湖北稻区农业资源特点和耕作方式新发展

本文论证了湖北稻区的资源具有三大特点。因此,认定该区应细分为:东南部早三熟双季稻区,中部单、双季稻两热三熟并存区,西北部单季稻两熟区。笔者认为,本区近10年发展麦稻、油稻稻、油稻减少肥稻稻、肥稻其主流是好的;讨论了紫云英大量减步后如何解决有机肥源匮乏的问题。主张今后应积极开发冬种,积极提倡冬作起厢分带间套,既稳定大宗作物的发展,又增产经作、饲料、蔬菜、绿肥,以提高稻田的经济效益。     

LANDSAT MID-INFRARED DATA AND GIS IN REGIONAL SURFACE SOIL-MOISTURE ASSESSMENT1

ABSTRACT: Landsat satellite Thematic Mapper (TM) data were used to assess regional soil moisture conditions. The mid-infrared (MIR) data of TM band 7 were overlain onto four principal land-use categories (Agricultural/Irrigated, Urban/Clearings, Forest/ Wetlands, Water) using a geographic information system (GIS). M data were used to assess four qualitative surface soil-moisture conditions (water/very wet, wet, moist, and dry) within each land-use category of a 208,354 ha southwestern Florida study area. The MIR response was inversely related to the qualitative surface soil-moisture content. Integration of Landsat TM MIR data with land use through GIS appears to be a useful technique for high-resolution regional soil moisture assessment, and further research to reline this technique is recommended.     

Channelization and levee construction in Illinois: Review and implications for management

The environmental impact of loss of natural stream and riparian habitat is of concern throughout the United States and Europe. Environmental impacts related to such activities as channelization of and levee construction along streams and rivers are particularly apparent in the Midwestern United States. The objective of the research presented here was to delineate the extent, relative degree of impact, and implications for management of channelization and levee construction along watercourses located in the state of Illinois. According to records maintained through the Illinois Streams Information System data base (Illinois Department of Conservation), nearly 25% of surface water resources in the state have been modified directly by channelization and/or levee construction. Reviews of agency records, elaboration of case histories, interviews with agency personnel, and inspections of impacted sites indicated that these alterations have occurred without the benefit of effective mitigation. Although permit records may provide suggestions for mitigation to be incorporated in the design of a particular project, permits issued generally do not require even minimal instream habitat and bank stabilization efforts in conjunction with channel alteration. Information derived from policy and case study analyses suggests that institutional constraints, rather than lack of particular understanding about mitigation, provide major barriers to protecting the state's surface water resources in terms of regulatory review, policy interpretation and implementation, and project evaluation. Recommendations for environmental management efforts regarding these and similar channel alterations are elaborated from these findings.     

DEVELOPMENT OF WATERSIIED MODELS FOR TWO SIERRA NEVADA BASINS USING A GEOGRAPHIC INFORMATION SYSTEM1

ABSTRACT: Techniques were developed using vector and raster data in a geographic information system (GIS) to define the spatial variability of watershed characteristics in the north-central Sierra Nevada of California and Nevada and to assist in computing model input parameters. The U.S. Geological Survey's Precipitation-Runoff Modeling System, a physically based, distributed-parameter watershed model, simulates runoff for a basin by partitioning a watershed into areas that each have a homogeneous hydrologic response to precipitation or snowmelt. These land units, known as hydrologic-response units (HRU's), are characterized according to physical properties, such as altitude, slope, aspect, land cover, soils, and geology, and climate patterns. Digital data were used to develop a GIS data base and HRIJ classification for the American River and Carson River basins. The following criteria are used in delineating HRU's: (1) Data layers are hydrologically significant and have a resolution appropriate to the watershed's natural spatial variability, (2) the technique for delineating HRU's accommodates different classification criteria and is reproducible, and (3) HRU's are not limited by hydrographic-subbasin boundaries. HRU's so defined are spatially noncontiguous. The result is an objective, efficient methodology for characterizing a watershed and for delineating HRU's. Also, digital data can be analyzed and transformed to assist in defining parameters and in calibrating the model.     

几种事故预测方法的探讨

本文根据生产单位事故发生的随机性特点,论证了未来时段中事故次数及其时间分布等各项指标,是能够用多种随机数学模型和灰色系统理论来预测的。用非随机的函数模型预測事故是不合适的。给出了几种事故预測方法,并提出了几种值得研究和试用的方法。     

智能型地理信息系统（AIGIS）在城市抗震防灾规划中的应用

本文简要介绍地理信息系统GIS的发展概况、主要功能以及在国内外的应用现状.对现有的GIS软件技术加以改进,引进人工神经元网络和模糊综合评判技术,发展了一种智能型的GIS,在我国若干城市的抗震设防区划工作中应用,取得良好的效果。     

石油化工建设项目环境保护管理的新形势和新要求

解读《建设项目环境保护管理条例》修订的要点,剖析当前石油化工建设项目环境保护管理体系的核心由“环评制度”逐步向“排污许可证制度”转变的现实情况,及与此相应的环保行政主管部门对建设单位和设计咨询单位的环保工作提出的新要求。从实际工作出发,总结了中国石化系统和民营企业石油化工建设项目在新形势下环保管理工作的特点、遇到的问题及解决方案。     

除尘系统加接新支管的理论和实践

对于一个现有的除尘系统,若其除尘器、通风机的工作能力有足够的富余量,则可以在该系统管网上加接新的支管,来治理新的扬尘点。     

浅谈钢筋混凝土结构的可靠性鉴定

系统介绍了混凝土结构检测的主要内容及方法,总结了我国目前可靠性鉴定三种方法的主要理论、优缺点及使用范围,并指出耐久性对可靠性鉴定的重要意义,以及耐久性评估所采用的理论和存在的问题。     

灰关联分析在故障树诊断中的应用

介绍一种灰色诊断法。在故障诊断模式识别中,运用灰关联分析,依据故障树的底事件重要度,通过关联度计算及排序,对故障树分析中,各种故障模式发生的可能性大小作出了准确的判断,从而为处理事故的先后、缓急提供了依据。