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Herbert M. Runkle Thomas H. Perkins 《Journal of the American Water Resources Association》1971,7(2):348-354
Time is running out on this country's planners. Generally speaking, the art of planning has retrogressed since the time of Christ. If we are to survive, this will have to be drastically changed by the year 2000. To achieve this, we need to begin to change our thinking, today. We badly need wider social planning, giving us more alternatives-more thought on where we are going. Reasonableness requires blending of planning and construction-but a sharp line of independence is essential. We must think about all the consequences of a particular act. Through intensive professional development and achievement of professional expertise, many outstanding technicians often move into vital decision making positions within their respective agencies. As planners, they see a part of the action but miss the big picture. Problem solutions become restricted to agency or individual authorities and are not always the best alternative. Thus, the planning field is overflowing with solutions to our every problem but many solutions offer spot control, and while the black spot is removed from the garment the white spot remaining from the solution offers little consolation to the wearer. 相似文献
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Herbert Ssegane Devendra M. Amatya E.W. Tollner Zhaohua Dai Jami E. Nettles 《Journal of the American Water Resources Association》2013,49(5):1150-1166
Commonly used methods to predict streamflow at ungauged watersheds implicitly predict streamflow magnitude and temporal sequence concurrently. An alternative approach that has not been fully explored is the conceptualization of streamflow as a composite of two separable components of magnitude and sequence, where each component is estimated separately and then combined. Magnitude is modeled using the flow duration curve (FDC), whereas sequence is modeled by transferring streamflow sequence of gauged watershed(s). This study tests the applicability of the approach on watersheds ranging in size from about 25‐7,226 km2 in Southeastern Coastal Plain (U.S.) with substantial surface storage of wetlands. A 19‐point regionalized FDC is developed to estimate streamflow magnitude using the three most selected variables (drainage area, hydrologic soil index, and maximum 24‐h precipitation with a recurrence interval of 100 years) by a greedy‐heuristic search process. The results of validation on four watersheds (Trent River, North Carolina: 02092500; Satilla River, Georgia: 02226500; Black River, South Carolina: 02136000; and Coosawhatchie River, South Carolina: 02176500) yielded Nash‐Sutcliffe efficiency values of 0.86‐0.98 for the predicted magnitude and 0.09‐0.84 for the predicted daily streamflow over a simulation period of 1960‐2010. The prediction accuracy of the method on two headwater watersheds at Santee Experimental Forest in coastal South Carolina was weak, but comparable to simulations by MIKE‐SHE. 相似文献
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Min Chen Dr Yung Hang Lam Chen Lung Lin Kwok Wah Chan Pui Wah Hui Mary Hoi Yin Tang Chin Peng Lee Pek Lan Khong 《黑龙江环境通报》2002,22(12):1067-1070
Enteric duplication cyst is a congenital abnormality that is believed to arise from abnormal recanalization of the bowel during embryogenesis. Previous reports suggest that the condition may be suspected prenatally by sonographic demonstration of an intra-abdominal cystic mass in the second and third trimesters. We present the sonographic features of a fetus with ileal duplication cyst at 12 weeks of gestation, which show that the condition may present in the first trimester of pregnancy. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献