On the Biomass of Four Major Tree Species in Vegetation Restoration Pattern Area of Beichuan Nature Reserve

In the experiment, by taking Quercus engleriana Seem., Betula albo- sinensis Burk., Abies faxoniana Rehd. and Fargesia rufa Yi, in the vegetation restoration pattern area of Beichuan Nature Reserve as the research objects, the study on the biomass models, the biomass distribution law of single plant and the growth rule of every organ of the four tree species was made. The results indicated that in the compositions of all of the species, the proportion of trunk biomass was the highest, while that of trunk biomass was the lowest, the proportions of branch and root biomasses varied depending on species; in the comparison of correlativity between the proportions of biomasses of all nutrition organs and biomass of single plant, the relations were generally significant, the tree trunks were positively related while the roots were negatively related; the proportion of trunk biomass of all species was significantly and negatively related to the proportions of leaf and branch biomasses, while the biomass of leaves was significantly and positively related to the biomass of branches.

Natural Suitability Evaluation of Habitat Environment in Transition Zone Based on GIS Spatial Analysis Technology—Taking Beichuan County as an Example

Analyzing and measuring the spatial distribution pattern of human settlement environment suitability in Beichuan County China is of great significance for optimizing population distribution and promoting human development and environmental protection. Based on the DEM data and other data of Beichuan County, this paper uses GIS and ENVI software to extract four spatial distribution data of vegetation coverage index, topographic relief, hydrological index and natural disaster risk, and the spatial distribution pattern of natural suitability of human settlement environment in Beichuan County was obtained through overlay analysis. The results show: 1) Most of the areas with small topographic relief are located in the southeast of the study area, which is New Beichuan County and Anchang Town and Yong’an Town. The vegetation coverage index in the eastern region is higher, while the vegetation coverage index in the western and other high altitude regions is lower because there are more grasslands. 2) From the perspective of spatial distribution, Beichuan County as a whole is rich in water resources in the central and eastern part of the county, while the west is short of water resources;Chenjiaba Township, Guixi Town and Old Beichuan County are located on the fault zone with high natural disaster risk, the natural disaster risk is high in Piankou Township and Xiaoba Town and Kaiping Township Area. 3) The human settlement environment index of Beichuan county is 19.72 - 85.25;The natural suitability is the highest in the southeast, followed by the central and western regions, and the worst is located in the Piankou-Xiaoba and Old Beichuan-Guixi fault zones. 4) The general suitable area in Beichuan County is the largest, accounting for 30.4% of the total area of the study area. More suitable area ranked second, accounting for 29.33%;critical fitness suitable area accounted for 17.87%;the area of suitable highly suitable area accounted for 14.06%, and the unsuitable area accounted for 8.32%. Reasonable and efficient development and use of local resources is an inevitable way for the sustainable development of Beichuan County.

Mapping of Landslides and Other Catastrophic Processes in the Area of the Beichuan City(Sichuan Province,China) after the Earthquake of May 12~th 2008

The Wenchuan earthquake of 2008 in the Sichuan Province(China)is one of the most destructive earthquakes in recent years.It killed about 89 thousand people and caused considerable economic damage.In the first phase of research the main objective was in detailed image interpretation and mapping of the territory of a key site around Beichuan City,at the initial stage of adaptation of the natural-technical environment after the catastrophic earthquake.For this purpose we used

Reexamining the Seismological Implications of the Present-day Stress State of the Yingxiu-Beichuan Fault after the Wenchuan Earthquake

The present-day stress state of the Yingxiu-Beichuan fault after the Wenchuan earthquake was re-estimated using measured in-situ stress data obtained after the Wenchuan earthquake. The results reveal that the gradient coefficients of principal stresses versus depth decrease from south to north along the Yingxiu-Beichuan fault, revealing that the stress level decreases from south to north. The consistency between the present-day stress levels and surface ruptures generated during the earthquake indicates that the accumulated tectonic stress beneath the Yingxiu-Beichuan fault before the Wenchuan earthquake was relieved in form of surface ruptures. This resulted in the stress remaining high in the southern section of the Yingxiu-Beichuan fault but relatively low in the northern section. Abnormal high pore pressure conditions and an extremely low frictional coefficient play important role in the interpretation of the stress field adjustment and seismic events observed after the Wenchuan earthquake along this fault, according to the estimation results using the Coulomb frictional-failure theory incorporating frictional coefficients ranging from 0.4 to 1.0. To accurately estimate the seismological hazard of the Yingxiu-Beichuan fault by analyzing fault instability using the Coulomb frictional-failure theory, much attention should be focused on the pore pressure conditions and the evolution state of the frictional coefficient under the present-day stress state.

