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1.
内蒙古草原气候特点与草原生态类型区域划分 总被引：6，自引：0，他引：6
为了合理开发利用气候资源，给草原畜牧业生产的分区管理提供科学依据，文章对内蒙古草原气候特点及气候对牧草生长、畜种分布和土壤环境的影响进行了分析，发现内蒙古气候湿润度的某些等值线与土壤带的分界线几乎完全重合，表明土壤带的形成与气候条件密切相关。而气候和土壤环境是草场类型及其生态系统的主要影响因素，因此以气候湿润度为主要依据，结合内蒙古土壤带的水平分布特征，进行草原生态类型区域的划分不仅具有合理性，而且具有稳定性。指出近年来的气候增暖以及由此引起的其他气候变化，虽使草原生产力有一定的提高，但并未使内蒙古草原的生态类型有所改变。 相似文献
2.
Hallie Eakin 《Climatic change》2000,45(1):19-36
The article explores the strategies employed by smallholder farmers in Mexico to cope with the affects of climatic variability, and how seasonal climate forecasts may assist these farmers in mitigating climatic risk. Recognizing that the decisions of smallholder farmers are intricately tied to the political-economic circumstances in which they operate, the article discusses how agricultural policy in Mexico affects the vulnerability of small-scale producers and may inhibit their ability to use climatic forecasts to their advantage. The article first reviews the literature on smallholder adaptation in Mexico, and discusses briefly policy and institutional issues affecting adaptation at the farm-level. Using the case of small-scale maize producers in Tlaxcala, Mexico, as an illustration, the article then argues that political-economic uncertainty outweighs climatic variability as a determinant of the production strategies of small-scale producers. In these circumstances, the farmers are unlikely to use new seasonal climate forecasts. 相似文献
3.
Environmental change in grasslands: Assessment using models 总被引：7，自引：0，他引：7
Modeling studies and observed data suggest that plant production, species distribution, disturbance regimes, grassland biome boundaries and secondary production (i.e., animal productivity) could be affected by potential changes in climate and by changes in land use practices. There are many studies in which computer models have been used to assess the impact of climate changes on grassland ecosystems. A global assessment of climate change impacts suggest that some grassland ecosystems will have higher plant production (humid temperate grasslands) while the production of extreme continental steppes (e.g., more arid regions of the temperate grasslands of North America and Eurasia) could be reduced substantially. All of the grassland systems studied are projected to lose soil carbon, with the greatest losses in the extreme continental grassland systems. There are large differences in the projected changes in plant production for some regions, while alterations in soil C are relatively similar over a range of climate change projections drawn from various General Circulation Models (GCM's). The potential impact of climatic change on cattle weight gains is unclear. The results of modeling studies also suggest that the direct impact of increased atmospheric CO2 on photosynthesis and water use in grasslands must be considered since these direct impacts could be as large as those due to climatic changes. In addition to its direct effects on photosynthesis and water use, elevated CO2 concentrations lower N content and reduce digestibility of the forage. 相似文献
4.
青海牧区近10年牧草产量变化与气象条件的关系 总被引：2，自引：0，他引：2
利用DPS统计中的相关、回归等方法分析近10年青海高原牧区5站点牧草产量变化与气象因子的关系,并建立了牧草产量的气象条件多元回归拟合模型。结果表明：近10年来牧草产量的年最高值河南、甘德总体呈下降趋势,曲麻莱、海北、兴海总体呈上升趋势;5站点牧草产量5月变幅最大为兴海,变幅最小的为海北,6—8月变幅最大的是曲麻莱,变幅最小的是海北;5站点8月牧草产量形成期总体上日照充足,降水除河南阶段性较充沛外,其余受限制,温度除河南在牧草生长季内当光温出现匹配不当时呈负相关外,其余均受限制;气象因子与5站点年最高牧草产量的拟合模式拟合效果较好,均可通过0.01检验。 相似文献
5.
