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.

Residents'environmental conservation behaviour in the mountain tourism destinations in China:Case studies of Jiuzhaigou and Mount Qingcheng

This study aimed at gaining an understanding of the formation of residents' Environmental Conservation Behaviour(ECB) to promote sustainable tourism development in Chinese mountain areas. In particular, a theoretical framework was constructed by merging residents' mountain attachment and their environmental values,and awareness of environmental consequences based on the Cognition Behaviour Theory. This research sampled 642 residents with convenience sampling method in Jiuzhaigou and Mount Qingcheng, and structural equation modelling analysis was conducted to identify the relationships among the above variables. Results verified that mountain attachment affected people's awareness of environmental consequences, which then affected their ECB.Environmental values and mountain attachment directly and positively influenced ECB. Moreover,awareness of environmental consequences played the most prominent role in predicting ECB among all the predictors in this study. In all, this study derived several significant implications which can not only contribute to environmental management policies in tourism field but also help to improve the levels of the antecedents of residents' ECB and promote sustainable tourism development in Chinese mountain areas.

THE ENVIRONMENTAL QUALITY AND RENOVATING PLAN OF THE LOESS PLATEAU AND LIUPANSHAN MOUNTAINOUS AREA IN NINGXIA

1. The environmental quality of the Loess Plateau and Liupanshan mountainous area in Ningxia The landuse structure in the studied region was very irrational in 1970s, the propor-tions covered by farming, forestry and animal husbandry are separately 50.91%, 6.32% and33.3%. Since 1980s, the farmland has been returned back to forestry and pasture so that

Study on Environmental-Geological Problem and Ecosystem Re-establishment Countermeasures About Quarry and Damaged Mountain in Peri-urban

The quarry and damaged mountain in peri-urban have an important influence to ecological environment. They have had a series of serious environmental -geological problems to the socio-economic development and urban modernization process, such as increased environmental pollution and soil erosion,destruction of landscape aesthetic。

Mountain evolution and environmental changes of Huangshan(Yellowmountain),China

Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1864 m above sea level. Formative ages of the Huangshan and its granite,process of mountain geomorphic evolution from the Eocene to Quaternary,environmental changes of Quaternary, formative origin of beautiful peaks and fascinating rocks were studied and the questionable 'Pleistocene glaciation' was also discussed in this paper.

Plant diversity-productivity patterns in the alpine steppe environment of the Central Tianshan Mountains

The biodiversity-productivity relationship is an important topic in the research of biodiversity and ecosystem function. The plant diversity productivity pattern is commonly unimodal and positively correlated. This paper researches the characteristics of plant diversity-productivity patterns in the Bayanbuluk alpine steppe in the central Tianshan Mountains, Xinjiang, China, and analyzes the effects of environmental factors on the distribution of plant communities, species composition, plant diversity and productivity in the steppe. The results show a positive correlation between plant diversity and productivity. DCCA (detrended canonical correspondence analysis) ordination reveals a significant relationship between the effects of air temperature, soil moisture content, available soil nitrogen, relative humidity and pH value on the distribution and composition of plant communities. There are significant correlations between the soil moisture content, relative humidity, pH value, air temperature and species richness and the aboveground biomass of Gramineae and Cyperaceae, and also significant correlations between the relative humidity, pH values and the total aboveground biomass of plant communities.

Quantitative Analysis on the Relationship between Population Distribution and Environment Factors in Mountain Area

[Objective] The aim was to analyze the relationship between population distribution and environment factors in mountain area quantitatively.[Method] Taking the contiguous area of Sichuan,Yunnan and Guizhou Province as study object,population density and residential point density were chosen as the indices of population distribution,and the quantitative relationship between population distribution and environment factors (including altitude,topography relief amplitude,land use,road network and river network) in mountain area was analyzed.[Result] Altitude and topography relief amplitude in mountain area had obvious negative correlation with population density and residential point density,and the correlation coefficients with population density were-0.731 and-0.743.In addition,residential points were fewer in the region far from rivers,but there was no obvious correlation between population density and river network density.Residential point density was higher in cultivated land and construction land,and population density had obvious positive correlation with the area proportions of cultivated land and construction land,with the correlation coefficients of 0.895 and 0.726,respectively.Besides,the more distant from road,the smaller residential point density,and there was obvious positive correlation between population density and road network density,with the correlation coefficient of 0.823.[Conclusion] The study could lay a foundation for the further development of spatiality of population data in study region.

