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Hoshimov Azamat Naziraliyevich, researcher, The Faculty of Natural Sciences Kokand State Pedagogical Institute, Uzbekistan E-mail: [email protected] Isakov Valijan Yunosovich, Head of the Department of Geography, professor, Kokand State Pedagogical Institute, Uzbekistan E-mail: [email protected]
GEO-ECOLOGICAL CONDITION OF THE CONE REMOVAL OF THE SOKH RIVER AND ITS CHANGES AS A RESULT OF THE HUMAN FACTOR
Abstract: The article describes the impact of irrigation and melioration on the hydrogeological and ecological conditions of the cone of Sokh River. Underground water bed saturation and mineralization changes, seasonal and multi-year cycles, dynamics are described. The relation between the rhythmic changes in the underground waters with the water level of the Sokh River and its fluctuations is shown in the article.
Keywords: Underground water, artesian basin, irrigation and amelioration measures, hydro geologic and ecologic conditions, bedding level and melioration, rhythm, mode, effluent, water consumption.
The underground water of this zone is close to surface water,
An institutional and legal framework for the use and protection of land and water resources has been created in the Republic of Uzbekistan. These are Law on nature protection, Law on state land cadastre, Law on farming, Law on subsoil, Land code and other laws. Within the framework of the Action Plan for the further development of Uzbekistan in 2017-2021, the goals of improving the reclamation of lands, the development of irrigation and land reclamation facilities and ensuring their safe and stable operation for the rational use of land and water resources.
Implementation of the set tasks requires a thorough scientific foundation, comprehensive study ofits geo-ecological, hydrogeological, soil-reclamation conditions in each particular region, a comprehensive analysis and ways of rational utilization of resources.
It is known that the conical spatial expansion of the Sokh River differs for its classic symmetrical structure. Its central and lower edges and wings are fully formed. Specifically, the hydrogeological zones of the mountain rivers are common. Sokh cone spread has a special place in the study of the mountain rivers spreads, the research work, and the use of the spatial areas in the national economy.
The following three hydrogeological zones are allocated within the cone spread areas [2; 4]: 1. The zone where surface water leakages to underground and underground water forms; 2. The zone of freshwater flows to the surface; 3. Mineralized water distribution or secondary sedimentation zone.
The main part of the cone spread consists of thick gray layers and forms the first hydrogeological zone. The underground water is formed by Sokh River and its branches, as well as irrigation canals, and partly atmospheric precipitation.
according to the mineralization and chemical composition. Mineralization of underground water is 0.3-0.4 g/l and river water is 0.2 g/l. According to the chemical composition it includes hydrocarbonate, magnesium-calcium.
The commissioning of the Great Fergana Canal (January, 1940) had a great impact on the depth of the settlement of underground water. The bottom was blocked by the flow of water flowing from the upper canal, which is much deeper than the surface of the water. As a result, the surface water levels have risen from 6-10 m to 2-3 m in most of the sand and stone areas. There has also been a dramatic change in the water regime. The level of underground water has been raised in canal when flows full in vegetation period and has been decreased when the water flow has been stopped during the winter months, the swamping of the soil was rising, but the mineralization of water remained unchanged. The saturation amplitude of the saturated water is 50-100 cm, the maximum is February, and the minimum is June-July.
V. A. Gaints [2] was in the second zone of the hydro-geological zone with the intensified flow of the watersheds and the weakest leakage zones. The first Great Fergana Canal boundary is 3-3.5 km wide. The upper boundary corresponds to the fine substances widespread. The third hydrogeological zone continues to the allyuvial plains of the Syrdarya river, 3.5-4 km north of the Great Fergana Canal.
Fergana valley, filled with Mesozoic and Cenozoic deposits formed on the paleozoic basin, formed as a huge tectonic sediment, is a common artezian haze [5]. Particularly rich in water, such as chalk, paleogene, neogene and quaternary deposits. There is an interconnected hydraulic link between
GEO-ECOLOGICAL CONDITION OF THE CONE REMOVAL OF THE SOKH RIVER AND ITS CHANGES AS A RESULT OF THE HUMAN FACTOR
them. Due to the size and quality of water resources in this basin, the cone splits the Sokh River.