A global map of drought risk has been elaborated at the sub-national administrative level. The motivation for this study is the observation that little research and no concerted efforts have been made at the global level to provide a consistent and equitable drought risk management framework for multiple regions, population groups and economic sectors. Drought risk is assessed for the period 2000–2014 and is based on the product of three independent determinants: hazard, exposure and vulnerability. Drought hazard is derived from a non-parametric analysis of historical precipitation deficits at the 0.5°; drought exposure is based on a non-parametric aggregation of gridded indicators of population and livestock densities, crop cover and water stress; and drought vulnerability is computed as the arithmetic composite of high level factors of social, economic and infrastructural indicators, collected at both the national and sub-national levels. The performance evaluation of the proposed models underlines their statistical robustness and emphasizes an empirical resemblance between the geographic patterns of potential drought impacts and previous results presented in the literature. Our findings support the idea that drought risk is driven by an exponential growth of regional exposure, while hazard and vulnerability exhibit a weaker relationship with the geographic distribution of risk values. Drought risk is lower for remote regions, such as tundras and tropical forests, and higher for populated areas and regions extensively exploited for crop production and livestock farming, such as South-Central Asia, Southeast of South America, Central Europe and Southeast of the United States. As climate change projections foresee an increase of drought frequency and intensity for these regions, then there is an aggravated risk for global food security and potential for civil conflict in the medium- to long-term. Since most agricultural regions show high infrastructural vulnerability to drought, then regional adaptation to climate change may begin through implementing and fostering the widespread use of irrigation and rainwater harvesting systems. In this context, reduction in drought risk may also benefit from diversifying regional economies on different sectors of activity and reducing the dependence of their GDP on agriculture. 相似文献
6.
STUDY ON THE MAIN CLIMATE MODES OF SHANDONG PRECIPITATION AND THEIR RELATIONS WITH THE EAST ASIAN WESTERLY JET 总被引：1，自引：0，他引：1
Summer precipitation patterns of Shandong Province are relatively independent with regard to the whole eastern China region.To study the rules and causes of precipitation variations,three main climate modes-on the annual,seasonal,and climatic intra-seasonal oscillation(CISO) scales-are extracted using a harmonic analysis method based on daily precipitation of Shandong during 1965-2009 and multi-year averaged pentad precipitation at 722 stations in China during 1971-2000.Among the three precipitation climate modes,the annual mode is closely related to the annual cycle of Earth-Atmosphere thermal system,which is characterized by the periodic dry and wet seasons.The seasonal mode reflects the monsoon effect on precipitation and the main flood season’s contribution to annual precipitation variations.As an important climatic signal,the CISO mode is more evident during summer monsoon.The gradual modulations of the CISO mode,seasonal mode,and annual mode control the annual variation of precipitation.To study the relationship between precipitation climate modes and atmospheric circulations,an East Asian Westerly Jet Index(EAWJI) is defined in this paper.It is revealed that precipitation of Shandong is closely related to EAWJI in all climate modes.A wet or dry phase of each climate mode corresponds to a specific atmospheric circulation pattern.The phase of the annual mode is reverse to that of EAWJI.During the wet phase of the seasonal mode(weak phase of EAWJI),the atmospheric circulation in and around Shandong is characterized by upper-level divergence and low-level convergence.A reversed atmospheric circulation exists for the dry phase(strong phase for EAWJI).In the summer wet phase of CISO mode(strong phase of EAWJI),Shandong is controlled by upper-level divergence and low-level convergence.Again,the dry phase is corresponding to a reversed circulation structure.The methodology employed in this research,i.e.studying the precipitation climatic variations in terms of independent components of different temporal scales,provides a new approach for annual and seasonal precipitation prediction. 相似文献
7.
分析了黄河三角洲地区主要栽培草种的气候生态适应性以及牧草生长季气候条件的优劣势。计算得出该区天然草场和人工草场的气候生产力、气候增产潜力，研究其时空分布规律，提出草场改良措施。结果表明：天然草场年气候生产力为９２１０—１１８２０ｋｇ／ｈａ。增产潜力为４５００—１０５００ｋｇ／ｈａ；种植紫花苜蓿的人工草场年气候生产力为２３７７５—２８０８０ｋｇ／ｈａ，增产潜力为６０００—１９５００ｋｇ／ｈａ。 相似文献
8.
