## 3 Results
### TCs Impacts: Emily, Stan, Wilma, and Dean
#### 3.2.3 Enhanced Vegetation Index (EVI) Spatial Patterns  
The EVI captured distinct changes in vegetation coverage after TC passage as shown in similar studies when assessing vegetation phenology or landscape-level vegetation differences [77; 90]. A reduction of EVI was associated with TC strength; higher values (29%) were registered after Wilma and throughout the YP as result of Dean's (20%) and Emily's (7%) impacts (Figure 7B). These values contrast with a minor impact by Stan as shown by limited changes after landing. Vegetation changes due to Emily show a decline in a narrow area where TC winds were above 119 km/h for periods before (11-27 July 2004) and after landfall (12-28 July 2005). These changes depict a wide 63 km/h and 119 km/h radii, which are derived as the average from four directions, in the NHC chronology [63]. The most significant loss is just to the right (northeast) of Emily's track, where speeds were nearly 119 km/h; the highest speed (180 km/h) occurred 24 km from the circulation center. In contrast, a limited decline in vegetation was observed to the left (southwest) of the storm core over western Yucatan, southern Quintana Roo, and Campeche.  
Wilma's maximum winds ranged from 222-241 km/h (Figure 5) and covered most of the YP northeastern tip. Areas with speeds above 119 km/h, and in the range of 63-119 km/h (tropical storm strength), comprised 14% and 48% of the YP total area, respectively. Wilma crossed Cozumel with approximately 215 km/h where a well-developed TC had an eye (Figure 6). In addition to the intense core, Wilma's main damage to infrastructure was compounded by slow motion, with rates under 10 km/h, thus lasting longer over land (>24 h) before exiting the YP along the GOM and the Yucatan Channel. Most of the EVI changes occurred inside a wind-speed band above 119 km/h (Figure 7B); beyond this band (western Yucatan and in Campeche), only limited vegetation losses or gains were observed.  
In the case of Dean, most of the vegetation losses were within 100 km from the Caribbean coast where mangrove forests were defoliated along the southern coast of Quintana Roo [91; 92]. Wind speeds over the YP, southern Quintana Roo, and central Campeche were above 119 km/h across a radii ranging  
Figure 8: Daily discharge (m\({}^{3}\)/s) (dark line) and long-term average (dotted gray line) at the Canasayab, Champion River gauge station during the passage of tropical cyclones Emily (**A**), Dean (**B**), Stan (**C**), and Wilma (**D**). The long-term average was computed from daily observations in the period from 1956–2014. The asterisk and dot symbols mark values at landfall; in blue is the net difference between the discharge value and the long-term average. Panels **C** and **D** show two net values due to the asynchrony between landfall time and the discharge response. The river catchment area is 2583 km\({}^{2}\) while the gauge station drainage area is 2330 km\({}^{2}\).  
from 50 to 150 km. In contrast, Stan's impact was minor and practically no areas with vegetation loss or gain were observed, even when speeds were in the range of 63-119 km/h while covering 24% of the YP. Comparatively, EVI profiles along the Emily (Figure 9A), Stan (Figure 9B), Wilma (Figure 9C), and Dean (Figure 9D) tracks revealed distinct differences. Yet, EVI averaged values were lower after landfall within the first 50-100 km, resulting in a net reduction in all four cases (Wilma: 29%, Dean: 20%, Emily: 7%, Stan: 2%; data not shown).