Water Resources Adaptation to Global Changes: Risk Management through Sustainable Infrastructure Planning and Management

摘要

Global changes due to climatic variations, demographic changes and economic development, have impacts on the quality and quantity of potable and irrigation source waters. Internal and external climatic forcings, for example, redistribute precipitation seasonally and spatially in the temperate contiguous United States. This change is expressed in hydrologic periodicity, dry and wet period switching frequency, and the change in maximum rainfall intensity. Spatially, the long-term change is shown by increased precipitation in the eastern U.S., flash floods in the lower Mississippi River basin, and intensified droughts in the Great Plain and Southwestern states, and the southern California. In Florida and other coastal areas, greater degrees of salt water intrusion to productive aquifers could materialize due to predicted rise in sea levels. Data mining of historical hydrologic records has shown the existence of these regional patterns. The results are in general agreement with the published general circulation model outputs. In addition, water usage has changed with time and water demand has been redistributed spatially as population centers shifted in the past decades. Quantitative impact analysis focusing on water availability and demand changes is important to risk management and adaptive infrastructure development at various watershed scales. In this approach, adaptive engineering techniques and management methods can be proposed for each relatively homogeneous hydrologic region. Examples include water reuse in the water-stressed Florida, the Great Plain states and California, salt-water intrusion mitigation in Florida and coastal areas, adaptive hydrological engineering in the eastern U.S., Ohio River valley, and lower Mississippi River basin. These results are discussed to highlight the importance of engineering factors (e.g., design storms, groundwater level control) in adaptation of water infrastructure planning and management.