## 5 Conclusions  
This study focuses on Laibin City and uses Landsat and Sentinel-2 remote sensing data for drought analysis. Obtain remote sensing images from the official websites of USGS and ESA, and produce NDVI and LST data. Through correlation analysis, TVDI was selected as the drought monitoring indicator to monitor vegetation drought in Laibin City from 2021 to 2023. Draw the following conclusion:  
1. TVDI was compared with RVI, NDWI, and VTCI indices in Pearson correlation analysis and Kendall's tau-b correlation analysis, and showed a strong negative correlation with soil relative humidity data, demonstrating the applicability and superiority of TVDI in drought monitoring in Laibin City. 2. From the perspective of spatial changes, Laibin City experienced varying degrees of drought between 2021 and 2023. In July 2021, the area experiencing severe drought was the largest, accounting for 57.06%, primarily in the southwest and central-eastern regions. From April to November, the area affected by moderate drought exceeded 45%, with September and November seeing over 70% of the area affected. The area experiencing mild drought was the largest in March, accounting for 60.85%. In January and February 2022, the area affected by mild drought or worse was extensive, and in June, the proportion of severe drought reached 87.89%, the highest in the past three years. The drought persisted from July to November, with conditions easing in December. In January 2023, there was no drought, but from February to September, moderate drought was prevalent. The areas affected by severe and moderate drought in June and August were the largest during the year. The drought situation eased in October, with mild drought prevailing in November, and in December, 73.12% of the area was affected by moderate drought, marking the only significant drought in December over the past three years. From the perspective of temporal changes, the drought situation in Laibin City from 2021 to 2023 mainly manifests as mild and moderate droughs, with less severe droughs. The period from April to October every year is a period of frequent droughs, with moderate droughs occurring in August for three consecutive years. There is less drought in winter, and there have been no droughs above the mild level in January and March during these three years. According to TVDI data, the average annual TVDI values for 2021, 2022, and 2023 are 0.61, 0.59, and 0.58, respectively, indicating a relatively stable drought trend. Laibin City is located in a monsoon-affected area, where there is a lack of water vapor transport in summer and autumn. In addition, long sunshine hours and high evaporation lead to frequent droughs, which have an impact on the ecological environment and agricultural economy. The significant changes in drought severity in Laibin City between 2021 and 2023 may primarily be attributed to its location in a monsoon-affected area, where rainfall distribution is extremely uneven, leading to a lack of water vapor transport during summer and autumn. The subtropical region where Laibin City is situated features long sunshine hours, high relative temperatures, and a high average evaporation rate. These factors, when combined, have resulted in frequent droughs during summer and autumn in Laibin City. In 2021, most regions of the world experienced greater drought than usual.The precipitation pattern in 2021 was influenced by climate change and La Nina events, leading to river flows below the long-term average. This climate change has had a more severe impact on the ecosystems of arid regions. These studies underscore the influence of climate change on the regional differentiation characteristics and driving factors of arid regions, further corroborating the close relationship between climate change and drought. This study employed Landsat series remote sensing imagery and the TVDI index to monitor and analyze vegetation drought in Laibin City from 2021 to 2023.