UDK 551.07

A.G.Koshim

Geographic Faculty, al-Farabi Kazakh National University, al-Farabi 71, Almaty, RK

IMPROVMENT OF MODERN PROCESSES ON THE

OIL AND GAS DEVELOPMENT AREAS

(Case study the West Kazakhstan)
Summary

Considered exogenous processes in the Caspian oil and gas regions, which are of aeolian processes, the process of salinization of soils and subsoils, sheet, gully and river erosion. Substantiated factors of their manifestations and dynamics of development. The connection with the manifestation of the processes of natural components

I. Introduction

Study of modern geomorphogenesis and development of environmental actions are becoming increasingly important. This fully applies to the West Kazakhstan, which is the main oil production region of the republic, where most clearly intensification of the current processes observed.
The investigated area belongs to the three landscape zones - steppe, semidesert and desert. They are: in the northern part of the region - within the Common Syrt on terraces above the floodplain of the Ural River and its tributaries (Derkul, Utva, Ilek), watersheds mostly alluvial drift from the slopes, and deposition of river alluvium, gullies and ravines, erosion and collapse of banks in result of lateral erosion, and Aeolian processes, salinization of soils, ground subsidence – in the southern part of the region.

II. Main part

The sheet flood occurrence is not equal everywhere. The process intensity depends on meteorological conditions, the filtration properties of the rock substrate and surface slope. This is well observed in the watershed of the rivers Utva, Ilek, as well as along the valleys the Derkul River where Upper Cretaceous deposits exposes to surface, represented the white writing chalk. The intensity of the process occurs during autumn rains and spring snowmelt, timing, basically, to the sides of dry logs and gullies, to gentle slopes of drainage basins, as well as to the slopes of hilly-ridged sands. Dry valleys of gullies and ravines are usually short. The bed in them can be traced only in the upper reaches, then the bottom is expanding and it also plane washout happens.

Despite the small amount of rainfall (average 200 mm), planar erosion plays a very significant role in shaping the modern image of the region, covering the gently sloping surface deluvial plains in the north-eastern part of the territory as its weak turfness, and its constituent soils are very unstable for soaking and washing.

The development of gully erosion occurs within the denudation plain of the Common Syrt, which is covered with a network of temporary stream flow. An erosional down-cutting of natural character occurs actively as a result of rare rainfall and in the process of snow melting, cover which is very low here (0,5-0,6m), but on the some areas of the marine plains in the south areas (near the Shubirtbala wintering) the erosional down-cutting formed as a result of wind-surge phenomena in the outflow of sea waves. Here no more than 2 m depth and 5 m width erosional down-cuttings formed.

Sometimes the erosional down-cutting reaches depths of 10-15 m and widths from 5 to 10-12 m within the denudation plain, forming gullies and ravines relief. Most of gullies and ravines have symmetrical sodded slopes. The depth of ephemeral streams channels in the surrounding plain from 0,3-0,5 m up to 7.5 m. Almost all of ravines and gullies have a submeridional strike. Its strike has been gradual deepening of valley bottom. Process of bottom gully erosion is developed at the bottom the most rapid gullies.

Brining with flood flow a sandy-clay or carbonate material accumulates at the bottoms of gullies and ravines. Most gullies and ravines covered with dense water-loving vegetation. In the upper of the Derkul River ravines, hollows have a V-shaped cross section and branching tree-like character, and in areas of flood plains and terrace above flood-plain of the Ural and Chagan rivers, gullies and ravines network is characterized by sharp outlines, steep slopes and have a stepped nature profile.

Erosion activity occurs intermittently, and makes only minor changes to the modern, in general, flat terrain area.

River erosion is the most actively occurs during the spring thaw, when the rivers are flooding, accompanied by cataract erosion of the ravines and river banks, as well as redeposition of sedimentary material in the form of numerous beach ridges and shoals. This process is developed only in the northern areas as the southern part of the region completely devoid of a permanent watercourse (the Mangistau oblast and the southern areas of the Atyrau oblast). The role of erosion activity is occurred in under washing and collapse of river banks of the Ural River and its major tributaries, and rivers Sagyz, Emba and therefore redeposition of material occurs with beach ridges and shoals formation. As a result of under washing clever and cliffs are developed.

Most active erosional process occurs on the Ural River; where all along the river can be traced 7 m cliff heights downstream and up to 12 m in the upper stream (within this territory). Such clever are observed on its tributaries Kushum, Derkul, but with less height - from 5 - to 8 m. Cliffs with 5 m height in the downstream and up to 8 m at the top occurs on the Sagyz River. The Emba River has less-developed river system, where the slopes have a height of 5-6 m. The erosion process is weakened in the downstream of the river, because of drying up of the stream and rock cliffs found here is very rare.

