# Assessment of Drought Severity and Vulnerability in the Lam Phaniang River Basin, Thailand
## 4 Conclusions  
This study assessed future climate and land use change impacts on drought severity and vulnerability of the Lam Phaniang River Basin. Based on the future simulations (2021-2100) of three GCMs, i.e., CNRM-CM5, EC-EARTH, and NorESM1-M under RCPs 4.5 and 8.5, against baseline (2000-2017), it was found that the average results of future rainfall, and maximum and minimum temperatures were expected to increase by 1.41 mm, and 0.015 \({}^{\circ}\)C/year and 0.019 \({}^{\circ}\)C/year, respectively, under RCP 4.5 and by about 2.72 mm, and 0.034 \({}^{\circ}\)C/year and 0.044 \({}^{\circ}\)C/year, respectively, under RCP 8.5. For change detection over the previous years (2010 to 2015), future land use from 2021 to 2100 were predicted. It was found that compared to the 2015 baseline, field crops would continue to decrease significantly through 2100 with a tremendous increase by 296.3 km\({}^{2}\) during 2081-2100, while in contrast perennial crops would continue to increase remarkably through 2100 with a maximum decrease by 335.5 km\({}^{2}\) during 2081-2100. The WEAP model was then applied in combination with downscaled climate and land use projections to indicate how the future status of water shortage would change due to ongoing changes. The WEAP simulation results revealed that compared to baseline, future annual water demand was projected to decrease by up to 31.81% under RCP 8.5 during 2061-2080. Consequently, a decrease of future water shortage seems to occur in which a maximum decrease of 51.61% was found during 2061-2080 under RCP 8.5 compared to baseline. The outputs of GCMs coupled with WEAP model and SPEI drought index were used to assess the drought risk at 3-, 12-, and 24-month time scales for the Lam Phaniang River Basin. For a better understanding of the spatial characteristics of drought risk prone areas, drought risk maps were created. Based on a river basin-wide assessment, the spatial pattern of drought risk tendency revealed that the Lam Phaniang River Basin is exposed to future climate and land use changes to varying degrees. Clearly, the vast majority of the upper and lower parts were dominated by low and moderate risk levels at all time scales under both RCP 4.5 and 8.5. In the central part, during 2021-2040, a very high risk level of the 12- and 24-month time scales under both RCP 4.5 and 8.5 was found especially in Na Wang District (Na Kae, Wang Pla Pom, and Wang Thong Sub-districts), Na Klang District (Dan Chang, Fang Daeng, and Uthai Sawan Sub-districts), and Nong Bua Lamphu Province. During 2041-2060, a very high risk level of the 12- and 24-month time scales under only RCP 8.5 was concentrated particularly in Na Wang District (Na Kae and Wang Thong Sub-districts), Na Klang District (Dan Chang, Fang Daeng, and Uthai Sawan Sub-districts), and Nong Bua Lamphu Province. For the period 2061-2080, the high drought risk level was identified at all time scales only under RCP 4.5, while low and moderate levels were determined at all time scales under RCP 8.5. Over the period 2081-2100, the drought risk decreases to low and moderate levels at all time scales under both RCP 4.5 and 8.5. The overall