Comprehensive assessment of regional selenium resources in soils based on the analytic hierarchy process: Assessment...

The redundancy or deficiency of selenium in soils can cause adverse effects on crops and even threaten human health. It was necessary to assess selenium resources with a rigorous scientific appraisal. Previous studies of selenium resource assessment were usually carried out using a single index evaluation. A multi-index evaluation method (analytic hierarchy process) was used in this study to establish a comprehensive assessment system based on consideration of selenium content, soil nutrients and soil environmental quality. The criteria for the comprehensive assessment system were classified by summing critical values in the standards with weights and a Geographical Information System was used to reflect the regional distribution of the assessment results. Boshan, a representative region for developing selenium-rich agriculture, was taken as a case area and classified into Zone I-V, which suggested priority areas for developing selenium-rich agriculture. Most parts of the North and Midlands of Boshan were relatively suitable for development of selenium-rich agriculture. Soils in south fractions were contaminated by Cd, PAHs, HCHs and DDTs, in which it was forbidden to farm. This study was expected to provide the basis for developing selenium-rich agriculture and an example for comprehensive evaluation of relevant resources in a region.