山区铁路隧道工程资源环境影响效应评估研究

山区地质复杂、环境敏感、生态脆弱,致使铁路隧道建设难度大,且在资源节约、环境保护等方面面临较高要求。绿色设计作为绿色建设的先行环节,对减少隧道建设对资源环境的扰动作用,达到资源节约、环境友好的目的起关键引领作用。为定量评估山区铁路隧道工程的资源环境影响效应、衡量隧道设计的绿色程度,提出一种山区铁路隧道工程资源环境影响效应分析方法。首先,基于“驱动力-状态-响应”模型(Driving force-State-Response,DSR),以隧道设计参数为驱动力指标、资源环境状况为状态指标、隧道设计措施为响应指标,构建山区铁路隧道工程资源环境影响效应评估指标体系,并建立各指标分级标准;其次,运用一种具有自学习自调整能力的支持向量回归模型(Support Vector Regression,SVR)对隧道工程的资源环境影响效应进行评估;再次,以驱动力指标和响应指标为分析对象,运用考虑指标间关联关系及叠加效应的敏感性分析法,甄别对隧道工程资源环境影响效应优化具有重要影响的隧道设计因素;最后,以某山区铁路隧道工程为例,得到该隧道工程的资源环境影响效应值为4.7157,对应等级为较好,表明该隧道工程绿色设计水平较好,资源集约节约利用较合理、环境保护力度较大,可为其他类似工况隧道工程的绿色设计提供借鉴。此外,分析结果显示,注浆加固效果是导致该隧道工程资源环境影响效应变化最敏感的因素,其次为清污分流比例,可着重从这2个方面进行优化设计,以实现隧道工程资源环境影响效应的进一步优化。研究结果验证了本文研究方法的适用性和可操作性,可为山区铁路隧道工程资源环境影响效应评估及明确隧道工程优化设计方向提供科学依据。

Rhizosphere Soil Fungal Diversity and Soil Physicochemical Properties of Different Vegetations in Tundra of Changbai Mountain

By studying the diversity and community structure of rhizosphere soil fungi of different plants in the tundra on the northern slope of Changbai Mountain, it provides theoretical support for the restoration of environmental degradation and in-depth study of fungal diversity in the tundra of Changbai Mountain. High-throughput sequencing technology was used to determine the ITS1 region of fungal amplicons, so as to analyze the diversity of fungal communities in the rhizosphere soil of six plants in the tundra of Changbai Mountain, and to analyze the correlation between the environment and the diversity and richness of fungal communities in combination with relevant soil physical and chemical factors. The diversity and richness of fungal community in the rhizosphere soil of six plants in Changbai Mountain tundra were different. The Simpson and Shannon indexes of Saxifraga stolonifera Curt were the highest, and the richness of fungal community in Dryas octopetala was the highest. The analysis of fungal community composition showed that the fungal colonies in plant rhizosphere soil samples mainly belonged to Ascomycota and Basidiomycota, which were the main dominant phyla. Mortierella, Fusarium and Sordariomycetes are common fungal genera in the rhizosphere soil of six plants, but their abundances are different among different plants. Water content was negatively correlated with fungal diversity, and TP was positively correlated with fungal community diversity. There were some differences in the composition and diversity of rhizosphere soil fungal communities of six plants in Changbai Mountain tundra. Ascomycota and Basidiomycota were the main soil fungal phyla in the rhizosphere of six plants in Changbai Mountain tundra. The results could provide theoretical guidance for ecological protection of Changbai Mountain tundra.

