Spatiotemporal dynamics of the vegetation in Ningxia, China using MODIS imagery

Abstract

The vegetation in the Ningxia Hui Autonomous Region (henceforth, Ningxia) of north-western China plays an important role in guarding regional ecological safety and sustainable development. However, it is unclear how climate affects vegetation growth in terms of seasonality and various vegetation types in Ningxia. Based on remote sensing vegetation index from 2001 to 2016, climatic parameters, and the Chinese vegetation type data, this article examines the spatiotemporal effects of climate parameters on vegetation. The relative importance to variability in the normalized difference vegetation index (NDVI) for different seasons and various vegetated types is also determined. The results demonstrate that the vegetation increased from 2001 to 2016 in Ningxia. The rate of NDVI increase was fastest in summer and slowest in spring. Areas with significant increases in vegetation occurred primarily in the southern mountain, Liupan Mountain, and central arid areas. Degraded vegetation occurred in the Yellow River irrigation area with intense human activity influence. The vegetation in most areas of Ningxia will continue to increase in the future. The sensitivity of vegetation to temperature, precipitation, sunshine duration, and wind velocity showed significantly seasonal variability. Sunshine duration and wind velocity were important climatic factors affecting vegetation growth in Ningxia. However, the impact of summer precipitation variation on summer NDVI (SMN) demonstrated a time lag effect. The impact of climate variation on vegetation was distinct among various vegetation types. Moreover, the spatial pattern of vegetation in Ningxia was also impacted by human activities.