共查询到18条相似文献，搜索用时 203 毫秒
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一种模拟农业干旱的方法─—作物自然缺水率法朱建英，宋玉（江苏省防汛办公室）水资源短缺已成为社会经济发展的重要制约因素。农业作为水资源的主要用户，人们越来越关注对农业干旱的研究，随之而来的是如何选择一个恰当的干旱模拟方法来评估旱情的课题。以往采用的干旱... 相似文献
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IPCC AR4多模式对中国地区干旱变化的模拟及预估 总被引：2，自引：1，他引：1
使用中国地区温度、降水格点观测数据以及多模式集合平均数据,计算了帕尔默干旱指数(Palmer Drought Severity Index),评估了全球气候模式对中国地区1961—2000年干旱变化特征的模拟能力,预估了SRES A1B情景下在2011—2050年干旱的可能变化.结果表明:对于衡量干旱变化特征的干旱频率、持续时间、干旱面积等几个指标,整个中国地区区域平均的模拟值与观测值较为符合;模式能够模拟再现西北地区的干旱变化特征,模拟的干旱程度在华北地区偏弱、长江以南地区偏强.2011—2050年SRES A1B情景下,中国地区表现为持续的干旱化趋势;总体干旱面积和干旱频率持续增加,其中极度干旱的持续增加占主要作用.从EOF分析结果看,未来40a中国地区以整体干旱分布型为主. 相似文献
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使用1982-2006年GIMMS AVHRR NDVI数据集与同期的CI、K、Pa、SPI、Z、PDSI等干旱指数做了对比分析, 讨论了河南省植被状态指数VCI对气象干旱的滞后效应及干旱监测能力. 结果表明: VCI指数与气象干旱指数的相关性受不同下垫面的影响较大, 农地的VCI与气象干旱指数相关性要明显高于林地, 农地VCI与气象干旱指数呈现正相关关系. 在河南省不同的作物生长阶段, VCI对气象干旱有着不同的滞后效应, 其中, 3-5月份冬小麦生长期VCI对气象条件的反应滞后1~3个月, 7、9月份夏玉米生长期VCI对气象条件的反应滞后1月. 总体上看, 结合前期的气象数据, VCI对河南省气象干旱有一定的指示作用和监测能力. 相似文献
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青海省气象干旱对粮食产量的影响及其评估方法研究 总被引：1，自引：0，他引：1
气象干旱是青海省发生最为频繁的气象灾害之一, 具有出现频率高、 持续时间长、 影响范围广等特点, 对农业生产造成极大的影响, 严重的干旱少雨之年常使农业大幅度减产, 甚至绝收. 为了研究气象干旱对青海省粮食产量产生的影响, 根据拉格朗日插值方法给出了青海省无干旱时"期望产量"的确定方法, 并据此求算出历年干旱对青海省粮食产量的损失量值, 然后依据农作物不同生育期所发生的干旱的强度、 范围以及作物对干旱的敏感度等关系, 建立了干旱损失量的统计和评估模式. 在2006-2010年青海省粮食产量评估中进行应用, 5 a中有4 a误差小于5%, 仅2006年误差百分率达到-9.38%; 由此, 证明了运用干旱损失评估方法, 可以评估出干旱对粮食产量的损失量, 从而评估出青海省的实际粮食产量, 效果较好, 可以在青海省今后的粮食产量预报和评估中推广应用. 相似文献
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干旱半干旱地区农田土壤NO3-N深层积累及其影响因素 总被引：7，自引：0，他引：7
以长期试验资料为基础,着重分析了干旱半干旱地区农田系统中施肥、作物、降水、耕作措施以及土壤类型和特性对产生土壤NO3-N深层积累的影响.分析发现,氮肥的过量施用和400～800 mm降水量偏低是导致干旱半干旱地区土壤NO3-N积累在100～300 cm土层的主要因素.随着氮肥用量的增加,NO3-N深层积累显著增加;氮磷配施有助于降低其积累量.不同作物对氮素的吸收利用效率也是影响NO3-N深层积累的因素,作物之间的轮作方式会有效降低NO3-N深层积累;休闲期种植合理植物可有效降低NO3-N深层积累.NO3-N深层积累主要产生在质地较重的土壤上,带正电荷粘土矿物对NO3-N吸附是导致热带土壤中NO3-N积累的主要因素.深入研究深层积累NO3-N的生物有效性、迁移变化机理、与作物根系之间的关系以及对土壤性状和环境的影响具有重要意义. 相似文献
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衡水地区农业旱情综合评价 总被引：2，自引：0，他引：2
从衡水地区气候特点出发,对农作物各生育期根系层土壤有效供水量与作物需水量进行了实验分析。考虑不同生育期缺水对产量影响的敏感性差异,建立了作物全生育期旱情评价模型。用模糊数学方法,考虑评价区域不同作物的受旱程度、播种面积、产量和价格等因素,建立了区域年度干旱评价指标体系。 相似文献
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文章利用CESM1.1(公共地球系统模式)模式过去千年集合试验结果,对模拟的过去千年中国东部持续性严重干旱事件的时空特征及发生机制进行了初步分析。模式模拟出过去千年中国东部发生了7次持续性严重干旱事件,分别为883~910年、951~977年、1253~1305年、1327~1346年、1471~1488年、1587~1610年和1688~1699年干旱事件,其中仅1471~1488年干旱事件与中国东部旱涝指数对应较好,表明模式对中国东部干旱事件的模拟能力较低。这7次干旱事件均与模拟的ENSO(厄尔尼诺-南方涛动)负位相状态相对应,揭示ENSO可能对中国东部干旱事件的发生起了非常重要的作用。模拟分析结果显示,1253~1305年干旱事件前期可能主要受火山活动驱动,后期则可能受到太阳活动和自然内部变率的影响。另外,1587~1610年干旱事件后期可能也受到火山活动的影响;883~910年和951~977年干旱事件则完全受自然内部变率的影响。对1327~1346年、1471~1488年和1688~1699年这3次干旱事件,无法分辨外强迫和内部变率ENSO的各自贡献。 相似文献
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The impact of irrigation water supply rate on agricultural drought disaster risk: a case about maize based on EPIC in Baicheng City,China 总被引：2，自引：0，他引：2
