1990年以来中国小麦农业气象灾害时空变化特征(英文)     

张朝  王品  陈一  张帅  陶福禄  刘晓菲 《地理学报(英文版)》2014,24(3):387-396

Agro-meteorological disasters(AMD) have become more frequent with climate warming. In this study, the temporal and spatial changes in the occurrence frequency of major meteorological disasters on wheat production were firstly explored by analyzing the observed records at national agro-meteorological stations(AMS) of China from 1991 to 2009. Furthermore, impact of climate change on AMD was discussed by comparing the warmer decade(2000–2009) with another decade(1991–2000). It was found that drought was the most frequent disaster during the last two decades, with a highest proportion of 79%. And the frequency of AMD increased significantly with climate change. Specifically, the main disasters occurred more frequently in the reproductive period than in the vegetative period. Besides, the spatial changes in the AMD frequency were characterized by region-specific. For example, the wheat cultivation areas located on the Loess Plateau and the middle-lower reaches of the Yellow River suffered mainly from drought. All these results were strongly linked to climate change in China. Therefore, sound adaptation options should be taken based on the latest changes of AMD under global warming to reduce agricultural damages.  相似文献   

Modeling and representation for earthquake emergency response knowledge: perspective for working with geo-ontology     

Jinghai Xu  Timothy L. Nyerges  Gaozhong Nie 《International journal of geographical information science》2014,28(1):185-205

Earthquake emergency response is one of the three earthquake disaster mitigation work systems in China, already achieving good results in some earthquake disaster mitigation situations. Earthquake emergency plans and emergency command systems are among the most important research and operations components of emergency response. These components commonly come with challenges, such as the pertinence of emergency commands and the operability of the countermeasures to be improved. The promise for solving this problem resides with applying knowledge that aids intelligence creation for decision-making. In this paper, we put forward a conceptual model of knowledge for earthquake disaster emergency response (EDER); compositions of EDER knowledge are introduced within architecture. A modeling method incorporating geo-ontology is used to build basic modeling primitives. Geo-ontology serves to represent geospatial characteristics of the EDER knowledge and addresses a need for semantic interoperability in the modeling process. A decision problem framework and a case study have been used as theoretical framework and an application test, respectively, to evaluate the EDER knowledge architecture and models. The EDER knowledge model provides a foundation for intelligent emergency response that helps solve knowledge problems to improve earthquake disaster response.  相似文献   

Denitrification potential of marsh soils in two natural saline-alkaline wetlands     

Junhong Bai  Qingqing Zhao  Junjing Wang  Qiongqiong Lu  Xiaofei Ye  Zhaoqin Gao 《中国地理科学(英文版)》2014,24(3):279-286

Little information is available on denitrification potential of marsh soils in natural saline-alkaline wetlands. The denitrification potentials of an open wetland in the floodplain(Erbaifangzi wetland) and a closed wetland(Fulaowenpao wetland) in backwater areas in Jilin Province of Northeast China were monitored by an anaerobic incubation at 30℃ for 25 days. Our results showed that the relative denitrification index(RDI) increased gradually with incubation time, and showed a rapid increase in the first 5 days of incubation. The RDI values declined quickly from surface soils to subsurface soils and then kept a small change in deeper soils along soil profiles over the incubation time. Denitrification proceeded much faster in the top 20 cm soils of open wetland than in the closed wetland, whereas no significant differences in RDI values were observed in deeper soils between both wetlands. The RDIs were significantly negatively correlated with bulk density and sand content, while a significantly positive correlation with clay content, soil organic matter, total nitrogen and phosphorous. The maximum net NO–3-N loss through denitrification in 1 m depth were higher in the open wetland than the closed wetland with higher soil pH values. Future research should be focused on understanding the influencing mechanisms of soil alkalinity.  相似文献   

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�Ա�  ������  ����  ��ΰ  �Ųʺ�  ̷��  ����� 《大地测量与地球动力学》2014,34(5):178-182

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南海北部深水区新生代岩浆岩分布规律及其与海底地质灾害的相关性   总被引：2，自引：1，他引：1  

