Mongolian Journal of Biological Sciences 2006 Vol. 4(2): 75-78

[Short Communication] Scientifi c Approaches and Methods in the Investigation of the Formation and Stability of Hydromorphic Natural Complexes of the River Valley System (The Part)

A. G. Tsaregorodtseva

Department of Ecology, Faculty of Biology and Chemistry, Pavlodar State University named after S. Toraigyrov, Lomova str. 5, Pavlodar, Kazakhstan

Abstract

The current geo-environmental situation of the Irtysh River valley system is connected with the high degree of control of the river drainage, which affects the functioning of its entire ecosystem and determines some morphological features of its channel. In the present work, the methodological approaches in the study of formation of the valley’s hydromorphic natural complexes are discussed, and the results of studies on the channel processes in the middle course of the Irtysh River are given.

Key words: Valley, fl oodplain, hydromorphic complex, river Irtysh, Kazakhstan

Introduction characterized by some stability and corresponds to the least resistance of the water stream. So, while According to the concept of ecological safety creating bends, the river stops their development of the Republic of Kazakhstan for 2006-2015, as soon as the radius of their curvature reaches the “The ecological safety is considered a component optimum size of the given stream. A big congestion of the national safety and is an obligatory of deposits in the channel creates resistance to condition of the sustainable development, and it the current, and the river deviates breaks into acts as a basis for preservation of natural systems sleeves, losing its stability. and maintenance of the corresponding quality The river Irtysh is one of the largest trans- of the environment”. The concept also concerns boundary waterways in Kazakhstan. The sources water resources of Kazakhstan, as it refers to the of the river are locate, in a glacier of the Mongol category of countries with a defi ciency of water in China, whence it fl ows in a resources. Currently, the valley of the Irtysh River northwesterly direction, crosses the frontier is undergoing signifi cant anthropogenic loading, between China and Kazakhstan and fl ows into and consequently the solution of problems Lake Zaisan below Bukhtarma water basin. After concerning the stabilization of hydromorphic Lake Zaisan the Irtysh River proceeds through the landscapes have huge national-economic values, western part of the Russian Altai Mountains and and is one of the serious regional problems of the the lowland of Western Siberia and fl ows into the republic. river ’. The formation of the valley paragenic In the territory of Pavlodar oblast’ the section of hydromorphic landscape complex is largely the middle watercourse is about 720 km long. The predetermined in many respects by the geologic- water area at the boundaries of the area (N50°36’ geomorphological and hydrological factors, and E79°30’) consists of 276200 square km. and inherently refl ects the features of ancient The valley landscape of the river Irtysh is paragenesis and modern functioning of the basin represented by channels, terraces and fl oodplain. geo-system. The area of the fl oodplain occupies 371 square km, It is well known that the river channel is and is characterized by high soil and humidifying considered a stable system under the infl uence freshet. The valley of the Irtysh is situated within of the stream as the result of washout or rock the limits of a large platform structure – the Irtysh deposition, and it does not cause any serious syneclise of the Western Siberian epipalaeozoic change in the river runway. Usually the river itself plate - and is characterized by a considerable creates the natural form of the channel, which is complexity of structural-geomorphological http://dx.doi.org/10.22353/mjbs.2006.04.19 75 76 Tsaregorodtseva. Formation & stablitiy of Irtysh river hydromorphology composition. The big variety of geomorphological deformations in various ways. types in the valley relief has been caused by a long The result of anthropogenic activity in the river history of its geological development. The character valley is the infringement of the geoecological and rates of the newest tectonic movements as skeleton that involves the degradation of well as anthropogenic activity rendered a strong grasslands and fi sh communities, development of infl uence on the geomorphological shape of the water-erosive processes within the river valley, valley. decrease in the recreational value of nature The river Irtysh crosses the territory of Pavlodar conservation objects etc. The current ecological from the south to the north, where its modern situation within the Kazakhstan part of the Irtysh fl oodplain valley makes a continuous strip of 1- requires the development of scientifi cally-proven 15 km on the left bank, and up to 4-6 km on the bases of conservation management of the valley’s right bank. The channel of the river within and natural-economic system. below the city only covers the valley slopes for On the basis of calculations of stability factors, short distances. the stability of the channel on the observable site The bases for the present work are references, of the river Irtysh has shown intensive channel archives, maps and mapping satellite photographs, deformations. The Irtysh is characterized by a and fi eld data of the author. Comparison of plans wandering river channel: Кс = 6.4. The range of of the river Irtysh based on research data from values of the cross-section stability index were 1901-1904, navigating and pilot-age cards, air between 0.9 and 2.1, i.e. the higher is A value, the photography made by hydro-geologic investigation lower is the intensity of horizontal deformations. in 1957, and also the study of the newest satellite The river Irtysh, within Pavlodar area, has the photographs of the valley, shows that on a number greatest range of values. The range of values of of sites, the river has strongly developed in width the stability factor by Lohtinov are W>15; in the and has deepened some new channels, and the Irtysh this factor mismatches stability (W=2.35). old channel has sometimes appeared strongly The calculation result allows the conclusion that constrained by shallows, spits and midpoints. the channel of the river Irtysh is comparatively The relative stability of the channels is defi ned in stable under anthropogenic loading. the form of settlement factors (indexes) referred to Deformation of the river Irtysh is infl uenced by by Lohtin’s number (1948), updated by Velikanov the display of transported deposits carried by the (1958). The index refl ecting the stability of the stream in the form of washout, carry and deposit channel in the current cross-section direction of material. The channel of the river meanders was developed