If you're thinking about buying a retractable awning, consider the value, longevity and cost. Purchasing a retractable deck awning is a big investment. While smaller, less-expensive awnings start at around $500, larger, higher-quality awnings can cost as much as $2,000 or more. Before you make the decision to buy a retractable awning, you should learn as much as possible about their benefits and drawbacks. Here are the top three pros and cons to consider.
Drainage basin. 558 pages on this wiki. A drainage basin is the area within the drainage basin divide (yellow outline), and drains the surface runoff and river discharge (blue lines) of a contiguous area.rainage basin. 558 pages on this wiki. A drainage basin is the area within the drainage basin divide (yellow outline), and drains the surface runoff and river discharge (blue lines) of a contiguous area.
The drainage basin includes both the streams and rivers that convey the water as well as the land surfaces from which water drains into those channels, and is separated from adjacent basins by a drainage divide.n North America, the term watershed is commonly used to mean a drainage basin, though in other English-speaking countries, it is used only in its original sense, to mean a drainage divide, the former meaning an area, the latter the high elevation perimeter of that area.