区域产业结构对灾后恢复韧性的影响——以汶川县和北川县为例

灾后恢复是评价地震恢复韧性的重要指标。不同的区域经济产业所提供的就业数量存在差异,将对灾后恢复韧性产生极大影响。该文基于5.12汶川地震中受灾最严重的汶川县和北川县共736户受灾家庭的灾后恢复调查,研究了区域产业结构对恢复韧性的影响。研究表明:北川的家庭生活恢复滞后汶川近2年,主要是由于北川的外地务工家庭比例(49.60%)高于汶川(5.79%),这些受灾家庭恢复重建的主要资金来源是外地务工,但家庭成员长期外出不能参与恢复重建,造成其灾后恢复缓慢。外地务工家庭比例高的原因是北川第一产业占比高达27.20%,汶川仅为8.40%,第一产业所提供的本地就业数量远低于第二产业。因此,农业产业为主地区是灾后恢复最缺乏韧性的地区,需要大力提高防灾减灾能力,也可以通过产业结构调整,提高韧性。

基于水文学法和SWAT模型的北川河流域生态需水量分析

为确定北川河流域生态需水量,采用线性趋势法、Mann-Kendall检验法、Spearman检验法分析了北川河流域1959—2013年径流变化趋势,并采用Pettitt检验、滑动t检验、滑动F检验和累积距平法综合诊断径流突变点,根据Tennant法和改进的年内同频率展布法确定的生态流量过程外包线计算河道内生态需水量,并基于SWAT模型计算了河道外生态需水量。结果表明:SWAT模型在研究区具有适用性,模型性能符合“好”的标准,SWAT模型模拟的降水量和蒸发量总体呈现增加趋势,产水量呈现减少趋势;北川河流域桥头水文站径流量呈现减少趋势,年平均减少率为0.104 m^(3)/s,径流突变点为1990年;北川河流域河道内生态需水量为2.95亿m^(3),河道外生态需水量为9.95亿~10.85亿m^(3),生态总需水量为12.90亿~13.80亿m^(3)。

陕西省柞水县北川沟铜矿成矿地质特征及控矿因素与找矿标志

北川沟铜矿区位于柞(水)-山(阳)泥盆纪热水沉积盆地中部,区域性凤镇-山阳深大断裂北侧,处于柞水-山阳菱铁多金属成矿带中段。此成矿带产于中泥盆统大西沟组地层中、上段中,印支-燕山期强烈的造山运动,形成了一系列近东西向断裂构造,并使矿源层中成矿物质活化,迁移于有利的构造部位富集形成热水沉积-改造型矿床。本文对北川沟铜矿地质特征、物化探资料进行分析,总结其控矿因素与找矿标志,希望能为今后在本区找矿工作提供借鉴。

“Crack”： Beichuan in Ruins

This discussion interrogates the ruins of Beichuan, a county town in North Sichuan that was destroyed and rendered uninhabitable by the 2008 Wenchuan earthquake. Those ruins exist today in two principal forms. The remains of the original townsite have been evacuated and opened to the public as an open-air memorial; and earthquake museums have preserved artifacts recovered from the townsite and organized them alongside supporting texts, images, exhibits, dioramas, and amusement attractions. The ghost town, it is argued, ruptures the reform-era sense of national progress and development, forcing its observers and participants to acknowledge loss and absence. Connecting to a wider discourse, the National Earthquake Memorial Museum （NEMM） attempts to piece that sensibility back together by creating a particular memory of the massive state-led relief effort, by ＂disciplining＂ the catastrophe through inquiry and education, and by sublimating the earthquake through science, planning, and building. Although they remain emotionally separate, the ruins and NEMM have a natural tension with one another. Away from the epicenter, the privately managed Wenchuan Earthquake Museum （WEM） combines ruins and narrative to capture the ＂strange objectivity＂ that comes from any effort to make sense of what is ultimately insensible.

北川县近30年气温降水变化特征

根据北川县1992-2019年逐月温度、1992-2022年逐月降水量资料,采用趋势分析法、Mann-kendall检验等方法分析了北川县温度、降水变化特征及其相关性。结果表明:1992-2019年,北川县年平均气温与四季气温均呈上升趋势,年平均气温的增温倾向率是﹙0.36℃/10a﹚,年平均气温于1998年、2001年、2004年、2005年发生了突变,四季平均气温具有一定周期性变化特征;1992-2022年,北川县多年平均降水量为886.3 mm,年平均降水量呈上升趋势,降水变化倾向率是(3.9 mm/10a),降水量增加的主要原因是大暴雨频率增加,年降水量于2013年、2016年发生了突变,且存在周期性特征;强降雨天气主要发生在夏季,呈现出连续增多趋势;降水量与气温的变化呈正相关关系。研究结果可为北川地区地质灾害的防治提供一定的理论支撑。

