CFD Investigation of Diffusion Law and Harmful Boundary of Buried Natural Gas Pipeline in the Mountainous Environment

The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment.In this study,computational fluid dynamics(CFD)method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment.Based on cloud chart,concentration at the monitoring site and hazard range of lower explosion limit(LEL)and upper explosion limit(UEL),the influences of leakage hole direction and shape,soil property,burial depth,obstacle type on the diffusion law and hazard range are analyzed.Results show that the leakage gas is not radially diffused until it reaches the ground,and the velocity of gas diffusion to the ground and the hazard range decrease as the angle between the leaking direction and the buoyancy direction increases.Triangular and square leak holes have a faster diffusion rate and a wider hazard range than circular.The diffusion rate of leakage gas in soil rises as soil granularity and porosity increase.The time of leakage gas diffusion to the ground increases significantly with the increase of burial depth,and the hazard range reduces as burial depth increases.Boulder-type obstacles will alter the diffusion path of the leakage gas and accelerate the expansion of the hazard distance,while trench-type obstacles will cause the natural gas to accumulate in the trench and form a high concentration region slowing the expansion of the surface gas concentration.

Influence of environmental predispositions on temperate mountain forest damage at different spatial scales during alternating drought and flood periods:case study in Hruby Jeseník Mts.(Czech Republic)

Mountain forests are more prone to environmental predispositions(EPs)than submountain ones.While remote sensing of mountain forests enables instantaneous damage mapping,the investigation of the causes requires field data.However,a local field or regionally modeled environmental characteristics influence remote data evaluation differently.This study focused on the evaluation of EPs effects damaging mountain forests between various spatial resolutions during environmental change.The evaluation was divided into managed and natural forests in the Hruby Jeseník Mts.(Czech Republic;240-1491 m a.s.l.;50.082°N,17.231°E).Damage was assessed through the discrimination analysis of the normalised difference vegetation index(NDVI)by MODIS VI during alternating drought and flood periods 2003-2014.The local environmental influence was assessed using the discrimination function(DF)separability of forest damage in the training sets.The regional influence was assessed through map algebra estimated via the DF and a forest decline spatial model based on EPs from differences between risk growth conditions and biomass fuzzy sets.Management,EPs and soil influenced forest NDVI at different levels.The management afflicted the NDVI more than the EPs.The EPs afflicted the NDVI more than the soil groups.Strong winters and droughts had a greater influence on the NDVI than the flood events,with the winter of 2005/2006 inverting the DF direction,and the 2003 drought increasing differences in managed forest biomass and decreasing differences in natural forest biomasses.More than 50% of declining managed forests in the training sets occurred on Leptosols,Podzols and Histosols.On a regional scale,the soil influence was eliminated by multiple predispositions.The EPs influenced 96% of natural forest and 65% of managed forest,though managed forest damage was more evident.The mountain forest NDVI decline was dependent on both management and risk predispositions.

Hydrogen Therapy Reduces Oxidative Stress-associated Risks Following Acute and Chronic Exposure to High-altitude Environment

Low pressure,low oxygen concentration,and intense ultraviolet（UV）radiation in high-altitude environments,can cause oxidative stress which can trigger mountain sickness.A recent study demonstrated that hydrogen gas with a good permeability in biological membranes can treat various disorders by exerting its selective anti-oxidation and anti-inflammatory effects,indicating that hydrogen therapy plays a role in scavenging free radicals and in balancing oxidation and anti-oxidation systems of ceils. Therefore, we hypothesize that inhaling low-dose hydrogen or drinking hydrogen-saturated water is a novel and simple method to prevent and treat oxidative stress injury caused by low pressure, low oxygen concentration and intense UV radiation in plateaus, thus reducing the risk of mountain sickness.

Combining Landsat-8 spectral bands with ancillary variables for land cover classification in mountainous terrains of northern Pakistan

Landsat-8 spectral values have been used to map the earth’s surface information for decades.However,forest types and other land-use/land-cover(LULC)in the mountain terrains exist on different altitudes and climatic conditions.Hence,spectral information alone cannot be sufficient to accurately classify the forest types and other LULC,especially in high mountain complex.In this study,the suitability of Landsat-8 spectral bands and ancillary variables to discriminate forest types,and other LULC,using random forest(RF)classification algorithm for the Hindu Kush mountain ranges of northern Pakistan,was discussed.After prior-examination(multicollinearity)of spectral bands and ancillary variables,three out of six spectral bands and five out of eight ancillary variables were selected with threshold correlation coefficients r2<0.7.The selected datasets were stepwise stacked together and six Input Datasets(ID)were created.The first ID-1 includes only the Surface Reflectance(SR)of spectral bands,and then in each ID,the extra one ancillary variable including Normalized Difference Vegetation Index(NDVI),Normalized Difference Water Index(NDWI),Normalized Difference Snow Index(NDSI),Land Surface Temperature(LST),and Digital Elevation Model(DEM)was added.We found an overall accuracy(OA)=72.8%and kappa coefficient(KC)=61.9%for the classification of forest types,and other LULC classes by using the only SR bands of Landsat-8.The OA=81.5%and KC=73.7%was improved by the addition of NDVI,NDWI,and NDSI to the spectral bands of Landsat-8.However,the addition of LST and DEM further increased the OA,and Kappa coefficient(KC)by 87.5%and 82.6%,respectively.This indicates that ancillary variables play an important role in the classification,especially in the mountain terrain,and should be adopted in addition to spectral bands.The output of the study will be useful for the protection and conservation,analysis,climate change research,and other mountains forest-related management information.

