ECONOMIC ANALYSIS OF IRRIGATION PRODUCTION FUNCTIONS: AN APPLICATION OF LINEAR PROGRAMMING1

ABSTRACT: Economic analysis of irrigation production functions is discussed using linear programming. The method provides advantages over the partial one-crop type of analyses because it captures intercrop tradeoffs in water and land use in response to economic policies or changes in water supply. A numerical example is used.     

PROJECTED EFFECTS OF ENERGY POLICIES ON AGRICULTURAL WATER USE AND IRRIGATION1

ABSTRACT: A national and interregional programming model was used in projecting the impacts of alternative energy policies and prices on agricultural production, land use, and irrigation. The alternatives analyzed include (a) natural gas deregulation, (b) natural gas curtailment, (c) doubled energy prices, and (d) tripled energy prices. These alternatives are compared with a base alternative where prices and conditions are at normal levels. Restraints in the model control availability of water, land, nitrogen fertilizers, and energy. Water production functions were used to adjust water use to conform with projected energy prices and policies. Natural gas curtailment would have the largest effect on nitrogen use on irrigated land. Values or shadow prices for lands that remains in irrigation would increase under all of the alternatives because of reduced supply. Increased energy prices generally would increase use of surface water for irrigation and reduce use of ground water due to higher pumping costs. Reductions of 50 percent or more in ground water use would occur in the South Central and Western regions of the United States. Water supply prices increase under all of the alternatives; with the amount varying by regions and the policy or price situation.     

SPATIAL AND TEMPORAL VARIABILITY IN SUSPENDED SEDIMENT YIELDS OF NORTH ISLAND BASINS,NEW ZEALAND1

ABSTRACT: Specific annual suspended sediment yields and their standard deviations are presented for 47 basins of North Island, New Zealand. Most of the variance in yields is explained by catchment mean rainfall. Rivers with similar flow range have similar suspended sediment concentration ratings, independent of differing watershed lithology and regolith, except for six basins having an abundance of soft fine sediments. Prediction equations for yield and its standard deviation are derived for four essentially arbitrary regions. AU feature rainfall as the independent variable. Differences between regions may owe to variations in intensity, frequency, and duration patterns of storms and, in one area, to bed material size as well. The temporal distribution of annual yields from a basin m be modeled by a two-parameter lognormal function: the prediction equations above may be used to evaluate this function at a site for which suspended sediment data are unavailable.     

Characteristics of roadside air pollution in Korean metropolitan city (Daegu) over last 5 to 6 years: temporal variations, standard exceedances, and dependence on meteorological conditions

The present study performed a roadside data analysis to provide baseline data for exploring associations between environmental exposure to four gaseous pollutants and health effects on residents living near roadways. The yearly roadside concentrations of CO and SO₂ showed a well-defined decreasing trend, whereas those of NO₂ and O₃ exhibited the reverse trend. In most cases, the diurnal trends of the roadside concentrations were well-defined for all seasons, plus the daytime concentrations were higher than the nighttime concentrations. In contrast to the other target pollutants, the daytime O₃ concentrations observed at the roadside sites were lower than those observed at the residential site, likely due to high-levels of fresh NO from traffic emissions that rapidly react with O₃, thereby reducing the O₃ roadside level. The Sunday roadside concentrations of CO, NO₂, and SO₂ were similar to or somewhat lower than the weekday concentrations. Conversely, for O_3, the Sunday roadside concentrations were similar to or somewhat higher than the weekday concentrations. The higher O₃ concentrations on Sunday may be due to the reduced titration from a decrease in NO_x emissions under VOC-limited conditions (low VOC/NO_x conditions). The monthly averages of O₃ concentrations exhibited the reverse seasonal variation to the other target compounds, with peak O₃ concentrations between April and June, and the second peak between August and October. It is also suggested that for O₃, the 8-h standard is more stringent than the 1-h standard, while for NO₂ and SO₂, the 1-h standard is more stringent than the 24-h standard. The multiple regression equations obtained from the relationship between the concentrations and five meteorological parameters indicated that the number and type of meteorological variables in the equations varied according to the pollutant, monitoring station, or season.     

示踪技术用于气体泄漏扩散模拟的多元线性回归分析

采用江苏工业学院油气储运安全综合实验模型平台,利用示踪技术(以CO2为示踪剂),模拟了有害气体瞬时泄漏扩散的整个过程.并结合多元线性回归分析的基本方法,定量分析了气体泄漏扩散过程,建立了多元线性回归模型,初步确定了泄漏气体浓度与相关物理量的变化关系,在此基础上得到了2个定量评价指标:确定性系数R=0.991,相关系数r=0.995.研究表明,在实验室建立的试验模型能较好地反映现实情况,模型仿真度较高,数据拟合效果较好.研究可为评价模型的相似性提供理论参考,对有害气体泄漏扩散事故应急救援、实施有效的现场控制,具有一定的科学参考价值.     

伊宁市空气中硫酸盐化速率与二氧化硫相关性研究

对伊宁市1999-2002年空气中硫酸盐化速率和二氧化硫监测值进行回归分析,结果表明,二者之间存在显著的线性正相关关系,但对各年度回归方程斜率和截距进行统计检验,则表现出显著的差异。     

油品真实蒸汽压多元非线性回归

油品蒸气压是从事油品蒸发损耗研究、计算油品蒸发损耗量的重要参数,但是仅有美国石油学会给出的诺模图,给利用计算机来计算储罐蒸发损耗带来了很大困难.为了利用计算机来计算储罐的蒸发损耗,运用Excel中的回归功能,对原始数据进行必要的转换,进行了真实蒸气压的多元非线性回归,回归出了油品真实蒸气压计算公式.结果显示,回归的方程具有很高的精度,利用回归方程编制了计算软件,为储罐蒸发损耗计算提供帮助.     

体育馆建筑内青年学生疏散预动作时间调查和分析

通过组织火灾应急疏散逃生演习、现场问卷调查等方式,统计了体育馆内人员的疏散预动作时间,进而建立多分变量逻辑斯蒂回归模型对该统计数据进行了研究.发现:男生选择疏散预动作时间为＜30 s的可能性是女生的0.886倍,选择疏散预动作时间为30-60 s的可能性是女生的2.818倍.预测人员疏散预动作时间为＜30 s、30 -60 s、＞60s的概率,男生分别为15.45％,75.61％、8.94％,而女生分别为24.14％,39.72％、36.14％;研究结果表明:人员性别的不同对疏散预动作时间有一定的影响,在体育馆类建筑中,青少年人员疏散预动作时间基本上小于60 s.     

建筑企业员工职业病危害认知影响因素的调查分析

随着建筑行业的持续快速发展,建筑企业作业场所中的职业病危害呈现出高发性、复杂性和持续性等特点.通过针对建筑企业员工的实际状况设计调查问卷获取第一手资料,并运用SPSS17.0统计软件建立相关分析、回归分析等模型进行数据分析,可以得知建筑企业作业场所员工遭受职业病危害的可能性与对安全知识的了解程度、从业时间、性别及文化背景这四个因素的线性相关性.通过对建筑企业作业人员职业病危害的调查与分析,辨识出影响职业病危害的人为因素,提出相关的建议措施以改善建筑企业作业场所职业病危害严重的局面,提高建筑企业员工自我保护意识,增加其职业病危害防护知识,减少职业病危害事故的发生.