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《中国农村水利水电》2016,(8)
基于水稻控制灌溉制度和水量平衡原理,考虑水稻移栽日期和生育期受温度变化的影响,研究了1961-2010年灌溉需水量变化规律,同时基于CMIP5三种气候模式下的4种气候情景(RCP2.6、RCP4.5、RCP6.0和RCP8.5)评估了未来气候变化对水稻控制灌溉生育期以及灌溉需水量的影响。结果表明:过去50年,气温的显著升高导致了移栽日期的显著提前和生育期长度的显著缩短,降水量的显著增加导致灌溉需水量在需水量小幅上升的基础上显著下降;在未来气候条件下,水稻移栽日期大幅提前11~36d,生育期长度缩短4~26d。水稻需水量在BCC-CSM1.1(m)和HadGEM2-ES两种模式下均大于基准期均值,而在GFDL-ESM2M模式下呈现出一定的下降趋势,水稻灌溉需水量变化特征与需水量相似,但变化幅度更大。 相似文献
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关中地区气候变化对主要作物需水量影响的研究 总被引：11，自引：2，他引：9
用关中地区30个气象站41年气象资料,探讨了关中地区主要作物冬小麦和夏玉米需水量与相应生育期内气候因子的变化趋势,分析了气候变化对作物需水量的影响。结果表明:关中地区冬小麦需水量无一致变化趋势,净灌溉需水量(NIWR)呈增加趋势;夏玉米需水量呈不显著减少趋势,净灌溉需水量无一致变化趋势。气象因子影响顺序为,冬小麦:相对湿度>最高气温>日照时数>降水量>平均气温>风速,夏玉米:日照时数>相对湿度>最高气温>平均气温>降水量>风速。日照时数和风速引起冬小麦需水量的降低趋势在很大程度上抵消了相对湿度和最高气温引起的冬小麦需水量的升高趋势,而冬小麦生育期降水的减少是造成冬小麦净灌溉需水量增加的主要原因;风速和日照时数的降低趋势是导致夏玉米需水量减少的主要原因。关中地区秋冬春季向暖干发展,夏季除风速显著降低外,其它气象因子变化不大。 相似文献
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泾惠渠灌区作物种植结构变化对灌溉需水量的影响 总被引：3，自引：0，他引：3
研究种植结构变化对灌区作物需水量和灌溉需水量的影响,能够为作物生育期的灌溉用水管理和农业水资源规划提供基础数据。依据泾惠渠灌区实测降水和蒸发蒸腾等气象数据,采用FAO推荐的Penman-Monteith公式和作物系数法计算灌区主要作物需水量;通过频率计算和配线法确定灌区丰水年(25%)、平水年(50%)和枯水年(75%)的有效降水量;根据1988—2014年Landsat卫星遥感影像提取的泾惠渠灌区不同历史时期农业种植结构数据,计算典型水文年份灌区总灌溉需水量,并分析作物需水量和灌溉需水量在不同典型水文年的年际和月际变化。结果表明,随着泾惠渠灌区农业种植结构的变化,灌区总的作物需水量和灌溉需水量都呈现显著下降趋势。但泾惠渠灌区在1988—2005年间,单位面积平均作物需水量和平均灌溉需水量都基本保持不变,随后均呈小幅下降趋势。各月份作物总需水量和总灌溉需水量除6月份之外,其余各月份都呈现显著下降趋势;但在此期间,灌区单位面积平均作物需水量和平均灌溉需水量除在4、8、9月份呈下降趋势,而6月份呈显著增加趋势外,其余各月份基本保持不变。灌区总的作物需水量和灌溉需水量的下降主要是由农作物种植面积大量减少所致,种植结构的变化对其影响较小,但灌区种植结构调整后的作物需水量状况更符合区域有效降水特点。 相似文献
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基于CROPWAT模型的昆明市水稻需水量及灌溉用水量研究 总被引：2，自引：1，他引：1
《灌溉排水学报》2015,(7)
利用昆明市日气象数据、水稻生育期数据和土壤数据,通过CROPWAT模型模拟研究1980—2012年水稻生育期内需水量和灌溉用水量年际变化特征及气象要素对其的影响。结果表明,1980—1999年,水稻需水量和灌溉用水量呈微弱下降趋势(p=0.08,p=0.8);1999―2012年,水稻需水量和灌溉用水量呈上升趋势(p0.01);近33a平均水稻需水量和灌溉用水量分别为603.6mm和638.8mm。作物需水量与温度、风速和日照时数正相关,与相对湿度负相关;灌溉用水量与降水量负相关,与日照时数正相关。气温、风速、湿度和日照时数的组合可以预测年尺度上作物需水量的变化趋势;降水和日照时数的组合可以预测年尺度上灌溉用水量的变化趋势。 相似文献
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水稻产量和灌溉需水量的气候敏感性分析及贡献量评估 总被引：1，自引：1，他引：0
以苏南地区单季稻为研究对象,基于ORYZA2000水稻模型结合去趋势的气象变量定量评估了研究区1961—2010年各气象变量对水稻产量、灌溉需水量和耗水量变化的贡献量,并进行了气象变量敏感性分析。结果表明,1961—2010年,水稻产量和灌溉需水量均呈下降趋势,其中产量下降趋势显著,而耗水量上升趋势显著;辐射的下降对水稻产量变化贡献量最大,导致了产量的显著下降,而风速和辐射的下降以及水气压的增加引起耗水量的下降,但气温升高对其贡献了更大的增加量,多变量共同作用导致耗水量显著增加,降水量的增加导致了灌溉需水量的下降;产量对辐射最敏感,其次是最高气温和最低气温;灌溉需水量和耗水量对最高气温最敏感,其次是最低气温和水气压。 相似文献
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通过CROPWAT模型分析泾惠渠灌区冬小麦和玉米蒸发蒸腾量及灌溉需水量的变化,同时运用SPSS软件,计算灌区作物需水量与气象因子的相关系数,分析结果表明:冬小麦整个生育期蒸发蒸腾量平均值为634.04 mm,蒸发蒸腾量最高峰出现在4月中旬—5月中旬,灌区各分区蒸发蒸腾量趋势基本一致;玉米蒸发蒸腾量平均值为525.22 mm,蒸发蒸腾量高峰期出现在7月中旬—8月下旬,其中三原最大为535.97 mm,富平最小为514.68 mm;灌区冬小麦在播种—越冬期灌溉需水量最低,返青—拔节期需水量增加;灌区玉米在拔节—抽雄期需水量增加,灌溉平均需水量为133.04 mm;7月—8月为籽粒形成乳熟期,需水量为359.15 mm,至9月下旬,玉米灌溉需水量下降;灌区作物需水量与气温呈正相关,与降水呈负相关,与风速和相对湿度相关性较小,气温、日照时数和相对湿度是影响作物需水量的主要因素. 相似文献
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《排灌机械工程学报》2016,(8)