C. W. Recha G. L. Makokha P. S. Traore C. Shisanya T. Lodoun A. Sako 《Theoretical and Applied Climatology》2012,108(3-4):479-494
The study quantified rainfall variability for March–May (MAM) and October–December (OND) seasons in Tharaka district, Kenya. The parameters analysed were inter-annual variability of seasonal rainfall, onset and cessation using daily rainfall data in three agro-ecological zones’ stations. Percentage mean cumulative method was used to determine onset and cessation, and seasonal variability was estimated using rainfall variability indices. Although both seasons are highly variable, OND has been persistently below mean over time while MAM shows high within-season variability. Despite the near uniformity in the mean onset and cessation dates, the former is highly variable on an inter-annual scale. The two rainfall seasons are inherently dissimilar and therefore require specific cropping in agro-ecological zone LM4 and LM4-5. It is possible that farmers in IL5 are missing an opportunity by under-utilising MAM rainfall. The results should be incorporated in implications of climate variability and vulnerability assessment in semi-arid Tharaka district. 相似文献
9.
Considering climatic uncertainties in management planning is a prerequisite for sustainable forest management (SFM). The aim
of the study was to evaluate climate change vulnerability of the current SFM strategy for commercial forests managed by the
Austrian Federal Forests. To that end vulnerability indicators were defined in a stakeholder process (selected indicators
were productivity, timber and carbon stocks, biodiversity, disturbances, a tree species’ position in fundamental niche space,
silvicultural flexibility and cost intensity) and their performance under climate change scenarios assessed with an ecosystem
model. Multi criteria analysis techniques were employed in a partial aggregation of indicators to locate forest stands on
a vulnerability surface. Results revealed high vulnerability particularly in the second half of the twenty-first century,
where 39.6% of the 164.550 ha study area were assessed highly vulnerable to climate change, indicating a strong decline in
the functions and services represented by the indicator system. Water-limited sites on calcareous bedrock were most negatively
affected whereas assessment units at higher altitudes responded predominately positive to climate warming. The presented approach,
transparently integrating multiple management objectives and allowing a quantitative comparison of vulnerabilities between
sites and management strategies, contributes to the development of operational and efficient climate change adaptation measures
in forest management. 相似文献
10.
Abstract An analysis of variance of the 1000–500 mb thickness field is performed to investigate the possibility of seasonal change in climatic variability during the period 1949 to 1975. The mean thickness and measures of transient eddy, standing eddy and north‐south variance, averaged over the region from 25°N to the Pole, are analysed for the annual average and for each of the four seasons. For the annually averaged data, the only statistically significant trend is a linear decrease in mean thickness. None of the variability measures display significant trends in annually averaged values. On a seasonal basis, a significant trend in mean thickness is found in three of the four seasons. Several seasonal measures of variability show statistically significant trends. The most notable result of the analysis is an apparent increasing trend in summer season values of both transient and standing eddy measures of variability. The results of this study reiterate those of a previous study that found no overall change in climatic variability during the period. In addition, however, the data suggest an increase in variability during the summer season although this increase is not sufficient to affect the overall annually averaged value. 相似文献
11.
Sensitivity of agricultural production to climatic change 总被引：2，自引：0，他引：2
P. A. Oram 《Climatic change》1985,7(1):129-152
Although the range of cultivated species is relatively restricted, domestic plants and animals exhibit considerable resilience to stochastic shocks, and the study of their ecological adaptability and critical physiological and phenological requirements is a valuable first step in determining their possible response to climatic change. Methods of assessing agroclimatic suitability and their limitations are discussed, and suggestions are made for simulating the probable impact of shifts in the main climatic parameters on the productivity and spatial distribution of key crops and livestock. Some regions and crops are climatically more vulnerable than others: some regions (in particular North America) are strategically more critical to the stability of world food supplies, while in others resources for agricultural production are under more severe pressure.As well as attempts to forecast long-term climatic trends and their effects on agriculture, combating climatic variability merits high priority. This is an ever-present source of instability in production and could be enhanced in association with changing climate. Its magnitude differs widely among crops and geographical regions, but its impact from year to year is often greater than that predicted from climatic change even in extreme scenarios. The paper indicates a number of potentially desirable areas for action and suggests that several of these would be beneficial both as a buffer against short-term effects of variability and as a means of combating climatic change. 相似文献
12.