中国式现代化视域下习近平生态文明思想整体系统观及其方法论

党的十八大以来,在推进中国式现代化建设的伟大征程中,以习近平同志为核心的党中央坚持系统观念,基于对西方现代化道路的深刻反思和对自然界作为有机系统整体的精准认识,赓续与拓新马克思主义和中华优秀传统文化关于人与自然真实图景的系统辩证思想,形成和确立了丰富完备、逻辑严密的习近平生态文明思想整体系统观。秉持山水林田湖草沙是生命共同体的系统理念,这一整体系统观锚定生态文明建设和环境治理的目标任务,坚持推进中国式现代化生态文明建设与环境治理的系统层级观,坚持共同体构架的国内外合作治理的系统联动机制,对其内核“是什么”的问题作了精要而又深邃的回答。习近平生态文明思想层层追问中国式现代化生态文明建设之道,彰显了其整体系统思维在回答生态文明建设根本性问题上的强大方法论功能;以系统工程方式“全方位全地域全过程”推进生态文明建设与环境治理的全面系统展开,立体呈现了习近平生态文明思想整体系统观鲜明的方法论特质,为中国式现代化新征程上全面推进美丽中国建设提供了科学思想方法,开拓了中国式现代化恢宏壮丽的生态篇章。

天山北坡雪岭云杉森林土壤微生物群落及影响因素研究

土壤微生物是维持森林生态系统平衡与土壤养分的一个重要因素。雪岭云杉林是天山重要的生态屏障和珍贵生物资源,其生态系统的固碳能力持续提升。研究雪岭云杉森林土壤微生物群落特征及微生物与土壤养分之间的互作关系,对维持雪岭云杉森林生态系统质量,促进雪岭云杉森林生态系统可持续发展至关重要。以天山北坡雪岭云杉林表层土为研究对象,利用宏基因组技术,探究天山北坡雪岭云杉林土壤微生物群落组成和多样性及其影响因素。结果表明,天山北坡雪岭云杉林土壤微生物群落特征表现为细菌相对丰度82.5%,真菌1.3%,古菌0.5%,其他15.7%。细菌Alpha多样性在中东部和西部之间有显著性差异;古菌Beta多样性在中部与西部存在显著差异,且中部和东部之间极显著;细菌Beta多样性在3个区域之间均有显著差异,其中西部与东部极显著;真菌Beta多样性仅中部与东部存在极显著差异。古菌多样性主要受有机碳、总氮、pH和土壤湿度的影响;细菌多样性主要受氮素、pH、年均降水量和年均摄氏温度的影响;真菌群落多样性主要受微生物碳和年均摄氏温度的影响。综上说明,土壤因素和水热条件在天山北坡雪岭云杉林土壤微生物群落分布中起主要控制作用,其中pH值和年均摄氏温度是微生物类群空间分异的主导因素。该研究探讨了环境因子对雪岭云杉林土壤微生物分布的调控作用,为今后森林的经营和可持续发展提供依据。

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。

“绿水青山就是金山银山”理论与实践指导下的《高等环境化学》课程建设

“绿水青山就是金山银山”是习近平总书记的重要环保理论,阐明了环境保护、经济发展和民生工程之间相辅相成的关系。本文根据2012年以来对于环境的投入、全国水质国控断面及长江与黄河重要流域Ⅰ-Ⅲ类和Ⅴ类水占比、森林覆盖率、生物物种数量、空气质量等翔实的数据分析了我国环境总体向好的趋势,进一步以国内生产总值、人均寿命等数据验证了“绿水青山就是金山银山”理论。研究生环境专业学生是未来环境保护和建设的主力军,在其《高等环境化学》课程教学中,融入“绿水青山就是金山银山”理论既能提升学生的环保意识、社会责任感和综合素质,更能加深学生的爱国爱家情怀,为实现“中国梦”培养创新型高素质人才奠定基础。

基于MaxEnt模型对燕山山脉东段狍生境适宜性评价

生境适宜性评价能够从宏观角度探索物种适合生存的空间和生境质量,判断影响物种分布的环境因子、预测适宜栖息地对于有效保护物种和管理栖息地至关重要。狍(Capreolus pygargus)是草食反刍动物,研究狍的生境适宜性,不仅有利于了解和保护这一物种,也有助于探索同域分布动物的潜在种群情况。本研究于2018年、2022年、2023年,在燕山山脉东段通过红外相机记录到114个狍的有效位点数据,利用MaxEnt模型对该地区狍的生境进行了适宜性分析。结果表明,该物种的适宜生境总面积约为8523 km^(2),占研究区总面积的14.59%。其中,高适宜生境占1.83%,主要分布于中东部;中适宜生境和低适宜生境分别占3.78%和9.00%,主要位于高适宜生境的周边区域。气温年较差、最热月最高温、植被类型是影响燕山山脉东段狍生境适宜性的主要环境变量,相对而言,最湿月降水量、海拔的影响较小。狍在燕山山脉东段偏好选择气温年较差为39.4~44.0℃,最热月最高温22.7~27.7℃,最湿月降水量超过155.8 mm,海拔775.7 m左右的环境,温带常见的植被类型如阔叶林、针叶林、灌丛等对于狍都是适宜的。本研究明确了狍适宜生境在燕山山脉东段的分布状况及关键环境影响因子,填补了该地区野生狍生境研究的空白,为下一步制定动物保护和生境管理提供理论依据。

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.