通过CROPWAT模型分析泾惠渠灌区冬小麦和玉米蒸发蒸腾量及灌溉需水量的变化,同时运用SPSS软件,计算灌区作物需水量与气象因子的相关系数,分析结果表明:冬小麦整个生育期蒸发蒸腾量平均值为634.04 mm,蒸发蒸腾量最高峰出现在4月中旬—5月中旬,灌区各分区蒸发蒸腾量趋势基本一致;玉米蒸发蒸腾量平均值为525.22 mm,蒸发蒸腾量高峰期出现在7月中旬—8月下旬,其中三原最大为535.97 mm,富平最小为514.68 mm;灌区冬小麦在播种—越冬期灌溉需水量最低,返青—拔节期需水量增加;灌区玉米在拔节—抽雄期需水量增加,灌溉平均需水量为133.04 mm;7月—8月为籽粒形成乳熟期,需水量为359.15 mm,至9月下旬,玉米灌溉需水量下降;灌区作物需水量与气温呈正相关,与降水呈负相关,与风速和相对湿度相关性较小,气温、日照时数和相对湿度是影响作物需水量的主要因素. 相似文献
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生育期的准确模拟是预估未来气候变化对作物耗水影响的关键,但不同生育期模型间差异较大,其不确定性还未充分研究。采用3种经充分率定和验证的水稻生育期模型(ORYZA2000、CERES-RICE和RCM)结合降尺度后的CMIP5大气环流模式,模拟两种情景下(RCP4.5、RCP8.5)未来3个时期(2020s、2050s、2080s)四川省水稻生育期的变化趋势,再结合水量平衡模型和水稻常规灌溉制度,预估灌溉需水量的变化,同时评估模拟结果的不确定性。结果表明,未来气温的显著升高导致四川省水稻生育期长度显著缩短,而降水量的显著增加导致了灌溉需水量的明显减少。不同生育期模型在模拟水稻生育期以及灌溉需水量时存在着一定的差异,3种生育期模型模拟未来水稻生育期长度的偏差分别为天-2.8 d、-2.3 d、+4.2 d,模拟的灌溉需水量偏差分别为-1.4%、-2.4%、+3.8%,表明3个模型的模拟结果偏差在可以接受的范围内。 相似文献
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基于CROPWAT模型,利用昆明地区气象数据、玉米生育期数据和土壤数据,模拟研究1980-2012年玉米生育期需水量和灌溉用水量年际变化特征及气象要素对其的影响。结果表明:1980-1999年玉米需水量和灌溉用水量呈现微弱下降的趋势(p=0.22,p=0.06);1999-2012年玉米需水量和灌溉用水量呈上升趋势为(p0.01),多年平均玉米需水量和灌溉用水量分别为354.5和64.0mm。玉米需水量与温度、风速和日照时数呈正相关而与降水量和相对湿度呈负相关;灌溉用水量与温度、风速和日照时数呈正相关而与降水量呈负相关。逐步回归分析表明气温、风速和日照时数的组合可以预测年尺度上玉米需水量的变化趋势;气温、风速和降水的组合可以预测年尺度上灌溉用水量的变化趋势。 相似文献
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提高降雨利用率是节约灌溉用水的一种有效途径。提出了一种考虑未来降水的灌溉风险决策方法,以广西青狮潭灌区为例验证这一方法的节水效果。收集了桂林站2013-2014两年早稻和晚稻生育期逐日对未来7d的气象预报数据和相应时段的气象观测数据,推求了两年淹灌和间歇灌溉两种灌溉模式下采用常规灌溉决策和风险灌溉决策的灌溉制度,并分析了风险决策的节水效果。结果表明,早稻和晚稻平均降低灌水量23.5和21.9mm,节水分别为38.3%和6.7%。采用风险决策可以避免因灌后遇雨造成的灌水浪费,从而减少灌溉用水量、排水量以及灌水次数。 相似文献
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干旱区玉米滴灌需水规律的田间试验研究 总被引：16，自引：0，他引：16
在内蒙古干旱区的一种砂土及砂质壤土上 ,对玉米滴灌需水规律进行了田间试验研究。试验设置高灌水定额 ( 3 0～ 40 mm)、中灌水定额 ( 2 0～ 3 0 mm)和低灌水定额 ( 1 5～ 2 5 mm ) 3个处理 ,灌水周期相同 ,在需水高峰期为 3 d,其它时间为 4～ 7d。试验结果表明 ,中灌水定额处理的株高、叶面积和产量均明显高于低灌水定额处理 ,而高灌水定额与低灌水定额处理之间差异很小。因此对所研究土壤来说 ,建议采用灌水定额 2 0～3 0 mm,灌水周期 3～ 5 d的灌溉制度。这种情况下 ,玉米生育期需水量为 466mm (生育期有效降雨 1 0 1 .1mm)。对滴灌玉米作物系数的计算方法进行比较后发现 ,双作物系数法可以较好地描述灌水或降雨后地表蒸发对作物腾发的影响 ;在作物生育中期 ,分段单值平均法、双作物系数法的计算结果与实测值吻合良好。 相似文献
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《灌溉排水学报》2019,(12)
【目的】揭示不同降水年型下东北寒区水稻需水对地下水埋深变动与灌溉的响应规律,进一步优化寒区水稻灌溉制度。【方法】以黑龙江庆安和平灌区灌溉试验站多年水稻灌溉试验及2017年地下水动态观测数据为依据,分析不同灌水模式下水稻耗水及地下水变化动态,验证AquaCrop模型在东北寒区水稻生长模拟中的适用性,并用于模拟分析25%、50%、75%降水年型下水稻需水与不同地下水埋深的相互关系及灌水量的响应规律,提出适宜该地区水稻高产的地下水埋深范围及其生育期净灌水量。【结果】①水稻生育期内,地下水埋深先浅后深,其中,分蘖期、拔节孕穗期和抽穗开花期耗水量大,灌溉和降雨较多,地下水埋深较浅;②构建了3种降水年型下ET与GD、I的多元回归方程,综合考虑了水稻需水量与地下水埋深、生育期灌水量之间的相关关系,可用于稻田高效耗用水管理和地下水资源持续利用;③为实现东北寒区水稻高产和地下水埋深基本稳定的双重目标,地下水埋深应控制在2.0～2.5 m之间,水稻生育期净灌水量为:枯水年不宜低于现状灌水量,即300 mm;丰水年和平水年净灌水量可适当减少至现状灌水量的0.8倍,即240 mm。【结论】提出了适宜该地区水稻高产的地下水埋深范围及生育期净灌水量,为促进我国东北地区节水增粮,保护湿地生态环境,提高农业用水效率提供了理论依据。 相似文献
