Improvement of mid- to long-term runoff forecasting based on physical causes: application in Nenjiang basin,China     

Hong-Yan Li  Lin Tian  Ya-nan Wu  Miao Xie 《水文科学杂志》2013,58(7):1414-1422

Abstract

An artificial neural network, mid- to long-term runoff forecasting model of the Nenjiang basin was established by deciding predictors using the physical analysis method, combined with long-term hydrological and meteorological information. The forecasting model was gradually improved while considering physical factors, such as the main flood season and non-flood season by stage, runoff sources and hydrological processes. The average relative errors in the simulation tests of the prediction model were 0.33 in the main flood season and 0.26 in the non-flood season, indicating that the prediction accuracy during the non-flood season was greater than that in the main flood season. Based on these standards, forecasting accuracy evaluation was conducted by comparing forecasting results with actual conditions: for 2001 to 2003 data, the pass rate of forecasting in the main flood season was 50%, while it was 93% in the non-flood season; for 2001–2010, the respective values were 45% and 72%. The accuracy of prediction was found to decrease as the length of record increases.

Editor D. Koutsoyiannis, Associate editor A. Viglione

Citation Li, H.-Y. Tian, L., Wu, Y., and Xie, M., 2013. Improvement of mid- to long-term runoff forecasting based on physical causes: application in Nenjiang basin, China. Hydrological Sciences Journal, 58 (7), 1414–1422.  相似文献   

延寿地震台水温梯度测量及结果分析     

李婧  吴海波  朱家明  柴红泽  李希文 《防灾减灾学报》2013,(4):67-69

根据《szw-1A型数字式温度计（2004）}安装规范要求,对延寿台1号观测井进行水温梯度测量,找到该井温度波动最小部位,重新确定地热探头投放位置,以提高水温观测数据质量,得到信噪比较高的地热前兆信息。  相似文献   

City on edge: immigrant businesses and the right to urban space in inner-city Johannesburg     

Richard Grant  Daniel Thompson 《Urban geography》2013,34(2):181-200

Paradoxically, Johannesburg is a quintessentially migrant city and also ranks among the least immigrant-friendly cities in the world. Over the past 20 years, inner-city Johannesburg has been vacated and then reconstituted as a hive of informal trade networks and migration circuits that extends well beyond national borders. Research on immigrants in Johannesburg has contributed significantly to understandings of xenophobic sentiments and immigrant identities, but there remains a large gap in knowledge about immigrant entrepreneurship, economic enclaves and economic mobility. Our research is based on extensive fieldwork, discussions with immigrant organizations and in-depth interviews with immigrants and South Africans engaged in business in three prominent inner-city immigrant business enclaves: Jeppe/Delvers, Eighth Avenue and Raleigh Street. Our research shows that these immigrant business zones each operate differently and vary in the degree to which they connect to urban and national economic grids; some retain stronger ties to transnational networks that link dispersed spaces to Johannesburg, creating specific local milieus. We advocate for a more geographically sensitive and nuanced understanding of immigrant entrepreneurs and a reconsideration of their rights to the city.  相似文献   

To Inhabit Well: Counterhegemonic Movements and the Right to the City     

Mark Purcell 《Urban geography》2013,34(4):560-574

A right to the city, understood as a conjoint claim to a right to inhabit urban space well, can be an effective starting point from which diverse urban movements can begin to build broad counterhegemonic coalitions for alternative urban futures. In this article, I argue that the right to the city supports the project of establishing relations of equivalence among members of coalitions––balancing relations of sameness/difference and interdependence/autonomy.  相似文献   

再议绿洲－沙漠过渡带——以策勒绿洲－沙漠过渡带为例   总被引：4，自引：0，他引：4       下载免费PDF全文

穆桂金  贺俊霞  雷加强  庞营军  邢文娟  杨发相  刘国军  毛东雷  岳健 《干旱区地理》2013,36(2):195-202

 被长期质疑的绿洲－荒漠过渡带在不断观测和丰富积累的基础上让我们有了一个完整的认识。以策勒绿洲为例对其进行剖析,作为绿洲－荒漠过渡带的一种典型类型,绿洲－沙漠过渡带可以界定为自绿洲边缘（人工防护体系或天然稀疏灌木林边界）到植被盖度为20%～25%的固定－半固定沙地为外缘边界（绿洲与流动沙漠之间）的荒漠地带。过渡带的内缘边界为绿洲外缘的人工防护体系,包括防风阻沙林带或天然稀疏灌木林。过渡带形成是因为从绿洲到外部荒漠存在水热环境因子的梯度变化,导致植被、土壤、地貌等综合景观展现出过渡特征,其组成与结构模式为：由绿洲向沙漠方向,稀疏灌木林（或边缘防护林体系）地－缓起伏灌草沉沙地－起伏灌丛沙堆和高起伏灌丛沙堆地。过渡带是乡土动植物重要的保留与保护地,是绿洲与沙漠间能流物流输送交换的缓冲带、绿洲的天然生态屏障,对地貌、土壤以及植被具有保护功能,且具有重要的固碳作用。  相似文献   

