**3. Results**

The aim of this research is to quantify how a large, tropical, coastal region with estuarine-dependent fisheries has spatially and temporally changed in a period of 14 years (2004–2017). We used four methods of change detection in the analysis.

#### *3.1. Post Classification Change Analysis*

Our post-classification change detection analysis for the Rocky Dam Creek/Cape Palmerston National Park region with images from 2004 and 2017 quantified the amount of change in each land cover type (Figure 5). Information classes with a positive change demonstrated an increase in percentage area, and those with a negative change described a decrease. A positive change was apparent for four of the information classes: cropping/grazing (0.45%, 1329 hectares); oceanic (14%, 13,280 hectares), the large variability for the oceanic class can be explained by the time of day the two images were taken (the 2004 image was captured at low tide and the 2017 image was captured at high tide) (Table 1); saltpan (1.69%, 1565 hectares); and sand flat (0.12%, 126 hectares). A negative change occurred for five of the information classes: open forest (−0.05%, −1851 hectares), mangrove forest (−3.31%, −1147 hectares), estuarine wetland (−3.88%, −1496 hectares), bare mudflat (−5.49%, −2627 hectares), and saltmarsh grass (−3.65%, −1551 hectares) (Table 5). Notably, we found a low occurrence of saltmarsh grass within the park boundary. The overall classification accuracy and Kappa coe fficient for 2004, 2006, 2009, 2013 2015, and 2017 land cover maps were 85%, 88%, 88%, 89% 81% and 92%, respectively, which were acceptable accuracy levels (Table 4; Tables S1 and S2 in Supplementary Materials). These values represent the general precision level that can be expected in mapping LULC when using the supervised classification technique.

**Figure 5.** Land use di fferences between 2004 and 2017 at Rocky Dam Creek/Cape Palmerston National Park.


**Table 5.** Post-classification change statistics for five land use classes: mangrove forest, estuarine wetland, saltmarsh grass, bare mudflat, and saltpan at Rocky Dam Creek/Cape Palmerston National Park.
