Spatial and temporal analysis of drought resistance of different vegetation in the Ta-pieh Mountains based on multi-source data

Abstract This study focuses on the ecological and environmental safety of Ta-pieh Mountain. Drought episodes can lead to ecological problems such as vegetation damage. Therefore, quantifying the response of vegetation to drought is essential for ecological management. The study utilized normalized difference vegetation index (NDVI) and precipitation datasets from 1999 to 2019 to derive seasonal NDVI and standardized precipitation index (SPI) data. Using Theil-Sen median trend analysis and Mann-Kendall significance test analysis, we initially examined the characteristics of vegetation and drought for the 21-year time series. SPI is used to investigate and assess the occurrence and severity of drought in the research region. Then, the strength and variability of cropland, woodland, and grassland drought resistance in the Ta-pieh Mountains were discussed using the ratio of coefficient of variation (RCV). Finally, the cross-spectrum was used to calculate the vegetation lag time to drought. The study found that NDVI increased across all seasons, while SPI increased in spring and autumn and decreased in summer and winter. The spring drought had the most significant impact on vegetation. Cropland showed the highest improvement in drought tolerance and woodland showed the highest drought tolerance. The lagged response periods of cropland, woodlands, and grassland to drought were 1.62 months, 8.94 months, and 2.49 months, respectively. These findings provide a scientific basis for the management and preservation of the ecology of the Ta-pieh Mountains.