DETERMINING THE EFFICIENCY COEFFICIENT OF THE NEW DARGOM CANAL THROUGH FIELD MEASUREMENTS

Аннотация

In this article, the efficiency coefficient of the Yangi Dargom Canal, which draws water from the left tributary of the Zarafshan River, was determined using generally accepted hydraulic laws and the hydrometric method. The water discharge of the branches receiving water from the canal was calculated and the results were compared. The main purpose of measuring water consumption is to achieve efficient water use in response to climate change in our region and the reduction of water resources in sources due to anthropogenic factors. This is accomplished through knowing water flow rates, which enables the development of water balance programs along major rivers, canals, and internal networks during low-water years. Keywords: Water discharge, flow velocity, canal, gauging station, branch. Introduction. Comprehensive measures have been implemented in the agriculture sector of our republic aimed at conserving water resources, ensuring their rational and efficient use, including maintaining reliable operation of irrigation systems, and significant results have been achieved. The Dargom Canal provides water to 67.5 thousand hectares of land in Samarkand region and 50 thousand hectares in Kashkadarya region. The annual flow volume amounts to 0.9-1.2 km3. The functioning of 562 km of inter-farm and intra-farm canals and 412 hydraulic structures in the Dargom irrigation system depends on the technical condition of the Dargom Canal. In recent years, intense erosion processes occurring in the canal bed have resulted in the collapse of canal banks, siltation of the channel, and consequently, a decrease in water carrying capacity, leading to a decline in the canal's efficiency. The primary cause of this is the high flow velocity due to the canal's steep longitudinal slope (average slope of 0.004). Instances have been observed where the progression of these channel processes has had negative impacts, potentially leading to emergency situations. However, the high kinetic energy of the flow also presents an opportunity for positive utilization of this condition. 101 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference Research subject: Water for the Yangi and Aylanma Dargom canals is drawn from the left-bank tributary of the Ravotkhoja hydroelectric complex built on the Zarafshan River. The Yangi Dargom canal is 10.2 km long and is fully lined with concrete. The canal is equipped with 10 water intake branches and a hydrological station. Figure 1. The river water intake section of the canal The climate of the canal area is highly variable, characterized by relatively dry, hot summers and cold winters. Annual precipitation amounts to 329 mm. The air in the region is dry with high evaporation rates (1135 mm). During summer, the absolute maximum air temperature reaches +38-40°C, while in winter, the minimum temperature drops to -26-30°C, with an average annual temperature of +12°C. The period of highest precipitation occurs from October to March, accounting for more than 75% of the annual amount. The area predominantly experiences winds from the northeast and north directions. The technical condition of the structures. All structures in the Dargom Canal are inspected after the vegetation period, during the autumn and spring seasons. The following observations are conducted to assess the condition of structures and equipment in the canal: water levels in the upper and lower reaches of structures, silt accumulation along the canal route in the upper reaches and erosion of the bottom and banks in the lower reaches, the impact of water flow on the condition of structures, monitoring of areas prone to damage and potential accidents, and filtration from structures and the canal. During the monitoring process, malfunctions in the structures are identified and measures to eliminate them are determined. Observations are conducted using visual or geodetic methods and other equipment. After a distance of 11 km from the main structure of New Dargom, the canals in this zone merge and flow into Old Dargom. The length is 10.5 km, with a 102 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference water discharge of 125 m3/s, and a total elevation drop of 55 m along its slope. There is a 600-meter tunnel along the canal route. The water energy generated from the steep slope is dissipated by 1 rapid-flow spillway and 13 stepped spillways (cascades). Натижалар ва мулоҳаза: Currently, the determination of the efficiency coefficient along the sections and length of the Yangi Dargom Canal is carried out primarily using the hydrometric method. In this method, a specific section of the canal is selected to determine its efficiency. Within the chosen section, the locations of the upper and lower cross-sections are identified, and the water discharge is measured using hydrometric instruments. The length of the selected section (segment) is determined by the following formula: L=67,4Pi/ 𝜎√𝑛𝑃 (1.1) Here, L r