首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
红松、兴安落叶松、红皮云杉苗圃苗木的换床试验研究   总被引:1,自引:0,他引:1  
通过对兴安落叶松、红松、红皮云杉等小兴安岭主要树种不同床高、不同解冻深度裸根苗的生长发育与土壤各层地温、主要气候因子关系的研究,表明:床高30—35cm对换床苗木生长较为有利。兴安落叶松以解冻15cm换床效果较好;红松以解冻25cm换床效果较好;红皮云杉以解冻20cm换床效果较好。气温、相对湿度、降水量、日照时数等主要气候因子对不同床高、不同解冻深度换床苗木生长的影响是多因子综合作用的结果,各气候因子之间相互制约、相互影响。  相似文献   

2.
兴安落叶松、红松、红皮云杉物候期及气象指标   总被引:1,自引:0,他引:1  
伊春市五营地区具有丰富的林业资源,掌握林木尤其是兴安落叶松、红松和红皮云杉这三大珍贵树种的物候节律及其与天气条件的关系,对林业经营具有重要意义。1观测地段和资料观测地段位于黑龙江省五营林业局中心苗圃管理区的东山风景林内,距离五营气象站观测场东南300...  相似文献   

3.
对温宿核桃物候期、生长气象条件及主要气象灾害进行了统计分析,以期为有效防灾减灾措施的提出提供参考依据。结果表明:2000年至今核桃花芽膨大期、果实成熟期差异变化不明显,展叶期和开花期逐年均呈偏早趋势;花期与开花期间≥3℃积温、4月日照时数呈显著正相关,积温越高、日照时数越多,花期越早;果实成熟期与6月日照时数相关最为显著,日照时数越多,成熟期越早,反之越晚;越冬期日最低气温-25℃以下持续7天以上,或极端低温-28℃以下持续24小时以上,核桃树就可能遭受冻害。花期主要影响气象灾害为大风浮尘、高温,果实生长期为高温、持续降水,越冬休眠期主要为低温冻害。  相似文献   

4.
贵州省优质烤烟气候区划指标的补充和修正   总被引:3,自引:1,他引:3  
罗文芳 《气象》1998,24(10):47-51
从贵州省优质烤烟气候区划指标出发,结合威宁县高海拔地区种烟的实际情况,详细分析了贵州省优质烤烟气候区划指标。得出表征热量与作物生长发育的关系,不仅要考虑日平均温度和持天数,还要考虑积温、昼夜温差、地温及叶面温度等。通过分析,对原指标中成熟期平均温度。大田生长期温度、旺长-成熟期天数等指标进行了修正。补充≥10℃活动积温≥2200℃,移栽期日平均气温≥14℃,月平均日较左≥8℃等指标。  相似文献   

5.
利用乌拉特前旗国家基本站1987—2016年地面和农业气象观测资料,对乌拉特前旗光热水资源及向日葵各发育期日数与≥0℃积温、日照时数和降水量的相关性进行分析。结果表明:全发育期天数呈减少趋势,各发育期天数呈增加趋势,各发育期天数和全发育期天数均通过信度p=0.01的显著性水平检验;全发育期≥0℃积温、日照时数和降水量的变化呈减少趋势,出苗和开花期≥0℃积温、日照时数趋势系数均通过信度p=0.01的显著性水平检验,全发育期日照时数通过信度p=0.01的显著性水平检验,降水量年际变化不显著;出苗期与≥0℃积温和日照时数的相关系数通过信度p=0.01负相关显著性检验,全发育期与≥0℃积温和日照时数的相关系数通过信度P=0.01正相关显著性检验。  相似文献   

6.
为了解气候变暖对铜仁市热量资源变化的影响,对农业热量资源利用及农业经济的发展提供科学依据,该文基于铜仁市近52 a(1960—2011年)的日平均气温数据,采用线性倾向估计等统计方法,分析界限温度0℃、5℃、10℃及15℃的起始日期、终止日期、持续天数和积温的变化特征。结果表明:1960—2011年期间热量资源呈显著增加趋势。≥0℃、≥5℃、≥10℃和≥15℃的积温和持续天数普遍显著增加,≥0℃、≥5℃、≥10℃和≥15℃的年均积温分别为6 285. 51℃·d、5 976. 0℃·d、5 412. 2℃·d及4 614. 9℃·d,分别以59. 4℃/10 a、54. 8℃/10 a、48. 9℃/10 a及79. 4℃/10 a的速率显著增暖。初始日期整体表现为提前趋势,终止日期则为延后趋势。持续天数显著增加,积温显著增强。  相似文献   

