دانلود رایگان کتاب GIS,Environmental Modeling and Engineering
That we are capable of destroying our life support system is beyond doubt. As a species, we have already been responsible for a considerable number of environmental disasters. If I scan the chapter titles of Goudie’s (1997) The Human Impact Reader, the list becomes long indeed, including (in no particular order): subsidence, sedimentation, salinization, soil erosion, desiccation, nutrient loss, nitrate pollution, acidification, deforestation, ozone
depletion, climate change, wetland loss, habitat fragmentation, and desertification. I could go on to mention specific events, such as Exxon Valdez, Bhopal, and Chernobyl, but this book is not going to be a catalog of dire issues accompanied by finger-wagging exhortations that something must be done
The cosmological event of the Big Bang created the universe and in so doing space–time emerged (some would say “switched on”) as an integral aspect of gravitational fields. Space and time are closely interwoven and should more properly be thought of as a four-dimensional (4D) continuum in which time and space, over short durations, are interchangeable. Nevertheless, we conventionally think of separate one-dimensional (1D) time and three-dimensional (3D) space. The terrestrial space on which we live, the Earth, is at least 4.5 billion years old and has been around for about 40% of the time since time began ….