Once a person is affected by a dengue virus, the platelets can no longer âactivateâ itself. So whenever there is damage, the platelets cannot form the mesh structure and the blood flows out of the vessel. As blood flows out, so does the platelets. This causes the platelet count to fall drastically. The blood that flows out causes internal. and external bleeding and leads to a haemorrhage.
1 Today, the Aswan Dam keeps the Nile from flooding modern cities. 2  The Ancient Egyptians called the Nile the Aur, which means black and comes from the black soil. 3  The Egyptians measured the height of the annual flood using a Nilometer.
nile river valley civilization The Nile River Valley Civilization started at the northern most peak of the Nile River at the time of the Neolithic Revolution. This early civilization formed down the lush fields of the Nile River. Protected by the water and desert, the civilization was able to grow into Egypt and surrounding colonies. Impact of Geography Geography for the Nile River Valley Civilization was very important. The Nile would flood each year starting in July and lasting until November. This flood would provide new, rich soil for the Egyptians and would wash away waste. The seas around the civilization served a barrier against war and disease.