莱州湾东部外航道回淤预测及影响因素     

朱龙海  徐永臣  王楠  胡日军  姜胜辉  张伟 《海洋科学》2015,39(6):72-80

为探讨外航道回淤特征,采用二维波浪潮流泥沙数学模型,模拟研究了莱州湾东部航道回淤情况并探讨了其影响因素,以期对航道泥沙输运研究提供借鉴。研究表明,正常天气下,水流跨越航道,流速减小、挟沙能力下降导致的悬沙落淤是航道淤积的主要原因,但淤积量有限。大风浪是造成航道淤积的主要动力因素,其淤积泥沙主要来源于海底侵蚀来沙,河流来沙和沿岸输沙对航道淤积的贡献不大。从水深地形、泥沙来源、底质类型、水文动力条件等方面分析,航道发生骤淤的可能性较小。  相似文献   

近33年新疆阿勒泰地区积雪变化特征及其与气象因子的关系     

李海花  刘大锋 《沙漠与绿洲气象(新疆气象)》2015,9(5):29-35

利用阿勒泰地区7个气象观测站1981-2013年积雪初、终日期、积雪期(积雪初、终日期间日数),以及同期平均气温、平均0厘米地面温度、降水量、日照时数和平均风速资料,分析了该区积雪的变化特征及其与五个气象因子的关系。结果表明：阿勒泰地区平均初日为11月3日,终日为4月2日,平均积雪期为152d;近33年阿勒泰地区积雪初日呈上升的趋势,而终日和积雪期是呈下降趋势;除了吉木乃站的积雪初日气候倾向率是负值外,其余各站均是正值的,积雪终日的气候倾向率各站均为负值,积雪期的气候倾向率除了吉木乃站外其余均是正值;各站在积雪期内与降水量呈显著的正相关,表明降水量越多积雪持续时间越长,而且七个站均通过了显著性检验,降水因子在五个因子的对各站积雪期的影响较大;阿勒泰地区的各站积雪期与积雪初、终日期间的风速、降水量、0厘米地温、日平均气温、日照时数五个因子的相关系数中有57%的通过信度0.05的显著性检验,还有20%的通过了信度0.001的显著性检验;  相似文献   

章丘地区土壤硒的含量分布及影响因素   总被引：2，自引：0，他引：2       下载免费PDF全文

赵西强  张贵丽 《山东国土资源》2015,31(3)

以章丘地区土壤为对象,系统分析了表层、深层土壤及8条剖面土壤中Se元素的含量水平,研究了土壤中Se的分布特征及其与土壤类型、成土母质、地形地貌和土壤理化性质及组分的关系。结果表明：章丘地区表层土壤中Se含量在0.1～0.8mg/kg之间,以中硒土壤为主,富硒土壤面积173km2。土壤类型中,水稻土Se平均含量水平最高,为0.55mg/kg;成土母质中以石炭—二叠纪泥页岩发育的土壤Se含量最高;剖面土壤中的Se主要在表层富集。影响章丘地区土壤Se含量分布的主要因素是成土母质、地形地貌、土壤pH、有机质及土壤中硫、铁铝氧化物等组分。  相似文献   

Spatial distribution rules and affecting factors of BIF in Anshan-Benxi area     

WANG Wenqi  ZHANG Wei  PENG Chong  ZHU Ming  XUE Linfu 《世界地质(英文版)》2015,18(2)

A detailed investigation on 3D spatial distribution rules of Banded Iron-bearing Formation(BIF) with methods of gravity-magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the Anshan-Benxi area.Three dimension spatial distribution types of BIF are concluded as hook-like,tabularlike and "W"-like.BIF was mainly developed in three types of space including(1) the syncline cores,(2)cover coverage area,and(3) the deeper buried area where the range of tectonic uplift is small.The influences of tectonism,magmatic intrusion and uplift-erosion on the spatial distribution shapes of BIF are clarified.  相似文献   

Research on China’s aquaculture efficiency evaluation and influencing factors with undesirable outputs     

Ji  Jianyue  Wang  Pingping 《中国海洋大学学报(英文版)》2015,14(3):569-574

Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable ...  相似文献   

An evaluation of remote sensing derived soil pH and average spring groundwater table for ecological assessments     