Experimental Method for Measuring Non-toilet Mountaineer＇s Excrement

The increasing number of mountain climbers made them a significant source of anthropopression. The paper is focused on the devastating impact of non-toilet human waste on high-mountain environment and discusses the scale of this phenomenon. Four male members, of mean age 31.5 （±0.5） years, volunteered for this study. The study was conducted above 12,286 feet （3,745 m）, and consisted of 12 days of measuring human excrement output, as well as calorie and liquid consumption. The average results showed the amount of human excrement remains left by climbers in high-mountain environment on a daily scale; i.e., feces of approximately 128 g （32 g without water） and approximately 1.8 L of urine. During this study, the average daily diet consisted of 4,000 （± 500） calories and average 3.6 （± 1.1） quarts （3.8 ± 1 L） of water. Based on these data, an example calculation of quantitative values of human feces and urine left by climbers in 2013 on Denali （Mount McKinley） was conducted. Results show that the 1,151 people that climbed Denali within 18 days （the mean residence time in the massif） left behind over 660 kg of feces and more than 37 thousand liters of urine in the massif in 2013 alone.

Differentiated payments for environmental services schemes: A methodology proposal

Payment schemes for environmental services face serious budget constraints in Mexico. Payments are equally distributed among forest owners, and the governmental agencies that make payments to beneficiaries do not evaluate the amount of environmental services produced by forested areas. This lack of evaluation could lead to economic and environmental deficiencies that restrict the possible benefits of such programmes. In general, these programmes do not achieve their conservation objectives, and local beneficiaries are not involved in the design or application of these programmes. Similarly, the Payments for Hydrological Environmental Services(PHES) programme of the State of Mexico, Mexico, makes equal payments to beneficiaries of forested areas considering tree density. The objective of the present work was to create a methodology for determining differentiated payments schemes for hydrological environmental services, prioritising areas that contribute the most to groundwater recharge and promote the participation of society. In the Nevado de Toluca Natural Protected Area, the environmental criteria of forest type, tree density and aquifer overexploitation as well as social participation were considered in a multi-criteria analysis implemented in a Geographic Information System. A methodology was developed to determine differentiated payments based on specific forest characteristics that influence the potential capacity of forests to recharge groundwater reserves in addition to the level of social participation. In particular, social participation is key as it could ensure the viability of PHES programmes as conservation alternatives in forested areas with high groundwater recharge potential.

秦岭北麓乡村可持续发展的环境美学评价体系构建

构建秦岭北麓乡村的环境美学评价体系,旨在优化景观发展,通过视觉美感、自然环境、生态平衡、文化传承和居民满意度等多维度指标,采用定量与定性分析,为乡村规划提供科学支持,促进生态文明,推动区域可持续发展,并为相似乡村地区提供参考。

Elite Dung Beetle Optimization Algorithm for Multi-UAV Cooperative Search in Mountainous Environments

This paper aims to address the problem of multi-UAV cooperative search for multiple targets in a mountainous environment,considering the constraints of UAV dynamics and prior environmental information.Firstly,using the target probability distribution map,two strategies of information fusion and information diffusion are employed to solve the problem of environmental information inconsistency caused by different UAVs searching different areas,thereby improving the coordination of UAV groups.Secondly,the task region is decomposed into several high-value sub-regions by using data clustering method.Based on this,a hierarchical search strategy is proposed,which allows precise or rough search in different probability areas by adjusting the altitude of the aircraft,thereby improving the search efficiency.Third,the Elite Dung Beetle Optimization Algorithm(EDBOA)is proposed based on bionics by accurately simulating the social behavior of dung beetles to plan paths that satisfy the UAV dynamics constraints and adapt to the mountainous terrain,where the mountain is considered as an obstacle to be avoided.Finally,the objective function for path optimization is formulated by considering factors such as coverage within the task region,smoothness of the search path,and path length.The effectiveness and superiority of the proposed schemes are verified by the simulation.

贫困山区资源环境系统的变化与农业持续发展对策——以湖北通山县为例

根据对贫困山区多年来的气候、生物和森林生态系统、土地资源等资源环境变化状况的分析 ,可以看出 ,在全球变化的背景下 ,贫困山区资源环境系统正经历一个动态不稳定的发展阶段 .这一动态变化以各种自然灾害明显增加的形式表现出来 .本文从系统平衡、森林生态系统的气候效应以及人类活动的环境效应等方面阐述了贫困山区资源环境系统失衡的原因和发展趋势 ,并提出这一类型区农业和社会经济持续发展的对策 .

