*4.3. Land-Cover Conversions*

From the outset, areas of dense dry forest and open forest have decreased from 10,722.53 km<sup>2</sup> and 17,547.75 km<sup>2</sup> to 7704.97 km<sup>2</sup> and 10,515.96 km2, respectively, between 1985 and 2000. During the same period, areas of crops/fallow and savannah have increased from 11,940.55 km<sup>2</sup> and 14,533.13 km<sup>2</sup> to 14,179.42 km<sup>2</sup> and 23,379.66 km2, respectively. Thus, we note a 3017.56 km<sup>2</sup> contraction for dry dense forests and 7031.80 km<sup>2</sup> of open forests, while crops/fallow lands expanded by 2238.86 km<sup>2</sup> and savannahs by 8846.53 km2. In 2020, these main classes occupied only 3785.27 km<sup>2</sup> for dense dry forests and 9709.70 km<sup>2</sup> for open forests, but 21,677.56 km<sup>2</sup> for crops/fallows and 20,146.17 km<sup>2</sup> for savannahs. These classes represent 6.68%, 17.13%, 38.25%, and 35.55%, respectively, of Togo's land surface area.

These changes correspond to a reduction of 64.70% of dense dry forests and 44.67% of open forests, versus an 81.55% increase in crops/fallows and 38.62% in savannahs compared to their respective starting areas. The water body area increased considerably between 1985 and 1990, through the construction of a large hydroelectric dam at Nangbeto in the southeastern part of the country (1987), together with the creation of other small water reservoirs. Built-up (buildings) and bare land (bare soil) class areas increased by +300%, from 281.79 km<sup>2</sup> in 1985 to 876.40 km<sup>2</sup> in 2020. In short, all land cover has changed during the period covered by the study, with a decrease in areas of dense dry forest and open forest, accompanied by a sharp increase in the areas of crops/fallow lands and savannahs. For illustrative purposes, the conversions from one land cover to another, as well as areas that were retained and not changed during the 2015 to 2020 period, are shown in Figure 5. The same types of charts for other time periods (1985 to 1990, 1990 to 2000, and 2000 to 2005) are provided (Figures A1–A3) in Appendix C.

**Figure 5.** Land-cover conversions that occurred between 2015 and 2020.

Maps of the changes were then produced (Figure 6) by combining all classes that had undergone conversions on one hand, and all those that had not undergone conversion during the periods that were considered on the other. The change map between the 2005 and 2015 classifications was not produced because images of the first four target years have one more land-cover class (i.e., clouds) than the last two. Therefore, the application of the change detection algorithm between these two years (with a different number of land-cover classes) generates several hybrid classes that do not reflect the situation on the ground.

### **Figure 6.** LULC change maps.

### *4.4. Evolution of Forest Cover*

When considering only dense dry forest and open forest classes, their respective starting areas were 10,722.53 km<sup>2</sup> and 17,547.75 km<sup>2</sup> in 1985, i.e., 18.92% and 30.97% of the nation's total territory. Under the effects of land-cover change, they have decreased to 16.05% and 25.37% in 1990, 13.60% and 18.56% in 2000, 15.01% and 18.42% in 2005, 7.39% and 15.09% in 2015, and to 6.68% and 17.13% in 2020. With an area of 3785.27 km<sup>2</sup> for dense dry forests and 9709.70 km<sup>2</sup> for open forests in 2020, forest areas have thus declined by 12.24% for the first category and 13.83% for the second, i.e., a total of 26.07% at the national level during the 35 years covered by this study. Details on the quantification of these two land covers in the different ecological zones and their changes over time are indicated in Appendix D (Table A3).

To facilitate the subsequent quantitative analysis of forest cover change, we have cumulated the two aforementioned occupancy classes to form the forest class. The trend line (Figure 7) that summarizes the percentage change in forest area relative to that of the country illustrates the degree of deforestation and forest degradation over the period that was considered. Forest area distributions as a land-cover percentage by ecological zone and by target year were estimated (Figure 8).

When we explored the data at the level of ecological zones to determine how these forest areas have changed through time, we noted that the deforestation or degradation of these forests has not proceeded at the same rate in these ecosystems. The evolutions of forest areas in the different ecological zones were illustrated by the distribution maps of forest cover of the target years from the period from 1985 to 2020 (Figure 9).

In ecological zones I, II, and III, these forested areas declined almost continuously from 1985 with a cumulative loss until 2020 of 16.73%, 48.62%, and 28.66%, respectively, compared to their starting size in these areas. We can, nevertheless, note a forest area recovery in the 2015 to 2020 period in zone I and between 2000 and 2005 in zone II. Zone IV (the smallest ecological zone) experienced a sharp decline in forest area (18.35%) between 1985 and 1990, followed by a smaller loss (7.41%) between 1990 and 2000, prior to its recovery and then contraction (to 1.58%) from 2015 to 2020. Zone V is characterized by a 30.49% loss of forest area between 1985 and 1990, then a rapid increase in area (21.73%) for a decade (1990–2000). These areas continued to increase until 2005 and then declined slightly from 2005 to 2015 before increasing again to 29.2% of the total area in 2020.

The finer-scale examination (zooming) of the maps produced from the results (Figure A4) in Appendix E shows the development of two towns (Sokodé and Tchamba), as well as the Abdoulaye Forest Reserve between 1985 and 2020. We noted the expansion over time of both these towns and agriculture, as well as the appearance of small new settlements at the expense of wooded areas. As a result of these two main factors, the average annual rate of change of forest cover to other land cover is about −2.11% between 1985 and 2020, leading to the disappearance of more than half of the forest areas during this period.

The results of calculating the annual rate of change in forest cover and annual deforestation between individual target years, and from the beginning to the end of the study period are shown (Table 7).

### *4.5. Land-Cover Changes at the Administrative Regions Scale*

Following the analysis of land-cover conversions at the national level and the evolution of forest cover in the ecological zones, the quantification of all changes that have occurred at the level of the administrative regions was mapped (Figure 10).

**Figure 7.** Countrywide forest percentage changes.

**Figure 8.** Forest change by ecological zone.

**Figure 9.** Forest evolution across ecological zones by target year.


**Table 7.** Evolution of forested areas between 1985 and 2020.

**Figure 10.** (**A**) Land-cover change gradient by region from 1985 to 2020; (**B**) area unchanged; (**C**) area with one to two changes; and (**D**) area with three to four changes.

In all of these administrative regions, original land covers were retained in part during the period covered by the study (Figure 10A). For those remaining parts where the land cover was altered, they had undergone at least one, two, three, or four changes between

1985 and 2020. Visual inspection reveals that parts where little or no change had been experienced were mostly forested areas (e.g., from the northeast to southwest), urban areas such as the national capital Lomé, and large bodies of water such as Lake Togo in the extreme south of the country. The Plateaux administrative region retained the most area (16.69%) of this land cover that had never changed (Figure 10B). This region is followed by the Centrale (11.48%), Kara (9.09%), and Maritime (6.12%) regions, while the Savanes region has the smallest proportion (2.84%) of its area not being affected by change over the 35-year period.

It can be observed that 65.75% of the Savanes region has undergone at least one to two changes in land cover (Figure 10C). In the Kara, Centrale, and Plateaux regions, slightly more than half of their respective areas have been similarly affected. In contrast to the areas by region that have never undergone change, the Maritime region has the largest percentage of the regional area (53.50%) that has undergone at least three to four land-cover changes (Figure 10D). For the same locations, land-cover changes have occurred more rapidly in the Maritime, followed by the Centrale (36.59%), Kara (34.98%), (31.44%), and Savanes (31.41%) regions.
