Assessment of ski condition reliability in the Spanish and Andorran Pyrenees for the second half of the 20th century     

《Applied geography (Sevenoaks, England)》2017

In this study temporal trends of 14 climate and snow parameters related to ski conditions were analyzed for 11 ski stations located in the central Pyrenees (Spain and Andorra). We also investigated whether there was a temporal association for the analyzed parameters, such that the occurrence in a particular year of good (or bad) climate or snow conditions as represented by one parameter was similarly reflected by the other parameters. The lack of reliable climate and snow measurements was overcome by the use of simulated climate data retrieved from a high resolution hindcast simulation available for the period 1960–2006. These data were also used as inputs for an energy and mass snow energy model to obtain snow series. The results showed trends in ski reliability parameters for the 1960–2006 period. The number of days having a snowpack deeper than 30 cm and 100 cm showed declines at low and mid altitudes. The start of the ski season appears progressively delayed for all stations, and the ski season shortened. The frequency of rainy days increased at 3 stations and decreased at 8, while the frequency of days having heavy snowfall increased at 8 stations and declined at 3. Days having potential for snowmaking declined at all stations. The number of days having a wind-chill < −20 °C also decreased markedly, as overall did the number of days having a wind speed greater than 80th percentile. The main findings from the assessment of temporal associations between climate and snow parameters were positive correlations between snow depth and windy conditions. Seasons having a higher frequency of very cold days had a lower frequency of heavy snowfall and rainy days. Thus, the adverse effects on the ski industry of lesser snow availability may have been partially negated by the occurrence of fewer days of closure because of high winds, or other adverse meteorological factors.  相似文献   

Impact of public bus system on spatial burglary patterns in a Chinese urban context     

《Applied geography (Sevenoaks, England)》2017

PurposeTo examine the impact of public bus system on spatial burglary pattern in a Chinese urban context, as well as the spatial variation of this impact.MethodsLocal Moran's I, boxplot-based classification, geo-visualization, Chi-square test, and correlation analysis are used to explore the spatial coupling relationships between bus stops and burglary. Guided by routine activity approach, negative binomial regressions are performed for the developed and developing parts of the DP peninsula, as well as the whole peninsula based on proxies of potential offenders, guardians, targets, and spatial dependence.ResultsStatistically positive correlations are observed between burglary count and bus stop service capability. However, net of other factors, one more unidirectional bus route is expected to reduce burglary by nearly 2 percent for the whole area, and 4 percent for the developed area, while no statistically significant relationship is found for the developing area.ConclusionsThe bus-burglary relationships differ between the developed and developing urban areas. For the former, although burglaries concentrate around bus stops with higher service capability, the increase of bus service capability has a net impact of slightly depressing the occurrence of burglaries. Four possible mechanisms explaining this negative bus-burglary relationship in the DP peninsula are presented.  相似文献   

The analysis and measurement of building patterns using texton co-occurrence matrices     

Wenhao Yu  Tinghua Ai  Pengcheng Liu  Xiaoqiang Cheng 《International journal of geographical information science》2017,31(6):1079-1100

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Applying multivariate conjugate priors in fishery-management system evaluation: how much quicker is it and does it bias the ranking of management options?     

Mcallister  M. K.; Kirkwood  G. P. 《ICES Journal of Marine Science》1999,56(6):884-899

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Estimating cropland carbon mitigation potentials in China affected by three improved cropland practices   总被引：1，自引：0，他引：1  

Fei Lun  Josep G. Canadell  Lu He  Bo Yang  Mou-cheng Liu  Zheng Yuan  Mi Tian  Jun-guo Liu  Wen-hua Li 《山地科学学报》2016,13(10):1840-1854

