固体废物管理电子政务系统的构建

固体废物管理面临着大量日常工作所必须的业务审批、各类业务数据的上报／接收、更新、查询、统计、分析和种类繁多的报表输出等属性数据的处理和利用任务,需要利用3S（GIS,GPS,RS）技术来快速、大面积获取信息及管理空间数据。我们在研究、开发“广州市固体废物管理GIS信息系统”的过程中,将MIS作为固废管理电子政务重要的组成部分,并与GIS,GPS,RS集成一体化,构建了“4S＇’集成一体化固体废物管理电子政务系统,有效地解决了数据共享和实时更新问题,使信息化能够真正全面促进办公管理效率、公众服务水平和科学决策水平的本质提高。文章简要阐述了“4S”集成一体化固体废物管理电子政务系统的组成、实现原理以及实际意义;并指出构建4S（MIS,GIS,GPS,RS）集成一体化的固体废物管理电子政务系统将会成为我国固废管理信息化发展的一个趋势。     

Integrated Assessment of Abatement Strategies to Improve Air Quality in Urban Environments, the USIAM Model

Planning effective strategies to combat air pollution in amajor city such as London requires integration ofinformation on atmospheric concentrations and where theyexceed prescribed air quality standards, detailed data onemissions and potential measures to reduce them includingcosts, and a good understanding of the relativecontributions of different emission sources to pollutantconcentrations plus the remaining background. The UrbanScale Integrated Assessment Model (USIAM) is designed as atool to integrate such information, and to explore andassess a variety of potential strategies for improving airquality. It is based on the same principles as theAbatement Strategies Assessment Model (ASAM) that has beenused in the UN Economic Commission for Europe. To startwith the USIAM model is being developed with respect to theparticulate PM₁₀ only, and in particular the primaryparticulate contribution. The secondary particulate istreated as part of the background superimposed on theprimary particulate concentrations; this may need to betreated more specifically at a later stage, particularlywith respect to nitrate formation over the city. The USIAMmodel therefore sets out to examine a selection of severeepisode conditions as well as long-term annual averageconcentrations, and aims to find strategies that aresuccessful in eliminating exceedance of the prescribedtarget concentrations. By ranking different options forabatement of emissions, for example in terms of cost orease of implementation, the USIAM model can also select andprioritise different potential strategies.     

中国西部地区旅游开发对策研究

我国西部旅游资源具有巨大的开发潜力,但旅游发展受到多方面的限制.旅游整合开发战略是在科学分析西部地区旅游发展优势和局限因素的基础上提出的科学决策,对西部旅游开发具有切实的指导意义.西部应着重以下工作:吸引资金,重视人才,实行政府主导型开发;改善基础设施落后面貌,做好旅游营销和宣传工作;增加资源开发的深度与广度,合理规划旅游路线,开发旅游商品;科学规划,加强监测,实行生态保护.     

民勤地区大震、古地理和沙尘暴的关系

民勤地区是中国沙尘暴发生年频次最高的地区。本文讨论了干旱、地震、古湖泊和风线对民勤地区沙尘暴形成所产生的综合作用。强地震破坏了土壤颗粒的团聚性,古湖泊环境提供了沙土混杂的地表层,风线决定了沙尘暴的飞扬和运移。     

AVERAGE DISCHARGE,PERENNIAL FLOW INITIATION,AND CHANNEL INITIATION ‐ SMALL SOUTHERN APPALACHIAN BASINS1

ABSTRACT: Regional average evapotranspiration estimates developed by water balance techniques are frequently used to estimate average discharge in ungaged streams. However, the lower stream size range for the validity of these techniques has not been explored. Flow records were collected and evaluated for 16 small streams in the Southern Appalachians to test whether the relationship between average discharge and drainage area in streams draining less than 200 acres was consistent with that of larger basins in the size range (> 10 square miles) typically gaged by the U.S. Geological Survey (USGS). This study was designed to evaluate predictors of average discharge in small ungaged streams for regulatory purposes, since many stream regulations, as well as recommendations for best management practices, are based on measures of stream size, including average discharge. The average discharge/drainage area relationship determined from gages on large streams held true down to the perennial flow initiation point. For the southern Appalachians, basin size corresponding to perennial flow is approximately 19 acres, ranging from 11 to 32 acres. There was a strong linear relationship (R²= 0.85) between average discharge and drainage area for all streams draining between 16 and 200 acres, and the average discharge for these streams was consistent with that predicted by the USGS Unit Area Runoff Map for Georgia. Drainage area was deemed an accurate predictor of average discharge, even in very small streams. Channel morphological features, such as active channel width, cross‐sectional area, and bankfull flow predicted from Manning's equation, were not accurate predictors of average discharge. Monthly baseflow statistics also were poor predictors of average discharge.     