西宁市北川河地表水水文化学特征

为了研究西宁市北川河地表水化学特征与水质变化情况,本文通过系统的样品采集,探究北川河空间分布特征、水化学分类等典型指标并进行相关性分析。结果表明:西宁市北川河地表水水化学类型较为复杂,其化学组分在空间分布上有一定的规律性;通过水化学分类可将北川河分为两段,下游段流经生态公园流域的离子含量明显降低,表明生态公园对河流的净化作用大于河流的自净化;地表水溶质来源以碳酸盐矿物风化为主,阳离子交换作用在河流全段均有发生;相关性分析表明部分离子与微量元素有相同的来源,聚类分析表明化学组分有明显区域性。

青海大通北川河源区国家级自然保护区生态建设存在的问题与管控建议

自然保护区对珍稀野生动植物、珍贵自然遗迹和典型生态系统保护发挥了重大作用。基于对国家自然保护地体系深刻理解和认识,从实际载畜量、农业生产值及植被覆盖度等方面总结青海大通北川河源区国家级自然保护区保护和发展现状,对自然保护区自然资源权属、体制机制及社区建设等存在的主要问题及成因进行了深入分析,结合自然保护区建设现状、发展问题及工作机制,提出了自然保护区应从体制机制、资金、人才及科技等多方面加强建设的建议。

Complicated phenomena of the Beichuan-Yingxiu surface fracture zone during Wenchuan Ms8.0 earthquake in Sichuan Province,China

After Wenchuan Ms8.0 earthquake,the surface fractures have been investigated in Beichuan City and Yingxiu Town.It was found that the Beichuan-Yingxiu earthquake fracture zone trends northeastward,dipping to northwest.The earthquake fracture zone is mainly characterized by thrust faulting with small amounts of strike-slip movement,and demonstrating various complexities for different areas.The phenomena related to dextral strike-slip displacement are found in Beichuan City and those related to left-lateral strike-slip movement in Yingxiu Town.The compressive shortening of the two surface fracture zones in Beichuan City is 2.8―3.9 m and the left-lateral strike-slip displacement of the surface fractures in Yingxiu Town is 0.52 m.

川西龙门山北段中生代差异构造隆升特征

川西龙门山冲断带内部发育多条大型断裂并经历了多期且复杂的构造演化。为探讨龙门山北段中生代以来主要断裂带之间的差异构造隆升,本文开展了锆石裂变径迹年龄测定工作,并计算了冷却速率等构造隆升参数。结果表明,锆石裂变径迹年龄主要集中在238~122 Ma之间,唐王寨向斜和仰天窝向斜核部冷却速率为1.211~1.438℃/Myr,剥蚀速率为0.038~0.048 mm/yr。向斜西北翼冷却速率和剥蚀速率相对稍高,分别为1.150~1.586℃/Myr和0.038~0.053 mm/yr,总体上,锆石裂变径迹年龄、冷却速率和岩石隆升幅度等参数在平面呈带状,且与主干断裂近于平行。各构造隆升参数在青川断裂、北川断裂和江油断裂所夹持的不同区域具有不同的变化范围,自北西至南东方向,构造变形兼具“前展式”和“后展式”特征。由前展式变形转变为后展式变形的时期为139~122 Ma。

映秀-北川断裂带北川段唐家湾滑坡活动历史与形成机制

以映秀-北川断裂带北川段唐家湾滑坡为研究对象,基于地形资料、多期遥感与航拍影像,结合14C测年的方法,细分了唐家湾滑坡的活动历史,分析了2016年唐家湾滑坡再次复活的主要控制因素。研究结果表明:(1)唐家湾斜坡历史上至少发生过四期滑动,其中第一期次滑坡发生在全新世以前;第二期次滑坡发生于全新世初期;第三期次滑坡发生在2008年汶川地震时期,系龙门山断裂带活动过程中产生的同震滑坡;第四期次滑坡分别发生在2016年和2018年,属于断裂带滑坡堆积体的再次局部复活;(2)2016年唐家湾滑坡的形成与断裂活动、河流侧蚀和水等因素有关,其中,上覆滑坡堆积体、下伏高陡基岩形成的二元斜坡结构,是唐家湾滑坡发生的决定性条件;断裂活动及其导致的浅地表最大主应力偏转是唐家湾滑坡变形的重要内因;(3)以唐家湾滑坡为例,初步讨论了基于地形条件控制的断裂带滑坡堆积体复活的地质模型,其形成演化表现为断裂带活动和河流侵蚀形成滑坡(或陡峭地形)→先期滑坡后壁(或陡峭地形)接受上部老滑坡堆积→二元斜坡结构控制下的老滑坡复活变形。该滑坡为研究地形控制断裂带滑坡复活提供了独特的案例,研究成果对于理解和评估该类滑坡,开展综合防治等方面具有重要的借鉴价值。

