Hydro-geological factors of formation

Aksu  makrogeosystem

 

Базарбаева Т.А.

 

The Kazakh National university him аль-Фараби (fizgeo@kazsu.kz)

 

Researches of last years it is established, that by the major factors determining dynamics{changes} of geosystems, are not only a superficial drain, but also hydro-geological features. In investigated territory we allocate the following makrogeosystems: Karatalskaya, Lepsinskaya, Aksuyskaya.

At studying modern condition Aksu makrogeosystem were defined{determined} both parameters of a superficial drain, and a mode of the subsoil waters dated to sand-gravel and sand-loamy adjournment of terraces of the river Aksu, and also character of the pressure head waters lieing in prolayers of sand, sandstones and gravel -shingle, generated in a thickness neogenois clays /1/. 

Waters of the paleozoic breeds composing the base of a hollow, are connected with tupho-sanding, aleurolites, diorites, gabro- diorites, granites. They are opened on depth from 25-150 up to 800-1000 m. Underground waters mainly salty, with a mineralization 10-50 g/l, chloride-sulphatic magnesium-natrium. Waters jurkiois adjournment in considered{examined} territory are distributed a little. On quality of water salty (a mineralization 6-8 g/l ), chloride -sulphatic natrium.  

Waters upper-chalk adjournment have the limited local distribution. Underground waters fresh{stale} and litlesalti (a mineralization 0,7-1,6 g/l) from hudro-carbond natrium up to chloride -sulphatic natrium. .

Waters paliegenois adjournment meet in the south, in the north, and in the center of a hollow. Paliegenois deposits lie under powerful, neogenois thicknesses and block paleozoic breeds. The mineralization of underground waters changes within the limits of 1,1-59,2 g/l, on structure they mainly chloride natrium.

Waters neogenois adjournment in southern - Balchashsky artesian pool are distributed everywhere. They are combined mainly regional sustained waterproof clays of the Aral, Pavlodar retinues. In neogenois adjournment it is possible to allocate following water-currviy horizons: sporadic distribution in Aral, Pavlodar and iliy retinues, and continuous - in chorgosky to retinue. On a chemical compound underground waters change from sulphatic-hudro carbonat natrium through sulphatic natrium up to chloride  natrium /2/.

From June till September In a seasonal mode of subsoil waters makrogeosystem, borrowed{occupied} irrigation agriculture, traces sharply expressed years{summer} maximal rise of a level of subsoil waters. The long steady minimum is observed from December till April. The size of years{summer} rise of a level on the irrigated areas in separate years is various, that is defined{determined} water-earrin the rivers and, hence, by various norm of watering. On the average the size of years{summer} rise of a level makes 1,8-2,2 m, sharply growing up to 4-5 m in makrogeosystems,  where former agricultural crops are replaced with other moistureloving cultures, demanding higher norms  watering .

The level of subsoil waters in makrogeosystems agricultural use rises from the beginning of water delivery on fields and becomes to constants after clousing superficial and subsoil waters. Recession of a level is observed during the intervegetative period when water delivery on fields is absent. In investigated territory subsoil waters are dated to guatering and partly to neogenois to adjournment.

Given Aksus makrogeosystems it is submitted by the territory generated by activity of the river Aksu which originates from northern slopes Dzungarian Ala Tau. Formation of a drain of the river Aksu and the river Sarkand is carried out almost completely due to thawing glaciers and snow-laden, a underground feed{meal} is insignificant a little.

The geological base given makrogeosystems is submitted eolovois, alluvial and alluvial- proluvial the adjournment composing channels and I shall understand the rivers Aksu. Litologies structure of breeds various. In upper valleys of the river are distributed boulder-gravel-shingle /4/. These breeds also represent litologies a basis for landscapes of a zone of formation of a drain which is submitted foothill alluvial- proluvial weak-breaked down by plain with differen-grass, bush, differen-galofits-grass vegetation. In process of movement to a lower reaches, boulder-gravel-shingle are replaced on shingles and the sand containing separate lenses clay and loams.

Makrogeosystems zones of driving a wadge into a drain are widely advanced in an average part of geosystem and represent gently rolling range-mound plain with wormwood with wight-ground vegetation. In this zone the river Aksu crossing plain Pribalhashskuju flow on a wide line, further being broken in a lower reaches on numerous channels also forms a number{line} of flowing lakes (Cane lakes). These channels and lakes bog up district and result in formation{education} of complex{difficult} delta. On bandgot the rivers prevail meadow and meadow-marsh ground also there are gray soils. Among vegetation conducting{leading} place is borrowed{occupied} with cereals and comlexflowers. In a cereal herbage the main dominants a feather grass - volosatiks, tipzak, barley Bogdanas, volonez narrow, shii brilliant. Family comlexflowers are characterized by a wide circulation of ice-holes. Worm wood pastures are distributed everywhere, on zone loamy soils, salti meadow, mountain-steppe undeveloped loamy soils on mountains/3/.

In a zone of transit of a drain character of landscapes gets typically deserted character. In functioning landscapes the active role is played with processes kserofitizaz, reflected on character of a soil - vegetative cover. In connection with downturn of absolute heights up to 500-600 m processes of a deflation which make active eolovois processes of a lower reaches makrogeosystems amplify. Landscapes of a zone of dispersion of a drain are dated for sandy files Zhalkum and Kushikzhal adjoining to the river Aksu. In a lower reaches from a settlement. Kuraksu up to a mouth the river loses waters on updating of stocks of underground waters and on evaporation from a surface of numerous reservoirs in delta in quantity{amount} 2,25 m3/ with. In an annual cut{section} the river on this site has complex{difficult} mutual relation with underground waters, receiving a time feed{meal} in December. Therefore the curve of a course of changes of a level of subsoil waters for this type of a mode depends exclusively on a mode of a water level in the river,  synchronously or with to be late for 1,2-2 months. On data U.M.Ahmedsafin /1951/,/1964/zone of influence of the river on levelat the mode is distributed by M.H.Dzhabasova up to 3-4 kms in shallow years and up to 5-7 kms in abounding in water, and the amplitude of fluctuation of a level of subsoil waters in comparison with amplitude of a level of the river decreases approximately in 2 times at removal{distance} from the river for 140 m and in 5-6 times - on distance up to 610 m/5/. Major factors causing change of a level of subsoil waters are an atmospheric precipitation, evaporation and moving plants.

Modern development given makrogeosystems, generated on continental winnowing fragment a material ancient Balkhash - Alakol of pool occurs in conditions of intensive formation{education} of barchans and the fine sandy, bared cells.