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Vera Potop Luboš Türkott Věra Kožnarová Martin Možný 《Theoretical and Applied Climatology》2010,99(3-4):373-388
This paper presents the methodology for assessment of drought episodes and their potential effects on winter and spring cereal crops in the Czech Republic (in the text referred to as Czechia). Historical climate and crop yields data for the period of 47 years (1961–2007) have been integrated into an agrometeorological database. The drought episodes were determined by three methods: according to the values of the standardized precipitation index (SPI), percentage of long-term precipitations (r), and on the basis of the Ped drought index (S i). Consequently, the combined SPI, S i, and r indices have been used as tools in identification of the severity, frequency, and extent of drought episodes. Additionally, the paper also presents the S i drought index and its potential use for real-time monitoring of spatial extension and severity of droughts in Czechia. The drought risk to crops was analyzed by identifying the relationships between the fluctuation of crop yields and drought index (S i) based on the multiple regression analysis with stepwise selection. In general, models explain that a high percentage of the variability of the yield is due to drought (more than 45% of yield variance). 相似文献
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作物系数是计算作物蒸散量的关键参数。利用2006—2008年和2011年辽宁锦州玉米农田生态系统的涡度相关、气象、作物发育期及叶面积指数观测数据,分析不受水分胁迫条件下玉米逐日作物系数特征及其与叶面积指数的关系。研究表明:作物系数与玉米农田实际蒸散均呈单峰型变化,约在7月末至8月初达到最大值 (玉米开花吐丝期)。在此基础上,建立了不受水分胁迫条件下玉米逐日作物系数与叶面积指数关系 (达到0.01显著性水平), 同时,采用积温表示的标准化生育期方法模拟相对叶面积指数,并建立了逐日作物系数与相对叶面积指数关系 (达到0.01显著性水平),解决了无叶面积观测地区玉米逐日实际蒸散量的计算。研究结果可为玉米农田用水管理以及灌溉措施的制定提供参考。 相似文献
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作物病虫害遥感监测与预测研究进展 总被引：1，自引：0，他引：1
作物病虫害作为严重的生物灾害已危及到世界农业生产和粮食安全,病虫害对我国粮食生产造成的损失日益加剧,植保部门目前使用的测报和防控方式无法满足大范围的精准、高效、绿色科学防控需求.因此,建立基于遥感手段的高效、无损的大面积病虫害监测预测方法,将提升我国大面积作物病虫害的监测和测报精度与防控水平,有利于减少农药施用,对保障国家粮食和食品安全,实现农业可持续发展具有重要战略意义.近年来出现的多种形式的作物病虫害遥感监测方法和技术手段为病虫害的有效防治和管理提供了重要支撑,通过对相关技术方法进行综述,本文从多尺度下的作物病虫害遥感监测与预测机理、监测方法、预测预报方法、典型模型与应用等方面阐述了作物病虫害遥感监测和预测预报研究进展,并探讨了作物病虫害遥感监测当前面临的挑战以及未来发展趋势,建议通过建立全国尺度的作物病虫害遥感监测预测系统,构建作物病虫害绿色智能防控体系,实现病虫害大面积、快速的监测、预测预报和精准、高效、绿色科学防控. 相似文献
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利用1981—2020年5—9月气象数据与玉米产量数据,通过改进逐日降水适宜度并构建逐日气候适宜度模型,建立基于相似年逐日气象要素的作物生育期气候适宜度序列,利用气象产量与气候适宜指数建立模型,设计逐日作物产量气象影响指数以表征气象条件对作物的影响程度,基于该指数构建东北地区玉米逐日产量预报模型并分析其逐日预报准确率,用以表明该指数的准确性。结果表明:利用3个相似年预报结果加权集成综合相似年逐日作物产量气象影响指数可提高逐日预报准确率,黑龙江年尺度逐日预报准确率年际间波动小于东北其他地区。综合相似年月尺度下,随着玉米发育期的推进和实时气象数据的引入,月尺度平均预报准确率逐渐提高。东北地区玉米产量8月31日的日尺度预报准确率普遍高于7月31日;辽宁日尺度预报差异较大,但随着玉米发育期推进逐日预报产量和实际产量接近,准确率也提高。基于气象要素构建的逐日作物产量影响指数和同期气象影响指数可以定量评估不同时段气象条件对作物产量的影响程度,在一定程度上可提高农业气象业务定量化评价水平。 相似文献
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在新型统计检验聚类分析 (CAST) 方法对山东省冬小麦种植区进行合理分区的基础上,利用基于作物产量历史丰歉气象影响指数、关键气象因子影响指数、气候适宜度指数、WOFOST (world food study) 作物生长模型分别建立各区域冬小麦产量动态预报方法,利用这4种方法分别对2004—2011年山东省冬小麦产量进行动态预报,在分析历史预报结果平均准确率的基础上,剔除预报准确率低于90.0%的预报方法,确定每种方法的权重系数,采用加权方法建立山东省冬小麦产量动态集成预报方法。结果表明:4种单一产量预报方法在各区域各时段的预报准确率很不稳定,波动范围较大。而集成预报方法对山东省各区域冬小麦产量动态预报准确率相对于4种单一预报方法均有所提高,预报准确率普遍在95.0%以上,且其预报结果稳定性较好,变化比较平稳, 集成预报方法更适合在业务上应用。 相似文献
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Vera Potop 《Theoretical and Applied Climatology》2011,105(3-4):469-483
