五台山积雪变化趋势及其影响因素     

范强  刘楠  任天晨 《水文》2023,43(4):111-115

基于MODIS积雪产品与微波遥感数据,分析五台山2000—2019水文年积雪时空分布、变化趋势及与影响因素的Pearson相关性,结果表明：（1）五台山积雪期为10月至翌年4月,年内呈单峰型变化趋势,积雪集中于西北部。（2）积雪面积和积雪日数的年际变化呈显著减少趋势（p<0.05）。（3）积雪面积和积雪日数与海拔正相关,积雪面积在北坡高于南坡。（4）积雪面积与气温相关程度高于降水量,积雪面积在年内与气温和降水量日值呈显著负相关（p<0.05）,在年际与气温年均值呈显著负相关（p<0.05）。  相似文献   

‘All in’: Snow crab,capitalization, and the future of small-scale fisheries in Newfoundland     

《Marine Policy》2015

The collapse of cod stocks off the coast of Newfoundland and Labrador in the early 1990s has been widely identified as one of the greatest human-ecological catastrophes of the 20th century. In the aftermath of the crisis, heated debates took place about how the fishery should be structured in the future in order to facilitate the recovery of stocks and sustain coastal livelihoods. In the end, the trade union representing fishers and fish processing plant workers in the province proved successful in resisting pressures from fish processing companies to introduce full-scale privatization. It was also able to expand access to the lucrative snow crab fishery, thereby improving incomes for most remaining independent fishers in the province. Nevertheless, this paper argues that policy changes made shortly after cod moratorium, in combination with changing environmental, demographic, and market conditions, have created a situation which now threatens to undermine the capacity for small-scale fishing enterprises to remain independently owned and operated into the future.  相似文献   

GIS-simulation of the spatial distribution of snow cover and observed ground temperatures in the Daisetsu Mountains,Japan     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):212-218

This paper describes one geometrical method of simulating the spatial distribution of snow cover. Geographical Information Systems (GIS) and precise Digital Elevation Model (DEM) were used in the simulation. The model is based on empirical parameters called coefficients depending on slope aspect and inclination. As a result, this model predicts that windward convex terrains remain snow-free during winter. This snow cover distribution was validated by usage of an air photograph taken in early spring, and the distribution of vegetation patches which represent the outer fringes of snow covered areas. Low ground temperatures together with high DC resistivities, which suggest the presence of permafrost, were identified in simulated snow-free areas.  相似文献   

青海地区常规观测积雪资料对比及积雪变化趋势研究   总被引：1，自引：1，他引：0  

雷俊  方之芳 《高原气象》2008,27(1):58-67

应用青海44个台站1962—2005年逐月积雪深度和积雪日数资料,对比了这两份常规积雪资料在表征青海地区积雪变化特征上的一致性,并对近十几年来的积雪变化新趋势做了分析。结果表明:积雪深度和积雪日数均能比较一致地反映整个青海地区积雪变化趋势:夏、秋季积雪从20世纪60年代至21世纪初为一致的减少趋势;冬、春季积雪在20世纪60年代至90年代初增加,而从20世纪90年代中期至21世纪初积雪呈显著减少趋势。后期的减少趋势远比前期的增加趋势明显。青海地区不同季节积雪深度和积雪日数趋势变化明显的区域基本一致,但中心位置存在一定的差异。冬季在32.5°~35°N,95°~102°E范围内的唐古拉山、巴颜喀拉山和阿尼玛卿山区,春季在青海东南部阿尼玛卿山区附近,均明显地表现出20世纪90年代中期以后积雪的减少和前期积雪的增加。不同季节积雪深度和积雪日数的相关系数分布存在一定差异:冬季两份资料相关相对较小的区域位于青海中南部巴颜喀拉山西区至阿尼玛卿山西区一线;春季相关系数小于冬季,青海东北边缘以及东南边缘地区,相关系数未能通过95%信度检验;夏、秋季积雪较少,相关较小的区域集中在青海东南部地区。而上述区域大多为各个季节积雪较多的地区,应慎重使用该区域的常规积雪资料。综合分析两份积雪资料,确定青海地区冬季多雪年为1964,1975,1993,1995和1998年,少雪年为1963,1965,1969,1997和2003年;春季多雪年是1977,1982,1987,1989和1990年,少雪年是1969,1979,1985,1999和2001年。  相似文献   

Characteristics and Environmental Significance of pH and EC in Summer Rainfall and Shallow Firn Profile at Yulong Snow Mountain,Lijiang City,China     

李宗省  何元庆  Wilfred H Theakstone  贾文雄  辛惠娟  张蔚  刘婧  王淑新 《中国地质大学学报(英文版)》2010,(2)

The seasonal and inter-annual variations of pH and EC(electrical conductivity) at Yu-long(玉龙) Snow Mountain,Lijiang(丽江) City,are sensitive to precipitation variations and are important indicators of the atmospheric environment.The pH of summer rainfall at Lijiang City ranges from 6.7 to 7.4,and alkaline mineral salts dominate the variations of rainfall acidity.pH values in theshallow firn profile at Baishui(白水) Glacier No.1 range from 5.6 to 6.3,and EC values from 2.4 to 7.3 μs/cm.The ranges are lower than ...  相似文献   

中国天山艾肯达坂透风式下导风防雪工程     

王中隆 《山地学报》1994,(4)

