国家环境保护规划评估的语义建模技术方法研究

在确定环境保护规划文本语义解析目标的基础上,列举了规划文本的形式分析和内容分析方法,研究提出了规划评估的两类建模技术:基于驱动力的模型构建技术和基于利益驱动的模型构建技术,并针对语义模型构建相关技术的未来研究方向提出建议:(1)推广计算机信息搜索与统计技术在文本形式分析技术方法领域的应用;(2)关注评估过程中的利益相关方的主张、焦虑、争议以及相应的解决办法.     

青岛市COD、SO_2排放的环境库兹涅茨曲线特征分析

选取青岛市2001~2010年环境统计数据,以全市人均GDP为因变量、污染物排放量为变量,进行环境库兹涅茨曲线模拟。结果表明:青岛市"三废"污染物排放和工业COD、SO2排放量均不符合典型的环境库兹涅茨曲线特征。通过模拟结果分析可得出,科学的产业结构调整、政府节能减排的大力推进等政策是单位GDP污染物排放量的降低和工业COD、SO2排放量呈现的正"N"型曲线特征的重要因素。     

线性拟合法评定水中砷的测量不确定度研究

测量不确定度是评定测量值分散程度的一项指标,对解释测量结果非常重要,对于一个分析方法若未进行不确定度评估,则无法确定测量结果间观测到的差值是否包含试验变异以外的信息,没有不确定度的信息,就存在错误处理结果的风险,甚至导致不必要的损失,不给出不确定度的测量数据是没有意义的数据.线性拟合法利用从方法确认、实验室内质控和实验室间协作定值等数据,注重从整体上、通过数月、数年等一段期间反映样品检测精密度数据直接评估测量不确定度.     

黑河流域磷迁移转化过程连续模拟研究

以西安市的主要供水水源黑河流域为例,在Matlab软件辅助下,使用蓄满产流模型、逆高斯分布汇流模型、水沙关系模型以及澳大利亚学者Viney所提出的营养物迁移转化模型对黑河流域1981～1990年磷的迁移转化过程进行了连续模拟,模拟了磷的输出情况,预测了黑河流域磷污染负荷量.结果表明:模拟结果符合磷素流失的一般规律,年径流量大的年份,从流域输出的磷素也较多,反之,则较小;对磷的连续模拟结果与实测插补延长后总磷年负荷量的相对误差基本上在±30%以内,结果较合理,由此表明该法可用于黑河流域磷素迁移转化的连续模拟.同时,本文模型只是流域非点源污染连续模拟的初步尝试,尚需进行进一步检验、改进和完善.     

CENTRIFUGE MODELING OF ONE-DIMENSIONAL SUBSURFACE CONTAMINATION1

ABSTRACT: One-dimensional contaminant transport through a saturated soil is modeled using a 1.2-m radius geotechnical centrifuge. Small-scale physical modeling in the centrifuge is achieved in relatively short time, at stress distributions that are similar to those experienced in the prototype (actual site). A 0.05 mol/l of sodium chloride solution is used as a contaminant and conductivity cells measure the concentration of the contaminant throughout the porous medium. Scaling analysis for centrifuge modeling and 1-g modeling are briefly discussed and it is concluded that centrifuge modeling simulates the effect of molecular diffusion; however, scaling of the effect of mechanical dispersion may be violated in the centrifuge if the interstitial fluid velocity is high. Centrifuge test results show good agreement with the predicted relationship between the coefficient of hydrodynamic dispersion and the Peclet number using column tests. Centrifuge modeling can be used as a complement of numerical modeling although the effect of mechanical dispersion may be overestimated in the former.     

