Computer analysis of water stress regimes of an irrigated agrocoenosis using the SWAP model and ground and space monitoring data

Abstract

Results of computer modeling of water stress regimes of the irrigated alfalfa, corn and soya bean crops at the level of a specific agrocenosis are presented. The SWAP model has been used for the analysis. Comparison of the results of the computer modeling of water stress with bioproductivity has been made on the basis of the data of ground monitoring carried out concurrently with satellite survey in 2012 in the fields of the farms located in Saratov Zavolzhye region. As a result, the correlation between the calculated values of the accumulated water stress of specified crops during vegetation period and the data of their productivity was revealed. The computer model used for calculation of water stress included blocks describing water and heat fluxes in the atmosphere-agrocenosis-soil-ground wa‑ ters system, as well as datasets of soil boundary conditions and parameters of soil hydrological char‑ acteristics. The datasets describing boundary conditions at soil surface were created from the results of ground and space monitoring, and also information from crops irrigation operational management. Parameters of hydrological characteristics of soil layers were calculated with the help of additive mod‑ els of soil structure with the use of physical‑mechanical characteristics of a soil texture.