7.
利用门源气象站1961—2008年逐日气温资料,以五日滑动平均法确定稳定通过≥0℃、≥3℃、≥5℃、≥10℃初、终日,求算初终日间持续日数、活动积温和有效积温,分析界限温度初终日、持续日数和积温的变化,应用PEARSON函数计算界限温度初终日、持续日数、积温与年平均气温的相关性并建立回归模式。研究表明:门源盆地各界限温度初日均呈提前趋势,终日均呈推迟趋势,初终日间持续日数均呈增加趋势,活动积温和有效积温均表现为增多趋势;各界限温度初日与年平均气温呈负相关,终日与年平均气温呈正相关,初终日间持续日数与年平均气温均呈正相关,活动积温和有效积温与年平均气温相关极显著;年平均气温每升高1℃,则≥5℃初日提前6天,终日推迟5天,≥10℃初日提前9天,终日推迟7天,各界限温度期间的持续日数延长3—16天,活动积温增加149~221℃·日,有效积温增加60~131℃·日。  相似文献   

8.
本利用柴达木盆地绿洲农业区5个气象站1961~2002年逐日平均气温资料,统计分析了日平均气温≥0℃、≥10℃积温近40年韵变化特征,研究了其对农业生产的影响。结果表明:日平均气温≥0℃、≥10℃界限温度初日普遍提前,终日稳定推后,积温显增多,生长季明显延长。平均而言,二十世纪90年代≥0℃初、终日与多年平均相比,初日平均提前5.5d,终日推后5.4d;≥10℃初日平均提前4.3d,终日推后5.9d;全年≥0℃积温平均增加136℃、≥10℃增加166℃。  相似文献   

9.
青海湖地区40多年来的气候变化   总被引:3,自引:0,他引:3  
本利用青海湖北岸的刚察气象站1958-1999年40多年的气象资料,计算了年平均气温、年降水量、年蒸发量、≥0℃积温、≥10℃积温的气候倾向率,并讨论了各要素的年代际变化特征和周期变化特征。结果表明,年平均气温和≥0℃积温都呈显的上升状况,而年蒸发量呈较明显的下降状况;90年代环湖地区气温最高,积极积温最多,降水量少,蒸发回升,是一个最干旱的时期;年降水量和≥10℃积温总的变化趋势比较平稳。有意义的是,蒸发、降水、≥10℃积温均存在2.22年的显周期,此外上述5项要素均存在3.8-4.4年和13.3年的显周期变化。这些结论有助于进一步认识青海湖地区气候变化的基本规律。  相似文献   

10.
利用阿勒泰基准站1980-2011年观测资料,分析了阿勒泰市春小麦发育期和光热资源变化,及各发育期日期与≥0℃积温、日照时数的相关性研究。结果表明:全发育期天数的变化是呈减少趋势的,分蘖、乳熟期、全发育期天数均通过了(P<0.01)显著性检验;全发育期的≥0℃积温和日照时数是呈线性减少趋势变化的,拔节、乳熟、成熟期的≥0℃积温与年份的相关系数通过了信度0.01的显著性检验;出苗、拔节、乳熟、成熟期和全发育期的日照时数与年份的相关系数通过了(P<0.01)的显著性检验。成熟期日期受成熟期间的日照时数的正相关影响(P<0.05),分蘖、乳熟期的日期受发育期间的≥0℃积温和日照时数的正相关影响(P<0.01)。造成这些差异的主要原因可能是各年的气候条件不同,其次是各年份的栽培条件、田间管理( 如灌溉、施肥、病虫害防治)等非气象因子的不同所致,各年作物的生长及发育都是气象因子和非气象因子共同作用的结果。  相似文献   

11.
12.
The few systematic international comparisons of climate policy strength made so far have serious weaknesses, particularly those that assign arbitrary weightings to different policy instrument types in order to calculate an aggregate score for policy strength. This article avoids these problems by ranking the six biggest emitters by far – China, the US, the EU, India, Russia, and Japan – on a set of six key policy instruments that are individually potent and together representative of climate policy as a whole: carbon taxes, emissions trading, feed-in tariffs, renewable energy quotas, fossil fuel power plant bans, and vehicle emissions standards. The results cast strong doubt on any idea that there is a clear hierarchy on climate policy with Europe at the top: the EU does lead on a number of policies but so does Japan. China, the US, and India each lead on one area. Russia is inactive on all fronts. At the same time climate policy everywhere remains weak compared to what it could be.