北川羌族自治县中羌药材产业SWOT分析及对策建议

该研究在介绍北川中羌药材资源分布状况及种植情况的基础上,阐明了北川中羌药材发展现状;运用SWOT法,对北川县中羌药材产业优势、劣势、机遇和挑战进行了综合分析,并从中羌药材全产业链的角度提出可持续发展的对策和建议,为北川制定产业规划、促进中羌药材产业快速高质量发展提供指导和参考。

北川河流域次降雨引发典型径流影响因素分析

为揭示引发北川河流域典型径流的次降雨特征及其影响因素,本研究通过整理不同历史时期北川河圪洞水文站降雨径流数据,采用最小二乘法对圪洞水文站典型径流与临近小流域不同雨量站降雨量间关系进行模拟。主要获得以下结论:(1)北川河流域进入21世纪以来的平均年降雨量有明显增加的趋势。降雨量年际变化差异大小为薛家沟>上阳湾>开府>方山>圪洞。降雨年际差异越大,其与圪洞水文站典型径流的相关性越大;(2)在不同历史时期圪洞站径流量与前期降雨量的相关度均远高于其与降雨量的相关性。(3)北川河流域引起明显径流的前期降雨以小雨和中雨为主,单次径流量大多数在20 m^(3)/s以内。20世纪60-90年代次降雨引发明显径流的雨型主要是中雨,而21世纪以来引发明显径流的次降雨雨型主要是大雨和暴雨。研究结果能为北川河流域在其周围小流域有针对性地实施水土保持措施提供可靠的依据。

基于QUAL2K模型的青海省北川河水质模拟研究

本文运用EPA开发的QUAL2K模型,对北川河水质状况进行模拟和预测,模拟结果较为准确地反映了北川河2013年逐月的水质状况,模拟值与实测值的相对误差在20%以内。因此,QUAL2K模型可以应用于北川河水质状况的模拟,并可以在中国北方河流的应用中做一定的推广。水质模型对于控制北川河河道污染、模拟和预测不同水文、水力条件下河流的情况并进行准确的水环境管理,具有非常重要的意义。

2017—2022年北川县臭氧污染特征分析

北川羌族自治县(简称北川县)位于四川盆地西北部,目前面临较大的大气污染防治压力。结合大气环境监测数据,本文分析2017—2022年北川县臭氧(O_(3))污染特征,明确臭氧污染的形成原因,并提出建议,以期为区域大气污染防治提供参考。监测结果显示,2018年、2020年臭氧污染天数最多,均为25 d;从季节分布来看,4—8月是臭氧污染的高发季节;从日变化来看,O_(3)浓度呈现出单峰结构。未来,北川县要因地制宜,综合施策,强化源头监管,全面治理臭氧污染,稳步推进区域大气污染防治。

2018—2022年北川县城区空气质量变化趋势分析

近年来,我国社会经济稳步发展,但环境污染问题依然比较严峻。其中,大气污染是影响人民群众身体健康和社会经济可持续发展的重要因素。随着环境保护意识的增强,空气质量备受大众关注。北川羌族自治县(简称北川县)隶属于四川省绵阳市,是长江上游重要生态屏障,也是国家重点生态功能区。本文以北川县城区为例,分析2018—2022年区域空气质量变化趋势,并提出改善策略。监测结果表明,北川县城区空气质量存在较为严重的污染,主要污染物为细颗粒物(PM_(2.5))和NO_(2)。未来,北川县要采取更加有力的大气污染治理措施,切实改善区域空气质量,保障人民群众的身体健康,实现经济和环境的可持续发展。

族群认同、身份重构、资源转化:传说动力学视域下北川大禹传说初探

四川省北川羌族自治县的禹里乡石纽村凭借大量的历史遗存、文献资料和口头传说,而被认为是远古先帝与治水英雄大禹的降生地。该地的大禹传说和祭禹文化传承千年,而后因故中断。20世纪80年代以来,当地民俗精英在志书修缮的过程中重拾族群记忆,并对大禹传说进行持续建构和转换运用。以传说动力学的相关视角来分析北川大禹传说,探讨传说生长和变化的动力系统,以及背后所隐含的群体性心理需求和时代性动力因素。