Droughts in Moldova were evaluated using meteorological data since 1955 and a long time series (1891?C2009). In addition, yields for corn (Zea mays L.), a crop widely grown in Moldova, were used to demonstrate drought impact. The main aim is to propose use of the S i (S i-a and S i-m) drought index while discussing its potential use in studying the evolution of drought severity in Moldova. Also, a new multi-scalar drought index, the standardized precipitation?Cevapotranspiration index (SPEI), is tested for the first time in identifying drought variability in Moldova while comparing it with the commonly used standardized precipitation index (SPI). S i-m, SPI, SPEI, and S i-a indices show an increasing tendency toward more intensive and prolonged severely dry and extremely dry summer months. Drought frequency increased through six decades, which included long dry periods in the 1990s and 2000s. Moreover, the evolution of summer evapotranspiration recorded a positive and significant trend (+3.3?mm/year, R 2?=?0.46; p????0.05) between 1955 and 2009. A yield model based on the S i-a agricultural index and historic corn yields explained 43% of observed variability in corn production when drought occurred in May, July, and August. Increasing severity of the 20-year drought during the critical part of the growing season is raising corn yield losses, as net losses have so far exceeded net gains. 相似文献
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在田间试验资料基础上，采用改进的发育模型和分区作物参数，结合前人有关研究成果建立了东北玉米区域动力模型，并利用模型模拟了12站40年 (1961~2000年) 玉米生长发育过程。确定抽雄期延迟天数为低温冷害指标，分析了历史低温冷害年及减产情况。模拟了典型冷害年和40年气候平均的0.25°×0.25°网格点玉米生长发育过程, 探讨了与区域气候模式结合进行低温冷害预报的方法。主要结论有:①玉米发育模型能够较好地模拟玉米发育期和发育期对低温冷害的响应，以抽雄期延迟天数为冷害指标评估的历史冷害发生状况基本符合历史实况。②模型有一定的模拟玉米生长量对低温冷害响应的能力，但还需要更多的试验数据校正品种参数，完善模型。③利用GIS技术，结合区域化的作物参数运行区域作物模型，是作物模型区域化应用的一种解决方案。④东北玉米区域动力模型解释性好，根据确定的害指标，以区域气候模式输出结果驱动玉米模型可以模拟和预测低温冷害，是农业气象灾害预测预报的一个有益的尝试。 相似文献
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基于植被供水指数的农田干旱遥感监测研究 总被引：21，自引：3，他引：21
应用1995-2000年NOAA卫星资料，结合广西贵港市的数字化土地利用信息，通过时序分析方法找出典型作物代表区，并计算各典型代表区的平均、最大、最小VSWI（Vegetation Supply Water Index；植被供水指数）特征值，归纳分析水田和旱地的干旱指标，继而根据典型代表区的平均VSWI值划分旱情等级，生成农田旱情遥感图像，评估干旱情况。试验表明，该方法可用于湿润、半湿润地区的农田干旱遥感监测。 相似文献
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面向Internet的农业气象产量动态预报 总被引：2，自引：1，他引：1
针对信息时代Internet网上用户对产量预报动态查询的需求 ,探讨了面向Inter net的农业气象产量预报的解决方案。试验结果表明 ,由于作物生长发育和产量形成是一个光、温、水、土条件长期、综合作用 ,生物量长期累积的过程 ,因此利用积分回归方法 ,考虑全生育期光、温、水气象因子的综合影响 ,根据已出现的天气实况 ,在假定后期天气条件正常的情况下 ,有可能预测出未来产量的趋势。随着天气实况的逐一出现 ,后期的预报结果可望逐步接近实际值。统计检验和试报结果误差均在允许范围内。 相似文献
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Pre-season prediction of regional rainfed wheat yield in Northern Greece with CERES-Wheat 总被引：1，自引：0，他引：1
T. Mavromatis 《Theoretical and Applied Climatology》2014,117(3-4):653-665
