The paper covers the development and research mathematical model of production and destruction processes in coastal system, based on the modern information technologies and computational methods to improve the accuracy of predictive modelling the ecological situations in waters during the summer. The model takes into account following: the movement of water flow; microturbulent diffusion; gravitational settling of pollutants; nonlinear interaction of plankton populations; the impact of salinity, temperature, as well as the pollution entrance and deposition from river flows and air. The scheme with weights was proposed for discretization of the developed model, that allowed significantly reduce the error and the computational time. Practical significance of the work is that the proposed model was software implemented; the limits and prospects of its use were defined. On the basis of a supercomputer, the experimental software was designed for mathematical modelling of possible development scenarios of the ecosystems of coastal waters on the example of the Azov Sea in the summer period, taking into account the influence of environment. Parallel implementation was performed using the decomposition methods for computationally labours diffusion-convection problems taking into account the architecture and parameters of multiprocessor computer system.

The probability of event occurrence can be determined by calculation, however for complex processes, accounting for multiple states is so complex that the probability of the final event cannot be determined differently than by collecting statistical data. This reduces the ability to predict outcomes in any process simulation, which affects the quality of advanced systems. The development of methods for predicting the probability of occurrence of an event when considering complex dynamic processes is a pressing task, the solution of which will help to improve the quality of modeling of technological processes and, as a result, to increase the efficiency of designing machines implementing them. The authors proposed a probability modeling method for dynamic processes, which is a special way of applying probability theory and is workable if the change in the parameters analyzed corresponds to the normal law of distribution. A study carried out on the analysis of the process of sowing corn seeds by vacuum sowing made it possible to predict with reliability more than 95% the probability of formation of “zero seed fodders” depending on their physical and mechanical properties, as well as parameters and adjustment modes of operation of the device.

In Algeria, the problems of erosion and sediment transport are critical, since they have the most dramatic consequences of the degradation of agricultural soils on the one hand and the siltation of the dam on the other .The sediment transport in the Algerian basins is very important especially during the periods of floods, It is in this sense that this study, which consists of estimating the sediment transport in suspension and determining the models of relation linking the liquid discharge and the sediment discharge in order to estimate the solid transport in the absence of suspended sediments concentration data at the Sidi Akkacha station at the outlet of the basin of Oued Allala which is subject to a high water erosion, it degrades from one year to the other under the effect of this phenomenon especially during the floods which drain high amounts of fine particles exceeding in general, the concentration of 150 g/l, the results obtained from the application of the models are very encouraging since the correlation between liquid and solid discharge exceeds 80 %.

The objective of flood frequency analysis (FFA) is to associate flood intensity with a probability of exceedance and for making probabilistic estimates of a future flood event in Allala basin based on the historical discharge record at Sidi Akkacha gauging station, the peak floods discharge of Allala river for 5, 10, 50, 100 years return period are estimated using exponential distribution and the stage at different position of river are calculated using HEC RAS model . Based on the modeling study carried out considering 62 cross sections for 8 km length of river, The Output HEC-RAS model show that the existing embankments system on the banks of Allala River is not sufficient to resist the peak flood discharge of 100 years return period, water level profile shows that a maximum of 1.25m in left bank((at 1.2 km downstream) is needed to protect the inundation of the low laying areas of Old tenes.

The discrete element method (DEM), based on particle dynamics, is used to simulate the technological process of soil tillage using agricultural machinery. A key aspect of the DEM for obtaining accurate agrotechnical and energy indicators of soil cultivation is the formulation of particle contact rules, determined by normal and tangential interactions as well as cohesion forces. This study presents a comprehensive analysis of discrete element method (DEM) contact models used to simulate soil cultivation processes. This study addresses a key issue—the absence of a systematic approach to selecting adequate contact models, which limits the accuracy of predicting soil behavior during interaction with agricultural machinery. A detailed classification of 17 combinations of contact models implemented in the commercial software Rocky DEM was performed, grouped into three categories: normal force models (Linear Spring [LSP], Hysteresis [HLS], Hertzian [HSD]), tangential force models (Coulomb, linear spring limit [linear], Mindlin–Deresiewicz), and cohesive force models (linear cohesion [linear], constant force [constant], Johnson–Kendall–Roberts [JKR]). Experimental validation was conducted by analyzing the angle of repose for various soil types (sandy loam, light loam, medium loam, and heavy clay) with moisture contents ranging from 11 to 31%. This analysis identified the nine most effective combinations of contact models to describe normal, tangential, and cohesive forces (LSP–Coulomb–linear, HLS–linear–linear, HLS–Coulomb–linear, HSD–linear–linear, HSD–linear–JKR, HSD–Coulomb–linear, HSD–Coulomb–JKR, HSD–Mindlin–Deresiewicz–linear, HSD–Mindlin–Deresiewicz–JKR), which showed reliable agreement with experimental angle of repose measurements at approximately 85% accuracy. This study significantly contributes to advancing computer modeling methods in agriculture by providing a scientifically grounded approach for selecting DEM contact models.

In order to ensure safe working conditions for drivers, strict requirements are imposed on the smooth running of agricultural vehicles. The purpose of this research was to study the vibration load on the driver’s seat when driving vehicle under agricultural conditions. Studies have revealed that the standard KamAZ-43255 car seat string system effectively damps vibrations with the frequency of more than 16 Hz, and practically does not damp vibrations below 4 Hz. It was determined that: at all speeds, the maximum values of vibration acceleration in the vertical plane are located in the second octave at the frequency of 2.0 Hz; peak values of vibration acceleration of the driver’s seat in the horizontal plane are located in the third octave at frequencies of 3.15 4.1 Hz; maximum mean square accelerations in the vertical plane are 3.76 times higher than the maximum permissible standards; at vehicle speed of V = 20 km/h, the acceleration of the driver’s seat in the vertical plane exceeds the permissible values in 3.9 times, in the horizontal plane it exceeds the permissible values in 2.75 ... 2.79 times. Therefore, on agricultural vehicles, it is necessary to install spring systems that are adaptive to operating conditions.