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About half of the total fresh water used for irrigation in Asia is used for rice production. Decreasing water resources and increasing water costs necessitates increasing water use efficiency for rice. The most common method of irrigation in northwestern India is through alternate wetting and drying with a fixed irrigation interval, irrespective of soil type and climatic demand resulting in over-irrigation or under-irrigation under different soil and weather situations. Soil matric potential may be an ideal criterion for irrigation, since variable atmospheric evaporativity, soil texture, cultural practices and water management affect rice irrigation water requirements. A 4-year field study was conducted to assess the feasibility of rice irrigation scheduling on the basis of soil matric potential and to determine the optimum matric potential so as to optimize irrigation water without any adverse effect on the yield. The treatments included scheduling irrigation to rice with tensiometers installed at 15–20 cm soil depth at five levels of soil matric suction viz. 80, 120, 160, 200 and 240±20 cm, in addition to the recommended practice of alternate wetting and drying with an interval of 2 days after complete infiltration of ponded water. The grain yield of rice remained unaffected up to soil moisture suction of 160±20 cm each year. Increasing soil matric suction to 200 and 240±20 cm decreased rice grain yield non-significantly by 0–7% and 2–15%, respectively, over different years compared to the recommended practice of the 2-day interval for scheduling irrigation. Irrigation at 160±20 cm soil matric suction helped save 30–35% irrigation water compared to that used with the 2-day interval irrigation. With a soil matric potential irrigation criterion the total amount of irrigation water used was a function of the number of rainy days and evaporation during the rice season. 相似文献
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《Agricultural Water Management》1999,39(1):35-46
Pin-Point (PP) irrigation is being used by rice producers in the southern US to suppress red rice (Oryza sativa), the major weed in rice production. In PP irrigation, germinated seed is dropped into the floodwater. After 24 h the field is drained, remains moist for 3 to 5 days, then reflooded until near harvest. Little is known about water use of the PP method in comparison to the conventional Flush-Flood (FF) method in which germinated seed is also dropped into the floodwater and the field is drained after 24 h, similar to PP, or the field is drill-seeded, flooded and drained, but permanent flood is delayed for 30 to 35 days. During this 30 to 35 days non-flood period, flushing (periodic irrigation) is used to maintain seedling contact with the soil and prevent water stress. Water use of PP and FF irrigated rice was studied during 1994 and 1995 growing seasons near Beaumont, TX. Three plots were subjected to the PP irrigation technique and three to the FF method. A flow meter measured irrigation water applied, and lysimeters measured evapotranspiration, transpiration, and evaporation. The FF method required an average of 113 mm more irrigation water than the PP method, due to flushing of FF plots during the non-flood period. Evapotranspiration (ET) was higher for PP plots during the period