# «Mathematical modeling of geophysical processes: direct and inverse problems»

The seminar is devoted to the consideration of various aspects of mathematical modeling of physical processes in the atmosphere, hydrosphere and active layer of land, associated with solving problems arising in the study of the problems of climate change and the natural environment.

Seminar Organizing Committee

 Leaders: Corr. RAS V.N.Lykosov (Marchuk Institute of Numerical Mathematics of RAS, RCC MSU) Doctor of Physics and Mathematics V.M. Stepanenko (RCC MSU, Geographical Faculty of Moscow State University) Secretary: A.V.Debolsky (RCC MSU, A.M. Obukhov Institute of Atmospheric Physics of RAS).
##### 17:15
 Matveev S. A. Lomonosov Moscow State University; Marchuk Institute of Computational Mathematics RAS Hasanov M. E. Skolkovo Institute of Science and Technology Pukalchik M. A. Sirius University Oseledets I. V. Skolkovo Institute of Science and Technology

### ANALYSIS OF SENSITIVITY AND APPLICATION OF OPTIMIZATION METHODS FOR ANALYSIS OF RESULTS OF MATHEMATICAL MODELS OF SOIL PRODUCTIVITY MONICA AND WOFOST

In this paper, we consider two multiscale mathematical models of soil productivity, MONICA and WOFOST, with a detailed description of a large number of physical and chemical processes occurring in the soil. In particular, these models describe the kinetics and transport of organic carbon and nitrogen along the soil profile, taking into account the processes of thermal conductivity, moisture capacity, etc.

When choosing the main indicator of the "results" of modeling as the yield of agricultural crops, the modeling problem can be considered as calculating the result y = f (x), where x are the input parameters of the model, y is the final yield of an agricultural crop.

The first part of the work is devoted to the application of the Sobol global sensitivity method to the considered mapping made it possible to make sure that the parameters of the upper layer (horizon) of the soil have the most significant effect on the yield, after which, for several crops using the same technique, we estimated the contribution of various parameters of the immediate upper soil horizon ... To speed up computations in sensitivity analysis, we used the natural parallelism inherent in the Sobol method, which made it possible to speed up computations more than tenfold using 96 processor cores of the Zhores supercomputer installed at the Skolkovo Institute of Science and Technology.

The second part of the work is devoted to the application of the NSGA-II optimization algorithm to solve the optimization problem with two goals: optimizing the irrigation regime to reduce the consumption of fresh water while increasing the yield of agricultural crops for a particular farm located in the Moscow region.

The seminar will be held in the form of a webinar on the Zoom platform.