加强安全生产基层基础工作的调查与思考

本文从安全生产基层基础工作入手,以湖北省为例,从安全监管机构设置不规范不健全、基层安全监管力量十分薄弱、安全投入和监管装备严重不足、基层安全监管队伍不稳定、安全生产政策法规体系不完善、安全生产工作机制不健全等六个方面分析了安全生产基层基础建设存在的突出问题。在此基础上,提出了实施"三三五五四"工程的建议,即:全面落实三个责任(企业主体责任、党委政府组织领导责任、相关部门职责);大力加强三项基本建设(基层安全监管机构建设、安全监管执法人员能力建设、安全监管基础设施及基本装备建设);进一步夯实五个基础(安全生产源头监管、企业安全生产标准化建设、安全生产隐患排查治理、职业病危害防治、基层安全生产网格化管理工程);建立健全五项激励约束机制(企业安全生产信用挂钩联动机制、安全生产激励机制、安全监管执法岗位特殊津贴制度、企业安全生产绩效工资制度、安全生产行政问责制);建立健全四个保障体系(投入保障体系、法制保障体系、宣教保障体系、科技支撑体系)。     

Temporal trends in agricultural water use and the relationships to hydroclimatic factors in the High Plains aquifer region

The High Plains aquifer (HPA) is the primary water source for agricultural irrigation in the US Great Plains. The water levels in many locations of the aquifer have declined steadily over the past several decades because the rate of water withdrawals exceeds recharge, which has been a serious concern to the water resources management in the region. We evaluated temporal trends and variations in agricultural water use and hydroclimatic variables including precipitation, air temperature, reference evapotranspiration, runoff, groundwater level, and terrestrial water storage across the HPA region for different periods from 1985 to 2020 at the grid, county, or region scale. The results showed that water withdrawals decreased from 21.3 km³/year in 1985 to 18.2 km³/year in 2015, while irrigated croplands increased from 71,928 km² in 1985 to 78,464 km² in 2015 in the entire HPA. The hydroclimatic time-series showed wetting trends in most of the northern HPA, but drying and warming trends in the southern region from 1985 to 2020. The groundwater level time-series indicated flat trends in the north, but significant declining in the central and southern HPA. Trends in irrigation water withdrawals and irrigation area across the HPA were controlled by the advancement of irrigation systems and technologies and the management of sustainable water use, but also were affected by dynamical changes in the hydroclimatic conditions.     

Effect of admixture of solid inertant on fire hazard of dust layers oriented at varying degrees of inclination

Unlike metallic dust layers, the layer flammability levels (LFL) of non-metallic dust layers exhibit a wide range from Class 1 (No self-sustained combustion) to Class 6 (explosive combustion). However, determinations of layer flammability have not considered the effect of inclination angle, thereby potentially underestimating fire hazard of combustible dust layers in many industrial situations. In this research, inclined dust layers showed greater fire hazard than did horizontally oriented dust layers. For example, LFL of wood dust jumped from class 3 to class 5 when layers were positioned with an incline. Flame spread rate of PMMA dust layers increased from 1.8 to 3.6 mm/s when the angle of inclination increased from 0 to 40°. Even small amounts of solid inertant significantly decreased surface layer fires. The required amount of inertant to completely inert layer fires was far less than that for smoldering layer fires or dust explosions.     

Confidence-based quantitative risk analysis for offshore accidental hydrocarbon release events

Quantitative risk analysis (QRA) has been widely used to conduct the assessment of offshore accidental risks. However, the accuracy and validity of QRA is significantly affected by uncertainties when subjective judgments are involved. Therefore, it is unrealistic to determine the probability of a hazardous event by using one single explicit value when safety experts have a relatively low confidence level in their judgments. This paper proposes a new methodology for incorporating uncertainties into conventional QRA using the concept of confidence level. Offshore hydrocarbon release hazards are focused on and a barrier and operational risk analysis (BORA-Release) method is selected as the basic model to illustrate the proposed methodology. A left–right (L–R) bell-shaped fuzzy number is employed and its membership curve is able to control its shape to represent different confidence levels. As to the complex geometry of the bell-shaped fuzzy number, an α-cut operation is introduced to conduct the arithmetic operations of the fuzzy number, and a defuzzification method with total integral value is chosen to match the α-cut operations and acquire complete information for the fuzzy numbers. In the meantime, an optimism index is used to describe the attitude of the decision-maker. One case study is provided in this paper to demonstrate the implementation of this method.     