The present study aims at forecasting hard wheat (Triticum turgidum L. var. durum) yield in northern Greece, a season prior to harvest. It is based on (a) crop simulated, with CERES-Wheat indicators at four planting dates and (b) reported crop yields at two regional levels (three NUTS2 [Nomenclature of Units for Territorial Statistics] and 16 NUTS3 regions), for the years 1979–2006. Principal component analysis (PCA) was applied to explore major patterns of joint variability in 20 crop simulated agroclimatic indicators of the growing season before harvest. Stepwise regression and hindcast were employed for the selection of the modes identified by PCA as predictors in multivariate linear regression models used for forecasting yield a season ahead of harvest. Forecasting skill varied to a large extent by spatial scale and planting date. When the simulation results aggregated to the larger spatial level (NUTS2), the yield forecasting skill, in terms of R2, was rated as high (ranging from 0.48 to 0.73) in three out of four planting dates for Central Macedonia and in one planting (R 2?=?0.57) for Thrace. Harvest index, nitrogen leaching and related soil water crop simulated output of the previous season, were the most important predictors. No forecasting skill was found in the third NUTS2 region. The performance of the regression models substantially deteriorated at the higher resolution spatial level (NUTS3). In four regions only (including the one where CERES-Wheat was calibrated) yield forecasting skill was moderate (R 2?>?0.25). The results demonstrate the potential of this approach for regional crop yield forecasting before the beginning of the cropping season. However, crop model calibration is required before its application. 相似文献
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Wang Futang 《Acta Meteorologica Sinica》1990,4(3):381-391
In this paper,the development of the studies on the weather-yield simulation and forecasting model inChina is briefly reviewed,and the main features of the current development stage are presented.Moreover,through examples the technical characters,approaches and experimental results are detailedly described anddiscussed of several major statistical forecasting models,dynamic crop growth simulation and the satelliteremote sensing methods to estimate crop yield.Finally,the line of further development and the applied fieldare pointed out.At the present time,in particular,using the above-mentioned modelling techniques to simu-late and evaluate the possible impact of climatic variation on agricultural production and further on man'ssurvival and activities are of a very practical significance as well as socioeconomic benefits. 相似文献
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一种由卫星遥感资料获得的修正的土壤调整植被指数 总被引：9，自引：2，他引：7
目前,通过卫星遥感资料确定区域面上植被分布、类型的研究受到许多实用领域的普遍重视,并由此提出了许多形式不同的植被指数。由于土壤背景噪声是造成植被指数不确定的重要原因之一,为此不同学者在标准化差值植被指数的基础上提出了多种旨在能消弱土壤背景噪声的土壤调整植被指数,如权重差值植被指数、土壤调整植被指数和转化土壤调整植被指数等等。这些植被指数不同程度上消弱了土壤背景噪声,但是必须预先已知下垫面植被的密度分布或覆盖百分比,也就是说仅适合于求解某一小范围植被覆盖变化较小下垫面上的植被指数,而且其动态范围也偏小。本文提出了一种修正的土壤调整植被指数,土壤调整因子由植被指数自身调整,不需要其它辅助信息。计算结果表明其动态范围较大,与最佳土壤调整因子下的土壤调整植被指数差异小,因此对应用卫星遥感资料求解区域面上土壤调整植被指数极其有效。 相似文献
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《Global Environmental Change》2000,10(1):69-80
CERES-Wheat, a dynamic process crop growth model, is specified and validated for seven sites in the major wheat-growing regions of Spain. Variables explaining a significant proportion of simulated yield variance are crop water (sum of precipitation and irrigation) and temperature during the growing season. A multiple linear regression model is developed to represent simulated yield response to these variables. Seven agro-climatic regions are defined based on K-mean cluster analysis of temperature and precipitation data from 329 meteorological stations and provincial crop yield data. The yield functions derived from the validated crop model were then used with the gridded agro-climatic database to conduct a spatial analysis of climate change impacts on national wheat production. Climate change scenarios with and without sulfate aerosols developed from the Hadley Centre (HCGG and HCGS) and Canadian Climate Centre (CCGG and CCGC) are tested. 相似文献
