Natural and human processes such as deforestation, agriculture, urban expansion and mining transform land cover at local to global scales.

What this dot point is asking

Land cover means the observable biophysical surface of the Earth: forests, grasslands, wetlands, croplands, bare ground, ice, water and built-up areas. It differs from land use, which is the human purpose for which land is employed, such as recreation or housing. The same land cover can serve different uses, and changing land use usually changes land cover. This unit focuses on how and why land cover changes, the rate and extent of that change, and its consequences.

Land cover changes through natural processes, including climate variation, glacial advance and retreat, volcanic activity, natural fire regimes and ecological succession. But over the past few centuries, and especially since 1945, human processes have become the dominant driver at a global scale. The principal anthropogenic processes are deforestation (clearing forest for timber, farming or development), the expansion and intensification of agriculture (converting natural vegetation to crops and pasture and farming it more intensively), rangeland modification and overgrazing, irrigation and land drainage (altering wetlands and water tables), land reclamation, urban expansion (spreading built surfaces over vegetation and soil) and mining (stripping vegetation and reshaping land).

These processes operate at different rates and extents. Deforestation in the Amazon and Southeast Asia clears vast areas rapidly for cattle and crops such as soy and oil palm, while urban expansion permanently seals land under buildings and roads near growing cities. Agriculture is the single largest cause of global land cover change, as natural ecosystems are converted to feed a growing, wealthier population. The scale is now so extensive that geographers argue no truly natural environments remain; all have been modified to some degree, producing anthropogenic biomes, or human-shaped landscapes.

Tasmania offers clear, locally relevant examples. European settlement transformed the Midlands and other lowlands from native grassy woodland to grazing and cropping land, fragmenting habitat. Conversion of native forest to plantation forestry and the clearing of land for agriculture have changed cover across parts of the state, contested between the timber and farming industries and conservation interests. Hydro-electric development flooded valleys such as the area around the original Lake Pedder, replacing land cover with water. Urban expansion around Greater Hobart and Launceston continues to convert farmland and bushland to built-up area, while mining at sites such as those on the west coast has stripped and reshaped land.

Detecting and measuring land cover change relies on spatial technologies. Satellites such as Landsat provide repeat imagery that, when compared across decades, quantify how much forest, farmland or built-up area has changed and how quickly. Geographic information systems layer this with other data to analyse drivers and consequences. You should be able to interpret such images, classify land cover types and describe patterns of change.

For TCE assessment, identify the processes transforming land cover in a given place, classify them as natural or anthropogenic, describe the rate and extent using imagery or data, and link them to drivers such as population, agriculture and economic demand. A Tasmanian example such as forest conversion or hydro flooding paired with a global case such as Amazon deforestation gives the range examiners expect, and sets up analysis of climate and biodiversity consequences.