glacial mudflows per year were used as indicators of the mudflow activity. 481 mudflows were recorded over 120 years of observations in the Zailiyskiy Alatau, and 24% of them were glacial mudflows. Glacial mudflows are the largest and most destructive. Of the nine mudflows with a volume of more than 1 million m3, seven were glacial mudflows. The chronicle of mudflow disasters is shown. From 1950 to 2019, 87 glacial mudflows were observed in the Zailiyskiy Alatau. Of these, 16 mudflows had volumes exceeding 100 thousand m3. The largest ones occurred in 1977 (6.0 million m3), 1963 (5.8 million m3), 1958 (4.0 million m3), and 1973 (3.8 million m3 ). The causes for formation of glacial mudflows are outbursts of moraine lakes or water from underground reservoirs, as well as collapses of moraines’ slopes. The largest of them occur when a lake is bursting through an open channel. Since 1951, occurrence of glacial mudflows has been increasing and reached its maximum in the 1970s. Since 1978, the number of glacial mudflows has been decreasing, although their volumes remained large until the late 1990s. From 1997 to 2013, mudflow activity was low. During 11 of the 15 years, no mudflow was observed. Every year only one mudflow happened with a volume below 10 thousand m3. Since 2014, there has been a tendency for an increase in mudflow activity. Large glacial mudflows were recorded in 2014 and 2019. To protect against mudflows in the valleys of the Zailiysky Alatau, 14 dams have been built and two more are planned. To prevent outbursts of moraine lakes, they are emptied using pumps and siphons. In 2019, the network of automated monitoring of early warning about mudflows is being organized, which will cover all the valleys of the Northern slope of the Zailiysky Alatau.Проанализированы данные о гляциальных, в том числе катастрофических, селях с 1900 по 2019 г., рассмотрены внутри- и межгодовые колебания селевой активности. С 1951 г. активность гляциальных селей стала расти и достигла максимума в 1970-х годах, с 1978 по 1996 г. активность таких селей снижалась, а с 1997 по 2013 г. была низкой. С 2014 г. наметилась тенденция усиления активности гляциальных селей
Оценка потенциала развития ледниковых озёр на Центральном Кавказе
Get PDFGlacier mass loss and consequent terminus retreat lead to formation and growth of glacier lakes. In Caucasus outbursts of glacial lakes formed in recent decades have led to human casualties and significant damage. In this study the location and volume of the potential glacier lakes in Central Caucasus was estimated based on ground and airborne GPR data, as well as using results of global ice thickness modelling. Selected glaciers are located in the Adyl-Su and Gerkhozhan-Su valleys as well on the southern and north-eastern slopes of Elbrus. The methodology was tested by retrospective modeling of Bolshoy Azau and Djikiugankez glaciers bed topography using 1957 topographic map. Seven existing lakes were predicted by the hydraulic potential in the areas where glaciers disappeared by 2017. Six overdeepenings on Djikiugankez glacier bed as of 1957 are currently absent, which might be related to the model uncertainties and the original DEMs errors, as well as to possible filling of lakes by sediments. Retrospective modeling of the Bashkara glacier bed topography based on SRTM DEM (2000) showed significant growth potential of the existing lake Lapa. Retrospective modeling of the Kaayarty glacier bed topography has not provided a clear answer whether the subglacial lake outburst flood was a trigger for catastrophic debris flow formation during the summer of 2000. In case of total disappearance of Bolshoy Azau, Djikiugankez and Bashkara glaciers at least 11 new lakes with total area of about 1.7 km2 and an average depth of 8 m will form. While the deepest lake will be formed at the ablation zone of Bolshoy Azau glacier (at elevation 3100–3400 m a.s.l.) the largest in area (1 km2) glacial lake will appear at the Djikiugankez snout with maximum depth of 40 m and mean depth of 7.2 m. The simulation also showed that subglacial lakes of different number and size may also exist under studied glaciers. Our estimates may contain uncertainties due to low resolution of airborne GPR data and the lack of GPR data for Kayaarty glacier, DEM and ice thickness model errors. Detailed ground-based radar survey will enable the assessment of the size and volume of the potential subglacial lakes.На основе данных радиолокационного зондирования и моделирования оценены объём и площадь потенциальных озёр, которые могут сформироваться на месте отступающих ледников в Приэльбрусье. Методика протестирована путём ретроспективного моделирования ложа ледников по материалам 1957 и 2000 гг. Установлено, что площадь потенциальных озёр, угрожающих объектам инфраструктуры, может достичь 1,7 км2, а объём – 130 млн м3
О влиянии гляциологических и гидрометеорологических условий на гляциальную опасность Заилийского Алатау
Get PDFA need to estimate a hazard of a mudflow stream appearance in the glacial-nival zone of the Northern slope of Zailiyskiy Alatau (Kasakhstan) is now one of the really urgent problems. The objective of this study was to inves‑ tigate influence of glacial and hydrometeorological factors on the condition of snow-glacial zone of Zailiyskiy Alatau and find out a mudflow-forming role of the mudflow centers arising due to climate warming and degra‑ dation of glaciation: periglacial lakes, intramoraine channels and reservoirs, and also talik massifs of morainic deposits. We analyzed glacial processes in the Zailiysky Alatau over a long period using meteorological data of the Almaty weather station and its close correlations with data from weather stations in the mountains. The area of glaciations was found out to be reduced after the maximum of the Little Ice Age. A combined diagram of occurrence of the mudflow manifestations and factors causing them had been constructed on the basis of sta‑ tistical data on the landslide phenomena. Glacial mudflows were the most frequent in 1960–1990, and later on activity of them became weaker. We believe, that in the next 10–20 years, the glacial mudflow hazard in Zailiys‑ kiy Alatau can sharply decrease, but at the same time, a probability of occurrence of the rainfall mudflows can increase in the mountainous zone of the ridge due the increase of areas with melted moraine and slope deposits.Для территории северного склона хр. Заилийский Алатау (Тянь-Шань) по натурным данным за 100-летний период исследованы изменения климата, характер деградации оледенения и динамика возникновения опасных гляциогидрологических явлений. Указанные явления опосредованно связаны с изменением климата и представляют собой следствие развития моренно-ледниковых комплексов до их опасного состояния при деградации оледенения. Такое состояние моренно-ледниковых комплексов было характерно для периода деградации оледенения в 1960–2000 гг., когда оно сократилось на 55–80% после максимума малого ледникового периода. В настоящее время опасность гляциальной зоны Заилийского Алатау находится на спаде