Policy relevance

This study enables climate policy strength, defined as the extent to which the statutory provisions of climate policies are likely to restrict GHG emissions if implemented as intended, to be assessed and compared more realistically across space and time. As such its availability for the six biggest emitters, which together account for over 70% of global CO2 emissions, should facilitate international negotiations (1) by giving participants a better idea of where major emitters stand relative to each other as far as climate policy stringency is concerned, and (2) by identifying areas of weakness that need action.  相似文献   


13.
This paper is a review of the recent development of researches on the stability of the Atlantic meridional overturning circulation (AMOC). In particular, we will review recent studies that attempt to best assess the stability of the AMOC in the past, present, and future by using a stability indicator related to the freshwater transport by the AMOC. These studies further illustrate a potentially systematic bias in the state-of-the-art atmosphere-ocean generM circulation models (AOCCMs), in which the AMOCs seem to be over-stabilized relative to that in the real world. This common model bias in the AMOC stability is contributed, partly, to a common tropical bias associated with the double intertropical convergence zone (ITCZ) in most state-of-the- art AOGCMs, casting doubts on future projection of abrupt climate changes in these climate models.  相似文献   

14.
<正>Drought is a recurring dry condition with below-normal precipitation and is often associated with warm temperatures or heatwaves. A drought event can develop slowly over several weeks or suddenly within days, commonly under abnormal atmospheric conditions(e.g., quasi-stationary high-pressure systems), and can persist for weeks, months, or even years,  相似文献   

15.
Globalization,Pacific Islands,and the paradox of resilience   总被引:1,自引:0,他引:1  
On April 2nd, 2007 a 12 m tsunami struck Simbo, a relatively remote island in Western Province, Solomon Islands. Although Simbo's population continues to depend on their own food production and small-scale governance regimes regulate access to resources, the island's way of life over the last century has increasingly been affected by processes associated with globalization. In this context of a rapidly globalizing world, this article examines the island's resilience and vulnerability to the tsunami and the adaptive capacities that enabled the response and recovery. The tsunami completely destroyed two villages and damaged fringing coral reefs, but casualties were low and social–ecological rebound relatively brisk. By combining social science methods (household surveys, focus group and ethnographic interviews) and underwater reef surveys we identify a number of countervailing challenges and opportunities presented by globalization that both nurture and suppress the island's resilience to high amplitude, low-frequency disturbances like tsunamis. Analysis suggests that certain adaptive capacities that sustain general system resilience come at the cost of more vulnerability to low-probability hazards. We discuss how communities undergoing increasingly complex processes of change must negotiate these kinds of trade-offs as they manage resilience at multiple spatial and temporal scales. Understanding the shifting dynamics of resilience may be critical for Pacific Island communities who seek to leverage globalization in their favor as they adapt to current social–ecological change and prepare for future large-scale ecological disturbances.  相似文献   

16.
The ongoing devolution of climate policy-making to sub-national levels has prompted growing interest in policy entrepreneurship by individuals who are politically and technically creative and institutionally resourceful. This paper investigates the case of the materials-management programme in the Oregon Department of Environmental Quality which has emerged as a national and international leader by focusing on the role of household consumption in greenhouse gas (GHG) emissions. Two noteworthy innovations involve the development of a consumption-based GHG emissions inventory and introduction of policies aimed at facilitating construction of small homes (so-called Accessory Dwelling Units, ADU). The case traces over several decades the higher order learning processes within the group and their entrepreneurship toward affecting broader changes in emission accounting and climate policies in Oregon. The paper identifies the enabling factors for these innovations, and considers: how to create the conditions for learning, experimentation, and policy entrepreneurship; how to reproduce these conditions in different locales; and how to recognize and foster innovations that arise outside the established mainstream ‘climate community’. It also stresses the benefits of breaking down the barriers between science-based analysis and policy. The two questions frequently raised in the climate policy debate – how to bring researchers and practitioners together to develop efficacious policies; and how to replicate successful programmes and policies across different communities, jurisdictions, and locations – should be re-examined. It may be more appropriate to ask instead: How to create conditions for learning, experimentation, and policy entrepreneurship; and how to reproduce these conditions in different locales.