张丙坤  李三忠  夏真  马云  余珊  王霄飞 《海洋学报》2014,36(11):90-100

前人对南海北部新生代陆缘盆地结构、构造样式和期次等做了大量的研究工作,但对于具体体现内动力过程的岩浆活动关注较少,尤其是北部深水区的研究鲜有涉及。本文基于二维地震剖面的解译分析,将南海北部新生代岩浆岩划分为3个集中分布区:琼东南-西沙区、神狐区和东沙区。各区域岩浆岩的产出状态有所差异,其中琼东南-西沙区岩浆岩的平面展布规律性极强,主要受右行右阶的走滑断裂控制;神狐区岩浆岩位于NW向与NE向断裂的交汇处,侵位空间受先存断裂制约;东沙区岩浆岩的产生与东沙运动期间区域伸展过程有直接关系。作为内动力的表征,岩浆作用对于海底地形地貌具有重要的改造作用,与活动断裂、海底滑坡、浅层气等海底地质灾害也具有成因上的关联。  相似文献   

Relationships between Interannual and Intraseasonal Variations of the Asian-Western Pacific Summer Monsoon Hindcasted by BCC_CSM1.1（m）   总被引：4，自引：0，他引：4  

LIU Xiangwen  ;WU Tongwen  ;YANG Song  ;LI Qiaoping  ;CHENG Yanjie  ;LIANG Xiaoyun  ;FANG Yongjie  ;JIE Weihua  ;NIE Suping 《大气科学进展》2014,31(5):1051-1064

Using hindcasts of the Beijing Climate Center Climate System Model, the relationships between interannual variability （IAV） and intraseasonal variability （ISV） of the Asian-western Pacific summer monsoon are diagnosed. Predictions show reasonable skill with respect to some basic characteristics of the ISV and IAV of the western North Pacific summer monsoon （WNPSM） and the Indian summer monsoon （ISM）. However, the links between the seasonally averaged ISV （SAISV） and seasonal mean of ISM are overestimated by the model. This deficiency may be partially attributable to the overestimated frequency of long breaks and underestimated frequency of long active spells of ISV in normal ISM years, although the model is capable of capturing the impact of ISV on the seasonal mean by its shift in the probability of phases. Furthermore, the interannual relationships of seasonal mean, SAISV, and seasonally averaged long-wave variability （SALWV; i.e., the part with periods longer than the intraseasonal scale） of the WNPSM and ISM with SST and low-level circulation are examined. The observed seasonal mean, SAISV, and SALWV show similar correlation patterns with SST and atmospheric circulation, but with different details. However, the model presents these correlation distributions with unrealistically small differences among different scales, and it somewhat overestimates the teleconnection between monsoon and tropical central-eastern Pacific SST for the ISM, but underestimates it for the WNPSM, the latter of which is partially related to the too-rapid decrease in the impact of E1 Nifio-Southern Oscillation with forecast time in the model.  相似文献   

Spatial and seasonal distributions of soil phosphorus in a typical seasonal flooding wetland of the Yellow River Delta,China   总被引：2，自引：0，他引：2  

Xiaofei Ye  Junhong Bai  Qiongqiong Lu  Qingqing Zhao  Junjing Wang 《Environmental Earth Sciences》2014,71(11):4811-4820

Soil samples from 0 to 100 cm depth were collected in four sampling sites (Sites A, B, C and D) along a 250-m length of sampling zone from the Yellow River channel to a tidal creek in a seasonal flooding wetland of the Yellow River Delta of China in fall of 2007 and spring of 2008 to investigate spatial and seasonal distribution patterns of total phosphorous (TP) and available phosphorus (AP) and their influencing factors. Our results showed that TP contents in spring and AP contents in both seasons in surface soils increased with increasing distances away from the Yellow River channel. TP contents in surface soils (0–10 cm) followed the order Site A (698.6 mg/kg) > Site B (688.0 mg/kg) > Site C (638.8 mg/kg) > Site D (599.2 mg/kg) in fall, while Site C (699.6 mg/kg) > Site D (651.7 mg/kg) > Site B (593.6 mg/kg) > Site A (577.5 mg/kg) in spring. Generally, lower TP content (630.6 mg/kg) and higher AP level (6.2 mg/kg) in surface soils were observed in spring compared to fall (656.2 mg/kg for TP and 5.2 mg/kg for AP). Both TP and AP exhibited similar profile distribution patterns and decreased with depth along soil profiles with one or two accumulation peaks at the depth of 40–80 cm. Although the mean TP content in soil profiles was slightly higher in spring (635.7 mg/kg) than that in fall (628.0 mg/kg), the mean TP stock was obviously lower in spring (959.9 g/m²) with an obvious accumulation at the 60–80 cm soil depth compared to fall (1124.6 g/m²). Topsoil concentration factors also indicated that TP and AP had shallower distribution in soil profiles. Correlation analysis showed that AP had significant and positive correlation with these soil properties such as soil organic matter, salinity, total nitrogen and Al (p < 0.01), but TP was just significantly correlated with TN and Al (p < 0.05).  相似文献   

