# Assessment of Drought Severity and Vulnerability in the Lam Phaniang River Basin, Thailand
## 3 Results and Discussion
### Comprehensive Analysis of Drought Risk Assessment
At the 24-month time scale under RCP 8.5, the high risk level was raised to a very high level at Wang Pla Pom (Sd-5) and Wang Thong (Sd-7) Sub-districts, Na Wang District, Nong Bua Lamphu Province, whereas the other risk zones and levels were found to be the same as RCP 4.5. Figure 7: Spatial drought risk maps of the Lam Phaniang River Basin during 2000–2017 at (**a**) 3-, (**b**) 12-, and (**c**) 24-month time scales. In Figure 8b, during 2041-2060, at the 3-month time scale under RCP 4.5, the drought risk in Na Wang District, i.e., Na Kae (Sd-3), Wang Pla Pom (Sd-5), and Wang Thong (Sd-7) Sub-districts and Na Klang District, i.e., Dan Chang (Sd-6), Fang Daeng (Sd-12), and Uthai Sawan (Sd-16) Sub-districts, Nong Bua Lamphu Province, was exacerbated from a moderate to high risk level when compared to RCP 8.5, in which the risk level in the areas of Loei Province, i.e., Na Duang Sub-district (Sd-2), Na Duang District and Nong Bua Lamphu Province, i.e., Na Klang Sub-district (Sd-8), Na Klang District, and Ban Kham (Sd-23), Hua Na (Sd-26), and Pa Mai Ngam (Sd-28) Sub-districts, Mueang District, was shifted from low to moderate. Considering the 12-month time scale, the low risk level under RCP 4.5 was converted to a very high risk level under RCP 8.5 in Na Wang District, i.e., Na Kae Sub-district (Sd-3) and Na Klang District, i.e., Dan Chang (Sd-6) and Uthai Sawan (Sd-16) Sub-districts, Nong Bua Lamphu Province, while the low risk level was also transferred to a high risk level at Na Wang District, i.e., Wang Pla Pom (Sd-5) and Wang Thong (Sd-7) Sub-districts, Na Klang District, i.e., Fang Daeng Sub-district (Sd-12), Mueang District, i.e., Na Kham Hai (Sd-9), Nong Bua (Sd-20), Non Khamin (Sd-21), Nong Wa (Sd-22), and Na Mafueang (Sd-25) Sub-districts, Nong Bua Lamphu Province. At the 24-month time scale, the risk levels remained unchanged from the 12-month time scale for both RCPs 4.5 and 8.5, except the risks under RCP 8.5 in the areas of Na Wang District, i.e., Wang Thong Sub-district (Sd-7), Na Klang District, i.e., Fang Daeng Sub-district (Sd-12),  
Figure 8: Spatial drought risk maps of the Lam Phaniang River Basin at 3-, 12-, and 24-month time scales under RCPs 4.5 and 8.5 during (**a**) 2021–2040, (**b**) 2041–2060, (**c**) 2061–2080, and (**d**) 2081–2100. and Mueang District, i.e., Nong Sawan (Sd-19) and Ban Pharo (Sd-24) Sub-districts, Nong Bua Lamphu Province, which were elevated from high to very high, high to very high, low to moderate, and moderate to high levels, respectively. Importantly, especially under the more severe RCP 8.5 scenario, the results for this period are also consistent with the near future period (2021-2040), which strongly indicates the high and very high drought risk levels for some districts located at the midstream of the Lam Phaniang River Basin. For the period 2061-2080 (Figure 8c), at the 3-month time scale under RCP 4.5, high risk was found at Na Wang District, i.e., Na Kae (Sd-3), Wang Pla Pom (Sd-5), and Wang Thong (Sd-7) Sub-districts, Na Klang District, i.e., Dan Chang (Sd-6), Fang Daeng (Sd-12), and Uthai Sawan (Sd-16) Sub-districts, and Mueang District, i.e., Nong Bua Sub-district (Sd-20), Nong Bua Lamphu Province, while the risk level at the same areas was determined to be on the moderate category under RCP 8.5. Based on the 12-month time-scale under RCP 4.5, a high risk level was only found at Na Wang District, i.e., Na Kae (Sd-3), Wang Pla Pom (Sd-5), and Wang Thong (Sd-7) Sub-districts and Mueang District, i.e., Nong Bua Sub-district (Sd-20), Nong Bua Lamphu Province, while under RCP 8.5, a moderate level was only observed at Mueang District, i.e., Nong Bua (Sd-20) and Nong Wa (Sd-22) Sub-districts, Nong Bua Lamphu Province, and the rest were low level.