The upper reaches of the Artezian basin are composed of quaternary beds, and in its geolithological section, complexes such as Sorgh, Tashkent, Mirzachul and Syrdarya are allotted. [1; 2].
Pressure groundwater from the Cone springs on the beds of the Tashkent complex and in the lower part of the thick gravel layers in the Mirzachul complex is the main source of water supply to the city of Kokand and its surroundings. In the XX century, especially in the second half of the century, comprehensive irrigation and melioration activities were carried out to manage the regime of the Sokh River basin and groundwater regime, to effectively utilize them, expand the area and improve the fertility. They, in turn, have had a strong influence on the natural hydro-phorescence and ecological conditions of the area which have been formed for decades. Average consumption of underground water flows formed at the top of the cone spread was 27 m3/sec, with 18 m3/sec partially returned to normal groundwater flow at outbreak zone. The groundwater flow of the reconstructed and reinforced canals of the irrigation system was 21.4 m3/sec. Its average annual consumption dropped to 4 m3/second and the amount of water outflow dropped to 7 m3/sec, while the amount of groundwater utilization increased by 7 m3/s [2].
Reinforcement of the irrigation system has reduced water saturation by 20-26 cm in 1964-1965. The amplitude of the phase fluctuations ranged from 5.5 to 8.4 m in the central part of the formation of surface and underground waters in these years and from 0.65 m to 1 m in the remote parts of the region. The average value of groundwater fluctuation between 1947 and 1964 was 3.14 m.
The wells located at the center part of the spread the relative debt vary from 10-15 l/sec to 50-60 l/sec. The level of water absorption of the periphery towards the wings and cones of the periphery decreases to 0.5-1 l/sec.
The layers of the Tashkent complex start at depths of 100-130 m and are 400-450 m thick. The volume of water consumption ofwells in the complex varies from several liters to 150 liters per second, and the flow of wells springs spontaneously from 5-10 l/sec to 30 l/sec. The relative debt of the wells in the head of cone spread are 0.03-3.4 l/sec, and 2.5-5.6 l/sec in the center, 4.5-8.8 l/sec in leakage zone, and 1.0-2.5 l/sec on the periphery.
Mineralization of pressurized waters in Tashkent and Mirzachul water complexes is almost the same, with an average dry residual amount of 0.2-0.3 g/l. At the top of Mirzachul complex water in the northern direction the dry residue rises to 0.5-0.8 g/l and does not change in deep layers. Min-
eralization type is hydrocarbonate, magnesium calcium rich in sulphates.
At present, the level of subsurface water is 60-100 m at the head of the soil and rocks beginning part of the cone layer, 50-60 m in the middle and 6-10 m in the marginal part. The unsaturated zone in this region have a filtration coefficient of 80-100 m/day, and water supply is 0.25-0.30.
Here, the undergroundwater regime has a stable rhythm in the long run: from summer to autumn it rises and falls from winter to summer. This rhythmic state of the maximal and minimal line represents the phase dynamics of the hydrogenological order of Sokh river. Due to the fact that the groundwater level is deep at the bottom of the surface, there is no direct hydraulic connection between them and the surface waters of the river. The maximum amount observed in July-August in river water is only 2-2.5 months (November-December) after groundwater [3].
Formation of the seasonal and long-term flow of the groundwater on irrigated fields of the cone spruce ponds depends on the balance between the water level of the Sokh River, infiltration of irrigation water, evaporation and transpiration volumes.
The maximum exposure level in the natural pitch of the cone periphery is observed in March and the lowest level of decline in November-December. However, the natural rhythmic status of the above-mentioned waters is affected by irrigation water during irrigated lands: during the year, the surface rises twice. The first seasonal rise is due to the spring salt washing, in March and the second, in the period July to September, due to summer vegetation irrigation.
The water level of the irrigated land was between 1-1.8 m depth during the 1935-1965 period. The mean annual minimum and maximum values of the line varied between 0.87-1.08 m in the amplitude. The mineralization level of the water ranged from 0.6 g/l to 16 g/l depending on the irrigation period. The fertilising effect of the irrigation water has increased over time. The newly-acquired land is characterized by high mineralization and low in old irrigated land.
