城市垃圾甲烷气体排放及减排对策

本文讲述了城市垃圾的现状以及影响垃圾甲烷排放的各种因素，并根据ＩＰＣＣＧｕｉｄｅｌｉｎｅｓ（１９９５）提供的方法对１９９０～２０１０年江浙沪地区城市垃圾甲烷排放量的变化趋势进行了预测统计计算，１９９０年江浙沪地区城市垃圾甲烷排放量为７１２３万吨，２０１０年预测的甲烷排放量为２６６７６万吨，本文就垃圾中甲烷的排放提出了切实可行的减排方案。     

机场内部噪声现状多指标评价与防治研究

为分析飞机噪声对机场内部人员的影响,在某军用机场场区内选取九个主要建筑物作为研究对象,对其进行现场噪声测量,在实测数据的基础上,采用多项指标进行机场内部噪声环境评价和分析。结果表明：机场工作人员一直暴露在高噪声环境中,而且各类噪声事件均对其工作和身体健康产生影响,内场营区的声环境质量比外场工作区稍好,但离标准声环境仍有较大距离。最后结合军用机场的特点提出一些有针对性的防治措施。     

Reconstructions of Soil Moisture for the Upper Colorado River Basin Using Tree‐Ring Chronologies1

Anderson, SallyRose, Glenn Tootle, and Henri Grissino‐Mayer, 2012. Reconstructions of Soil Moisture for the Upper Colorado River Basin Using Tree‐Ring Chronologies. Journal of the American Water Resources Association (JAWRA) 48(4): 849‐858. DOI: 10.1111/j.1752‐1688.2012.00651.x Abstract: Soil moisture is an important factor in the global hydrologic cycle, but existing reconstructions of historic soil moisture are limited. We used tree‐ring chronologies to reconstruct annual soil moisture in the Upper Colorado River Basin (UCRB). Gridded soil moisture data were spatially regionalized using principal components analysis and k‐nearest neighbor techniques. We correlated moisture sensitive tree‐ring chronologies in and adjacent to the UCRB with regional soil moisture and tested the relationships for temporal stability. Chronologies that were positively correlated and stable for the calibration period were retained. We used stepwise linear regression to identify the best predictor combinations for each soil moisture region. The regressions explained 42‐78% of the variability in soil moisture data. We performed reconstructions for individual soil moisture grid cells to enhance understanding of the disparity in reconstructive skill across the regions. Reconstructions that used chronologies based on ponderosa pines (Pinus ponderosa) and pinyon pines (Pinus edulis) explained more variance in the datasets. Reconstructed soil moisture data was standardized and compared with standardized reconstructed streamflow and snow water equivalent data from the same region. Soil moisture and other hydrologic variables were highly correlated, indicating reconstructions of soil moisture in the UCRB using tree‐ring chronologies successfully represent hydrologic trends.     

Mitigation of hydrogen fluoride aerosols by dry powders

Fluid bed tests were used to determine overall reaction rates for eight different dry powders of low hazard and toxicity before and after reaction with HF. In flow chamber tests, a representative oxide, hydroxide and carbonate were used to measure the efficiency of mitigation of an HF aerosol cloud. The results show that dry powders provide a valid alternative to water spray mitigation. Powder efficiencies are higher than water efficiencies at constant weight ratio.

At present, no attempt has been made to provide any technical designs or layouts for powder mitigation systems. However, the technology for smaller systems is available through manufacturers of dry powder chemical fire extinguisher equipment. When these powders are kept dry and under nitrogen atmosphere, a shelf life of several years can be expected.     

WATER SUPPLY IMPACTS OF NUCLEAR FALL1

ABSTRACT: “Nuclear winter,” more properly called “nuclear fall,” could be caused by injection of large amounts of dust into the atmosphere. Besides causing a decrease in temperature, it could be accompanied by “nuclear drought,” a catastrophic decrease in precipitation. Dry land agriculture would then be impossible, and municipal, industrial, and irrigation water supplies would be diminished. It has been argued that nuclear winter/fall poses a much greater threat to human survival than do fall out or the direct impacts of a conflict. However, this does not appear to be true, at least for the U.S. Even under the unprecedented drought that could result from nuclear fall, water supplies would be available for many essential activities. For the most part, ground water supplies would be relatively invulnerable to nuclear drought, and adequate surface supplies would be available for potable uses. This assumes that conveyance facilities and power supplies survive a conflict largely intact or can be repaired.     

POTENTIAL EFFECTS OF CHANGED CLIMATES ON HEAVY RAINFALL FREQUENCIES IN TIlE MIDWEST1

ABSTRACT: An important question posed by potential future shifts in climate relates to possible shifts in heavy rainfall events (intensity and/or frequency) used to design hydraulic structures. Heavy rain events were defined as those producing amounts having average recurrence intervals of two years or longer for a specific storm period at a given location. Estimates of such heavy rainfall shifts in the humid continental climate of the midwest were derived by using spatial and temporal analogs. Comparisons in areas of relatively warm, wet conditions were made with those having measurably cooler, drier average conditions. The spatial-temporal analogs provided comparative differences in precipitation and temperature similar to the magnitude of changes obtained from GCM estimates. Spatial analogs/analyses indicated 10 to 15 percent increases in the frequency distribution of rain events having recurrence intervals of 5 to 50 years. Two periods of notably drier and warmer conditions during the past 90 years revealed 5 to 15 percent decreases in the number of 2- to 10-year heavy rain events. The suppression percentages showed a strong tendency to increase with increasing recurrence interval from 2 to 10 years.