## 5 Discussion  
### Effects of Factors on Vegetation Vulnerability in the MRB  
All cases of projected vegetation show high vegetation vulnerability, even under the lowest emissions scenario, the indicators identify extensive areas of potentially substantial ecological change [5]. Our vulnerability results agree with a vulnerability analysis based on potential novel climates in Africa [34]. Vegetation changes may alter the provision of ecosystem services [35], possibly affecting the livelihoods of many people. The Mara River Basin is a vegetation vulnerability area in East Africa, and the balance between social development and vegetation protection is not good [23]. The Mau Forest in the upstream was severely vulnerable for the base period and was severely vulnerable for the near future period and distinct future period. In recent years, the Mau Forest has been extensively transformed into farmland for agricultural development [17], increasing the vegetation vulnerability of the forest. Therefore, under the SSP5-8.5, which is the most significant \begin{table}
\begin{tabular}{c c c c c c} \hline  & & \multicolumn{5}{c}{**Base Period**} \\ \cline{3-6}  & & **Mild** & **Moderate** & **Severe** & **Extreme** \\ \hline \multirow{4}{*}{Near future period SSP1-2.6} & Mild & 1427.61 & 1057.06 & 73.70 & 0.08 \\  & Moderate & 1676.52 & 1379.37 & 503.02 & 86.39 \\  & Severe & 22.74 & 1289.47 & 464.29 & 954.46 \\  & Extreme & 0.00 & 106.47 & 1559.48 & 455.86 \\ \hline \multirow{4}{*}{Near future period SSP2-4.5} & Mild & 1351.47 & 1024.37 & 73.73 & 0.13 \\  & Moderate & 1752.05 & 1041.04 & 415.79 & 102.43 \\  & Severe & 24.24 & 1496.44 & 424.03 & 901.02 \\  & Extreme & 0.00 & 170.01 & 1687.06 & 493.15 \\ \hline \multirow{4}{*}{Near future period SSP5-8.5} & Mild & 1338.22 & 979.58 & 68.75 & 0.05 \\  & Moderate & 1752.92 & 959.38 & 309.23 & 73.93 \\  & Severe & 36.71 & 1413.57 & 544.01 & 795.42 \\  & Extreme & 0.00 & 379.88 & 1678.56 & 625.36 \\ \hline \multirow{4}{*}{Distinct future period SSP1-2.6} & Mild & 1459.88 & 1094.89 & 76.52 & 0.13 \\  & Moderate & 1660.31 & 1041.00 & 513.20 & 86.40 \\  & Severe & 7.25 & 1410.49 & 585.67 & 836.62 \\  & Extreme & 0.00 & 187.05 & 1425.16 & 573.64 \\ \hline \multirow{4}{*}{Distinct future period SSP2-4.5} & Mild & 577.33 & 480.51 & 28.75 & 0.00 \\  & Moderate & 2535.59 & 1406.58 & 445.61 & 35.13 \\  & Severe & 16.63 & 1435.84 & 496.37 & 780.14 \\  & Extreme & 0.00 & 407.28 & 1628.81 & 679.34 \\ \hline \multirow{4}{*}{Distinct future period SSP5-8.5} & Mild & 506.43 & 502.26 & 40.70 & 0.00 \\  & Moderate & 2604.85 & 983.15 & 293.66 & 15.30 \\ \cline{1-1}  & Severe & 18.47 & 1584.28 & 493.95 & 373.88 \\ \cline{1-1}  & Extreme & 0.00 & 660.82 & 1771.22 & 1108.06 \\ \hline \end{tabular}
\end{table} 
Table 6: Stochastic matrix of vegetation vulnerability of different periods in MRB. scenario for human activities, the vegetation vulnerability increased the most upstream of the MRB. There are many protected areas midstream and human activities are relatively less [36], but as the emission increased, the area of mild vulnerability decreased obviously for the near future period and distinct future period, indicating that even in areas with good protection, an increasing emission can still cause significant damage to the vegetation [22]. The vegetation vulnerability downstream increased from the base period to the near future period and distinct future period. There is Mara Mine downstream in MRB, and mining activities often grab the vegetation water [26], leading to insufficient vegetation water demand, and increasing vegetation vulnerability. The elevation of the MRB is a gradual decrease from upstream to downstream, high altitude is not conducive to water aggregation [37], so the vegetation vulnerability decreased from upstream to downstream for all periods. The high temperature and little precipitation in tropical regions are highly likely to increase the impact of drought on vegetation. Droughts have an important impact on the vulnerability in the Masai Mara [38].