流域环境系统演化概念模型:山-河-湖-海互动及对全球变化的敏感响应──以长江为例

流域是一个复杂的环境系统。长江流域环境研究表明，山-河-湖-海互动是流域环境系统变化的实质，同时也是流域对全球变化响应最敏感、最直接的体现。地貌过程变化，水、沙等物理通量变化，C、P、N等化学通量变化是系统内各子系统之间联系的纽带，也是流域环境系统中最活跃的因子。以山-河-湖-海互动为核心的流域环境系统模型，主要包括：山、河、湖、海各系统之间的能量流与物质流的输入、迁移和输出理论，系统演化平衡理论和系统自组织、自反馈理论。

山区城市环境系统的污染及其变异的典型研究

本文以重庆市为代表，讨论山区城市环境系统中大气、地表水、土壤、地下水、包气带、生物体等六个子系统的污染状况。并研究了由此而引发的环境系统的变异，它涉及到气候变迁，土壤酸化，物种退化．水质恶化，建筑物表面和文物的损害，人群和生物生存的潜在变化等诸多方面，为制定防治污染策略提供科学依据．

井冈山生态旅游景点环境监测指标体系的建立

在对井冈山生态旅游景点进行多角度多视角生态调查的基础上,对井冈山生态旅游景点的特点、环境现状及演化趋势做了系统的研究;对生态旅游景点的环境监测及环境保护管理中存在的主要问题进行了分析,并建立了井冈山生态旅游景点环境监测指标体系,优选出旅游活动、水环境、土壤环境3大类监测对象的监测指标。为后续建立旅游景点环境监测标准奠定基础,为其他景区景点的生态环境监测工作提供参考和技术支撑。

百花山自然保护区环境解说系统问题分析及对策

从相关问卷调查和实地考察结果可看出,百花山环境解说系统存在着解说系统不成体系、解说信息可获得性不高、维护和管理力度不够以及环境教育宣传力度弱等问题,应从官方网站信息化解说、游客中心概况性解说、导游服务活化解说、标示系统结构性解说和牌示系统科学性解说等方面对其环境解说系统加以完善。

南充金城山物种多样性研究

以典型样地取样的数据为基础计算南充金城山的物种多样性指数,并运用灰色系统理论的关联度分析对物种多样性及其生态因子的相关性进行了研究.结果表明,南充金城山乔木、灌木、草本三层植被组成单一,8个生态因子对三层的多样性指数影响不一致,乔木、灌木层海拔略占优势,而草本层土壤的pH值略占优势.

柔性防护网在石太铁路山体病害整治中的应用

简要介绍SNS(GPS2型)主动防护系统的特点,并结合其在石太铁路山体病害治理中的应用,就GPS2型主动防护网的施工技术、质量安全问题等作了探讨。

喀斯特山区生态旅游环境承载力评价体系的构建

旅游环境承载力的评价可为生态旅游合理开发提供依据。本研究从自然资源、生态环境、社会环境和经济环境4个角度出发构建了喀斯特山区生态旅游环境承载力评价体系,根据专家评价的结果,运用层次分析法对各个指标进行了权重计算,得出了最主要的影响因素是自然资源承载力和生态环境承载力,其中自然资源承载力又起主导作用的结论。

山区土地利用总体规划环境影响评价

根据"压力—状态—响应"模式,按照"土地需求压力—土地状态变化—响应即环境影响"思路,分析探讨了土地利用总体规划环境影响指标体系,运用耕地需求压力指数、城镇用地需求压力指数等7个指标,探讨了土地规划实施后可能产生的环境影响。结果表明,与以往土地利用规划环境影响评价指标不同,该文提出土地利用规划环境影响评价的7项指标真正从整体上揭示了土地利用规划对环境的综合影响,符合规划的宏观性、综合性和超前性特征,避免了规划环评与项目环评的雷同,具有较强的实用性和科学性,应用于贵州省土地利用总体规划环境影响评价,效果较好。

广西恭城瑶族习惯法中的长山制度研究

广西恭城瑶族自治县(以下简称广西恭城县)的瑶族人民在长期的生活实践中形成了完整的习惯法体系,在物权归属和环境保护方面通过习惯法的形式确立了长山制度1,规定住所地附近的山林属于公产,归属集体,同时安排了具体保护措施,以这样的公共契约明确权属,保护林木,维持生态平衡。恭城瑶族习惯法中的长山制度对于我们今天的物权制度和环境治理都具有积极的启发意义,值得进行分析研究。

云南“长藤结瓜”式的山地灌溉系统及其环境变迁研究——以泸西地区的灌溉系统为例

"长藤结瓜"灌溉系统是丘陵山地地区较为普遍和典型的水利系统,是实现丘陵和山地水利化的主要措施。这一水利系统的兴建和推广使用,对农业生产发展起到了重要的促进作用。由于其适用型较强,促使更多的山地面积被开垦为耕地,挤占了原生植被的生存空间,成为当地生态环境变迁的促动因素之一。