Presentation-ch1课件.ppt

WHAT IS ENVIRONMENTAL SCIENCE?1.1 Environmental science: is defined as the study of the earth, air, water and living environments, and the effect of technology thereon. The EnvironmentAir, water, life, earth, and technology are strongly interconnected as shown in Figure below. Traditionally, environmental science has been divided among the study of the atmosphere, the hydrosphere, the geosphere, and the biosphere.;Figure 1.1. Illustration of the close relationships among the air, water, and earth environments with each other and with living systems, as well as the tie-in with technology (the anthrosphere).;The atmosphere: is the thin layer of gases that cover Earth’s surface. Altitude: 10000 kmSignificant of the atmosphere. a reservoir of the important gases, i.e Oxygen, Nitrogen and Water vapor Protector for Earth’s temperature, absorbs energy and damaging UV radiation from the sun, Serves as a pathway for vapor-phase movement of water in the hydrologic cycle. The hydrosphere: It is the water Reservoir that contains Earth’s water. Location:-Over 97% of Earth’s water is in oceans, -most of the remaining fresh water is in the form of ice. Therefore, only a relatively small percentage of the total water on Earth is actually involved with terrestrial, atmospheric, and biological processes. Exclusive of seawater, the water that circulates through environmental processes and cycles occurs in the atmosphere, underground as groundwater, and as surface water in streams, rivers, lakes, ponds, and reservoirs. ;The geosphere: consists of the solid earth, including soil, Lithosphere: is The part of the geosphere that is directly involved with environmental processes through contact with the atmosphere, the hydrosphere, and living things is the solid. The lithosphere varies from 50 to 100 km in thickness. The most important part of it insofar as interactions with the other spheres of the environment are concerned is its thin outer skin composed largely of light