Agriculture is a large source of carbon emissions. The cropland practices of fertilizer substitution, crop straw and conservation tillage are beneficial and help to rebuild local soil carbon stocks and reduce soil carbon emissions, in addition to reducing the consumption of fertilizers and fossil fuels. These improved cropland practices can directly and indirectly mitigate carbon emissions, benefiting the sustainability of croplands. For these three improved practices, we estimated carbon mitigation potentials in rice, wheat and maize croplands in China. The combined contribution of these practices to carbon mitigation was 38.8 Tg C yr^-1, with fertilizer substitution, crop straw return, and conservation tillage contributing 26.6, 3.6 and 8.6 Tg C yr^-1, respectively. Rice, wheat and maize croplands had potentials to mitigate 13.4, 11.9 and 15.5 Tg C yr^-1, respectively, with the combined direct and indirect potential of 33.8 and 5.0 Tg C yr^-1. Because of differences in local climate and specific diets, the regional cropland carbon mitigation potentials differed greatly among provinces in China. In China, 18 provinces had a “target surplus” for which the carbon mitigation from these three practices was larger than the mitigation target set for 2020. At the national level, a net “target surplus” of 4.84 Tg C yr^-1 would be attained for Chinese croplands with full implementation of the three improved practices. Regional cooperation must be developed to achieve carbon mitigation targets using such measures as carbon trading, establishing regional associations, and strengthening research programs to improve practices.  相似文献   

The impacts of climate change on hydrology in a typical glacier region—A case study in Hailuo Creek watershed of Mt. Gongga in China     

GuoFeng Zhu  YuanQing He  DaHe Qin  HongKai Gao  Tao Pu  DongDong Chen  Kai Wang 《寒旱区科学》2016,8(3):227-240

The glaciers of the Hengduan Mountains play an important role in the hydrology processes of this region. In this study, the HBV Light model, which relies on a degree-day model to simulate glacier melting, was employed to simulate both glacier runoff and total runoff. The daily temperature and precipitation at the Hailuo Creek No. 1 Glacier from 1952 to 2009 were obtained from daily meteorological observed data at the glacier and from six national meteorological stations near the Hailuo Creek Basin. The daily air temperature, precipitation, runoff depth, and monthly potential evaporation in 1995, 1996, and 2002 were used to obtain a set of optimal parameters, and the annual total runoff and glacier runoff of the Hailuo Creek Glacier(1952–2009) were calculated using the HBV Light model. Results showed the average annual runoff in the Hailuo Creek Basin was 2,114 mm from 1952 to 2009, of which glacial melting accounted for about 1,078 mm. The river runoff in the Hailuo Creek catchment increased as a result of increased glacier runoff. Glacier runoff accounted for 51.1% of the Hailuo Creek stream flow in 1994 and increased to 72.6% in 2006. About 95% of the increased stream flow derived from the increased glacier runoff.  相似文献   

Assessing linkages between ecosystem services,land-use and well-being in an agroforestry landscape using public participation GIS     

《Applied geography (Sevenoaks, England)》2016

While a number of studies have applied public participation GIS (PPGIS) approaches to the spatial assessment of ecosystem services, few have considered the associations between the spatial distribution of ecosystem services and the context-specific nature of self-reported well-being. In this study, we engage the general public to identify and map a range of ecosystem services that originate in place-based, local knowledge and explore the context-dependent nature of subjective well-being. We conducted a PPGIS survey with 219 local residents in a Spanish agroforestry (dehesa) landscapes and analysed the spatial patterns of mapped ecosystem services, their relation to land cover, protected area and common land patterns. In addition, we explored the landscape values contributing to people’s well-being; and the relationships between ecosystem services in different land covers, landscape values and socio-demographic characteristics. A mosaic of landscape types (i.e., the landscape) provided more ecosystem services (especially cultural and provisioning) to people compared with the individual land system of agroforestry. However, land tenure and public access significantly guided the spatial practices and values of the people beyond the preferred landscape types. The contribution of the landscape to well-being is largely related to values based on interactions among people and the landscape, as tranquillity/relaxation and people-people interactions such as being with family and friends. We discuss the specific contribution of agroforestry landscapes to the provision of ecosystem services and human well-being. We conclude that the integration of the applied methods of social-cultural assessment on the one hand links to ecosystem services frameworks but on the other hand represents a more holistic conceptualisation of people’s benefits from landscapes.  相似文献   

