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汉中市水稻产量特征及气候要素对其影响研究 总被引：1，自引：0，他引：1
通过分析1949—2010年汉中市水稻产量特征、气候产量与气候条件的相关性及气候变化对产量的影响,结果表明：水稻单产年际变化呈增一减一增趋势;气候产量年际波动较大,1970一1993年气候产量多为正值,1993年后负值年份明显增多;水稻生育期间7月日照、8月降水、5月温度、7月温度对产量的影响为负效应,5月降水、8月日照为正效应。5—9月的旱、涝程度与气候产量呈明显的负相关,旱、涝程度越重．产量减产越严重。增温对汉中水稻产量的影响是减产,因此气候变暖使水稻呈减产趋势。 相似文献
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东北地区水稻生产的风险评估 总被引：1，自引：0，他引：1
利用东北地区40年的水稻实际产量资料,采用直线滑动平均法分离出趋势产量和气象产量．以相对气象产量序列为研究对象,选取平均减产率、产量变异系数和风险指数作为评价指标,分析了低温冷害等气候条件下东北地区历年水稻生产的风险水平。 相似文献
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研究和建立作物产量与气候条件关系的模式,对挖掘气候潜力,提高作物产量有一定的作用。 一、铜仁水稻气候产量模式 在气候条件中,光热水是水稻生育及产量形成的重要因子。其中水分条件较易得到改善,而光热条件是难以改变的。因此,在水肥、农技措施均能满足的情况下,水稻产量依光热条件而变化,即水稻产量y是太阳总辐射Q及温度Τ的函数(y=f(Q,Τ)。 据有关单位测定,水稻产量80％以上都是来源于抽穗后光合产物的积累,而光合强度取决于太阳总辐 相似文献
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气候变化对越南北方水稻生产的影响 总被引：9，自引：0，他引：9
利用越南北方各省19个代表站近50a的气候和水稻资料,采用EOF等数理统计方法,分析了气候变化对越南北方水稻生产的影响。同时讨论了水稻趋势产量和气象产量变化的特征,气温、降水等要素与水稻产量之间的关系以及1959年以来气象灾害对越南北方水稻产量形成的影响,并通过积分回归分析探讨了不同因子在不同时段对水稻生产的作用,进而提出在未来气候变暖背景下越南北方应采取的相应对策。 相似文献
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云南水稻气候敏感性和栽培适应性 总被引：3，自引：0，他引：3
分析了低纬高原水稻生长独有的气候特点，将云南省不同地区的水稻产量与水稻生育期气象条件进行积分回归数植模拟分析，得出各地水稻气候敏感性综合数学表达式，区域划分指标以及空间分布规律。同时分析影响云南水稻产量的主要气候敏感因子和关键气候敏感期，并讨论了适应当地气候特点的水稻栽培要点。 相似文献
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运用现代统计学方法和模糊数学理论，普查确定了影响辽阳地区水稻产量的5项气候要素及其各自权重，建立了水稻产量的气候模型，揭示了各单因素对水稻丰歉的模糊关系。通过模糊运算，确立了水稻丰歉农业气候综合影响指标。 相似文献
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福建省茶树生长的气候适应性 总被引：1，自引：0，他引：1
福建省目前茶叶总产量已占全国的17%,是我国主要产茶区.近几年来福建茶叶产量和品质发生了波动,与近几年福建气候的变化是否有一定的关系,本文通过分析茶树对气候条件的要求及福建种茶气候条件的要求及福建种茶气候特征,从气候上分析近年来福建茶叶产量和质量的原因,为福建茶叶的高产优质出谋划策. 相似文献
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籼型杂交水稻气候适应性的研究 总被引：1，自引：0，他引：1
全国杂交稻气象科研协作组 《南京气象学院学报》1981,(2)
气候条件是影响杂交水稻产量和分布的重要因素。本文通过全国联合试验,研究了籼型杂交水稻生育期的时空变化和产量构成因素的地区差异,计算了各地区的产量结构气候指数,为杂交稻的布局提供了农业气候依据。 相似文献
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我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格. 相似文献
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准两年振荡对大气中微量气体分布的影响 总被引：6，自引：5，他引：6
NCAR的包含化学、辐射、动力相互作用的两维模式（SOCRATES）移植回国后进行了初步的模拟试验,用以研究某些对环境问题重要的微量气体的化学、辐射、动力传输过程。在不考虑极地平流层云和气溶胶表面非均相化学等情况下,模式积分多年,计算结果稳定,模拟的风场、温度场显示出正常的季节变化,模拟的微量气体分布与卫星实测资料对照,结果也比较一致。为了探讨热带平流层风场的准两年周期振荡（QBO）对平流层微量气体分布的影响,我们做了QBO强迫的数值试验,即在模式中加入QBO强迫,并与不考虑QBO强迫的模拟结果对比。结果表明,QBO与其相关的次级环流所引起动力输送的变化,使平流层微量气体分布发生变化。 相似文献
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Comparing the theoretical versions of the Beaufort scale, the T-Scale and the Fujita scale 总被引：1，自引：0，他引：1
G. Terence Meaden S. Kochev L. Kolendowicz A. Kosa-Kiss Izolda Marcinoniene Michalis Sioutas Heino Tooming John Tyrrell 《Atmospheric Research》2007,83(2-4):446-449
2005 is the bicentenary of the Beaufort Scale and its wind-speed codes: the marine version in 1805 and the land version later. In the 1920s when anemometers had come into general use, the Beaufort Scale was quantified by a formula based on experiment. In the early 1970s two tornado wind-speed scales were proposed: (1) an International T-Scale based on the Beaufort Scale; and (2) Fujita's damage scale developed for North America. The International Beaufort Scale and the T-Scale share a common root in having an integral theoretical relationship with an established scientific basis, whereas Fujita's Scale introduces criteria that make its intensities non-integral with Beaufort. Forces on the T-Scale, where T stands for Tornado force, span the range 0 to 10 which is highly useful world wide. The shorter range of Fujita's Scale (0 to 5) is acceptable for American use but less convenient elsewhere. To illustrate the simplicity of the decimal T-Scale, mean hurricane wind speed of Beaufort 12 is T2 on the T-Scale but F1.121 on the F-Scale; while a tornado wind speed of T9 (= B26) becomes F4.761. However, the three wind scales can be uni-fied by either making F-Scale numbers exactly half the magnitude of T-Scale numbers [i.e. F′half = T / 2 = (B / 4) − 4] or by doubling the numbers of this revised version to give integral equivalence with the T-Scale. The result is a decimal formula F′double = T = (B / 2) − 4 named the TF-Scale where TF stands for Tornado Force. This harmonious 10-digit scale has all the criteria needed for world-wide practical effectiveness. 相似文献
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Summary ?Some features of the climate system that can be considered predictors of the onset and end of the convective season over