The essence of aeolian process is the active interaction of wind with the underlying surface in the surface layer with a constant and binding leading role of wind and with the active participation of a number of other natural factors. The aeolian processes appear intensively in the weakly attached vegetation, sandy and loamy marine sediments of the Upper Valley. Dust sands are process more intensively, less - loamy light sands.

A large array of scattered sands – the Naryn sands developed in the northwestern part of the territory in conditions of an arid climate and frequent strong winds, where the sand hills, dunes, ridges almost universally overlook the deflationary depressions of 2-3, sometimes 10-15m. Unconsolidated sediments of saline desert and semidesert areas are also exposed to bloating and deflation (the Pre Caspian Kara Kum, near the Sarkamys Village) where surface soils are usually loosened up into small particles during the salts crystallization. Increase of wind erosion is also observed in the cultivated areas of sandy and sandy soils. Here sand hills form on non-vegetation areas in the dry season.

The alluvial-deltaic watersheds areas forming sandy rocks have also been intensively reworked by the wind and form small arrays semibound hummocky eolian sands. In some places the aeolian processing of the alluvial-deltaic plains going so far as to the origin of the delta show only the contours of the sandy areas and drying up the ancient channel. There are numerous sandy massifs on the plain stretching along the direction of the rivers. This indicates on the alluvial origin of the sand massifs in the further processed by the aeolian processes, due to which mounds, ridges, dunes and deflation basins were formed. The largest in the delta are the Kugalykum, Tolpankum, Kasyrkum sandy massifs and etc.

The sandy massifs often react to tectonic movements, which are expressed by straightness of the some sandy massifs’ rows or boundaries. Such straightness boundaries observed near the Besoba, Karakol villages. Relative height of a relief within the delta plain is 6-8 m. Small areas of massifs liable to deflation processes – round shaped deflation basins with 50-100 m diameter and 1,5-2,0 m depth. Extensive large hillocky sandy massifs developed in the south of the Aralsor Lake. They have 2-4 m height, but there are also sand ridges having 5-8 m height, pulse-oriented. Deflation forms, mesh and deflation basins developed here along with the accumulative eolian relief. They have round shape with a diameter of 100-150 m and 3.5 m depth. Most part of dunes fixed by vegetation, although there are some areas are partly fixed and observed blown sands. There are separate 2-4 m height sand dunes or submeridional orientation barchan fringe among them. Pit and mount sand massifs are mainly developed on south, the lower hypsometric levels. The height of individual mounds do not exceed 1,5-2,0 m

Development of the aeolian sand massifs has indiscriminately orientation and various forms in the plan. At the present time increasing distortion of vegetative cover is observed which are attach sands due to human activity that leads to more deflation.

Salinization process development related to pulling up of groundwater to surface which happens due to strong surface evaporation, salt water crystallizing recovered from rock by water, inflowing salts from weathered strata-igneous rocks as well as redistribution and transportation of salts from sediments previously accumulated salt mass.

Relief making role of this process is very significant. Alkaline lands form on depressions formed by clay, loam, sandy loam and less sandy rocks in close proximity level of the groundwater. Surface of sors or blinkers, lake visible depressions occupied by the alkaline lands, are covered with white alkali, usually relatively thin (2-5 mm, rarely up to 1 cm) below which lies stratum of damaged, not attached saline rocks (salt content in the soil more than 1%, usually 3-5%).

This process actively observes in the area of new Caspian sand deposits’ distribution, isolated along the coast of the Caspian Sea and characterized by a strong magnesium-sodium, sulfate-chloride-dominated salinity in the salt complex chlorides. The Mertivy Koltyk sor could be called such site which is located at the south-western region. It is the most extensive salinization basin, annually updated with new salt storage, developed from sea water during spring tides, and demolished from banks. Very strong sodium chloride salinity observed here which mineralization increases from the periphery to the center.

The salinization process also occurs at the lower areas, at the catholes where the groundwater level is 1,5 to 5,0 m. Dry lakes and sor depressions where intensive salinization process have flat bottoms of different sizes. Their coast lines are greatly dissected. Lake depressions areas often range from tens to several hundred meters. These are the dry lakes like the Tuzdykol and Itmurynkol.

III. Conclusions

Thus, the development of modern exogenous processes related mostly with natural factors. The exogenous processes of the region have an area and local nature and presented by the aeolian processes, the soils salinization process, rain-wash, by gully and river erosion.

REFERENCES

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2. Gerasimov I.P. 1970. Modern relief-forming processes. The level of scientific knowledge, new problems and methods. // Modern exogenic relief forming processes. Moscow, Nauka.

3. Doskach A.G, Gael. 1970. Еolian processes in the steppe regions of Russia. //Modern exogenic relief forming processes Moscow, Nauka. pp. 138-149.

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6. Kovda V.A., 1974, Soil Processes in Arid Regions. Moscow.