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1.
基于遥感信息的华北冬小麦区域生长模型及模拟研究   总被引:21,自引:1,他引:21  
卫星遥感估产和作物生长模拟在作物监测和产量预测方面有各自不可替代的优势。但是,遥感估产难以揭示作物生长发育和产量形成的内在机理,作物模拟在区域应用时初始值的获取和参数的区域化遇到很多困难。如何利用二者的互补性使其相互结合受到人们关注。该文在Wofost模型本地化和区域化的基础上,首次利用同化法的思路探讨了MODIS遥感信息与华北冬小麦生长模拟模型结合的可行性和方法,初步建立了潜在生产水平(水分适宜条件)下区域遥感-作物模拟框架模型(WSPFRS模型)。模拟结果显示:WSPFRS模型对区域尺度的出苗期重新初始化后,模拟的开花期、成熟期空间分布的准确性比Wofost模拟结果有所改进;利用遥感信息对区域尺度上返青期生物量重新初始化后,模拟贮存器官干重的空间分布更接近实际单产的分布,贮存器官干重的高值区与实际高产区基本相符。该研究将为下一步实际水分供应条件下基于遥感信息的冬小麦区域生长模拟研究奠定了基础。  相似文献   

2.
WOFOST模型在东北春玉米产区的验证与适应性评价   总被引:2,自引:0,他引:2  
校准与验证春玉米WOFOST模型,为模型本地化、区域化应用提供研究依据。采用东北春玉米田间观测数据,使用全局敏感性分析EFAST方法对WOFOST模型参数进行敏感性分析,结合土壤数据和同期气象数据等资料对模型进行参数校正与优化,确定春玉米的作物参数;利用独立的观测数据,对春玉米生育期、叶面积指数、各生物量等指标进行详细的验证与适应性评价。结果表明:1)针对不同区域进行作物模型敏感性分析筛选出的作物参数有一定差异,但对产量影响最敏感的前5位总敏感参数相同。2)模型对春玉米生育期的模拟较好,开花期和乳熟期的相对模拟平均误差在1 d左右,在成熟期的平均误差在3 d左右。3)模型对各生物量模拟的回归系数α与确定系数R2较好,均通过显著性检验,从模型整体模拟效果来看,地上部分总生物量和叶面积指数为89%和86%,整体模拟性能较好;残差聚集指数(CRM)为14%和4%,表明模型对地上生物量和叶面积指数的模拟值略偏低。4)通过校准模型作物参数值,WOFOST模型能够较好地模拟东北春玉米生长发育及其生物量的动态积累过程,能够应用于东北地区春玉米生产。  相似文献   

3.
作物长势评估指数的设计与应用   总被引:2,自引:0,他引:2       下载免费PDF全文
合理有效地开展作物长势评估,可以及时反映作物生长状况及其对天气气候条件的响应。由于WOFOST模型、ORYZA2000模型在模拟冬小麦、玉米和水稻生长发育过程具备较强机理性,研究基于2001年以来全国冬小麦、玉米、水稻主产区逐日模拟的作物发育进程、叶面积指数和地上总生物量,通过隶属函数构建评估指数,开展高时空分辨率的作物长势评估。结果表明:长势综合评估指数在作物生长前期以发育进程、叶面积指数和地上总生物量三要素加权集合表征,中后期以发育进程和地上总生物量与穗重相关性的加权集合表征;长势评估指数与常规地面观测和遥感长势监测一致性较好,可以反映天气气候条件影响。在作物生长季内,以日为单位构建了作物长势评估指数数据库;根据长势评估指数将作物长势分为长势好、长势偏好、长势持平、长势偏差、长势差,实现空间上的长势监测、对比;以空间集成的方式,开展省级作物长势对比分析;利用长势评估指数变化反映典型天气气候条件对作物生长发育的影响。上述基于作物模型的作物长势评估指数符合现代化农业气象科研与业务服务发展的需求。  相似文献   

4.
为进一步研究WOFOST模型在河南省冬麦区的适用性,以河南省30个农业气象观测站1991—2014年冬小麦观测资料、历史气象资料和土壤资料为依据,对WOFOST模型进行逐站调参和验证,分别建立了30个站的冬小麦模型参数。其中1991—2010年为模型调参年份,2011—2014年为模型验证年份。各站开花期和成熟期调参模拟的归一化均方根误差NRMSE分别小于5%和3%,验证误差分别为3.7%和2.9%。除潢川和固始外,模型对其余各站产量模拟的归一化均方根误差NRMSE全省各站均小于20.0%,验证误差全省平均为15.2%,大部分站点观测值和模拟值相关系数r通过了显著检验。利用调参后的模型模拟2011—2014年冬小麦生长动态变化可知,模拟地上部总干物重与实测单株干物重、模拟LAI与单株叶面积有较一致的变化趋势,拟合度较高。因此,WOFOST模型对河南省冬小麦主要发育阶段、产量及干物质积累模拟能力较强,具有良好的应用前景。  相似文献   

