Hazard Assessment of Co-seismic Landslides Based on Information Value Method:A Case in 2018 MW6.6 Hokkaido Earthquake,Japan

An MW6.6 earthquake occurred in eastern Hokkaido,Japan on September 6th,2018.Based on the pre-earthquake image from Google Earth and the post-earthquake image from high resolution(3 m)planet satellite,we manually interpret 9293 coseismic landslides and select 7 influencing factors of seismic landslide,such as elevation,slope,slope direction,road distance,flow distance,peak ground acceleration(PGA)and lithology.Then,9293 landslide points are randomly divided into training samples and validation samples with a proportion of 7:3.In detail,the training sample has 6505 landslide points and the validation sample has 2788 landslide points.The hazard risk assessment of seismic landslide is conducted by using the information value method and the study area is further divided into five risk grades,including very low risk area,low risk area,moderate risk area high risk area and very high risk area.The results show that there are 7576 landslides in high risk area and very high risk area,accounting for81.52%of the total landslide number,and the landslide area is 22.93 km^2,accounting for 74.35%of the total area.The hazard zoning is in high accordance with the actual situation.The evaluation results are tested by using the curve of cumulative percentage of hazardous area and cumulative percentage of landslides number.The results show that the success rate of the information value method is 78.50%and the prediction rate is 78.43%.The evaluation results are satisfactory,indicating that the hazard risk assessment results based on information value method may provide scientific reference for landslide hazard risk assessment as well as the disaster prevention and mitigation in the study area.

Northward-propagating nighttime medium-scale traveling ionospheric disturbances observed with SuperDARN Hokkaido HF radar and GEONET

We report on the characteristics of nighttime medium-scale traveling ionospheric disturbances （MSTIDs） propagating northward observed with the SuperDARN Hokkaido HF radar, which has a field of view to the north of Japan, and occasionally with the GNSS Earth Observation NETwork （GEONET）, which provides total electron content （TEC） data over Japan. From statis- tical analysis of MSTIDs observed with the Hokkaido radar during nighttime （1700-0700 LT） from January 2007 to July 2009, we find that these MSTIDs traveling northward, although rare in comparison with those traveling southwestward, have a relatively high occurrence rate after sunset and around midnight in May and August, which is partly consistent with the occurrence rate of MSTIDs over Japan observed with GEONET in 2002, when the MSTID event database is available. We also use the data from simultaneous observation of nightside MSTIDs by the Hokkaido radar and GEONET to find that when the HF radar observed northward-propagating MSTIDs, GEONET did not always observe such MSTIDs with the same propagation direction. Judging from this result and considering the HF radar field of view located to the north of the GEONET coverage area, we speculate that some physical parameters of the ionosphere/thermosphere over Japan differ from those to the north of Japan, which may result in the inconsistency of MSTID propagation direction. The present results provide new knowledge of MSTIDs propagating northward using the Hokkaido radar, whose field of view was not covered by GEONET.

Study of ionospheric disturbances during solar flare events using the SuperDARN Hokkaido radar

It is well known that many types of ionospheric disturbances occur during solar flare events. The sudden increase in total electron content （SITEC） has been studied for several decades, but total electron content （TEC） data do not provide information on the altitudinal distribution of electron density changes. Previous studies used HF Doppler system data to investigate the contributions of the D-region and F-region ionospheric electron density changes by examining the HF radio wave frequency dependence on the Doppler shift values. In this study we examined the dependence of the elevation angle of the Doppler shift of ground scatter echoes using the SuperDARN Hokkaido radar. We analyzed solar flare events from Dec 2006 to Mar 2012. A sudden fade-out of echoes was observed in almost all the events we analyzed, which was the result of the radio absorption associated with a significant increase in electron density within the D-region ionosphere. In addition, we discovered positive Doppler shifts just before the sudden fade-out of echoes. The Doppler shift is negatively correlated with the elevation angle of received radar waves. It indicates that variation of electron density in the D-region ionosphere is dominant during solar flare events. This result is consistent with a previous study. We also compared the irradiation by X-ray and extreme ultra violet rays observed by the GOES-14 and GOES-15 satellites, which generated Doppler shifts. A positive Doppler shift is consistent with a change of X-ray

Evaluation of Nitrogen Cycling Associated with Agricultural Production and Environmental Load in a Mountain Region,in Hokkaido,Japan

This study examined the nitrogen cycling associated with agricultural production and environmental load in central Hokkaido. The nitrogen (N) budget analysis model offers a new set of tools for evaluating N cycling in agro-ecosystems. The cycling index (CI) is a useful tool for estimating optimal N flows in farmlands. The fertilization index (FI) is a useful indicator for characterizing the N flows related to farms. Using these parameters, we analyzed all farm systems to estimate the optimal N cycling for minimizing N pollution in groundwater and maximizing agricultural production in mountain regions of Japan. The results showed that the critical N application rate (chemical fertilizer + manure) was 143.3 kg N ha-1 y-1. The critical inter-system input (chemical fertilizer N, imported food and feed N, and natural supplied N) was 169.2 kg N ha-1 y-1.