by Dzjankhen based on Altunin’s strongly through the whole valley. The presence hydromorphological dependence (Altunin, 1958). of plenty of islands in the channel, dead channels The index refl ecting the intensity of horizontal and lakes in the fl oodplain determine the typical deformations, considered a morphological features of deformation of the river bed and the parameter of the channel, was developed by mode of river deposits. Non-uniformity of the Glushkov (1961). There are a number of factors deposit distribution along the river is basically that can characterize the integrated stability of explained by the change in morphology of the the channel, for example, the factor of erosion- valley and channel, leading to varying intensity of morphometric stability by Karasev (1975), and channel formation (meandering in the fl oodplain, also the coeffi cient of stability by Makkaveev widening and narrowing of sections, formation of (1955). the channel etc.). In the years when river waters abound there is a general increase in channel Results and Discussion erosion activity, leading to an increase of deposit drain owing to sedimentation in the low and wide The results of my research revealed that fl ooded plains. In shallow water years, when the within the boundaries of Pavlodar city the river fl oodplain is fi lled only occasionally and the river has become distanced from the slopes of the just runs in the channel, the loss of deposit drain valley, where we observed only redound of earlier is little. deposits and a local increase or reduction of fi rm The feed by deposits due to the stream material. The non-uniformity of the fi rm material undermining valley slopes replenishes the drain on different sites of the river affects channel of the river as the general extent of sites on which Mongolian Journal of Biological Sciences 2006 Vol. 4(2) 77 the river is “pressed” to the slopes of the valley of Pavlodar leads to the following conclusion: the is about half the entire length of the river Irtysh channel is infl uenced both by spontaneous (natural) within the limits of Pavlodar area. Deformations and anthropogenic factors. In accordance with of the channel in the reaches and shallows become the conducted research, the infl uence rendered greater, judging by the presence in many sites of on the intensity of erosive ability is shown by large ground deposits in the channel (pebbles). natural infl uences, i.e. large deposits, pitch, Fine deposits are carried by the river in suspension current speed, and water regime. Anthropogenic and their deposits are not too developed. Near the components infl uencing the stability of the river Pavlodar city the river Irtysh widens considerably, channel involve hydroelectric power stations, and the slopes have a less limiting infl uence on water transport, dredging, and water supply, which the development of the meandering process. Also lead in their turn to a change in morphological the channel of the river becomes twisted. characteristics of the river channel, in particular On the site of the investigated area where to rectifying the channel. the river appears “pressed” to the valley slopes, We made the calculation of stability of the meanders of the channel are scarce and it is channel to anthropogenic loading: the range of sometimes almost rectilinear. For example, near values of the stability factor by Lohtin (1948) the city Pavlodar the channel follows the outlines makes W>15, i.e. the channel is motionless. of the valley slope precisely (Karasev, 1975). Within the vicinity of city Pavlodar, this index is During the development of meanders there is 5 times lower than the former (W=2.35), and it sometimes a tearing away of parts of convex banks in its turn mismatches the stability of the channel due to fl oodplain washout by the stream because and shows the small mobility of the channel. of a high level of water. For calculation of stability of the channel we As a result of the economic activities in the used a criterion which allows the assumption that river Irtysh valley, water-economic conditions the channel is washed away, and so is relatively have become complicated and led to a certain stable because of the high parameter of the change. One of the widespread and most intensive factor of ground deposits that participate in the anthropogenic loading on the river Irtysh since movement together with water. This calculation the mid 20th century is dredging for maintenance has been confi rmed by a differential curve of and improvement of waterways. The channel the granule-metric of ground deposits within the of Irtysh River within the Pavlodar city area is area Pavlodar city, and it shows that deposits in characterized by relative mobility, with periodic a suspension occupy the greatest area, and this vertical deformations of shallows by 1-2 meters shows the high degree of channel erosion. and it recedes from the banks by some meters There are more than 1000 lakes in the Irtysh a year. These deformations correspond to the River valley. The majority of them are saline and average indexes of stability. So near to the city self-sedimentary lakes and have round superfi cial Pavlodar the parameter G was equal to 17.1; the hollows. The group of lakes in the northern part complex index F – 0.15; Cs – 6.4 and A – 33.8. of the Pavlodar region is in the forest-steppe zone Comparison of these values testifi es that with a warm and comparatively humid climate. despite extensive dredging the stability of the The second group of lakes located in the steppe channel changes, but insignifi cantly. A sharp zone, both on the left and right sides of the Irtysh change of stability of the channel is possible valley, are in an area with a warm and insuffi ciently under the control of water drain. The large water damp climate. The third group of lakes is located basins of Bukhtarma and Shulba regulate the in a forest zone of the Kazakh low hills, with a drain of the river over the long-term by water- warm and suffi ciently humid climate. The fourth power engineering, and can also lead to a change group of lakes can be found in the inundated in morphological characteristics of the Irtysh parts of the Irtysh, with an original microclimate, River channel, in particular to the rectifying of transitive from steppe to forest-steppe zone. Close the channels. The calculations have shown that underground waters (0.2-1.0 m) have a special the Irtysh river channel within the territory of the signifi cance in the formation of the microclimate Pavlodar city is relatively stable. and the feed of inundated lakes. Establishing the factors infl uencing the Territorially, the lakes of the Irtysh river valley stability of the channel of the Irtysh within the city can be divided into the following groups: 78 Tsaregorodtseva. Formation & stablitiy of Irtysh river hydromorphology