据艾肯达坂风雪流形成条件，提出了贴地气层分离是公路吹雪堆积的机理，通过对密闭式下导风能量转换和流场结构的剖析，创造了透风式下导风防雪工程。其实施后，改变了公路因冬半年严重雪阻而不能通车的状况，经济效益和社会效益俱佳；  相似文献   

Field measurements of snow-drift threshold and mass fluxes,and related model simulations   总被引：2，自引：2，他引：0  

Judith?J.?JDoorschot  Michael?LehningEmail author  Anouck?Vrouwe 《Boundary-Layer Meteorology》2004,113(3):347-368

Field measurements were carried out to calculate the threshold friction velocity for snow saltation, and mass fluxes during snow drift. The wind was measured in three components by an ultrasonic anemometer, and the mass fluxes were determined using an optical sensor (snow particle counter), acoustic sensors (Flowcapt) and mechanical traps. The threshold friction velocity was found to be correlated to the grain size (R²=0.75). The mass flux measurements were compared with numerical simulations of snow drift, and it was demonstrated that the maximum snow transport takes place at shear stress values of roughly two times the average shear stress over 20 min. By implementing a probability distribution for the shear stress the mass flux was simulated with only the mean measured value of the shear stress as input. This procedure enables the future use of the numerical model for operational applications.  相似文献   

Review of behaviour of oil in freezing environments   总被引：2，自引：0，他引：2  

Fingas MF  Hollebone BP 《Marine pollution bulletin》2003,47(9-12):333-340

The current knowledge of the physical fate and behaviour of crude oil and petroleum products spilled in Arctic situations is reviewed. The fate and final deposition of oil in marine conditions is presented as based on the extant literature.

Spreading models were evaluated for oil on ice, under ice, in snow, in brash ice, and between blocks of ice. Models of oil transport under sheet and broken ice were considered, both for sea and river conditions. The ability of ice sheets to trap oil is discussed in relation to oil storage capacity. The effects of oil on a growing ice sheet were examined, both in terms of ice formation and the thermal effects of oil inclusions in ice. The migration of oil through ice was reviewed, focussing primarily on the movement through brine channels. The effects of oil on the surface of ice were considered, with emphasis on the effects of surface pools on ice melt. Similar consideration was given to the effects of oil on snow on the surface of ice.

The few quantitative studies of oil in open and dynamic ice conditions are reviewed. Observations of intentional small-scale spills in leads and ice fields are reviewed and compared with observations from real spills. The conditions under which “oil pumping” from leads occurs were quantified. The most common ultimate fate of oil in an ice field is to be released onto the water surface.  相似文献   

STARTER: a statistical GIS-based model for the prediction of snow avalanche susceptibility using terrain features—application to Alta Val Badia, Italian Dolomites   总被引：1，自引：0，他引：1  

Alessandro Ghinoi  Chang-Jo Chung   《Geomorphology》2005,66(1-4):305

This article describes a methodology to localise areas with high potential towards natural snowpack instability under particular meteorological conditions, at the scale of an Alpine valley. Localisation is based on statistically relating known release areas of past avalanche events to maps of: (1) slope inclination, (2) slope orientation (aspect), (3) elevation, (4) distance from crest lines, (5) terrain roughness and (6) concavities/convexities. The maps have been built using two different GIS softwares while the statistical analyses have been performed with a specific software handling also Fuzzy Set theory algorithms. The results of the statistical analyses have been verified on test release—areas which have not been used as input data for the statistical analyses. Verification allowed to quantify how reliably the susceptibility values were calculated, to compare the values obtained using different combinations of terrain features and to finally decide on the most efficient combination. The susceptibility maps were calculated and verified for three different meteorological scenarios (given by three classes of snow depth). Verification has shown that the accuracy of the susceptibility maps was between 67% and 82%. The three susceptibility maps show a remarkable difference in the spatial pattern of the highest susceptibility pixels suggesting that for different meteorological scenarios different classes of terrain features need to be considered.The possibility to make combinations of terrain features and to assess and verify their statistical relationship with release areas of past avalanche events is the major original step made by STARTER. Linking those release areas to meteorological scenarios is an attempt to include in the analysis the combined influence of terrain features and meteorological conditions towards snowpack instability.  相似文献   

积雪季节变化特征的数值模拟及其敏感性试验   总被引：4，自引：0，他引：4  

陈海山  孙照渤 《气象学报》2004,62(3):269-284

文中利用综合陆面模式 (ComprehensiveLandSurfaceModel,CLSM )对法国ColdePorte 1 993/ 1 994 ,1 994 / 1 995年及BOREASSSA OJP 1 994 / 1 995年积雪个例进行了模拟试验 ,通过模拟结果与观测资料的对比 ,检验了CLSM对积雪变化特征的模拟能力 ,并通过敏感性试验探讨了降雪密度、积雪持水量等积雪参数化方案及植被对积雪模拟可能产生的影响。结果表明 :(1 )CLSM能够准确地模拟出积雪的变化过程 ,对积雪的演变特征作出了合理的描述 ;(2 )降雪密度、积雪持水量参数化方案对积雪模拟结果均具有一定的影响 :降雪密度参数化主要对积雪深度的模拟产生影响 ;而积雪持水量参数化方案对积雪的演变过程 ,尤其是积雪的消融 ,具有重要的作用 ;(3)有、无植被存在的情况下 ,积雪 土壤系统的变化过程存在显著的差别 ,植被通过改变积雪 /土壤表面的能量平衡 ,对积雪及土壤的变化过程产生重要影响 :植被的存在有利于积雪的维持 ,使得积雪融化进程推迟 ,冻结土壤的增温明显偏慢  相似文献