东南极格罗夫山：普里兹造山带中一个典型的泛非期变质地体   总被引：2，自引：0，他引：2       下载免费PDF全文

刘晓春  赵越  胡健民  刘小汉  曲玮 《极地研究》2013,25(1):7-24

提要：距我国中山站以南约400 km的格罗夫山是普里兹造山带向南极内陆的延伸部分,其基底地体由约在920?910 Ma期间侵入的镁铁质－长英质火成岩和少量中元古代的沉积岩构成,这些岩石仅在泛非期（约570?500 Ma）经历了单相变质－构造旋回,因此是一个典型的泛非期变质地体。泛非期高峰变质作用并不象前人所认为的那样仅为中低压麻粒岩相,而是高达770?840?C、1.18?1.40 GPa,并在随后经历了近等温减压（约0.6 GPa）的P-T演化过程。大规模的A型紫苏花岗岩和花岗岩在同造山－后造山阶段侵位,并造成了麻粒岩地体近等压降温的P-T轨迹。这些花岗质岩石是由长期富集地幔的底侵物质（碱性玄武质岩石）经部分溶融而形成的。结合相邻地质体的研究资料,我们认为普里兹造山带可能发育在太古宙－格林维尔期基底地体之上,这些基底地体可能与新元古代（？）盖层卷入到了统一的泛非期造山作用过程。在泛非期造山作用过程中,地壳曾被增厚约达40?50 km,而后又经历了厚约20 km的地壳伸展垮塌和剥蚀。所以,普里兹造山带应代表东冈瓦纳陆块内部由板块缝合作用所形成的一条泛非期碰撞造山带。  相似文献   

Engaging Communities for Success: social impact assessment and social licence to operate at Northparkes Mines,NSW     

Grace Michell 《The Australian geographer》2013,44(4):435-459

Social issues are critical to the mining industry. This study investigates how social issues have been, and are being, assessed and managed within this industry through a case study of Northparkes Mines in central west New South Wales (NSW). The research involved 29 interviews with mining executives, environmental consultants and citizens of Parkes, plus a document analysis of four environmental impact statements prepared between 1990 and 2012. Where appropriate, findings were extrapolated to the wider mining industry. The standard for social impact assessment in NSW and emerging industry guidelines on social responsibility were analysed against internationally accepted good practice. Interviews indicated greater potential to recognise the social impacts of mining in NSW and identified good practice impact assessment as only one component of a successful community engagement strategy. Complementary strategies are essential to extend the benefits of development to local communities and for companies to establish a ‘social licence to operate’. The successful approach taken by Northparkes Mines combined good practice impact assessment with a localised workforce, an integrated management team and context-specific community engagement practices. This study highlights that local communities can be empowered through development, that benefits can extend to both the community and the business and that the ongoing management of social issues will increasingly be critical to the success of the mining industry.  相似文献   

Transitional rural landscapes: The role of small-scale commercial farming in former homelands of Post-Apartheid KwaZulu-Natal     

Jytte Agergaard  Torben Birch-Thomsen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):87-102

Geografisk Tidsskrift, Danish Journal of Geography 106(2): 87–102, 2006

The paper presents trends in past and present land use patterns in parts of a former homeland of KwaZulu-Natal, and discusses the changing role of farming. It suggests that an understanding of the transition in rural land must take into account the impact of rural-urban relations and the Colonial and Apartheid socio-spatial policies. A sequence of map data is analysed and compared with interviews with residents of the studied area and official data concerning actual and prospected development. The data demonstrate how population pressures and changing sources of income during the Apartheid period have resulted in a land use system dominated by home gardens and some attempts to develop small-scale commercial farming, while traditional subsistence farming has gradually decreased. On this background the prospects for small-scale commercial farming are discussed. It is argued that at least four aspects may explain why commercial farming is still marginal: the troubled land allocation system, the continued dependency on cash income for successful farming, the institutional obstacles to farmers from the homeland who wish to develop market relations, and the changing territorial logics that have characterized demarcation and land use in the post-Apartheid period.  相似文献   

Building Green: The Emerging Geography of LEED-Certified Buildings and Professionals     

Julie Cidell 《The Professional geographer》2013,65(2):200-215

One of the most important attempts to reduce the environmental impacts of the built environment is through the construction of green buildings. This article examines the geography of the emerging green building industry through a study of the spatial distribution of two different elements of that industry. The first element is the location and diffusion of green buildings themselves as certified by the U.S. Green Building Council (USGBC) through their Leadership in Energy and Environmental Design (LEED) standards. There is a clear shift from an original concentration in major coastal cities to a more even distribution across the country, with broad representation across commercial, public, and nonprofit owners. The second area of study is the spatial distribution of LEED-accredited professionals, who are accredited by the USGBC to oversee the certification process. The distribution of these professionals matches existing concentrations of population, suggesting two different geographies of building green.  相似文献   

Recent Publications     

Sara Macdonald  Roger Keil 《The Professional geographer》2013,65(1):125-145

The government of Ontario, Canada, has passed legislation to protect large parts of the southern portions of the province from most development. An extensive plan for a Greenbelt that surrounds the Greater Toronto Area and other regional growth centers was introduced. This article looks at the new policy as a spatial strategy that shifts the scales of environmental and growth management policy in Ontario. The legislation also sets the framework for a state spatial project; that is, a set of changes in how the regional state internally operates. The current Greenbelt legislation is a new step in a longer term development by which governments in Ontario have attempted to regulate the relationships between cities and regions, town and hinterland. Overlapping strongly with what is usually called the Toronto bioregion between the Niagara Escarpment, Oak Ridges Moraine, and Lake Ontario, the Greenbelt reorganizes space in southern Ontario in ways that would further ecosystem policies and practices in the area. Theoretically guided by newer debates on rescaling and regionalism, and based on close reading of the planning and policy documents on the Greenbelt as well as a series of expert interviews, we argue that the current Greenbelt legislation is an act of up-scaling traditional urban-regional regulation in southern Ontario, which we shall call extended metropolitanization. Such rescaling recasts traditional political conflicts in new terms. We conclude that extended metropolitanization in southern Ontario has been a process that has brought nature, the state, and governance together into a new regional sustainability fix.  相似文献