内蒙古雪灾保险费率的厘定——基于自然灾害系统理论的研究

中国巨灾保险赔款占直接经济损失的比率比国际平均水平低的多,2008年初南方雨雪冰冻灾害和"5.12"汶川地震两次巨灾过后,国家加紧推进巨灾保险体系的建立。其中,巨灾保险费率厘定是基础。基于自然灾害系统理论,构建了以危险性曲线和脆弱性曲线为核心的巨灾风险保险费率厘定方法体系,改进了以往农业保险仅从致灾因子角度厘定费率的片面性。最后,借鉴美国洪水保险、日本地震保险以灾种为对象(而非承灾体种类为对象)构建巨灾保险体系的优势,以雪灾保险为例,厘定了内蒙古12盟市雪灾保险费率。结果显示,位于中部地区的锡林郭勒盟雪灾保险费率最高,为3.10%;位于西部地区的阿拉善盟、乌海市雪灾保险费率最低,为1.09%。     

新疆拟建铁路沿线雪风灾分区和致灾性分析

对1990-2000年新疆铁路沿线地区220个大风灾害日和2000-2010年300个大(暴)雪日灾情进行了分析,以1961-2008年年均冬季最大雪深、1961-2010年年均最大风速和致灾性大风日数及承灾体脆弱性作为铁路沿线雪风灾评价指标,基于GIS空间分析对拟建铁路沿线地区的雪风灾进行了区域划分和致灾性定量分析。结果表明:①冬春季是铁路沿线雪灾高发季。拟建铁路阿勒泰-富蕴段、塔城-额敏段为重雪灾区。在铁路弯道设计、防风墙建设方面应进行严格科学论证,作好积雪防护。②大风致灾事件多发生在4-6月。拟建铁路吐鲁番境内柴窝铺-了墩段位于大风高值区,年均大风日60 d以上,哈密-若羌段40 d左右,塔什库尔干-阿克陶段25 d左右。建议在大风地区修建"挡风墙"并修建防护林带和保护铁路沿线现有稀疏植被。     

Use of observed hydroclimatic trends to constrain projections of snowmelt season runoff in the Rio Grande headwaters

A method is developed for choosing 21st Century streamflow projections among widely varying results from a large ensemble of climate model-driven simulations. We quantify observed trends in climate–streamflow relationships in the Rio Grande headwaters, which has experienced warming temperature and declining snowpack since the mid-20th Century. Prominent trends in the snowmelt runoff season are used to assess corresponding statistics in downscaled global climate model projections. We define “Observationally Consistent (OC)” simulations as those that reproduce historical changes to linear statistics of diminished snowpack–streamflow coupling in the headwaters and an associated increase in the contribution of spring season (post-peak snowpack) precipitation to streamflow. Only a modest fraction of the ensemble of simulations meets these consistency metrics. The subset of OC simulations projects significant decreases in headwaters flow, whereas the simulations that poorly replicate historical trends exhibit a much wider range of projected changes. These results bolster confidence in model-based projections of declining runoff in the Rio Grande headwaters in the snowmelt runoff season and offer an example of a methodology for evaluating model-based projections in basins with similar hydroclimates that have experienced pronounced climate changes in the recent historical record.     

融雪剂对大叶黄杨生长和生理特性的影响

为了研究融雪剂对道路绿化植物的影响,以大叶黄杨(Euonymus japonicus Thunb)为研究材料,研究了其在3种融雪剂(JLR-01、LBR-4、芦笛一号)不同施用量影响下的生长量和生理特性。结果表明:随着融雪剂LBR-4和芦笛一号的施用量的增大,大叶黄杨叶片的相对生长量和株高相对生长量、光合速率(Pn)、水分利用效率(WUE)、蒸腾速率(Tr)和气孔导度(Gs)随之减小,而低施用量的融雪剂JLR-01对大叶黄杨生长量、Pn、WUE和Tr有促进作用。随着融雪剂作用时间的延长,3种融雪剂的Pn和WUE也随之减小,Tr则是先减小后有所增大。当融雪剂施用量较小和胁迫时间较短时,Pn下降是因为气孔关闭;而当施用量较大和胁迫时间较长时,Pn下降是因为叶肉同化能力下降;3种融雪剂对大叶黄杨的胁迫程度由大到小的次序为:芦笛一号>LBR-4>JLR-01;大叶黄杨对3种融雪剂施用量的忍耐阈值在80 g.m-2左右,大叶黄杨对施用LBR-4和芦笛一号的耐受时间阈值大约为3周,对施用JLR-01的耐受时间阈值为3周以上。     

