Air is then breathed into the windpipe and lungs, while the mucus is swallowed (figure 3). Other. Other interesting structures associated with the nasal and sinus tract: Tear duct (called the nasolacrimal duct): drains tears from the inside corner of the eye into the nasal cavity (figure 1).
Human activity is the main cause of soil degradation. Agriculture plays a large part in soil degradation, especially clearing, irrigation, the spreading of chemical fertilizer â¦ s and pesticides, overgrazing and even the passage of heavy farming equipment. Tillage and the clearing and deforestation of large plots of land also lead to soil degradation.
Wind erosion. Wind erosion is a common cause of land degradation in the arid and semi arid grazing lands of inland Queensland. It is one of the processes leading to desertification. Significant wind erosion occurs when strong winds blow over light-textured soils that have been heavily grazed during periods of drought. Wind erosion is also a natural process.