VDCALC framework: A comprehensive approach for assessing vegetation dynamics

Information on vegetation dynamics is important for agricultural and ecological management. However, a systematic framework for the study of vegetation dynamics is still lacking. Therefore, this study developed the Vegetation Dynamic Change And Land Cover (VDCALC) framework to achieve a comprehensive analysis of vegetation dynamic change. The framework uses the Normalized Difference Vegetation Index (NDVI) data derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Global Inventory Modeling and Mapping Studies (GIMMS), along with land cover data as input. It combines several models, including the Theil-Sen median, Mann-Kendall test and coefficient of variation, which can qualitatively and quantitatively study the spatiotemporal dynamic change of vegetation, and Hurst exponent model, which was used to predict the future change. Meteorological and statistical data were used as auxiliary data in this framework to analyze the influencing factors of vegetation change. Results showed that the degradation area was mainly concentrated in the coastal areas of the peninsula, Rizhao, Weifang, Linyi and Zibo during the period from 2001 to 2015, accounting for 36.05%. Based on annual-scale data, the NDVI showed an overall improvement trend, with significant increases in spring and autumn. However, predictions indicated that the degraded area would account for 37.18% in the future. In addition, meteorological factors were found to influence vegetation growth differently depending on the season. This study demonstrated a complete and reliable framework for effectively reflecting regional vegetation changes. It is recommended for application in large-scale areas to guide agricultural and ecological management.