In the 1980's, the total area of irrigated area of the Sokh River cone was 129063 hectares. Today, the value is about 150000 hectares. In today's environments with the type of collector-puddle, the ground waters with a depth of 1.5-2.0 m are predominant in all areas of the study area. The area of this group has grown to 8500 hectares in the last 20 years, and the land area with a surface area of 2 m is significantly reduced. There is also a tendency to increase the mineralization of the waste water. Water mineralization with the reduction of land areas up to 1 g/l, the area of land with mineralization 1-3 and 3-5 g/l has increased.
The groundwaters of the Sokh River cone spread are highly valued by the quality. The importance of water for the
population as well as for irrigation purposes is unmatched and the capacity utilization is increasing. From 1911 to 1914, seven artesian wells were dug. Their number reached 34 at the beginning of the 1950s, and in 1962, there were 390 wells for water supply. Since then, the construction of the integrated water intake facilities for irrigation and water supply purposes has begun. In the 1960s, Shoimbek, the largest water intake facility, was constructed in the north-west of the slopes, 65 wells with a total output of1.6 m/sec, Ganiabad water intake facility in the south-west of the cone with 27 wells with 325 l/sec, the Tomosha Association has 29 wells for 290 l/sec. A total of 505 wells (453 phantoms) of wells with water are 5.2 m per second.
The number of wells used for the purposes of drinking and agricultural needs, irrigation and drainage in the Sokh River Cone Spread exceeds 2100, the total water volume is 18.2 m3/second. However, over the past few decades, the number of informal artesian wells has increased: they can be found in farms, neighborhoods, villages, and some businesses.
At present, the probable reserves of condensed groundwater are 3126000 m3/day, in practice their use makes up 45%.
Based on the aforementioned, it should be noted that over the last century, the transformation of human activity has changed dramatically. In particular, The Great Fergana Canal (1940) was put into operation. The type of collector-dump and the system of sinking canals (1936-1941, 1947-1948)
were constructed, in the 60s its specific length was increased to 60 degrees in some places. Sokh irrigation system was reconstructed, canals were reinforced. From 1992 to 1993, the Sokh reservoir began to collect river water. The number of wells for drinking, irrigation and drainage purposes has exceeded 2100. The amount of water withdrawn from them exceeded 18.2 m/sec, which is expected to increase further in the future. In connection with the above, the water supply of irrigated areas has improved, new lands have been utilized, the land areas have been abandoned, and the water supply was dumped. Depth of water flow and its hydrochemical content have changed dramatically. At the same time, Kokand city and its affiliated industrial enterprises in the center of contaminated soil are a source of pollution of groundwater, and their disposal and waste contaminated not only in the 1980s and 1990s, but also groundwater (1-12). The above mentioned high quality of underground waters was mentioned above.
Unfortunately, because of the misuse of the upper part of the Sokh cone spill, the quality of underground wastewater was broken, and the waters turned into pollution. The water hardness of calcium and magnesium carbonates increases.
Thus, the creation of sustainable water supply for irrigated lands in the cone of the Sokh River, improvement of land reclamation, and raising agricultural production are connected with the solution of the existing problems of the existing hy-drogeological and ecological conditions.
References:
1. Васильковский Н. П. К стратиграфии четвертичных отложений Ферганы. Материалы по геологии Средней Азии. Вып. 2.- Ташкент, 1935.
2. Гейнц В. А. Подземные воды четвертичных отложений Юго-западной Ферганы.- Ташкент: Фан, 1967.
3. Исаков В. Ю., Отабоев А. Х., Солиев Р. Э., Абдурахманов Г. А. К характеристике гидрогеологических условий Сохского месторождения подземных вод в Ферганской долине // Материалы V Международной конференции. Ресурсовоспроизводящие малоотходные и природоохранные технологии освоения недр.- Москва-Кызыл Кия, 18-22 сентября, 2006.
4. Легостаев В. М. Мелиорация засоленных земель.- Ташкент: Госиздат, 1959.
5. Ходжибаев Н. Н. Гидрогеолого-мелиоративное районирование.- Ташкент: Фан, 1975.
