Evaluation of reclamation in Hequ open-pit coal mine dump: soil fertility restoration model

Abstract

This study established a comprehensive evaluation model for soil fertility in an open-pit coal mine dump in Jiuxian County of Hequ by drawing on Fuzzy Analytic Hierarchy Process (FAHP) and expert scoring theory. 4 criteria and 25 factors were applied for soil structural stability, water retention capacity, fertility retention capacity, and biological activity. Using the YAAHP calculation software, this study proposed the weights of various influencing factors on the soil fertility restoration ability of the waste dump. The results indicate that soil fertility retention ability bears the highest weight (0.547 7), followed by soil water retention ability (0.198 0), soil biological activity (0.140 8), and soil structural stability (0.113 5) in the evaluation rubric, while organic matter F1 bears the highest weight (0.116 2) among other factors; Based on on-site sampling, results showed that the soil quality in the reclaimed area outperformed the uncultivated area, but still persists at lower to medium levels. The main factor for soil resilience is soil fertility retention capacity, especially the content of soil organic matter. Soil fertility restoration model offers references for improving soil quality in waste dump, accelerating soil reconstruction, and promoting soil ecosystem restoration.

Keywords

• open-pit coal mine dump
• reclaim
• soil resilience
• fuzzy analytic hierarchy process
• soil fertility