某磷石膏尾矿库堆积坝渗透稳定性分析     

褚学伟  许模  王中美 《工程地质学报》2016,24(4):661-667

随着尾矿库堆积坝高度的增加,库内的地下水渗流场将发生改变,当尾矿堆积坝处的实际水力梯度大于临界水力梯度时,尾矿库堆积坝将产生渗透变形或失稳破坏。为了预测某已建磷石膏尾矿库堆积坝的渗透稳定性,本文运用地下水位计水位恢复试验去确定磷石膏尾矿渗透系数并计算水力梯度,同时采用Geo-studio软件中的SEEP/W模块分析磷石膏堆积坝在不同工况下的渗透稳定性。计算和分析结果表明当堆积坝处于945m堆积高程,在无干滩和100m干滩情况下,实际水力梯度分别为0.784和0.583;当堆积坝处于960m堆积高程,无干滩情况下,实际水力梯度为0.692,在以上两种情况下,堆积坝渗出点高程高于初始坝高程,堆积坝将出现流土变形,坝体处于不稳定状态。当堆积坝处于960m堆积高程100m干滩时,堆积坝上无渗出点,堆积坝处于稳定状态。分析研究结果对该尾矿库的安全运行和维护管理提供技术依据,同时为同类型尾矿库堆积坝渗透稳定性评价提供参考。  相似文献   

原子光谱测定中表面活性剂对铅锌矿粉末悬浮液雾化效率的影响     

何昌璟  刘文涵  滕渊洁  郑存江  胡勇平  刘江美 《岩矿测试》2016,35(3):245-250

滇黔地区的"白泥塘层"与锰矿具有密切的成因联系,前人对其地球化学特征研究时关注的主要是硅质灰岩全岩,并非硅质成分本身,而硅质岩全岩能否真实地反映"白泥塘层"中硅质的来源有待研究。本文以滇黔地区"白泥塘层"硅质灰岩为研究对象,用盐酸去除硅质灰岩中的碳酸盐矿物,获得成分较为单一的硅质组分,采用ICP-MS和ICP-OES测定全岩与去除碳酸盐的硅质组分中的微量元素,通过对比两者的微量元素地球化学特征研究"白泥塘层"中硅质的来源问题。结果表明:去除碳酸盐的硅质组分的Th/U=0.02~0.05,低于全岩的Th/U值(0.08~0.2),Eu/Eu^*=0.86~1.54(均值1.15),显示为正Eu异常,此特征不同于全岩(全岩的Eu/Eu^*=0.87~0.93,均值0.90,显示为弱的负Eu异常);硅质组分及全岩的稀土含量均表现为轻稀土较重稀土富集,但硅质组分中的轻稀土所占比重大于全岩。以上特征确切地表明了"白泥塘层"硅质灰岩中的硅质成分来自于热水,对于解释二叠系时期锰矿的形成具有重要的指示意义。  相似文献   

Re-Os同位素在晚新元古代至早寒武世测年及古环境演绎中的应用进展     

王富良  付勇  江冉  周文喜  葛枝华  魏帅超  梁厚鹏  张鹏 《岩矿测试》2016,35(5):530-541

晚新元古代至早寒武世是地球演化历史上极其重要的时期,该时期地层年龄框架的厘定以及古海水、古大气、古气候等方面的研究一直是国际地学界的关注热点。Re-Os同位素测年法是近十几年来兴起的地层测年法,其对于晚新元古代至早寒武世重要时间节点上沉积的富有机质黑色页岩具有测年及示踪古环境的双重优势。本文以晚新元古代至早寒武世地层为例,阐述了Re-Os同位素测年法在年代地层学研究中的应用,通过与大量的、精确的锆石U-Pb年龄对比,论证了Re-Os同位素测定沉积地层年龄的可靠性。对于震旦系陡山沱组地层建阶及留茶坡组地层的年代学研究,黑色页岩Re-Os同位素测年法可发挥重要的作用。结合前人所做的Sr同位素变化曲线以及收集的晚新元古代—早寒武世Os同位素初始值的测试数据,阐述了Os同位素在该时段古环境演绎及Ni-Mo-V多金属层来源追溯上发挥的作用。黑色页岩难以进行~(87)Sr/~(86)Sr的分析,而Os同位素初始值能较好地弥补这一缺陷,二者的相互结合将为晚新元古代至早寒武世古环境演化的研究作出贡献。本文指出,随着Re-Os同位素分析技术的发展以及更多实验流程的建立,该项技术在未来年代地层学,尤其对一些古老地层的年代厘定具有广阔的应用前景。  相似文献