Erosion is a natural process that forms part of the lifecycle of sites, resulting from the action of wind or water. It can refer to the gradual wearing away of a site or of the ground itself, revealing previously buried parts of a site, or the burial of a site by eroded earth. In some parts of Egypt, for example, the changes in ground level have been so extreme, entire pyramids have been buried! It is only when part of the site is actually removed that it is considered to cause damage, although revealing previously buried parts of sites can place them at increased risk. Here are five examples of natural erosion:

Figure 1: This DigitalGlobe satellite image from September 2009, viewed on Google Earth, shows the erosion of Krokodilo Roman Fort in Egypt, which has been gradually washed away by the wadi to the north.

Figure 2: This DigitalGlobe satellite image from February 2014 shows the site of Sabratha in Libya, which is slowly washing away into the sea.

Figure 3: Mudbrick, a common building material throughout history for much of the Middle East and North Africa, is particularly susceptible to erosion caused by rain. This aerial photograph of the site of Nippur in Iraq in September 2005 shows large sections of the site washing away (APAAME_20050926_GK-3557 Nippur).

Figure 4: This 2005 aerial photograph shows Moukha al-Zeblijah (also known as Zibliyat), in Iraq, thought to be a ruined mudbrick tower that has mostly washed away (APAAME_20050604_GK-0130 Moukha Al-Zeblijah (Zibliyat)). The entire site of Zibliyat, of which this large tower is a part, measures over 2,000m north–south, and 800 m east–west.

Figure 5: This 2008 aerial photograph shows the site of Qasr el-Aseikhim, in Jordan (APAAME_20080909_DLK-0201 Qasr el-Aseikhim). As can be seen, the stone walls have slowly collapsed from erosion. In addition, the visible track was caused by a bulldozer going through the walls (see Bulldozing). The people in the right of the image are probably illegal looters.