Key policy insights

  • Using a consumption-based greenhouse gas emission inventory instead of a sector-based inventory radically changes climate policy priorities, shifting the emphasis from technological fixes to curbing household consumption.

  • Policy innovations thrive in teams that combine technical and scientific competencies with: a commitment to addressing societal problems; interest in inquiry, experimentation, and learning; entrepreneurship; and strategic and political savvy.

  • These qualities require breaking down artificial barriers between science and policy.

  • Transformative policy ideas can originate within institutional nodes that operate outside of an established community of expertise and authority; and these should be identified and fostered.

  相似文献   

17.
Free tropospheric measurements of ozone, peroxyacetylnitrate andprecursors (CO, NMHC) that were made within the framework of the EUROTRACsub-project TOR (Tropospheric Ozone Research) between 1990 and 1995 at theGAW station Izana, Tenerife (28°18N, 16°30W) arediscussed. The average annual cycles reveal the importance of transport fromnorthern mid-latitudes and the role of photo-chemistry. According toair-mass trajectories, which were supplied to us from AEROCE(Atmosphere/Ocean Chemistry Experiment), transport from northernmid-latitudes is associated with high precursor concentrations in winter,whereas ozone concentrations in winter are not much influenced by transportpatterns, suggesting a rather uniform distribution over the northern part ofthe Northern Hemisphere around mean value of 43 ± 5 ppb. In summer,high ozone concentrations of up to 90 ppb are often encountered duringtransport from north, while the levels of precursors are much lower than inwinter, because of photochemical destruction. Trajectories from southerlylatitudes and the Sahara usually have the lowest ozone concentrationsassociated with them.  相似文献   

18.
Motivated in part by the mathematical problems associated with the application of open boundary conditions to the hydrostatic primitive equations (PE), Browning et al. (1990, Dyn. Atmos. Oceans, 14: 303–332) proposed the use of the reduced system (RS) of equations to replace PE for oceanographic problems. The RS are essentially the Boussinesq equations (BO) with the non-hydrostatic terms in the vertical momentum equation multiplied by a constant δ2 ? 1. This artificially alters the physics (e.g. changing the intemal-inertial wave properties) to facilitate numerical integration, but the changes are assumed to have negligible effects on the dynamics of interest. We assess the accuracy and utility of the RS (following the guidelines for the choice of δ) by comparing numerical finite difference solutions of RS, PE and BO for initial-value problems involving three-dimensional instability of an ocean front and atmospheric frontal development in a two-dimensional Eady wave. Both explicit (BO, PE) and semi-implicit (BOSI, PESI) time-difference schemes are used for the Boussinesq and primitive equations. For RS, the same explicit scheme as for BO is used where δ ? 1 allows larger time steps than with the other explicit models. It is found that relative to BO solutions, the errors for RS are small but increase rapidly and monotonically with increasing δ (over a range consistent with the guidelines) and are greater than the errors for the other models. The use of BOSI allows time steps at least as large as those for RS and results in smaller errors than RS. For these problems, BOSI is the preferable model to replace PE.  相似文献   

19.
Recent advances in the study of the characteristics, processes, and causes of spatio-temporal variabilities of the East Asian monsoon (EAM) system are reviewed in this paper. The understanding of the EAM system has improved in many aspects:the basic characteristics of horizontal and vertical structures, the annual cycle of the East Asian summer monsoon (EASM) system and the East Asian winter monsoon (EAWM) system, the characteristics of the spatio-temporal variabilities of the EASM system and the EAWM system, and especially the multiple modes of the EAM system and their spatio-temporal variabilities. Some new results have also been achieved in understanding the atmosphere-ocean interaction and atmosphere-land interaction processes that affect the variability of the EAM system. Based on recent studies, the EAM system can be seen as more than a circulation system, it can be viewed as an atmosphere-ocean-land coupled system, namely, the EAM climate system. In addition, further progress has been made in diagnosing the internal physical mechanisms of EAM climate system variability, especially regarding the characteristics and properties of the East Asia-Pacific (EAP) teleconnection over East Asia and the North Pacific, the "Silk Road" teleconnection along the westerly jet stream in the upper troposphere over the Asian continent, and the dynamical effects of quasi-stationary planetary wave activity on EAM system variability. At the end of the paper, some scientific problems regarding understanding the EAM system variability are proposed for further study.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号