During the construction of open drainages, to achieve economic efficiency, it is very important an accurate assessment of their parameters and projection size. The article is devoted to the creation of a mathematical model by taking into account the variability of flow movement and discharge rate in open drainages. The appearance of a mode of uneven movement as a result of the influx of infiltration water from the sown area to the drainage is described. Recommendations are given for determining the hydraulic parameters of drains. To study the movement of water flow in open drainage, the results of studies in the Boevut drainage system of the Syrdarya region are disclosed. The results of the analysis of the studies are presented. Based on the analysis results, a method for designing open drainages is proposed. The hydraulic parameters of the constructed new open drainage are determined in field conditions. The data determined in the field conditions are compared with the values of the proposed design method. Based on the comparison results, the reliability of the proposed design method was evaluated.

Irrigation channels plays particular importance role to provide water for irrigated areas. In recent years, the irrigation channels of Central Asia have been negatively affected by deformation phenomena. As a result, their hydraulic parameters changed and their throughput decreased. The results of recent studies in the field of the phenomena of deformations in open and in the planning of irrigation channels show that a lot of work has been completed. Ensuring the static and dynamic stability of the channels, increasing the efficiency of the channels currently require to cover the channels with concrete cladding. A high cost of covering the channels with concrete cladding brings reveals the problems in these works. The best solution is to reduce concrete consumption. The article proposes a method for projecting a concrete channel from the condition of a hydraulically most advantageous section. According to the proposed method, the consumption of concrete mixture is reduced by 36% and increased the dynamic stability of the channel (when assessing the nanotransport ability of the channel) is increased by 26%. The rehabilitee of research results are confirmed by the formulas used in practice.

The quality and quantity of agricultural products depend on land reclamation. Collector-drainage systems are used to improve the reclamation state of irrigated areas. The article discusses the stability of slopes of open collector-drainage networks in the irrigated lands of the Hungry Steppe. Discussed problems create during construction and providing productivity of drainages system in irrigation fields. The causes of the deformation process are discussed. The deformation process occurring as a result of landslides of the banks of open collectors is estimated. Recommendations for determining the stability of the banks of an open collector are based on the definition of a model of circular cylindrical sliding surfaces. Used statistic law of mechanics in calculation work based on the model of the ground movement around a cylindrical surface. During calculations, the main attention is given to the weight force, hydrodynamic force, and bite force of the ground. Stability coefficient calculated according to keeping moment (М1) moving moment (М2). In determining the stability of the soil, the main factor of the coupling of the adhesion between the soil particles is substantiated. The suffusion process occurring as a result of moistening and salinization of the soil of the shores of an open reservoir is estimated and analyzed, decreasing of stagnation coefficient in a result of ground absorption process. Analyzing soil samples of various salinities under laboratory conditions, soil adhesion was evaluated. Based on the studies, recommendations are given for the restoration of the shores of open drainages. The given recommendations are based on increasing the drainage's resilience and preventing deformation processes from constructing the drainage in slopes.

Accurate and correct hydraulic calculations are important in the projection of open drainage systems. Because of the hydraulic calculations, it is possible to determine the parameters while constructing it. For calculating the hydraulic, it is necessary to determine the amount of filtration water from the cultivated fields. Crops and irrigation norms differ in the irrigated areas. Of these, rice is the most demanded of water. This article describes how to use GIS to determine the drainage water flow discharge into the open drainage system in the area under cultivation. The research object was the Central Mirzachul open drainage system which was constructed on irrigated land in the south of the Syrdarya region, located in the Mirzachul area. Sentinel 2 satellite imagery was used to identify rice fields in the study area. Downloaded satellite images were analysed using the ArcMap application of ArcGIS, and several steps were taken to create and map a study area. Based on the results of the analysis, the surface and size of the rice fields are determined. Hydraulic calculations were provided based on the determined data. As a result of hydraulic calculations, it was determined that the collector drainage system with the length of 1200 m drops 4.1 m3/s water from the rice fields.

This scientific piece of work shows findings from tests of the technology designed for remote determination of the soil moisture in the use of drip irrigation system in Samarkand region. The average annual rainfall of the research area is 370 mm, the area is 240 000 m2. The site where the technology was subject for tests, is located 634 m above the sea level in Payariq district of Samarkand region 40°00’43.97’’ 66°54’51.35. The area was divided into 12 smaller sites, humidity measuring sensors were installed in each of the sites and GSM modules were used for their communication. To ensure efficiency and accuracy of the results, we would check the data collected by each sensor once every 2 days by thermostats, using a classical method. A graph and a table of maximum sensor mutual distances were developed based on the humidity levels measured in the classical way as well as applying the humidity difference in the sensors. The main difference between the conducted scientific work and practical experiments is that monitoring of the moisture levels was carried out at 3 different depths of the soil and in layers of the light-, medium- and heavy loams. As a matter of fact, currently, such technologies are highly demanded as the area of lands in the drip irrigation system covers in average 15-20 hectares, and the soil moisture is important for determining the irrigation intervals and time. However, it is not always possible, time-wise, to determine the soil samples using the classic-, thermostat- or head drying methods. This article will review the methods applied for determining the two types of soil and their accuracy levels.