A Survey of Community Pharmacists about Work-Related Issues, How they Solve them, and who they Consult with to Solve them: Comparison of Results from the Hokkaido Area vs. a Nationwide Survey

We surveyed the drug information retrieval practices among community pharmacists in more rural Hokkaido and in entire Japan in order to explore local characteristics of work-related issues, how community pharmacists access information to address such issues, and with whom they consult to solve them. Based on the findings, we propose a strategy for improvements in similar support systems. The percentage of respondents who had experience with home care services was significantly lower in the Hokkaido group (56.0% of 207) than in the nationwide group (70.0% of 250), as was the percentage of respondents who consulted the pharmacist association and branch board (13.0% and 20.4%, respectively). The Hokkaido group also made significantly less use of websites such as d.m3.com and e.CareNet.com. The results of this survey thus indicate that the drug information retrieval in the Hokkaido group had a low implementation rate of home care services. In addition, there were low levels of utilization of the local pharmacist association, and low utilization of the websites d.m3.com and e.CareNet.com. To enhance the Hokkaido community-based integrated care system (and ones like it), we propose that it is necessary to: 1) support activities of local pharmacist associations, and 2) promote proactive implementation of drug information retrieval through education.

2018年日本北海道M_(W)6.6地震震源动力学破裂过程

2018年9月5日日本北海道东胆振地区发生了M_(W)6.6地震,震源深度37 km,超过了地壳与上地幔脆韧性边界的深度,且在地表产生了较强的破坏.为研究北海道地震震源区发震构造及产生强地面运动的物理机制,本文基于此次地震的震源运动学模型,针对其震源动力学模型开展了研究,尝试反演了动力学破裂过程.首先,由北海道地震运动学模型分析计算了断层面上的剪切应力,确定其破裂过程基本上是遵循滑动弱化摩擦准则,并由此获得初始模型的震源动力学参数,然后通过试错法反演了这次地震的震源动力学破裂过程.研究结果显示,北海道地震动力学破裂为自破裂起始处以走滑为主,先NE后SW,最终向断层面上倾方向传播,并在断层几何的弯折处产生逆冲破裂.在逆冲破裂的位置,滑动速率和滑动量达到最大值,结合运动学和动力学反演结果分析,推断该区域为强运动生成区,在地面产生的高频地震动是该中等、较深震源地震破坏性较强的主因.

北海道鲱鱼渔场建筑的谱系——海洋文化传播视角下的建筑空间及其近代化

聚焦日本北海道鲱鱼渔场建筑的结构特征,从历史与环境变迁的交叠对其表现形式进行解读,并梳理其谱系。以18个鲱鱼渔场建筑案例为研究对象,基于相关研究将代表性建筑形式分为5类:19世纪的“运上屋”和“渔家”,以及20世纪前后的“番屋建筑”“积丹式民家”和“仕込屋”。通过各建筑类型的空间特点总结出两条谱系——从运上屋到仕込屋的谱系,以及从渔家到番屋建筑的谱系——由此论证鲱鱼渔场建筑在19世纪上半叶从日本传统民居派生形成,并在20世纪向渔业生产的功能空间转变的发展脉络;此外,从木构建筑文化的视角来看,南部硕大粗犷的梁柱结构以及北部屋架的抗风雪性能和顶梁柱形式是其突出特征。今后的研究发展方向包括:渔场建筑群整体的产业空间特征,以及日本东北与北海道地区的木构文化传播。

人口收缩时代日本北海道中小城市的精明收缩策略研究

城市收缩正在成为新的常态化现象席卷全球,引发一系列城市可持续发展问题。在国内外社会经济环境条件的叠加作用下,我国部分中小城市开始出现以人口减少为表征的城市收缩现象,营造高品质生活环境的现代化城市治理政策将成为收缩城市的崭新命题。通过对日本北海道的人口收缩城市案例及其推动的收缩应对策略进行研究分析,探讨得出将来适合中国收缩型中小城市规划发展的有益启示:(1)遵循精明收缩理念,通过城市功能紧凑化战略和公共交通网络化战略推动多中心网络化紧凑城市建设;(2)发展升级产业和优化产业结构,促进产业和就业的良性互动;(3)城市政府向高质量服务型转变,构建引导市民自发参与城市建设的协作体制机制。