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为了提高产量趋势预报的准确性和定量预报的准确率,利用1962—2002年气象、早稻产量和田间观测资料,建立基于气候适宜度、关键气象因子、作物生长模型的湖南省早稻产量动态预报方法,进行回代检验;并利用2003—2012年资料进行预报检验。分析表明:3种方法的预报准确率比较接近,平均在93.8%以上;基于气候适宜度预报方法的趋势预报准确性最高,较基于关键气象因子的预报方法高4%~6%;基于作物生长模型预报方法的误差5%以内样本百分率最高,较基于气候适宜度的预报方法高2%~20%。研究结果为湖南省早稻产量动态预报筛选出了较优的方法,即产量趋势预报选用基于气候适宜度的方法,定量预报选用基于作物生长模型的方法,同时可供我国其他早稻区的产量动态预报方法研究借鉴。 相似文献
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目前, 数值预报中卫星资料的应用主要只是针对晴空条件, 大量受云和降水影响的卫星资料被丢弃不加以使用。但是, 云雨区观测往往包含有大量与天气系统发生发展密切相关的大气信息, 对这部分资料的同化应用由此成为当前研究的一个重要问题。在快速辐射传输模式中云雨粒子辐射效应的考虑还有待于进一步完善情况下, 云雨区卫星资料的应用通常是采用云检测方案对观测受云影响的严重程度进行判识并决定使用的取舍。以0604号热带气旋Bilis作为研究个例, 该文设计了一组受云影响微波卫星资料不同云检测方案和通道选择的应用试验。对AMSU-A资料, 云检测方案包括散射因子、降水概率和小雨检测3种, AMSU-B卫星资料的云检测方法选用了通道2亮温模拟观测误差和Bennartz散射因子。在对进入分析系统卫星资料与天气系统的配置关系、卫星模拟与实际观测偏差特征的统计以及对初始分析影响研究的基础上, 探讨了它们对台风不同阶段数值预报效果的影响。 相似文献
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结合新疆尉犁县胡杨林区实际情况,通过数据采集、确定评价因子、建立评价模型,提出了一种基于3S技术,利用气象资料、EOS/MODIS卫星资料以及基础地理信息数据计算胡杨林区生态环境质量综合评价指数的方法,同时提出利用生态环境综合指数反映区域生态环境状况的思路。将此方法应用于新疆尉犁县胡杨林区2005—2007年7、8月份生态环境监测与综合评价,获得了近3a同期生态环境质量综合评价及动态对比结果。 相似文献
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A comparative performance analysis was studied on well-known drought indices (Standardized Precipitation Index, Palmer Drought Severity Index (PDSI) and its moisture anomaly index (Orig-Z), and self-calibrated Palmer Drought Severity Index (SC-PDSI) and its moisture anomaly index (SC-Z)) to determine the most appropriate index for assessing olive (O. europaea L.) yield for oil in seven crop regions (Mu?la, Ayd?n, ?zmir, Manisa, Bal?kesir, ?anakkale, and Bursa) in western Turkey and to evaluate the vulnerability of olive yield for oil to climate change with future projections provided by the Hadley Centre for Climate Prediction and Research ENSEMBLES project (HadCM3Q0). A series of curvilinear regression-based crop yield models were developed for each of the olive-growing regions based on the drought indices. The crop yield model that performed the best was the SC-PDSI model in Mu?la, Ayd?n, ?zmir, and Manisa regions and the PDSI model in ?anakkale, Bal?kesir, and Bursa regions. The SC-PDSI index-based model described 65%, 62%, 61%, and 62% of the measured variability of olive yield in Mu?la, Ayd?n, ?zmir, and Manisa regions, respectively. The PDSI index-based model explained 59%, 58%, and 64% of the measured variability of olive yield in Bal?kesir, ?anakkale, and Bursa regions, respectively. The vulnerability of the olive yield for oil to HadCM3Q0 future climate projections was evaluated for Ayd?n and ?anakkale regions due to the resolution of the regional climate model. In terms of the future scenarios, the expected decrease in olive yield residuals was 2.5?ton (103 trees)?1 and 1.78?ton (103 trees)?1 in Ayd?n and ?anakkale regions, respectively. 相似文献