Norms for Behavior and Conditions in Two National Park Campgrounds in Korea

/ This study was conducted to examine norm prevalence, norm agreement, and norm stability in an international setting. Data were collected at two campgrounds in Chiri-Mountain National Park, Korea, in 1993 and 1994. Results showed that a high proportion of users could specify norms for various types of campground impacts. Users who rated high importance on impacts tended to show a higher level of norm prevalence. Generally there were differences in social norms and norm agreement across locations. Among those impacts that showed differences, social norms in a less developed area were more restrictive and norm agreement was higher. The results of this study are consistent with normative studies conducted in North America, suggesting that a normative approach can be applied in a variety of settings. Social norms for selected impact indicators were also stable over a one-year time period. Implications are discussed.KEY WORDS: Norms; Norm prevalence; Norm agreement; Norm stability     

ASSESSING STREAM CHANNEL STABILITY THRESHOLDS USING FLOW COMPETENCE ESTIMATES AT BANKFULL STAGE1

ABSTRACT: Stream channel stability is affected by peak flows rather than average annual water yield. Timber harvesting and other land management activities that contribute to soil compaction, vegetation removal, or increased drainage density can increase peak discharges and decrease the recurrence interval of bankfull discharges. Increased peak discharges can cause more frequent movement of large streambed materials, leading to more rapid stream channel change or instability. This study proposes a relationship between increased discharge and channel stability, and presents a methodology that can be used to evaluate stream channel stability thresholds on a stream reach basis. Detailed surveys of the channel cross section, water surface slope, streambed particle size distribution, and field identification of bankfull stage are used to estimate existing bankfull flow conditions. These site specific stream channel characteristics are used in bed load movement formulae to predict critical flow conditions for entrainment of coarse bed material (D₈₄ size fraction). The “relative bed stability” index, defined as the ratio of critical flow condition to the existing condition at bankfull discharge, can predict whether increased peak discharges will exceed stream channel thresholds.     

煤与瓦斯突出延期发生的原因探讨──“球壳失稳”假说的解释性研究之一

依据球壳失稳假说的原理对煤与瓦斯突出延期发生的原因进行了探讨，并且针对延期突出的危害和特点提出了相应的对策。     

HUMAN STABILITY IN A HIGH FLOOD HAZARD ZONE1

ABSTRACT: The delineation of high flood hazard zones within a flood plain is usually independent of the hydraulic parameters that constitute a life threatening situation. In order to define human instability in high hazard areas, a study was conducted to identify when an adult human could not stand or maneuver in a simulated flood flow. An analysis was performed on a rigid body monolith resulting in a toppling hazard envelope curve (velocity vs. depth). A 120 lb monolith was then constructed and tested to relate the actual flow velocity and depth at toppling to theory. A series of human subjects (90–201 Ibs) were placed in a recirculating flume and tested to determine the velocity and depth of flow that caused their instability. The test results determined that the product number, which is the product of the velocity and depth at toppling of the monolith, closely compared to the theoretical envelope curve. The monolith results represent the lower limit of human stability. Also, the product number appeared to be a predictor of human instability in flood flow. A relationship was developed to estimate the product number at which a human subject becomes unstable as a function of the height and weight of the subject.     

FLUVIAL PROCESSES AND MORPHOLOGICAL THRESHOLDS IN INCISED CHANNEL RESTORATION1

ABSTRACT: Incised channels are those in which an imbalance between sediment transport capacity and sediment supply has led to degradation of their beds. This is a frequent response to stream channelization, changes in land use, or lowering of base level. If the degradation causes a critical bank-height threshold to be exceeded, which is dependent on the geotechnical properties of the bank materials, then bank failure and channel widening follow. Interdependent adjustments of channel slope and cross-sectional area occur until a new state of dynamic equilibrium with the imposed discharge and sediment load is attained. These geomorphic adjustments can be described and quantified by using location-for-time substitution and a model of channel evolution can be formulated. Three approaches to rehabilitation of the degraded channels are possible; geomorphic, engineering and rational. The rational approach, which integrates elements of both the engineering and geomorphic approaches, is based on the channel evolution model, and it generally involves control of grade, control of discharge, or a combination of both.     

Changes in interacting species with disturbance

Human-influenced changes in the diversity and abundance of native wildlife in a southern boreal forest area, which became a national park in 1975, are used to develop working hypotheses for predicting and subsequently measuring the effects of disturbance or restoration programs on groups of interacting species. Changes from presettlement conditions began with early 1900 hunting, which eliminated woodland caribou (Rangifer tarandus) and elk (Cervus elaphus), and reduced moose (Alces alces) to the low numbers which still persist. Increases in white-tailed deer (Odocoileus virginianus), as these other cervid species became less abundant or absent, provided enough alternative food to sustain the system's carnivores until plant succession on previously burned or logged areas also caused deer to decline. With increased competition for reduced food, carnivore species also became less abundant or absent and overexploited some prey populations. The abilities of interacting species to maintain dynamically stable populations or persist varied with their different capacities to compensate for increased exploitation or competition. These relationships suggested a possible solution to the problem of predicting the stability of populations in disturbed systems. For the 1976–1985 period, a hypothesis that the increased protection of wildlife from exploitation in a national park would restore a more diverse, abundant, and productive fauna had to be rejected.     

新滩滑坡稳定性的有限元分析

根据新滩滑坡的地质背景和工程地质特征，建立了滑坡地质模型，运用有限元数值模拟方法对其稳定性与地质环境的关系进行了分析，并对影响因素作了比较，明确了其形成机理。     

贵阳市人工边坡稳定性模糊综合评判

在充分考虑了影响人工边坡稳定性的自然地质条件、诱发因素、人类工程活动等多项指标的基础上,用模糊综合评判方法对贵阳市近十年来发生的崩滑灾害和典型人工边坡的稳定性进行了综合分析和评价,评判结果与实际一致。     

山阳中学滑坡稳定分析及治理方案的优选

山阳中学滑坡位于陕西省山阳县城以东2.5km处,自1984年以来,出现多次局部滑动现象.本文在分析该滑坡基本特征的基础上提出了滑坡治理方案,通过对三种方案在造价、环境影响、施工难度和未来发展的要求等方面的比较,提出了推荐方案.     

由通风网络结构数据自动生成通风网络图研究

通风网络图是矿井通风管理的一种重要图件.本文根据通风网络图的特点,介绍了一种由通风网络结构数据自动生成通风网络图的方法,并进行了开发实现和实践应用.