L. Tomassini S. Hagemann Ch. Moseley A. Haumann R. Podzun D. Jacob 《Climate Dynamics》2011,36(11-12):2371-2397
A high-resolution pre-industrial control simulation with the regional climate model REMO is analyzed in detail for different European subregions. To our knowledge, this is the first long pre-industrial control simulation by a regional climate model as well as at comparable resolution. We assess the ability of the climate model to reproduce the observed climate variability in various parts of the continent. In order to investigate the representation of extreme events in the model under pre-industrial greenhouse gas concentrations, selected seasons are examined with regard to the atmospheric circulation and other climatic characteristics that have contributed to the occurrences. A special focus is dedicated to land-atmosphere interactions. Extreme seasons are simulated by the model under various circumstances, some of them strongly resemble observed periods of extraordinary conditions like the summer 2003 or autumn 2006 in parts of Europe. The regional perspective turns out to be of importance when analyzing events that are constituted by meso-scale atmospheric dynamics. Moreover, the predictability of the European climate on seasonal to decadal time scales is examined by relating the statistics of surface variables to large-scale modes of variability impacting the North Atlantic sector like the Meridional Overturning Circulation, the El Niño Southern Oscillation, and the North Atlantic Oscillation. For this purpose, we introduce a measure of tail dependence that quantifies the correlation between extreme values in two variables that describe the state of the climate system. Significant dependence of extreme events can be detected in various situations. 相似文献
13.
Sabine L. Perch-Nielsen 《Climatic change》2010,100(3-4):579-606
The attractiveness of a region for touristic activities depends strongly on the local weather and climate. This paper analyses the vulnerability of the beach tourism sector towards climate change by means of an index approach on a country level. A vulnerability framework for the tourism sector is developed and on its basis, indicators are defined for exposure, sensitivity and adaptive capacity. A transparent index approach, including a robustness analysis with multiple transformation methods and weighting sets, yields an assessment of the overall relative vulnerability of the beach tourism sector in 51 countries. Aggregate results on an annual level are presented as a starting point for a more detailed comparison of countries based on the individual indicators. The important limitations regarding the availability of accurate indicators as well as the concept of vulnerability itself are discussed. Despite these limitations, the present study contributes to integrating the numerous direct as well as indirect effects climate change may have on beach tourism. 相似文献
14.
本文在全海洋地球的假定下,建立了一个包括太阳辐射、海面温度等季节变化的理想动力气候模式。模拟结果指出:平衡态及其对外参数敏感性的季节变化很大,而且都是夏季比其它季节大得多;四个季节敏感性的平均值也比年平均模式的敏感性大,这可能主要是太阳辐射季节变化引起的。另外,当太阳常数或二氧化碳浓度减小至一定值时,会出现分岔,若继续减小到分岔点以下,则会发生气候灾变—"深冻"。分岔点上外参数的值在夏季要比其它三个季节大得多。以上结果表明物理过程的季节变化在长期气候变化的研究中是不可忽视的。 相似文献
15.
Munang Tingem Mike Rivington Gianni Bellocchi Jeremy Colls 《Theoretical and Applied Climatology》2009,96(3-4):275-280
A crop simulation model must first be capable of representing the actual performance of crops grown in any region before it can be applied to the prediction of climate variability and change impacts. A cropping systems model (CropSyst) simulations of crop productivity in the sub-Saharan Central African (using Cameroon as the case study) region, under the current climate were compared with observed yields of maize, sorghum, groundnut, bambara groundnut and soybean from eight sites. The model produced both over-and-under estimates, but with a mean percentage difference of only –2.8%, ranging from –0.6% to –4.5%. Based on these results, we judged the CropSyst simulations sufficiently reliable to justify use of the model in assessing crop growth vulnerability to climatic changes in Cameroon and else where. 相似文献
16.
A. A. Tashilova L. A. Kesheva N. V. Teunova Z. A. Taubekova 《Russian Meteorology and Hydrology》2016,41(9):601-609
Annual and seasonal series of temperature values are analyzed using the data of Akhty, Teberda, and Terskol weather stations (the height above the sea level is >1000 m) for 1961-2013 as well as from 1976 to 2013 in order to reveal changes in the mountain climate in the period of contemporary global warming. Mean values, standard deviations, norms, and anomalies of annual and seasonal values of temperature as well as the rate of their variation in the mentioned periods are obtained. It is found that the temperature rise is observed in all seasons and for the year as a whole at the mountain weather stations except Terskol station. According to the results of studying temperature variability, Akhty and Teberda weather stations were united into the group “mountain weather stations” with the subsequent averaging of climatic variables. Terskol weather station was singled out as an independent high-mountain weather station. 相似文献
17.