WATER YIELD INCREASES THROUGH SURFACE DUSTING OF A PERMANENT ICEFIELD1

ABSTRACT: Water yields from a permanent icefield were increased by 28 percent through surface dusting with carbon black. On July 4, 1972, approximately 15 acres (60,700 m²) of a permanent icefield were treated with 150 lbs. per acre (16.8 g/m²) of commercial carbon black. The icefield was located on the eastern slope of the Colorado Front Range at an elevation of 11,500 feet (3500 m). The carbon black was applied by helicopter using a dry applicator slung below a helicopter. The treatment effect was evaluated by control plot observations of melt and streamflow comparison before and after treatment. The ablation plot studies and runoff comparison with an adjacent watershed both indicated a 28 percent increase in ablation and meltwater runoff, respectively, for the months of July and August. The study indicates icefields could be used as cold-storage reservoirs for use in periods of critical water shortages.     

A NEW METHOD FOR SAMPLING SNOW MELT AND RAINFALL IN FORESTS1

ABSTRACT: Monitoring snow melt rates in high elevation, high snowfall forest stands is difficult mechanically and often impossible due to winter inaccessibility. A method for continuous unattended measurements of melt rate is described. With individual lysimeter pans connected to a common collector, any reasonable number of pans can be installed at each site.     

WATERSHED RESPONSES TO CLIMATE CHANGE AT GLACIER NATIONAL PARK1

ABSTRACT: We have developed an approach which examines ecosystem function and the potential effects of climatic shifts. The Lake McDonald watershed of Glacier National Park was the focus for two linked research activities: acquisition of baseline data on hydrologic, chemical and aquatic organism attributes that characterize this pristine northern rocky mountain watershed, and further developing the Regional Hydro-Ecosystem Simulation System (RHESSys), a collection of integrated models which collectively provide spatially explicit, mechanistically-derived outputs of ecosystem processes, including hydrologic outflow, soil moisture, and snow-pack water equivalence. In this unique setting field validation of RHESSys, outputs demonstrated that reasonable estimates of SWE and streamflow are being produced. RHESSys was used to predict annual stream discharge and temperature. The predictions, in conjunction with the field data, indicated that aquatic resources of the park may be significantly affected. Utilizing RHESSys to predict potential climate scenarios and response of other key ecosystem components can provide scientific insights as well as proactive guidelines for national park management.     

Photodegradation of halobenzenes in water ice

Results from the photolysis of o, p-dichlorobenzene, bromobenzene, and p-dibromobenzene in water ice are reported. All phototransformations appeared to be based on dehalogenation, coupling, and rearrangement reactions in ice cavities. No photosolvolysis products, i.e. products from intermolecular reactions between organic and water molecules, were found. Many of the products were very toxic substances of a high environmental risk, such as PCBs. The results support our model, in which secondary, very toxic, pollutants can be formed in ice, snow, and atmospheric ice particles from primary pollutants through the action of solar irradiation. The photoproducts may be released to the environment by ice melting and evaporation.     

积雪灾害防治中的积雪深度与风速的计算

为防止积雪灾害的发生或采取必要的防治措施,必须弄清积雪灾害特征,分析积雪的影响因素,研究积雪灾害的发生机理,理顺积雪灾害的类型,探讨积雪灾害发生的规模,以确保工程建设及人民生命安全。降水量是积雪灾害首要因素,是积雪灾害物质的来源;气温的高低是造成积雪的前提;风不仅对水汽和降雪有影响,而且对积雪有再分配的作用;降雪量直接影响积雪分布,地形、风向、风速(风力)、植被、坡向等对积雪分布也有一定影响。在分析研究灾害积雪的特征、类型、影响因素、发生机制、规模以及发生的规律等同时,探讨了最大积雪深度、最大风速的计算方法。通过定量计算,为研究积雪灾害的防治提供依据。     

FOREST GROWTH IMPACT ON PEAK SNOW PACK MEASUREMENTS AT LONG TERM SNOW COURSES1

ABSTRACT: Snow course surveys in late winter provide stream‐flow forecasters with their best information for making water supply and flood forecasts for the subsequent spring and summer runoff period in mountainous regions of western North America. Snow survey data analyses are generally based on a 30‐year “normal” period. It is well documented that forest cover changes over time will affect snow accumulation on the ground within forests. This paper seeks to determine if forest cover changes over decades at long term snow courses decrease measured peak snow water equivalent (SWE) enough to affect runoff prediction. Annual peak SWE records were analyzed at four snow courses in two different forest types having at least 25 years of snowpack data to detect any decreases in SWE due to forest growth. No statistically significant decreases in annual peak SWE over time were found at any of these four snow courses. The wide range of annual winter precipitation and correspondingly highly variable peak snowpack accumulation, as well as many other weather and site variables, masked any minor trends in the data.