|
Abstract:
|
[Objective] To explore the Guangxi Xijiang River Basin change rule and influence factors of autumn drought. [Result] The autumn drought in the study area increase gradually from 9 month to 11month. The main area of heavy drought in the distributed in the northeast, the drought distribution from the north to the south of diminishing trend. TVDI change trend of average was 0.33%, high value area distribution in the northwest and southeast, central is low. The proportion of karst area drought for 76.66%,the proportion of semi-karst area drought for 71.9%,and the proportion of non-karst area drought for 68.1%, Karst area drought ratio is greater than the non-karst area. Drought distribution of Guangxi Xijiang River Basin significantly affected by altitude. With the rise of altitude, drought area ratio showed an increasing trend.[Conclusion]Even though the most study got TDVI from NDVI-LST feature space, TVDI calculated from EVI-LST feature space could also be suitable for drought monitoring. EVI－LST feature spaces established in this paper accorded with triangular relationship. Previous studies have shown that TVDI can be used in one-day drought monitoring ,but this study shows that TVDI is also fit for long-time drought monitoring. From the drought comparison between September and November, the conclusion can also be drawn that TVDI can be applied for dynamic drought monitoring. TVDI can be greatly used in drought early warning and monitoring of Guangxi Xijiang River Basin, this method can be used in long-term and large-scale drought monitor and forecast in real-time.
|
