Study on the Impact of Vegetation Restoration on Local Convective Activity in Kubuqi Desert

Increased vegetation alters surface soil moisture, enhances local water cycle processes, and influences land surface dynamics and atmospheric circulation. The Kubuqi Desert is one of the most successful regions in China for ecological restoration and desertification reversal. To investigate the impact of vegetation increase on local convective activity in the Kubuqi Desert, this study utilizes hourly precipitation, temperature, relative humidity data from the Kubuqi Desert and surrounding stations during 1962–2022, as well as PKU GIMMS global normalized difference vegetation index (NDVI) data during 1982–2022. The results show that both annual mean NDVI and growing-season NDVI in the Kubuqi Desert exhibited an increasing trend from 1982 to 2022, with a significant increase in the oasis area north of the Yellow River. At the Yikesu station, located in the desert hinterland, convective precipitation accounted for 80% of the total during 00:00–12:00 in the early treatment period (1982–1984), but this proportion decreased to 51.6% in the later treatment period (2020–2022), while the proportions during 13:00–17:00 and 21:00–23:00 increased to 21.0% and 15.4%, respectively. At Dengkou, Linhe, and Wuyuan stations, the occurrence time of convective precipitation was delayed in the later treatment period. Numerical sensitivity experiments show that when vegetation increases by 10%, the surface temperature in the sensitivity experiment is 0.1°C–0.4°C lower than that in the control experiment, sensible heat flux decreases by 1–24 W m?2, and the convective initiation time and precipitation onset time are delayed by 20–40 minutes. Both observational data and numerical simulations confirm that increased vegetation alters surface heat and moisture exchanges, thereby influencing the generation and evolution of convective systems.