GIS and quantitative geography     

Keiji Yano 《GeoJournal》2000,52(3):173-180

The purpose of this paper is to explore the development of the GIS revolution within the field of geography in the 1980s and 1990s, taking into consideration the influence of external and internal factors on disciplinary change. Geography is rapidly changing by the impact of external factors on geographical research and also as a consequence of economic recession and cutbacks in higher education. Most geography departments in universities have tried to approach this impact by promoting or shifting to human geography as an applied science, and by offering relevant skills through GIS as an approach to contemporary problems. It is concluded that quantitative geography is essential for the further expansion of GIS within geography and also for the survival of geography. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

日本中期数值预报传真图在桂东地区春播预报中的应用     

梁飞燕 《气象研究与应用》2000,21(2):12-14

用近几年的日本中期数值预报传真图的96～120h500hPa环流、涡度预报场、850hPa温度预报场及地面形势预报场与桂东地区受冷空气影响时段及低温阴雨天气过程进行对比分析,发现传真图对春播期的每次冷空气南下过程都能提前报出,对冷空气有较强的预报能力,为此,对这些传真图进行了归纳分析,找出一些桂东地区低温阴雨天气过程在日本中期数值预报传真图中的特征。  相似文献   

Source Diversity of Ore Sulfur from Mesozoic-Cenozoic Mineral Deposits in the Korean Peninsula Region   总被引：2，自引：0，他引：2  

Shunso ISHIHARA  Myung–Shik JIN  Akira SASAKI 《Resource Geology》2000,50(4):203-212

Abstract: Sulfides from the Daebo Jurassic granitoids and some ore deposits from Korean Peninsula and Sikhote Alin occurring in different basement settings were analyzed for δ³⁴S values. Highly positive values were obtained from Jurassic Mo skarn deposit at Geumseong of the Ogcheon belt (average +13. 0%), Au‐quartz vein deposits at Unsan, North Korea (+6. 7%), and late Paleozoic Sn‐F deposit at Votnesenka (+8. 2%), Khanka massif, Russia. Together with published data of that region, regional variation of δ³⁴S values is shown across Korean Peninsula. Sulfur isotopic data published are compiled on 88 ore deposits, whose mineralization epochs belong to Cretaceous (58 deposits), Jurassic (25 deposits) and Precambrian (4 deposits) in South Korea. Average sulfur isotopic values vary across South Korea as follows: Cretaceous deposits in the Gyeongsang basin, +4. 8% ranging +1.2 ? +12.7‰ (n=28); Jurassic and Cretaceous deposits in the Sobaegsan massif, +3. 5% ranging 0.0 ? +7.8‰ (n=20); those of the Ogcheon belt, +6. 4% ranging ‐0.5 ? +15.4‰(n=19); those of the Gyeonggi massif, +5. 5% ranging +2.1 ? +9.0‰(n = 21). The δ³⁴S values of South Korea tend to be concentrated around +5. 5 permil, exhibiting little, if any, a systematic variation across the geotectonic belts. This tendency is seen also in North Korea and Northeast China within the Cino‐Korean Block, and may be called as Cino‐Korean type. Sulfur of this type is derived mostly from the crystalline basement. Khanka massif of Russia seems to have features of the Cino‐Korean type. In contrast, paired positive/negative belts corresponding to magnetite‐series/ilmenite‐series granitic belts are overwhelming in the Japanese Islands, especially in Southwest Japan. The similar trend is also seen in southern Sikhote Alin and northern Okhotsk Rim, which may be called as Japanese type. Source of the sulfur in this type is likely in the subducting oceanic slab for positive value and accreted sedimentary complex for the negative value, respectively. The Daebo granitoids have an average rock δ³⁴S value of +5. 3 permil, which should have reflected that of the source rocks in the continental crust. The ore sulfur heavier than this value may have been originated in other granitoids having even higher δ³⁴S values, or the ore fluids interacted directly with sulfate sulfur of the host evaporites or carbonate rocks. Rock isotopic values of granitoids and basement rocks need to be examined in future from the above point of view in mind.  相似文献   

Novel mass-aggregation-based calibration of an acoustic method of monitoring bedload flux by infrequent desert flash floods     