天空蓝色饱和程度与城市空气质量等级的相关性

以大气散射理论为基础,结合颜色学、大气环境监测及城市空气质量日报等相关原理,从理论分析与实证研究2个方面证实了天空蓝色饱和程度与城市空气质量等级之间存在着显著的负相关性,即:天空蓝色饱和程度越低,空气污染等级越高,空气质量状况越差;天空蓝色饱和程度越高,空气污染等级较低,空气质量状况越好;通过相关及回归分析与检验,制得“城市空气质量等级目测色卡”,适用于晴朗天气肉眼观察天空颜色,进而目测估计空气质量等级状况,以采取必要防护措施。     

Morphologic development, relative sea level rise and sustainable management of water and sediment in the Ebre Delta, Spain

The Ebre (Ebro) Delta is one of the most important wetland areas in the western Mediterranean. Ca. 40 % of the delta plain is less than 0.5 m above mean sea level and part of the southern margin of the delta is at mean sea level in an area protected by dikes. Both mean rates of secular subsidence in the Ebre Delta and eustatic sea level rise are ca. 1 – 2 mm/yr. Thus, the present annual relative sea level rise (RSLR) rate in the Ebre Delta may be at least 3 mm/yr. Measured accretion rates in the delta range from 4 mm/yr in the wetlands surrounding the river mouth to <0.1 mm/yr in impounded salt marshes and rice fields. The annual sediment deficit in the delta plain to offset RSLR is close to 1 million m³/yr. Accretion rates in the rice fields prior to the construction of large dams in the Ebre watershed were higher than RSLR rates, from 3 – 15 mm/yr. At present, >99 % of the riverine sediments are retained in the reservoirs and rice fields are losing ca. 0.2 mm/yr. Future management plans should take RSLR into account and include control of freshwater and sediment flows from the river in order to offset negative effects from waterlogging and salt intrusion, and maintain land elevation. This will include the partial removal of sediments trapped behind the Ribarroja and Mequinença dams. Stocks and inputs of sediments in the corresponding reservoirs are large enough for land elevation of ca. 50 cm in the whole delta plain. Advantages of this solution include (1) new sediments to the delta to offset subsidence (via rice fields) and coastal retreat, (2) enhanced functioning of the delta (productivity and nutrient processing), (3) avoidance of accumulation of sediments in the reservoirs. Hence, it is important to manage river discharges at the dams from an integrated viewpoint, whereas currently only hydropower and agricultural requirements are considered. It is also crucial to maintain periods of high discharge, to have enough river energy to transport as much sediments as possible.     

某矿区老硐口毁闭爆破空气冲击波效应的评价

本文就某金矿区在对非法开采的平硐进行毁闭爆破时产生的空气冲击波的效应进行了分析评价,指出空气冲击波对附近村庄民房不构成破坏,只是由于强烈的爆破噪音给人以恐怖感,干扰了附近居民宁静正常的生活和生产。     

乌江流域县域社会经济发展的综合评价与分析

在简要阐述了县域社会经济发展综合评价原则的基础上,建立了悬域社会经济发展综合评价的指标体系,利用层次分析法确定了各评价因子的权重。接着以乌江流域为例,对流域内４０个县域的社会经济发展水平进行了定量评价,指出了流域内县域社会经济发展中存在的问题,并提出了相应的对策,旨在为促进乌江流域的县域社会经济协调发展提供某些科学依据。     

连云港海平面变化与地震相关性的探讨

为探索海平面变化与地震相关的前兆信息,利用了连云港验潮站长达４３年的验潮资料。结合华北地区４次７级以上强震和江苏及其以东黄海海域１８次中强以上地震的震例分析后认为：经基本消除主要干扰因素的连云港平均海平面变化,表征了与地震有关的地壳形变信息。它对监测华北地区强震和江苏及邻近地区的中强震,具有一定的参考价值。     

成都市大气降尘放射性水平分析

本文介绍了成都市大气降尘放射性水平的监测结果。发现降尘中除有少量天然核素外,还尚存有以往大气层核试验释放的裂变核素９０Ｓｒ和１３７Ｃｓ。平均年沉降量９０Ｓｒ为１０２Ｂｑ·ｍ－２·Ｙ－１,１３７Ｃｓ为１３１Ｂｑ·ｍ－２·Ｙ－１。由大气９０Ｓｒ和１３７Ｃｓ沉降所致公众辐射剂量为１６８μＳｒ·ａ－１,是限值的２‰。所以,降尘中放射性造成的辐射影响是很小的。