the Amazon were identified using one-month lag correlations and field composites. The fields analyzed were sea surface temperature
(SST), outgoing long-wave radiation (OLR), vertical velocity and upper tropospheric winds.
Warm (cold) anomalies in the SST in the tropical North Atlantic and the Caribbean Sea tend to be associated with delayed (early)
onsets. Likewise, there is a tendency towards a delayed (early) end of the convective season with cold (warm) anomalies in
these ocean regions. In addition, the SST in the cold tongue region of the equatorial Pacific is negatively, though weakly
correlated with the onset date. The signal of this SST is more evident in the case of the end date, which is earlier with
respect to its mean date in most of El Ni?o cases.
The convective activity intensity itself conditions the onset and the end of the convective season, as it is evidenced by
the behavior of the OLR and the vertical velocity fields. The more (less) intense the convective activity over South America
during the preceding month, the earlier the onset and the later the end of the convective season on the Amazon region.
The prediction of the onset and end dates of the convective season in the Amazon region was explored using a simple multiple
regression technique based on the variables that have shown precursor signals with respect to these dates. The correlation
coefficient between the predicted and the observed onset date is 0.81, and in the case of the end date, it is 0.76. The skill
to predict early, delayed and normal categories was high, since in more than two thirds of the cases the category was successfully
predicted, and there were no predictions of categories opposed to those observed.
Received July 23, 2001; revised February 22, 2002; accepted April 26, 2002 相似文献
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流场配置及地形对西南低涡形成的动力作用 总被引：10，自引：8，他引：10
本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用. 相似文献
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由中国历史气候记录对季风导致唐朝灭亡说的质疑 总被引：1，自引：0，他引：1
张德二 《气候变化研究进展》2008,4(2):126-130
2007年1月4日杂志发表了Yancheva等10人的题为"Influence of the intertropical convergence zone on the East-Asian monsoon"(热带辐合带对东亚季风的影响)的论文[1],这是德国波兹坦地学研究中心气候动力与沉积学科的主管豪格(G.H.Haug)率领的科研小组的一项成果,认为是季风的变化引起的长期干旱导致了唐朝的灭亡. 相似文献
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Chunguang CUI Wen ZHOU Hao YANG Xiaokang WANG Yi DENG Xiaofang WANG Guirong XU Jingyu WANG 《大气科学进展》2023,40(4):711-724
Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230... 相似文献
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The impact of high resolution modern vegetation cover on the West African climate is examined using the International Centre for Theoretical Physics Regional Climate Model implementing the NCAR Community Land Model. Two high resolution 25 km long-term simulations driven by the output from a coarser 50-km resolution simulation are performed for the period 1998–2010. One high resolution simulation uses an earlier and coarser-resolution version of plant functional type distribution and leaf area index, while the other uses a more recent, higher-quality, and finer-resolution version of the data. The results indicate that the new land cover distribution substantially alters the distribution of temperature with warming in Central Nigeria, northern Gulf of Guinea and part of the Sahel due to the replacement of C4 grass with corn; and cooling along the coastlines of the Gulf of Guinea and in Central Africa due to the replacement of C4 grass with tropical broadleaf evergreen trees. Changes in latent heat flux appear to be largely responsible for these temperature changes with a net decrease (increase) in regions of warming (cooling). The improved land cover distribution also results in a wetter monsoon season. The presence of corn tends to favor larger precipitation amounts via more intense events, while the presence of tropical broadleaf evergreen trees tends to favor the occurrence of both more intense and more frequent events. The wetter conditions appear to be sustained via (1) an enhanced soil moisture feedback; and (2) elevated moisture transport due to increased low-level convergence in regions south of 10N where the most substantial land cover differences are present. Overall the changes induced by the improved vegetation cover improve, to some extent, the performance of the high resolution regional climate model in simulating the main West African summer monsoon features. 相似文献
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