Optimal allocation of nonpoint source pollution control measures using two modern comprehensive evaluation methods

Abstract

Nonpoint source (NPS) pollution has been studied for many years but it exhibits random, widespread, complex uncertainties which make it difficult to manage and control. We employ group decision-making utilizing the fuzzy comprehensive evaluation method (FCE) and the analytic hierarchy process method (AHP) and comparatively evaluate the optimal allocation of NPS pollution control measures. Here, we present the top-three evaluation results ranked as follows: combination of contour tillage and vegetative filter strips (CT & VFS), vegetative filter strips (VFS), and combination of contour tillage and fertilizer reduction and vegetative filter strips (CT & FR & VFS). The fourth, fifth and sixth results by FCE method are chemical fertilizer reduction (FR), returning farmland to forest or pasture (RF), and combination of contour tillage and fertilizer reduction (CT & FR), while the corresponding results by AHP method are returning farmland to forest or pasture (RF), combination of contour tillage and fertilizer reduction (CT & FR), and fertilizer reduction (FR). The seventh results for each of the two methods are contour tillage (CT), which has a positive but limited effect on nutrient loss reduction. Our results provide new underlying insights needed to guide the resonable allocation of NPS pollution control measures.