《International Journal of Applied Earth Observation and Geoinformation》2015

Ecological assessments such as species distribution modelling and benchmarking site quality towards regulations often rely on full spatial coverage information of site factors such as soil acidity, moisture regime or nutrient availability. To determine if remote sensing (RS) is a viable alternative to traditional data sources of site factor estimates, we analysed the accuracy (using ground truth validation measurements) of traditional and RS sources of pH and mean spring groundwater level (MSL, in m) estimates. Traditional sources were a soil map and hydrological model. RS estimates were obtained using vegetation indicator values (IVs) from a Dutch national system as an intermediate between site factors and spectral response. IVs relate to those site factors that dictate vegetation occurrence, whilst also providing a robust link to canopy spectra. For pH, the soil map and the RS estimate were nearly as accurate. For MSL, the RS estimates were much closer to the observed groundwater levels than the hydrological model, but the error margin of the estimates still exceeded the tolerance range of moisture sensitive vegetation. The relatively high accuracy of the RS estimates was made possible by the availability of local calibration points and large environmental gradients in the study site. In addition, the error composition of the RS estimates could be analysed step-by-step, whereas the traditional sources had to be accepted ‘as-is’. Also considering that RS offers high spatial and temporal resolution at low costs, RS offered advantages over traditional sources. This will likely hold true for any other situation where prerequisites of accurate RS estimates have been met.  相似文献   

耕地自然质量空间分布及其影响因子分析——以北京市大兴区为例   总被引：1，自引：0，他引：1  

张超  张海锋  杨建宇  赵龙  蒋坤萍  杜贞容 《测绘学报》2015,(Z1):75-81

定量分析耕地质量的空间分布特征,是制定与实施耕地保护措施的重要依据。本文以耕地质量等级补充完善成果为基础,以自然等指数为空间变量,采用空间自相关分析方法对北京市大兴区耕地自然质量的空间分布特征进行了研究,并采用变异系数、二元相关分析和偏相关分析方法对其影响机制进行分析,揭示了耕地自然质量空间差异的主导影响因子。研究结果表明:大兴区耕地自然质量在200~900m尺度范围内呈显著的空间正相关性,正相关HH型高等地明显聚集分布,LL型低等地面积较大且聚集性较低,负相关类型(HL和LH型)耕地无明显集中区域,零星分布。土壤有机质、表土质地和土壤剖面构型是影响耕地自然质量空间分布格局的主导因子,但影响程度有所差异。  相似文献   

大城市居住用地扩展特征及驱动力分析——以南京市中心城区(长江以南)为例   总被引：1，自引：0，他引：1  

谢中凯  李飞雪  李满春  洪武扬 《测绘科学》2015,40(6):92-97

针对城市建成区的空间异质性不能反映城市居住空间结构的问题,该文选取南京市中心城区(长江以南)2001—2007年的新增居住用地,从扩展方位和强度两方面分析空间扩展特征,以直方图和Logistic回归模型揭示主导驱动因素。结果表明东北、东南、西南方向是新增居住用地的3个主要扩展方向,分别对应仙林新市区、东山新市区和河西新城区;居住用地扩展是多种驱动因素共同作用的结果,人口和经济驱动因素对郊区居住用地增加影响显著,对主城区影响有限,自然和政策驱动因素中反映政府政策的政府建设用地规划区是最重要的主导驱动因素,其次为与小学的距离,最后为与地铁站点的距离。  相似文献   

Is self-regulation a myth? Case study on Spanish groundwater user associations and the role of higher-level authorities   总被引：2，自引：0，他引：2  

E. Lopez-Gunn  Luis Martinez Cortina 《Hydrogeology Journal》2006,14(3):361-379

Self-regulation of groundwater users offers tremendous potential for effective groundwater management. The attributes of higher-level authorities that are more likely to facilitate the beneficial management of groundwater in economic, social and environmental terms are discussed. For this purpose, eight groundwater user associations in Spain have been compared. Factors that support institutional change were analyzed, namely: salience, common understanding, trust and reciprocity, autonomy, prior organizational experience and local leadership. These factors are complemented by features that strengthen actions by higher-level authorities that oversee self-regulation by water users (clear boundaries, legitimate recognition of appropriators, facilitating roles, trust in cross-scale linkages, clear division of responsibilities, institutional culture and co-management model choices). Self-regulation includes the creation of reflexive organizations that are capable of learning, provided first, the administration itself is modernized to meet the challenges of self-regulation, and second, that ‘regulatory capture’ is avoided by external organizations, ensuring that the regulator and the regulated are not so close in their relationship as to be detrimental to effectiveness.

E. Lopez-GunnEmail:

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隧洞断层破碎带岩体涌水量分析——安哥拉某水电站为例     

李辰舟  苏传洋  邓争荣  李林  袁洋洋 《西北地质》2022,(1):255-261

隧道涌水量预测对隧道的设计和施工至关重要.笔者以安哥拉某水电站进厂交通洞涌水为例,基于涌水发生后实测的涌水量、水温、水化学、附近地下水位变化等特征,分析涌水成因.根据涌水洞段岩体透水性的不同,将隧洞断层区岩体划分为3个透水性段.根据建立的模型,采用流体力学伯努利方程对最大涌水量进行估算;利用稳定流裘布依理论公式对正常涌...  相似文献