5.
利用遥感信息研究区域冬小麦气孔导度的时空分布   总被引:5,自引:0,他引:5  
气孔导度是影响作物蒸散和作物的光合速率进而影响作物产量的重要因子。文中通过利用NOAA-AVHRR数据首次对华北平原典型区冬小麦气孔导度分布进行了研究,给出了华北平原典型区冬小麦不同生长季节的气孔导度空间分布状况,为进一步研究田间水分和作物蒸散对产量影响以及建立遥感作物水分胁迫生物量模型和监测不同生育期的农田缺水等提供依据。  相似文献   

6.
利用修订的WOFOST模型,结合全球气候变化的大背景以及江苏省冬小麦的实际情况,在冬小麦灌浆期进行了升温胁迫和干旱胁迫模拟,研究了江苏省冬小麦在气候变化背景下的农业气象灾害损失,并检验了WOFOST模型对复合胁迫的模拟能力.利用江苏省徐州、淮安和常州三个站点2008—2017年气象、土壤和冬小麦产量等资料,基于WOFOST作物模型,从地上部分的干物重和干物质分配两个角度探讨升温胁迫和干旱胁迫以及二者的复合胁迫对冬小麦产量形成的影响.结果表明,灌浆期升温和干旱复合胁迫严重影响冬小麦籽粒干物质积累和产量.升温(1℃、2℃、3℃)胁迫、干旱(轻度、中度、重度)胁迫以及二者复合胁迫均导致冬小麦减产率不同程度增大,籽粒干物质分配比例不同程度降低,复合胁迫的影响程度大于单一胁迫.升温对江苏南部冬小麦减产程度最大,籽粒干物质积累受阻最为严重;干旱对江苏中部冬小麦产量影响最为严重,籽粒干物质积累程度由南到北递减;复合胁迫下,减产率多表现为由南至北递增,而干物质积累程度递减.  相似文献   

7.
为研究WOFOST模型对于云南烤烟的适用性,使用2010—2011年在云南烟区玉溪、昭通的烤烟田间实验数据,应用WOFOST模型对云南烤烟潜在生长进行了模拟和验证.用昭通2010年的实验数据作参数校正,得到云南本地化的参数,再用其余实验数据验证.结果显示:WOFOST模型可以较好模拟云南烤烟的潜在生长过程,目前烤烟的产量水平仅相当于其生产潜力的88%左右,仍有提升的空间.  相似文献   

8.
在内蒙古东南部地区引入成熟的作物模型并进行适应性验证,可为模型区域化应用提供研究依据。文章基于内蒙古东南部地区田间试验数据、农业气象观测数据结合同期气象数据和土壤数据,利用"试错法"对WOFOST模型参数进行了调试,对WOFOST模型发育期、叶面积指数及各器官生物量、产量等的模拟能力进行了验证。结果表明,模型对玉米发育期模拟较好,抽雄期和成熟期的模拟误差在6d以内,其中对抽雄期的模拟效果更好,在3d左右;模型对生育期内叶面积指数和各器官模拟良好,实测值和模型值的决定系数R2较高,均通过显著性检验,模拟各器官生物量和产量的均方根误差(RMSE)在641~1414kg·hm-2,其中模拟LAI的均方根误差(RMSE)为1.22。通过校准模型参数值,WOFOST模型能够较好地模拟内蒙古东南部地区春玉米生长发育及其生物量的动态积累过程,能够应用于内蒙古东南部地区春玉米生产。  相似文献   

9.
郑昌玲  王春乙 《气象学报》2005,63(2):184-191
在试验研究的基础上,文中尝试利用数值模拟方法评估O3和CO2浓度变化对作物的影响.以农田生态系统碳氮生物化学模型(DNDC)为基础,对其中的作物子模型进行改进,加入O3对冬小麦光合作用和叶片生长影响的模拟,结合原模型中有关CO2对冬小麦光合作用影响的模拟,建立反映O3和CO2浓度变化对冬小麦生长发育和产量形成影响的作物模型.文章对DNDC模型进行了参数修正以适用于中国华北地区;文章参考前人的工作,引用了两种O3对作物光合作用影响的模拟方法进行比较,分别是O3对初始光利用率的影响和O3对叶片光合作用的直接影响;在此基础上,进一步考虑O3对冬小麦叶片生长的影响,根据试验资料,建立了O3对叶片生长影响系数.  相似文献   

10.
全球气候变暖已经成为一个不争的事实,开展气候变化对冬小麦产量影响的数值模拟对制定农业政策以适应气候变化具有重要意义。本文使用荷兰瓦赫宁根大学开发的WOFOST模型,利用太谷2000年和2001年的数据对WOFOST模型进行验证,确定该模型在山西太谷地区的适用性。文章分析了太谷地区气温变化趋势,假定以1985年-2007年的变暖趋势增温,假设其它条件不变,从而构建了100年内每10a的时间间隔的气象情形。以这些气象情形驱动验证好的模型模拟100年内每10a的时间间隔气候变暖对冬小麦产量的影响。模拟结果表明,气温变化对冬小麦产量的影响不是单一的,未来冬小麦的产量是波动变化的。  相似文献   

11.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.  相似文献   

12.
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.  相似文献   

13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.  相似文献   

14.
正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.  相似文献   

15.
Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.  相似文献   

16.
The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.  相似文献   

17.
Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.  相似文献   

18.
Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.  相似文献   

19.
Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.  相似文献   

20.
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on  相似文献   

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