I have been reading published papers on computing soil quality index (SQI). Majority of these papers have not been very clear about the calculations, making it difficult to understand. However, I found a common pattern among these papers that I think has been used. I will appreciate it if someone with experience in calculating SQI can please agree or disagree with the calculations I have made below, using part of my own data.

weighting using PCA (Wi)

PC_1 | PC_2 | PC_2 | PC_3

CEC 0.40 | SOC 0.125 | pH 0.125 | BD 0.16

non-linear scoring function (Si)

CEC 0.702 | SOC 0.533 | pH 0.485 | BD 0.489

SQI = sum (Wi x Si).

[(0.40 x 0.702)+(0.125 x 0.533)+(0.125 x 0.485)+(0.16 x 0.489)] x 100 = 48.34

Thank you for you guidance.