Eran Halfi  Dror Paz  Kyle Stark  Uri Yogev  Ian Reid  Michael Dorman  Jonathan B. Laronne 《地球表面变化过程与地形》2020,45(14):3510-3524

The monitoring of bedload flux under flash flood conditions has been successfully achieved since 1992 using slot samplers in the semiarid Nahal Eshtemoa. In the present study, a surrogate bedload monitoring technique - the Japanese plate microphone - has been deployed and calibrated against data from the slot samplers. Since a slot sampler has a sensitivity threshold that becomes especially important when transport rates are low, different averaging periods should be considered for high and low fluxes. In order to overcome the deficiencies of time-based aggregation used hitherto, we have developed a new method involving mass aggregation and commensurably variable intervals, thereby enabling a more accurate analysis and optimizing the bedload sampler's capabilities. The data derived with this new method has then been utilized to calibrate the Japanese plate microphone. The Eshtemoa is an ephemeral gravel bed channel with a high proportion of fine gravel (< 0.02 m); for these conditions, acoustic sensors have not been calibrated as yet. Two multiple linear regression models incorporating the effect of median bedload grain size on pulse rate have been established to predict bedload flux and cumulative transported bedload mass. The coefficients in these models are statistically significant. Good predictions are obtained for bedload flux (adj. r² = 0.83) and for cumulative bedload mass (adj. r² = 0.98) during flood recession. Overall, the multiple linear regression models, used in conjunction with the mass aggregation method of estimating bedload flux, suggest that field calibration of acoustic devices is feasible under these conditions for ca. 90% of the duration of bedload transport. © 2020 John Wiley & Sons, Ltd.  相似文献   

Origin of the early Cenozoic belt boundary thrust and Izanagi–Pacific ridge subduction in the western Pacific margin     

Gaku Kimura  Yujin Kitamura  Asuka Yamaguchi  Jun Kameda  Yoshitaka Hashimoto  Mari Hamahashi 《Island Arc》2019,28(5)

The belt boundary thrust within the Cretaceous–Neogene accretionary complex of the Shimanto Belt, southwestern Japan, extends for more than ~ 1 000 km along the Japanese islands. A common understanding of the origin of the thrust is that it is an out of sequence thrust as a result of continuous accretion since the late Cretaceous and there is a kinematic reason for its maintaining a critically tapered wedge. The timing of the accretion gap and thrusting, however, coincides with the collision of the Paleocene–early Eocene Izanagi–Pacific spreading ridges with the trench along the western Pacific margin, which has been recently re‐hypothesized as younger than the previous assumption with respect to the Kula‐Pacific ridge subduction during the late Cretaceous. The ridge subduction hypothesis provides a consistent explanation for the cessation of magmatic activity along the continental margin and the presence of an unconformity in the forearc basin. This is not only the case in southwestern Japan, but also along the more northern Asian margin in Hokkaido, Sakhalin, and Sikhote‐Alin. This Paleocene–early Eocene ridge subduction hypothesis is also consistent with recently acquired tomographic images beneath the Asian continent. The timing of the Izanagi–Pacific ridge subduction along the western Pacific margin allows for a revision of the classic hypothesis of a great reorganization of the Pacific Plate motion between ~ 47 Ma and 42 Ma, illustrated by the bend in the Hawaii–Emperor chain, because of the change in subduction torque balance and the Oligocene–Miocene back arc spreading after the ridge subduction in the western Pacific margin.  相似文献   

基于耳石微结构的黄、渤海蓝点马鲛幼鱼日龄与生长     

朱庆环  田永军  张弛  叶振江  徐宾铎 《海洋学报》2020,42(2):87-95

鱼类的生长是影响群体资源量的要素,研究鱼类的生长规律是开展资源评估工作的基础。本研究依据2016年9-10月和2017年8-10月在黄渤海采集的当年生蓝点马鲛(Scomberomorus niphonius)幼鱼,通过耳石微结构分析,确定了蓝点马鲛孵化期,建立了生长模型并估算了生长率。结果显示,幼鱼日龄范围为64~151 d,孵化日期为5月3日至6月15日,高峰期集中在5月20日至6月3日。叉长和体质量的生长符合Logistic生长模型。叉长平均绝对生长率和特定生长率分别为2.45 mm/d和0.85%/d,生长率随着日龄增大而小幅度减小。体质量平均绝对生长率和特定生长率分别为5.33 g/d和2.68%/d,最大绝对生长率和最大特定生长率分别出现在111~120 d和91~100 d。本研究表明,蓝点马鲛幼鱼生长随日龄发生变化,早期生长较以往进一步加快。  相似文献   