基于环境DNA技术的黄河流域下游山区河流大型底栖动物群落多样性特征及其影响要素分析

河流生物群落组成由多种环境因子共同作用形成,但其影响机制尚不清楚。本研究基于环境DNA技术,选择黄河流域下游4条山区河流(锦绣川、锦阳川、锦云川和三川汇合后河流)的10个样点开展大型底栖动物监测。结果发现:不同溪段水质状况有所差异,锦云川盐化程度(以电导率EC表征)和营养盐浓度较高,锦阳川抗生素浓度较高,锦绣川水质较好。山区河流大型底栖动物群落组成差异明显,锦绣川以水生昆虫为主,软体动物占比较低。其中,昆虫纲的大蚊(Tipula abdominalis)、天角蜉(Uracanthella punctisetae)和寡毛纲的顠体虫(Aeolosoma sp.)是造成锦绣川与其他河流大型底栖动物群落结构差异的关键物种。冗余分析和变差分解分析结果表明,盐化、营养盐和抗生素均会对大型底栖动物群落组成产生影响。其中,EC的解释率为22.86%,营养盐中的TP、NH_(3)-N和TN的解释率分别为20.12%、13.25%和7.81%;此外,盐化可与营养盐和抗生素通过耦合效应对大型底栖动物群落组成产生影响,贡献率分别为21.60%和16.20%;抗生素与营养盐的贡献率为19.60%。逐步判别回归模型结果显示,Margalef指数(d)受盐化(EC)和营养盐(NH_(3)-N和NO_(3)^(-)-N)的共同影响;随着河流中EC浓度升高,d与NH_(3)-N之间的正响应关系及其与NO_(3)^(-)-N之间的负响应关系显著增强。因此,多环境因子对水生生物的影响不容忽视,在大型底栖动物生物多样性保护中应关注各类环境因子的影响贡献。

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.

习近平生态文明思想的哲学基础与内生逻辑

习近平生态文明思想具有科学完备、系统完整的哲学基础与内在逻辑。“人与自然是生命共同体”论是其哲学立论之基,论证了人与自然的辩证统一关系;“两山”理论是其核心理念,揭示了经济社会发展与生态环境保护之间的辩证统一关系,指明了我国经济社会的绿色发展之路;环境生产力论是其内在理论依据,指明了我国经济发展要加快绿色转型的内在要求;环境民生论是其宗旨要求,明确了我国加强生态文明建设的价值旨归。深入学习分析习近平生态文明思想的哲学基础及内在逻辑,牢牢把握其深刻内涵,对于加深“两个结合”、推进生态环境治理工作、走人与自然和谐共生的现代化道路具有重要意义。

植物群落沿海拔梯度的分布规律——以滇西北哈巴雪山东坡矿场路为例

[目的]探究哈巴雪山东坡矿场路植物群落在遭受破坏后,植物群落沿海拔的演替规律及种群的更新能力。[方法]以哈巴雪山东坡矿场路沿海拔梯度设置23个样方,分析哈巴雪山东坡矿场路植物群落生物多样性指数垂直分布格局。[结果]23个样地中,乔木27种,灌木65种,草本196种。物种丰富度呈明显的单峰分布格局,峰值最大出现在中海拔群落,乔木层和草本层植物的物种丰富度随海拔先升高后降低,而灌木层植物的物种丰富度随海拔的上升呈明显下降的格局。α多样性随海拔梯度的变化与物种丰富度相似,β多样性基本也符合单峰格局,但是受矿厂区干扰峰值波动起伏较大。[结论]海拔梯度、人为干扰、小地形破坏对群落物种多样性都有着重要影响。