when FF plots were dry. During the flood period, ET in FF plots was higher than in PP plots in 1994, due to mainly a lower leaf area index and a more open canopy which led to greater evaporation from the water surface. No differences in ET were found in 1995. Stomatal conductance was lower in FF plots during the non-flood period, indicating some degree of water stress. Irrigation method did not affect yield, but the PP method reduced time to 100% heading by 5 to 7 days. These results suggest that the PP method can be useful not only to suppress red rice, but also to save water and produce an earlier maturing crop. Early maturity is particularly important in areas where ratoon cropping is practiced. 相似文献
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《Agricultural Water Management》2004,68(2):117-133
Continuous cropping of winter wheat and summer maize is the main cropping pattern in North China Plain lying in a seasonal frost area. Irrigation scheduling of one crop will influence soil water regime and irrigation scheduling of the subsequent crop. Therefore, irrigation scheduling of winter wheat and maize should be studied as a whole. Considering the meteorological and crop characteristics of the area lying in a seasonal frost area, a cropping year is divided into crop growing period and frost period. Model of simultaneous moisture and heat transfer (SMHT) for the frost period and model of soil water transfer (SWT) for the crop growing period were developed, and used jointly for the simulation of soil water dynamics and irrigation scheduling for a whole cropping year. The model was calibrated and validated with field experiment of winter wheat and maize in Beijing, China. Then the model was applied to the simulation of water dynamics and irrigation scheduling with different precipitation and irrigation treatments. From the simulation results, precipitation can meet the crop water requirement of maize to a great extent, and irrigation at the seeding stage may be necessary. Precipitation and irrigation had no significant influence on evaporation and transpiration of maize. On the other hand, irrigation scheduling of winter wheat mainly depends on irrigation standard. Irrigation at the seeding stage and before soil freezing is usually necessary. For high irrigation standard, four times of irrigation are required after greening. While for medium irrigation, only once (rainy year) or twice (medium and dry years) of irrigation is required after greening. Transpiration of winter wheat is very close for high and medium irrigation, but it decreases significantly for low irrigation and will result in a reduction of crop yield. Irrigation with proper time and amount is necessary for winter wheat. Considering irrigation quota and crop transpiration comprehensively, medium irrigation is recommended for the irrigation of winter wheat in the studying area, which can reduce the irrigation quota of over 150 mm with little water stress for crop growth. 相似文献