Dynamic Monitoring of Winter Wheat Health in Mining Subsidence Areas by Combined Active and Passive Remote Sensing Technology

Abstract

The contradiction between efficient coal mining and arable land capacity enhancement in the coal–grain production overlapping area has constrained grain output and threatened food security. In this study, DInSAR was used to extract the mining subsidence areas (SAs). Multiple red-edged vegetation indices were introduced to explore the growth differences between winter wheat in the SAs and Check Areas (CKs). A crop health index (SACHI) was proposed to comprehensively evaluate the health of winter wheat in SAs. The results showed that: (1) Compared with the CKs, the onset of over wintering season (OWS), start of growing season (SOS), and end of growing season (EOS) of winter wheat lagged behind in the SAs. (2) The winter wheat growths were slower in the SAs and their decline rates were faster than that in the CKs. (3) The SACHI could effectively synthesize the information contained in each component and was highly correlated with them. (4) Mining subsidence had a significant impact on the winter wheat health in the length of growing season (LOS), while the impact was weakened during the OWS. Based on the multi-vegetation indices and the SACHI, the impact of mining subsidence on the winter wheat health can be effectively diagnosed and estimated.