This study presents a methodology for risk analysis, assessment, and combination of drought disasters under the different irrigational levels in Baicheng City, which is supported by run theory, copula functions, crop growth model, and technique of natural disaster risk assessment from the viewpoints of climatology, geography, hydrology, agricultural science, disaster science, environmental science, and so on. Along with the global warming, the occurrences of water-related disasters become more frequent and more serious. It is necessary to determine the laws of the relationship between irrigational ability and the loss caused by drought. Drought events were identified by using run theory; the drought frequency was calculated by using copula function; the loss of every drought event was simulated by using EPIC model; and the relationship curves under the different irrigational supply conditions between the drought frequency and the yield reduction rate of the drought event were fitted to assess the impact of irrigational supply rate on the loss caused by drought. The results show that in the range of crop water demand, the loss caused by drought decreases as the result of the increase in irrigational supply rate; however, their variations are not proportional. The loss caused by the certain frequency drought event under the certain irrigational supply condition could be calculated by the curve of drought disaster risk assessment constructed by this study. The results obtained from this study are specifically intended to support local and national governmental agencies on agricultural disaster management. 相似文献
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M. Domrös Prof. Dr. 《GeoJournal》1981,5(2):133-138
Drought is a distinct agroclimatological hazard with far reaching consequences upon crop production. Among them, famines are
regarded the most serious effects of climatological drought. Although there is no doubt about the principally valid relationship
between drought and production losses it seems more problematic how this relationship can be proved statistically. In this
paper annual rainfall data and production figures of the three major crops of Sri Lanka, rice (paddy), tea and rubber, are
correlated, but only partially a true relationship between dry years and production losses could be observed. Reason for this
may be the moderate degree of annual drought. From the results shown, the question arises how agricultural drought can be
defined and how the climatic effects upon crop production can be studied satisfactorily. 相似文献
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采用淮河流域内1959—2008年110个气象站的逐日降水资料,结合流域1978—2008年农作物旱涝灾害受灾面积数据,基于降水致灾因子与农作物承灾体受损程度等研究,提出旱、涝致灾气候阈值概念,在此基础上分析旱涝灾害发生的时空特征,确定淮河流域合理的旱涝致灾气候阈值区间并建立致灾气候阈值与农作物受灾面积之间的定量关系。结果表明:① 致灾气候阈值可通过计算发生旱涝事件时间段累积降水量除以1959—2008年相应时段累积降水量的平均值来定义,得到的旱、涝致灾气候阈值在不同尺度下对旱、涝灾害事件均有较好地稳定反映,可满足研究区旱、涝事件分析需求;② 洪涝致灾气候阈值与农作物受灾面积存在一致的变化趋势,而干旱致灾气候阈值与农作物受灾面积相关系数高达0.96,构建了基于干旱致灾气候阈值的农作物受灾面积预测模型。 相似文献
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河北省平原区农田粮食增产与灌溉节水对地下水开采量的影响 总被引：5，自引：0，他引：5
河北平原是中国粮食和蔬菜的主要产区之一,也是以地下水作为主要供给水源的地区。近50年来粮食持续大幅增产,驱动区内地下水开采量不断增大。在这一过程中,农田灌溉节水有效地缓解了粮食增产对地下水开采量增加的速率,拓展了在有限的可利用地下水资源条件下粮食增产的发展空间。在1977年之前,每增产10000t小麦和玉米,多年平均地下水实际开采量增加0.14×108m3,1978年以来,每增产10000t小麦和玉米,多年平均实际开采量只增加0.04×108m3。因此,大力发展抗旱节水作物,合理调控农业种植结构,是缓解河北平原农田区地下水超采状况的重要途径。 相似文献
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Xianglian Li Xiusheng Yang Qiong Gao Yu Li Suocheng Dong 《Frontiers of Earth Science》2009,3(2):198-207
This study presents a basin-scale integrative hydrological, ecological, and economic (HEE) modeling system, aimed at evaluating
the impact of resources management, especially agricultural water resources management, on the sustainability of regional