Do foreign subsidiaries innovate and perform better in a cluster? A spatial analysis of Japanese subsidiaries in the US     

《Applied geography (Sevenoaks, England)》2013

The interrelationship between clustering, innovation, and performance of Japanese subsidiaries in the US is examined in this paper. First, we apply Kulldorff's spatial scan statistic to identify process innovation clustering among Japanese subsidiaries. The scale at which clustering occurs is regional rather than local, and cluster location captures the geographical environment of home-transplants from Japan. Second, we apply spatial autoregressive models to test the relationship between cluster location and innovation among Japanese subsidiaries. The results indicate that cluster location strengthens the relationship between subsidiary innovation and firm performance. Negative spatial autocorrelation shows that clustering contributes to innovation by facilitating proximate learning between less innovative laggards, and, leading innovative Japanese subsidiaries.  相似文献   

Response of Japanese anchovy (Engraulis japonicus) to the Pacific Decadal Oscillation in the Yellow Sea over the past 400 a     

Haoyu Li  Qisheng Tang  Yao Sun 《海洋学报(英文版)》2022,41(8):31-40

Quantitative identification of long-term changes in the abundance of Japanese anchovy (Engraulis japonicus) in the Yellow Sea is particularly important for understanding evolutionary processes of the Yellow Sea ecosystem. Unfortunately, the driving mechanisms of climate variability on the anchovy are still unclear due to the lack of long-term observational data. In this study, we used the fish scale deposition rate in the central Yellow Sea to reconstruct the time series of the anchovy stock over the past 400 a. On this basis, we further explored the impacts of the Pacific Decadal Oscillation (PDO) on the anchovy. Our results show that the anchovy stock is positively correlated with the PDO on a decadal time scale. In addition, anchovy abundance was relatively high during 1620–1860 AD (the Little Ice Age, LIA), though in a state of constant fluctuation; anchovy abundance maintained at a relatively low level after ~1860 AD. In particular, followed by overfishing since the 1980s, the anchovy stock has declined sharply. Based on these findings, we infer that fluctuations of the anchovy stock may be regulated by basin-scale “atmosphere–ocean” interactions. Nevertheless, the role of overfishing should not be ignored.  相似文献   

Japanese ratification of the Kyoto Protocol     

《Climate Policy》2013,13(3):343-362

Abstract

This paper discusses Japan's quantitative Kyoto target in the context of the country's socio-economic and political background and its desire to express international leadership. Japan's initial negotiating target was developed as a compromise between domestic industrial considerations and its international ambitions, and was strengthened further under the pressures to achieve success at Kyoto.

The original projections relied heavily upon nuclear expansion that will not be realized. Though economic stagnation has helped emissions to decline from their mid-1990s peak, it has also reduced the attention devoted to climate change and the willingness to bear costs, and Japan's commitment remains daunting. Japanese bureaucrats and diplomats are called to work closer together and in an integrated manner in order to develop a new, more realistic policy package for achieving their target. This report analyses various scenarios for additional policies for Japan, including fuel switching, carbon taxation and emissions trading, and concludes that the introduction of gas in the context of energy market liberalization is a key possibility. It also considers the sink and the nuclear energy issues both of high importance for the country.  相似文献   

芥川龙之介《水虎》三元比较研究     

毛娟 《广东海洋大学学报》2006,26(5):105-108

芥川龙之介的《水虎》与果戈理的《狂人日记》、鲁迅的《狂人日记》均采用了现实主义与象征主义相结合的创作方法,一针见血地揭露了社会制度的黑暗与腐朽。但他们在创作方法上使用的象征主义和对社会现实揭露的广度与深度不完全相同,主人公的思想高度更是各不相同。作品创作的背景、历史条件,作者的思想高度、性格特点和创作风格是造成这些差别的根源。  相似文献