Geoinformation Modeling of Determination a Soil Pollution by Lead Compounds in Highway Agroecosystems

This work examines the method of geoinformation modeling in determining the degree of soil pollution by Pb compounds in the highway ecosystems, used as agricultural areas. The methodology allows identifying the spatial parameters of the area of pollution and the territories safe for cultivating crops by determining the actual level of soil contamination. The actual level of pollution (ALP) reflects the estimated balance of Pb compounds in soils over a specified period of time and the duration of pollution (or decontamination) period under the conditions of existing anthropogenic pressure. ALP is defined as the difference between the calculated amount of Pb compounds that have been introduced into the soils of the geosystems from the main sources of emissions and their calculated amount that has been lost from the soil and/or removed from migratory flows (by being transferred to the state conditionally inaccessible by plants), for the same time interval. Methodology verification took place in the geographic area representative of forest-steppe zone of Ukraine by its environmental conditions and agricultural use. Methodology implementation was conducted by building spatial regional databases, utilizing the data from field and laboratory soils studies and open sources of digital spatial data. Based on geoinformation modeling, we determined the configuration and quantitative characteristics of the primary zone of contamination of the soil surface layer with Pb compounds. We presented the calculation procedure of quantitative indicators of soil decontamination from Pb compounds as they redistribute through the soil profile via main geochemical scenarios. We also provided the rate of this process under the conditions of the existing anthropogenic pressure. Using modeling results, we mapped areas of removal, transit and accumulation of Pb compounds and territories receiving pollution from highway geosystems. Verification of the modeling results during laboratory studies proved the objectivity of the proposed methodology in determining the current levels of pollution with Pb compounds. Our methodology could be utilized for a set of different environmental factors as well as other heavy metals with a purpose of identifying areas safe for cultivating crops.