Đang chuẩn bị liên kết để tải về tài liệu:
WETLAND AND WATER RESOURCE MODELING AND ASSESSMENT: A Watershed Perspective - Chapter 5

Không đóng trình duyệt đến khi xuất hiện nút TẢI XUỐNG Tải xuống

Tình trạng thiếu nước thường được coi là một vấn đề ở miền Tây Hoa Kỳ, nơi cung cấp nước được giới hạn so với nửa phía đông của đất nước. Tuy nhiên, tình trạng thiếu nước định kỳ cũng phổ biến ở miền đông nam Hoa do nhu cầu nước cao và hạn hán định kỳ. Đông Nam thành phố Mỹ dành hàng tỷ đô la để phát triển khả năng lưu trữ nước như một vùng đệm chống lại hạn hán định kỳ. Bộ đệm chống lại tình trạng thiếu nước bao gồm sự phát triển của các. | Part II Wetland Hydrology and Water Budget 2008 by Taylor Francis Group LLC 5 Change in the Southern U.S. Water Demand and Supply over the Next Forty Years Steven G. McNulty Ge Sun Erika C. Cohen and Jennifer A. Moore Myers 5.1 INTRODUCTION Water shortages are often considered a problem in the western United States where water supply is limited compared to the eastern half of the country. However periodic water shortages are also common in the southeastern United States due to high water demand and periodic drought. Southeastern U.S. municipalities spend billions of dollars to develop water storage capacity as a buffer against periodic drought. Buffers against water shortage include the development of water reservoirs and well excavation to mine ancient aquifers. It is important to have good estimates of future water supply and demand to prevent wasting money by creating more reservoir capacity than is needed by a community. Conversely a lack of water reserve capacity can lead to the need for water restrictions. Many factors impact the amount of water that is available and the amount of water that is required by a community. Precipitation is the major determinant of water availability over the long term. In addition to precipitation air temperature and land cover also impact water availability by modifying how much precipitation is evaporated and transpired back into the atmosphere. Finally ancient aquifers provide a significant proportion of needed water in some parts of the southern United States such as Texas and Arkansas. The water recharge rates for deep aquifers are very low i.e. hundred of years so water is essentially mined from these areas. There are also several factors that control water demand. In addition to residential water use a great deal of water is also required by industry irrigated farming and the energy production sectors. In total domestic and commercial sectors account for only 5 of the surface water use and 10 of the groundwater use. The .