The influence of oil exploitation on the degradation of vegetation: A case study in the Yellow River Delta Nature Reserve, China

Crude oil is harmful to plants when it is leaked into the soil. The influence of oil exploitation on the degradation of vegetation is still unclear. Oil wells in the Yellow River Delta Natural Reserve (YRDNR) is an ideal region for the research of oil exploitation on vegetation given that this region is less influenced by other human activities. Field investigation and high-resolution remote sensing images were employed to explore the effect of oil exploitation on vegetation. Eighteen sample quadrats and three vegetation sampling strips were investigated near the oil wells. The total petroleum hydrocarbon (TPH) concentrations of the soil affected soil water content negatively. The water content of the sampled soil exhibited a significant positive effect on the species number, Shannon–Wiener index, and aboveground biomass (AGB) of the vegetation. Furthermore, crude oil contamination lowered plant height and quantity, and plant tolerance to crude oil pollutants differed across various species. Oil production has an impact range of 40 m on the surrounding vegetation. Two indices (Normalized Difference Vegetation Index (NDVI) and New Normalized Difference Water Indices 1 (NNDWI1) were employed in a high-resolution remote sensing image interpretation experiment to identify ground objects, the overall accuracy improved 11% compared with the NDVI utilization approach. Moreover, there existed an excellent linear regression relationship between NDVI and field investigated AGB (R2=0.813). The degradation rate of AGB caused by oil exploitation, directly and indirectly, was about 16.49% in the YRDNR.