Quantitative Assessment of the Intertidal Environment of Kuwait II: Controlling Factors

Multivariate analysis of variance, canonical correlation and canonical discriminate analysis were performed on environmental data collected from the Kuwaiti intertidal zone to determine the statistical relationships between the sediment, chemical, biological, spatial and temporal variables. The quantitative analysis showed that the sediment type was the paramount factor influencing the distribution and composition of the intertidal benthic fauna. The muddy, sandy and rocky shores support three distinct faunal communities. The seasonal variation in the benthic fauna community was not statistically significant but variation in biological data due to differences in transect location and tidal level were significant. This spatial variation has been attributed to differences in sediment and substrate types. The physico-chemical parameters were found to correlate positively with the mud content of the sediments but were unimportant in the overall composition of the intertidal fauna. This paper complements the results reported in Al Bakriet al. (1997–Part I) in establishing a valuable benchmark for assessing environmental impacts and for developing sustainable coastal zone management in Kuwait. The integrated approach outlined here could be adopted to develop a sound basis for the protection and management of coastal environments and resources in similar areas.     

Modeling the Effects of Land Use Change on the Water Temperature in Unregulated Urban Streams

Streams, in their natural state, are typically diverse and biologically productive environments. Streams subject to urbanization often experience degradation brought about by the cumulative effects of flow alteration, unsanitary discharge and channelization. One of the water quality parameters affected by urbanization is stream temperature. This study offers a model for predicting the impact of land use change on the temperature of non-regulated streams during extreme events. A stream temperature model was created by considering the gains and losses of thermal energy resulting from radiation, convection, conduction, evaporation and advection. A sensitivity analysis showed that out of 14 variables, shade/transmissivity of riparian vegetation, groundwater discharge, and stream width had the greatest influence on stream temperature. These same three variables are highly influenced by land use. Individual component models were developed to predict how urbanization changes stream width and baseflow discharge. Using 3-D computer modeling, a model was also developed to illustrate the effects of altering the extent and composition of riparian vegetation on streams with different orientations. By modeling these three variables as a function of urbanization, the results became inputs into the stream temperature model. The critical urban stream temperature model (CrUSTe), an aggregation of these four models, allows the prediction of stream temperature change as a result of amount, type and location of urbanization within a watershed. It has the potential to become a valuable tool for environmental managers.     

HYDRAULIC GEOMETRY AND STREAM CHANNEL BEHAVIOR: A UNCERTAIN LINK1

ABSTRACT: The at-a-station hydraulic geometry of stream channels can serve as a predictor of alluvial stream channel behavior. This geometry is the empirical relations describing changes in water surface width, mean depth, and mean velocity with changing discharge. The exponent values are correlated with channel morphology and behavior such as scour and fill, flow resistance, bank resistance, and competence. Channel behavior and morphology are apparently related, but some causes for effects are uncertain. Several studies, using empirical and theoretical bases, are reviewed here to illustrate the relation between hydraulic geometry and channel behavior, but the relations are not always consistent. Hydraulic geometry variables are easy to measure and readily available, but they do not always reflect what may be more important ones such as turbulence, the velocity distribution profile, and distribution and cohesion of sediment particles. This paper illustrates some of these problems, provides some solutions, and addresses need for more work to better predict stream channel behavior from hydraulic geometry     

USE OF INCISED CHANNEL EVOLUTION MODELS IN UNDERSTANDING REHABILITATION ALTERNATIVES1

ABSTRACT: Incised channels are caused by an imbalance between sediment transport capacity and sediment supply to the stream. The resulting bed and bank erosion alter channel morphology and stability. Geomorphological models of incised channel evolution can provide guidance in the selection of engineering design alternatives for incised channel rehabilitation. This paper describes how incised channel evolution models may be coupled with a dimensionless stability diagram to facilitate evaluation of rehabilitation alternatives. In combination, the models provide complementary views of channel processes from geomorphic and engineering perspectives.     

风幕集烟尘风机治理焊烟污染的研究

介绍了工业电焊烟尘的产生原理及特点,重点论述了风幕集烟尘风机在治理工业焊烟中的理论研究,论证了利用“短路流场”控制烟尘理论的可行性和先进性。讨论了造成“短路流场”的风幕集烟尘风机的结构及集烟尘原理。该项技术经对各种型式样机的研制和多次烟尘试验及大量测试分析,从理论上建立了“短路流场”数学模型,实际烟尘试验验证了其良好的集烟尘效果。为适应现场状况,提出了烟尘净化综合处理系统方案。