Sue Walker 《Climatic change》2005,70(1-2):311-318
Agricultural meteorologists are concerned with many operational aspects of the effects of climate on crop production, livestock,
and natural resource management. For them to continue to make a contribution to the economy of a country they must continually
sharpen their skills and remain updated on the latest available information. Training should include a variety of skills,
including transferable skills (e.g. communication, numeracy), professional skills (including cognitive skills) and information
technology skills. Problem-based learning can be used to promote critical thinking, decision making and analytical skills.
More use should be made of computer-aided learning for agricultural meteorologists’ in-service training. In particular, the
Internet or CDs could be used to disseminate specific recently developed techniques and applications to improve the understanding
of the variability in climate and its effect on agricultural production and natural resource management. Examples that can
address the vulnerability of farmers include crop–climate matching, the use of indices, crop modelling and risk assessment
together with seasonal outlooks. A strategy needs to be formulated to address these needs and implement changes in the education
and training of agricultural meteorologists. These training needs must be constantly updated to meet the changing demands
of new technology to cope with climate change and climate variability. 相似文献
18.
The absence of memory in the climatic forcing of glaciers 总被引：1，自引：1，他引：0
Glaciers respond to both long-term, persistent climate changes as well as the year-to-year variability that is inherent to a constant climate. Distinguishing between these two causes of length change is important for identifying the true climatic cause of past glacier fluctuations. A key step in addressing this is to determine the relative importance of year-to-year variability in climate relative to more persistent climate fluctuations. We address this question for European climate using several long-term observational records: a century-long, Europe-wide atmospheric gridded dataset; longer-term instrumental measurements of summertime temperature where available (up to 250 years); and seasonal and annual records of glacier mass balance (between 30 and 50 years). After linear detrending of the datasets, we find that throughout Europe persistence in both melt-season temperature and annual accumulation is generally indistinguishable from zero. The main exception is in Southern Europe where a degree of interannual persistence can be identified in summertime temperatures. On the basis of this analysis, we conclude that year-to-year variability dominates the natural climate forcing of glacier fluctuations on timescales up to a few centuries. 相似文献
19.
The threat of global climate change has caused concern among scientists because crop production could be severely affected by changes in key climatic variables that could compromise food security both globally and locally. Although it is true that extreme climatic events can severely impact small farmers, available data is just a gross approximation at understanding the heterogeneity of small scale agriculture ignoring the myriad of strategies that thousands of traditional farmers have used and still use to deal with climatic variability. Scientists have now realized that many small farmers cope with and even prepare for climate change, minimizing crop failure through a series of agroecological practices. Observations of agricultural performance after extreme climatic events in the last two decades have revealed that resiliency to climate disasters is closely linked to the high level of on-farm biodiversity, a typical feature of traditional farming systems.Based on this evidence, various experts have suggested that rescuing traditional management systems combined with the use of agroecologically based management strategies may represent the only viable and robust path to increase the productivity, sustainability and resilience of peasant-based agricultural production under predicted climate scenarios. In this paper we explore a number of ways in which three key traditional agroecological strategies (biodiversification, soil management and water harvesting) can be implemented in the design and management of agroecosystems allowing farmers to adopt a strategy that both increases resilience and provides economic benefits, including mitigation of global warming. 相似文献
20.
利用聂拉木和定日国家气象观测站1967~2019年月气温和降水资料,开展了珠穆朗玛峰（简称珠峰）地区季、年气温和降水变化特征分析及变化趋势检验。结果表明:近53a珠峰地区季、年平均气温呈显著升高趋势,冬季增温幅度最大,年平均气温在1997年之前为波动下降而1997年之后则是波动增加,进入21世纪后气温升高愈发明显且在冬季尤为突出;珠峰地区1967~2019年降水量呈波动变化但变化趋势不显著;珠峰地区气温和降水体现出较强的局地性差异,其南、北坡气温和降水呈现出不同的变化特征。 相似文献