## 3 Results
### Image Classification  
The classification maps for the years 1973, 1990, 1995, 2000, 2009, and 2020 show the LULC changes in Chwaka Bay in the last 47 years (Figure 3). Figure 4 depicts the percentage area covered under each class, i.e., water, bare land, mangroves, agriculture, and other forests in Chwaka Bay in 1973, 1990, 1995, 2000, 2009, and 2020. Significant LULC changes can be observed from one period to another, e.g., bare land, mangrove forests, agricultural land, and other forests in 1973 occupied, c., 8%, 24%, 19%, and 22%, respectively, but by 2020, they occupied, c., 9%, 12%, 35%, and 17%, respectively. Therefore, by the year 2020, only a portion of the mangrove forests remained, which is about half the area covered by mangroves in 1973. Between 1973 and 2020, the area covered by water increased by, c., 3%.  
Figure 5 shows the distribution of LULCs in Menai Bay between 1973 and 2020. It can be observed from the 1973 land cover map that mangroves and other forests were distributed over the study area, but in 2010 and 2020, mangroves and other forests were cleared. The 2020 map shows that only a narrow strip of mangroves remained in a southwest-northeast direction. Only a handful of other forests remained in the northern part of the study area.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & **Band 1** & **Band 2** & **Band 3** & **Band 4** & **Band 5** & **Band 6** & **Band 7** \\ \hline Band 1 & \(\longleftarrows\) & 0.99 & 0.98 & 0.99 & 0.68 & 0.79 & 0.90 \\ Band 2 & \(\longleftarrows\) & 0.98 & 0.99 & 0.66 & 0.78 & 0.89 \\ Band 3 & & \(\longleftarrows\) & 0.99 & 0.78 & 0.87 & 0.92 \\ Band 4 & & & \(\longleftarrows\) & 0.71 & 0.82 & 0.93 \\ Band 5 & & & & \(\longleftarrows\) & 0.96 & 0.87 \\ Band 6 & & & & & \(\longleftarrows\) & 0.96 \\ Band 7 & & & & & & \(\longleftarrows\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Pairwise correlations between Landsat bands for the scene covering Chwaka Bay and Menai Bay in Unguja, Zanzibar.  
Figure 4: Percentage coverage of land use and land cover in Chwaka bay in 1973, 1990, 1995, 2000, 2009, and 2020; W—water, OF—other forests, MF—magnrove forest, BL—bare land, and A—agriculture. Error bars are 95% confidence intervals.  
Figure 3: Classified land use and land cover maps for the years 1973, 1990, 1995, 2000, 2009, and 2020—Chwaka bay, Unguja, Zanzibar.  
The dynamics of the LULCs in Menai Bay, for the years 1973, 1990, 1995, 2000, 2009, and 2020, are shown in Figure 6. In 1973, mangrove forests occupied 18.4% of the study area, but by 2020, only 13.2% remained. Agricultural land and bare land increased from 21.5% to 43.8% and 12.4% to 15.3%, respectively, while water and other forests declined from 27.4% to 19.6% and 20.3% to 8.1%, respectively. Mangrove forests showed a decrease of 5.2%.  
Figure 5: Classified land use and land cover maps for the years 1973, 1990, 1995, 2000, 2009, and 2020—Menai Bay, Unguja, Zanzibar.  
Figure 6: Percentage coverage of land use and land cover in Menai Bay in 1973, 1990, 1995, 2000, 2009, and 2020); W—water, OF—other forests, MF—magnrove forest, BL—bare land, and A—agriculture. Error bars are 95% confidence intervals.