东准造山带原泥盆系的形成时代及源区：碎屑锆石U-Pb年代学证据   总被引：1，自引：0，他引：1       下载免费PDF全文

聂峰  田晓丽  李振生 《地质科学》2014,(2):695-717

新疆东准地区晚古生代地层出露广泛,其沉积时限的精确限定对理解中亚造山带的增生和拼贴过程、确立该地区构造框架及油气开发具有深远意义。然而,目前的研究主要集中于岩浆岩方面,对于晚古生代地层时代及其空间展布的研究则相对缺乏,特别是石炭系和泥盆系沉积地层标定较为模糊。为此,本文选取了3个原泥盆系砂岩进行了细致的野外剖面测制、岩石学观测和碎屑锆石U-Pb年代学分析。研究显示：原泥盆纪砂岩的最年轻碎屑锆石年龄为346～312 Ma,碎屑锆石年龄谱图分为：380～310 Ma（晚泥盆世-早石炭世,71.8%）、445～385 Ma（志留纪-早-中泥盆世,11.7%）、480～450 Ma（奥陶纪,3.9%）、540～485 Ma（寒武纪,4.5%）和前寒武纪年龄段（8.1%）,碎屑锆石年龄谱图区域上具有由南向北、由西向东呈简单化趋势且晚古生代年龄比重增加。结合该区岩浆岩年代学研究成果,将研究区原泥盆系沉积时代重新厘定到晚石炭系早-中期,认为东准地区的碰撞拼贴时间应发生于晚石炭世,并非是不同期次碰撞拼贴之产物。  相似文献   

黄河流域煤炭富集区煤炭水足迹演变及驱动效应研究     

刘秀丽  王昕  郭丕斌  熊睿  聂雷  申俊  张静 《地理科学》2022,42(2):293-302

煤炭与水资源相互影响和制约,如何评价煤炭耗水的演变趋势及其影响机制对煤炭和水资源进行协同管理具有重要意义。基于国际标准的煤炭水足迹测算模型,分析2000—2017年黄河流域煤炭富集区——晋陕蒙煤炭水足迹的时空演变趋势,构建煤炭水足迹压力指数评价区域煤炭和水资源的匹配关系,并运用LMDI模型定量分析煤炭水足迹的驱动效应。结论如下：① 煤炭水足迹总量在研究期内呈增长趋势,主要以原煤和火力发电水足迹为主,山西和内蒙古煤炭水足迹最高,陕西最低。② 研究区整体煤炭水足迹压力指数逐渐增大,由煤–水关系缓和型逐渐演变为煤–水关系制约型,从空间分异来看,山西最大,研究期内均属于煤–水紧张型,陕西次之,内蒙古最小,均由煤–水关系缓和型演变为煤–水关系制约型。③ 影响煤炭水足迹的主要驱动因素是经济效应和技术效应,前者对煤炭水足迹的影响逐渐增强,后者对煤炭水足迹压力的影响先增强后减弱,各驱动效应空间分异明显。研究结果可为煤炭富集区煤炭和水资源可持续利用提供决策参考,为黄河流域生态保护和高质量发展的资源管理提供决策支持。  相似文献   

不同食物与放养水层对九孔鲍生长的影响     

聂宗庆  王素平  陈才松 《广东海洋大学学报》2000,20(3):37-40

采用室内池子多层笼养殖方式 ,以加工海带、鲜江艹离 与 A,B2种片状饲料为饵料 ,试验了不同食物与不同放养水层对九孔鲍生长影响 ,结果表明 :( 1)从壳长增长上 ,海带与饲料 B近似 ,各为 11.3与 11.2 mm;其次为饲料 A,10 .2 mm;而江 艹离 最差 ,仅 7.7mm;( 2 )在体重增长上 ,以饲料 B最高 ,平均每只为 3.3g,其次为饲料 A与海带 ,平均每只 2 .9g,而江艹离 仅 1.8g;( 3)从试验期间所获体重增长比壳长增长看 ,两种饲料 ( B为 2 95,A为 2 84 mg/mm)均比两种海藻高 (海带为 2 57,江艹离 为 2 34mg/mm) ;( 4 )从垂直 11层笼子九孔鲍生长的比较 ,下层的好于上层 ,越是下层越好 ,投喂两种饲料在体重上差别更明显。  相似文献