近百年来中国东北与日本北海道地区气温变化对比

利用东北及北海道地区7个气象站点1909～2003年逐月气温数据，建立两地区近百年来年、季气温序列，对近百年来两地区气温变化特征进行对比分析，结果表明：近百年来东北及北海道地区气温变化存在显著的增温趋势，前者进入显著升温期早于后者，其中对年均温上升趋势贡献较大的是冬、春两季，夏季升温幅度最小。两地区年均温表现出强的增温持续性，未来气候将继续变暖；两地区都存在9、28、40—42a的变化周期，但两者主周期的次序所有不同；近百年来两地区气温变化在不同时间尺度上具有不同突变点。

2003年日本北海道8.0级地震次声波特征研究

利用在北京昌平安装的次声三点阵,记录了2003年9月26日日本北海道地震的前兆次声波和震后次声波。实际记录的P-t曲线及波速波向图,经快速傅立叶变换得到其三维动态频谱。结果表明:①强震前2-7天能测到振幅很强、方向可测的地震前兆次声波。其频谱特点是:振幅由弱(10-15 Pa)逐渐加强到(50-80 Pa)或更大;先为短周期波(10-30 min),紧跟着长周期波(30-50 min),然后又出现更长的周期波,最后长短周期的波一起出现连成一片(2-62 min);②地震前兆次声波的产生和记录较容易,而当地次声波和震中次声波记录和识别比较困难;③若两地的三点阵波向相交,可预测震中位置。故地震前兆次声波的测量研究。

日本北海道的土层改良技术的评介

自19世纪末以来 ,特别是第二次世界大战以后 ,日本北海道在土层改良研究方面不断取得进展 ,已经探索出一系列适用于不同土壤的改土技术 ,如暗管排水、心土耕、混层耕、翻转客土、改良式翻转客土及心土培肥技术等。本文在评述北海道土层改良技术发展过程及其效果的基础上 。

北海道观赏性农田景观的多元价值

北海道以特色花卉为主体打造观赏性农田景观,通过区域经营管理体制与政策协同支持,在发展过程中构建了生态、经济、文化、社会和美学多元价值,形成了以多元价值的成功开发为基础,提升景观品质、带动区域经济整体发展的特色路径,为国际观赏性农田景观发展提供范例.通过分析北海道观赏性农田景观多元价值的构建基础、内容及作用,以期对我国观赏性农田景观的多元价值开发起到一定启示作用.

Analysis of forest structural complexity using airborne LiDAR data and aerial photography in a mixed conifer–broadleaf forest in northern Japan

Determining forest structural complexity,i.e.,a measure of the number of different attributes of a forest and the relative abundance of each attribute,is important for forest management and conservation.In this study,we examined the structural complexity of mixed conifer–broadleaf forests by integrating multiple forest structural attributes derived from airborne Li DAR data and aerial photography.We sampled 76 plots from an unmanaged mixed conifer–broadleaf forest reserve in northern Japan.Plot-level metrics were computed for all plots using both field and remote sensing data to assess their ability to capture the vertical and horizontal variations of forest structure.A multivariate set of forest structural attributes that included three Li DAR metrics(95 th percentile canopy height,canopy density and surface area ratio) and one image metric(proportion of broadleaf cover),was used to classify forest structure into structural complexity classes.Our results revealed significant correlation between field and remote sensing metrics,indicating that these two sets of measurements captured similar patterns of structure in mixed conifer–broadleaf forests.Further,cluster analysis identified six forest structural complexity classes includingtwo low-complexity classes and four high-complexity classes that were distributed in different elevation ranges.In this study,we could reliably analyze the structural complexity of mixed conifer–broadleaf forests using a simple and easy to calculate set of forest structural attributes derived from airborne Li DAR data and high-resolution aerial photography.This study provides a good example of the use of airborne Li DAR data sets for wider purposes in forest ecology as well as in forest management.