Safer Truck Front Design for Pedestrian Impacts*

Truck and bus frontal impacts account for a major proportion of pedestrian fatalities in many less motorized countries. To understand this phenomenon, we have collected injury data on pedestrian impacts with buses and trucks and performed computer simulations to identify critical design parameters at 15–45 km/h impact velocities for further investigation. A male dummy which was scaled to fifty percentile Indian dimensions has been used for simulations using MADYMO. Bumper height, bumper offset and grille inclination affect the pelvis and thorax forces and Head Injury Criterion values critically. Bumper width has less effect. Simulations were performed to optimize for the above–mentioned three parameters. Changes in front geometric parameters reduce injury to the upper body and head below safety limits for the existing force–displacement properties but do not affect leg injuries significantly. Hence bumpers need to be made less stiff. Injury data shows that pedestrians also sustain tibia fractures in bus/truck impacts in apparent low velocity impacts. The computer modeling does not offer adequate explanation for this phenomenon. These simulations confirm that it is theoretically possible to make truck/bus fronts safer for pedestrians in impacts up to 35 km/h.     

URBAN INFLUENCE ON PHOSPHORUS AND SEDIMENT LOADING OF WEST POINT LAKE,GEORGIA1

ABSTRACT: West Point Lake is a 10,360 ha mainstream impoundment of the Chattahoochee River located 95 kilometers downstream of Atlanta, Georgia. Origins and magnitude of external total phosphorus (TP) and total suspended solids (TSS) loads from the West Point Lake basin were estimated over a one-year period. Partitioning the drainage basin allowed the sources of these loads to be determined. The upper subbasin area, from Franklin, Georgia, to the headwaters of the Chattahoochee River, contributed 96 percent of the discharge and 97 percent of the TP and TSS loads into West Point Lake. The lower subbasin area, from Franklin to West Point Lake dam, only contributed 3 percent of the TP and TSS loads. Ninety-one percent and 87 percent of the TP and TSS loads, respectively, from the upper subbasin originated from the Atlanta area. Point sources discharged 70 percent and 3 percent of the upper subbasin TP and TSS loads, respectively. A large portion (66 percent) of the TP from the upper subbasin was in the bioavailable form.     

CO-KRIGING TO INCORPORATE SCREENING DATA: HUDSON RIVER SEDIMENT PCBs1

ABSTRACT: Kriging methods of geostatistical analysis provide valuable techniques for analysis of sediment contamination problems, including interpolation of concentration maps from point data and estimation of global mean concentrations. Sample collection efforts frequently include preliminary screening data of considerably more extensive coverage than the laboratory analyses on which estimation is usually based. How should these be incorporated in kriging? Screening and laboratory analysis constitute two separate estimates of the same spatial field but of very different characteristics. A modified version of co-kriging is developed to include the imprecise screening information in the analysis of contaminant distribution. Use of the method is demonstrated on a data set of sediment PCB samples from the Upper Hudson River, for which preliminary categorical mass spectrometry screening was used to select a smaller set of samples for gas chromatograph analysis. The method is widely applicable to many situations of contaminant and natural resource estimation.     

A COMPARISON OF HAND- AND SPLINE-DRAWN PRECIPITATION MAPS FOR MOUNTAINOUS MONTANA1

ABSTRACT: Average annual precipitation for the period 1961–1990 was estimated for a mountainous region in Montana with a Laplacian thin-plate spline (ANUSPLIN) and compared to a hand-drawn map. Input data included latitude, longitude, and elevation from a three-arc-second U.S. Geological Survey Digital Elevation Model of the Bozeman and Billings 1 × 2 topographic quadrangles and precipitation data at 96 stations. The two maps are similar in appearance. Digital comparison of the two maps with ARC/INFO's Grid tools shows that mean annual precipitation for the hand-contoured map is 22.9 inches and for the ANUSPLIN map is 23.7 inches. Of the 5,760,000 cells, 53 percent showed no difference between ANUSPLIN and hand-drawn maps; 19 percent showed a two-inch difference, and 28 percent showed more than 2 inches difference. Input data and model output at the same location are not different (standard deviation 1.77, p-value 0.76). Hand-drawn maps show two inches more precipitation during the 1961–90 period than during the 1941–1970 period. Similarly, measured data at 73 sites for the period 1961–1990 are on average 2.4 inches higher than the same stations during the 1941–1970 period. The difference is significant (p-value > 0.0001).