Application of the Best-Worst Method as a tool for soil quality evaluation

Marie Grace Ihirwe

Master's thesis

Abstract:

Soil quality is the capacity of soil to provide ecosystem services. To measure the soil quality is important in order to maintain it. However quantification of the soil quality is not easy as there is no standard for it, as the term can vary acording to purpose of that quantification. The Soil Quality Index (SQI) is a numerical indicator of a soil's ability to perform one or more functions and is based on a set of indicators that are interrelated. In this thesis SQI aiming to assess soil’s ability and sustainability to fulfil ecosystem services was determined on the area of five districts (4290 km2) from Central Bohemia region in the Czech Republic. Altogether 278 sampling points from a countrywide database called Systematic Soil Survey that was conducted in years 1961-1970 were included together with information about the Evaluated Soil Ecological Units (ESEU). Using 15 soil quality indicators, SQI has been calculated. 15 indicators have been grouped into three categories which are geographical, physical and chemical category. Those used 15 indicators are: climatic region, hydrologic soil class, slope & aspect, percentage of clay, percentage of sand, percentage of silt, field capacity, wilting capacity, stoniness & soil depth, soil organic matter content, base saturation, cation exchange capacity, pH, P2O5 and K2O contents. Standard Scoring Functions “More is Better, Less is Better and Optimum Range” were used in data preparation. Best-Worst Multicriteria Method was used to assign weight to soil quality indicators by pairwise comparison of the best indicator to others and the worst indicator to others and in the end linear combination method was utilized to calculate SQI. As the most convenient of different interpolation methods the Radial Basis Function (Completely Regularized Spline) with lowest root mean square error was used for the resulting map of SQI. Results were compared with currently used system of soil protection classes and high resemblance was found. The suggested method can be utilized as an alternative to the conventional methods for soil evaluation not just in the Czech Republic, but all over the world. The Best-Worst Method was found as a very useful and efficient method for weighting the indicators for soil quality evaluation.

Keywords

analytical hierarchical process, best-worst method, linear combination method, GIS, Multicriteria decision analysis

Language used: English

Date on which the thesis was submitted / produced: 19. 4. 2023

Thesis defence

• Date of defence: 23. 5. 2024
• Supervisor: Ing. Markéta Miháliková, Ph.D.
• Reader: Orhan Dengiz, externi

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme:
Natural Resources Management and Ecological Engineering