## 4 Results  
### Monitoring and Assessing the 2009 Drought in Victoria  
Figure 3 shows the temporal dynamics of all the studied variables during the 2009 drought period (from January to March) for general Victoria region (Figure 3a), crop land (Figure 3b) and evergreen broadleaf forest land (Figure 3c). According to Figure 3a, Victoria experienced a fairly higher temperature and a lower rainfall than the historical mean values in January 2009. The inter-annual precipitation variation is strong (large standard deviations), which indicates the extent of rainfall variation changes dramatically in Victoria. High temperatures and drops in precipitation rapidly depleted soil moisture through evapotranspiration, causing a severe reduction in vegetation productivity ([PERSON] et al., 2017). GPP, SIF, APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) showed a decreasing tendency from January 2009 to March 2009. GPP and SIF from January to March for 2009 were lower than their historical averages for 2007-2013. On the contrary, both APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) were slightly higher in January 2009 relative to their multiyear means. SIF decreased by approximately 17.2% in February 2009, which was much higher than the declines in APAR\({}_{\text{NDVI}}\) (6.9%) and APAR\({}_{\text{EVI}}\) (5.9%). The relative SIF and GPP anomalies decreased more sharply from January 2009 to February 2009 than did the relative APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) anomalies from January to February for general Victoria region. For crop land (Figure 3b), SIF, APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) showed similar relative anomalies in January 2009. Yet SIF decreased by approximately 20.1% in February 2009, which was higher than the observed decreases for APAR\({}_{\text{NDVI}}\) (9.7%) and APAR\({}_{\text{EVI}}\) (7.5%). Regarding evergreen broadleaf forest land (Figure 3c), APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) exhibited positive relative anomalies in February 2009, while SIF decreased by approximately 11.3% and GPP decreased by approximately 8.5%. These results indicate that the relative GPP anomaly had a more consistent change with the relative SIF anomaly than with the relative APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) anomalies, especially for evergreen broadleaf forest land. The spatial and temporal variations of the normalized anomalies of all the considered variables in Victoria from January to March 2009 are shown in Figure 4. It is seen that Victoria was struck by extremely high temperature in January 2009, and part of the Victoria area showed drought stress which was indicated by the normalized anomalies of vegetation proxies. In February 2009, the temperature was lower than the multiyear mean temperature while the water availability was still deficient, which indicates the persistence of drought stress in Victoria. Both GPP and SIF showed drought-induced anomalies in most areas of Victoria. In southeastern Victoria, where evergreen broadleaf forest consists of the main vegetation type (Figure 1), the normalized APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) anomalies exhibited more positive anomalies than did SIF anomaly in February 2009. These results indicate that during the studied 2009 drought event, APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) are less sensitive to meteorological drought stress compared with SIF in evergreen broadleaf forest land. In March 2009, drought stress was not completely alleviated. The normalized APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) anomalies indicated that drought still persisted in Victoria except for most evergreen broadleaf forest areas. Figure 5 shows the statistics of anomalous areas calculated by the normalized GPP, SIF, APAR\({}_{\text{NDVI}}\) and APAR\({}_{\text{EVI}}\) anomalies based on the results, shown in Figure 4. Figure 5a shows the percentages of negative and positive anomaly areas calculated by all pixels located in the general region of Victoria.