a. Pavlodar group, represented by small of the river slope. Also this research allowed us to reservoirs (Moyldy, Jalauly, Big and Small offer a genetic classifi cation of the inundated lakes Tavoljan, Chungur, Usun-sor, Balkyldak). distributed in the valley of the Irtysh river, which b. Lebyazhye group, whose lakes are scattered are confi ned the following classifi cation types: over the vast area and are at a signifi cant distance endogenous, class: hydrogenic, subclass: erosion- from each other (Maraldy, Chagalinkoye, Anarcha, accumulative (river), sort: lakes inundated, lakes Goloye, Naked, Bi and Small Yamyshevskoye of terraces above the fl ood plain; kind: lake- etc.). In the self-sedimentary lakes of the left bank channels, lakes-girths. of the Irtysh table salt is accumulated. c. Ekibastuz group of basically self-sedimentary References lakes (Jaman-Tuz, Ekibastuz, Atybai, Ansar-sor, Big and Small Kalkaman, Kener-Tuz, Karasor). Altunin, S. Т., 1958. Flooding Reservoir and Some sites of the fl oodplain are boggy, abounding Erode the Channels into Lower Dam. River- in numerous girths, horns, branches and freshwater bed Process. Press of Academy of Sciences, lakes. USSR, Мoscow, 47 pp. (in Russian) According to the degree of development and Velikanov М. А., 1958. River-bed Process. State character of relief forms, the channel of the river Press of literature in Physics and Mathematics, is broken into a set of islands and sandy spits, Moscow, 23 pp. (in Russian) separate horns, branches, gullies-hollows and Glushkov, V. G., 1961. Aspects of Theory and girths, which are not connected with the river Methods of Hydrological Investigation. Press surface drain and feed the whole fl ood plain with of Academy of Sciences, USSR, Мoscow, 51 subsoil waters. pp. (in Russian) Our studies conducted during the strip survey Каrаsеv, I. F., 1975. River-bed Process During the have shown that modern landscape conditions in Flow Processing. State Meteorological Press, the reservoirs of the investigated lakes were formed Leningrad, 35 pp. (in Russian) under the infl uence of many factors. The leading Lohtin, V. М., 1948. About the Mechanisms of factors in the formation and development of lakes River Channel. Aspects of Hydro-technics of are the integrated geographical factors: relief, Rivers. Moscow, 15 pp. (in Russian) climate and drain. In each lake-like reservoir, Маkkаvееv, Н. И. 1955. River Channels and there are physical, chemical and biological processes whose joint action defi nes its regime. Erosion in its Basin. М.: Изд-во АН СССР, The intensity and direction of these processes Press of Academy of Sciences, USSR, is in their turn determined by the infl uence of Мoscow, 50 pp. (in Russian) geographical conditions, under which the lakes exist. Another prominent feature of the lakes is Хураангуй their accumulation of an overwhelming number of suspended particles, fractional load and dissolved Иртыш мөрний нуга, татмын elements, products of wind deposits appearing геоэкологийн асуудал нь үндсэндээ голын during the drain, and also the material arising in гольдрол, урсгалын хяналт, зохицуулалтаас the lake as a result of the vital functions of water ихээхэн хамааралтай болсон бөгөөд энэ нь тус organisms and interaction of the water body with голын сав газрын экосистемийн үйл ажиллагаа, the hollow. геоморфологийн хэв шинж зэрэгт тодорхой The analysis of modern satellite images has өөрчлөлтийг бий болгосон нь илрэв. Энэхүү shown that the degree of bending and branching өгүүлэлд Иртыш мөрний нугын гидроморф of the river, promoting the formation of inundated шинж бүрэлдэн бий болох онцлогийг судлах lakes, has the highest value in the vicinity of арга зүйн асуудал болон уг голын дунд хэсгийн Pavlodar city, where the factors on average were 1.2 урсгалын шинж төлвийг судалсан дүнг нэгтгэн and 1.95 respectively, and increase with reduction оруулсан болно.

Received: 16 June 2007 Accepted: 30 January 2008