基于EMD北海道地区50年降水及南方涛动的分析

[目的]树木年轮δ^18O资料有助于重建过去降水情况；利用EMD法分析北海道地区50年的降水情况及南方涛动指数（SOI）。[方法]利用北海道大学地球环境科学学院实验室的橡树树轮资料和NCEP公布的1953-2002年的SOI资料，采用EMD法对北海道地区的树轮的δ^18O进行分析。[结果]该地区的降水存在着3、6、11、22、33年的周期。时SOI进行EMD的分析发现，南方涛动同样存在着3,6、22、33、50年的周期；而SOI指数能够反映南方涛动现象。通过对比这两个EMD结果，在相同的时间范围内，北海道地区的降水与南方涛动的周期尺度基本上是相同的，进而推测，北海道地区的降水在很大程度上受到南方涛动的影响。[结论]通过分析得到的北海道地区降水多时间尺度周期，对分析我国的降水资料有一定的启示作用。

战后日本北海道开发及其新方向

北海道开发以政府投入为驱动力,以综合计划作为手段,在政府一元化的组织领导下,经济社会生活取得了突破性发展。但是北海道经济缺乏独立性、经济发展不均衡以及产业结构内部不尽合理也是政府主导型开发模式矛盾长期积累的结果。在新世纪,实现北海道经济的自立发展并着力培育新兴产业,构建北方国际交流中心,实现环境与开发相融合,构建尽享各种不同生活方式和文化的北海道成为新世纪开发的重要方向和目标。

北海道黄杨扦插繁殖的研究

北海道黄杨当年生枝条,用不同外源激素、不同时间和不同浓度处理后插入蛭石中培养。试验结果表明:当年生枝条生根率优于带一段老枝的当年生枝条生根率,扦插 30d后,生根率达 84.71%。IBA和NAA对促进北海道黄杨生根均有一定效果,但生根率IBA高于NAA,使用IBA和NAA进行高浓度短时间处理时,以浓度为 80 0mg/L时效果最好,经IBA处理后的插条,平均根数为 2 5.6 7条,经NAA处理后的插条平均根数为 9.0 1条。使用IBA和NAA进行低浓度长时间处理时,生根效果随激素浓度的升高而增加,IBA以浓度为 16 0mg/L处理 14～ 18h效果最好,平均根数为 4 9.88条;NAA以浓度为 16 0mg/L处理 10～ 14h效果最好,平均根数为 14.33条。

温度对北海道黄杨叶片光系统Ⅱ功能的影响

人工控温对北海道黄杨扦插苗叶片光系统Ⅱ的功能进行研究。结果表明:20～25℃之间是北海道黄杨叶片光系统Ⅱ作用最强的温度范围,低于或高于这一温度范围,北海道黄杨叶片的叶绿素a荧光动力学曲线发生了明显改变:FV/Fm,FV/F0值降低,导致光系统Ⅱ的原初光能转换率和潜在光合活力均受到抑制;荧光光化学猝灭系数(qP)降低,荧光非光化学猝灭系数(qN)提高,抑制了叶绿体把捕获的光能用于光合作用。

日本家庭牧场农牧业纵横一体化规模经营启示

目前家庭养殖业面临成本高、风险大、产品质量要求高,以及污染物处理难等问题。所以,需要创新养殖业规模化经营模式。文章通过对日本北海道家庭牧场经营模式的调查分析,得出结论为:农牧业纵横一体化是家庭牧场经营的一种有效而理想的模式,该模式横向一体化是指以饲料饲草和肥料为纽带的种养业结合经营,纵向一体化是家庭牧场与加工企业、服务组织等联结的模式。并提出对策建议:引导农牧业经营主体采用横向一体化经营模式;鼓励农牧业经营主体采用纵向一体化经营模式;完善农牧业纵横一体化经营机制。

日本青函隧道的技术特点及应用情况

青函隧道作为日本世纪性的海底隧道工程,建设期间经历无数艰险,克服了多项技术难题,在开通后近30年的运营中获得了诸多宝贵经验。实践表明,青函隧道目前涌水处于可控程度、应急救援设备切实有效,但也存在超前导坑变形、轨道电路易发生短路事故、共用区间有待提速等问题。从青函隧道的技术特点出发,介绍隧道多年来的应用情况,为我国铁路海底隧道的设计和建设提供参考和借鉴。

日本北海道大学的通识教育实践与启示

通识教育是世界一流大学建设的重要组成部分。日本的一流研究型大学——北海道大学秉承通识教育与专业教育的融合发展理念,创建了日本具有先驱意义的全校共建式通识教育模式——"北大方式",由独立于各院系的"高等教育推进机构"统筹运营;课程设计遵循跨学科原则,重视国际化发展以及大学组织间的资源优势共享;坚持"由最好的教师进行最好的通识教育"的宗旨,选拔各院系及相关机构的优秀学者任教;构建了较为完善的教师发展支持体系以及以学生自主学习为核心的学业支持体系。日本北海道大学的通识教育模式及实践经验为我国高校推动通识教育改革、加快推进中国特色世界一流大学建设提供了良好的参考与借鉴。