water resources. The hydrological model in the modeling system was adapted from SWAT, the Soil and Water Assessment Tool,
to simulate the water balance in terms of soil moisture, evapotranspiration, and streamflow. An ecological model was integrated
into the hydrological model to compute the ecosystem production of biomass production and yield for different land use types.
The economic model estimated the monetary values of crop production and water productivity over irrigated areas. The modeling
system was primarily integrated and run on a Windows platform and was able to produce simulation results at daily time steps
with a spatial resolution of hydrological response unit (HRU). The modeling system was then calibrated over the period from
1983 to 1991 for the upper and middle parts of the Yellow River basin, China. Calibration results showed that the efficiencies
of the modeling system in simulating monthly streamflow over 5 hydrological stations were from 0.54 to 0.68 with an average
of 0.64, indicating an acceptable calibration. Preliminary simulation results from 1986 to 1995 revealed that water use in
the study region has largely reduced the streamflow in many parts of the area except for that in the riverhead. Spatial distribution
of biomass production, and crop yield showed a strong impact of irrigation on agricultural production. Water productivity
over irrigated cropland ranged from 1 to 1640 USD/(ha·mm−1), indicating a wide variation of the production conditions within the study region and a great potential in promoting water
use efficiency in low water productivity areas. Generally, simulation results from this study indicated that the modeling
system was capable of tracking the temporal and spatial variability of pertinent water balance variables, ecosystem dynamics,
and regional economy, and provided a useful simulation tool in evaluating long-term water resources management strategies
in a basin scale. 相似文献
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A quantitative approach for hydrological drought characterization, based on non-seasonal water storage deficit data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellite mission, is assessed. Non-seasonal storage deficit is the negative terrestrial water storage after deducting trend, acceleration and seasonal signals, and it is designated as a drought event when it persists for three or more continuous months. The non-seasonal water storage deficit is used for measuring the hydrological drought in southwestern China. It is found that this storage-deficit method clearly identifies hydrological drought onset, end and duration, and quantifies instantaneous severity, peak drought magnitude, and time to recovery. Moreover, it is found that severe droughts have frequently struck southwestern China in the past several decades, among which, the drought of 2011–2012 was the most severe; the duration was 10 months, the severity was ?208.92 km3/month, and the time to recovery was 17 months. These results compare well with the National Climate Center of China drought databases, which signifies that the GRACE-based non-seasonal water storage deficit has a quantitative effect on hydrological drought characterization and provides an effective tool for researching droughts. 相似文献