基于ET0冬小麦需水量计算及其规律

选取豫东平原安阳、西华、信阳、许昌、郑州、驻马店等地冬小麦为研究对象,采用作物系数法计算了ET0频率25％、50％和75％条件下各地冬小麦需水量并进行分析.结果表明,安阳、许昌、郑州、驻马店冬小麦全生育期需水量呈现出湿润年较低、干旱年较高的趋势,最大值介于396.1～729.0mm.各地冬小麦需水量最大的生育阶段均为抽穗—成熟,平均占全生育期需水量45.9％;西华、郑州该生育阶段需水量占全生育期百分比随ET0频率增大而上升,呈现为相对干旱年份需水更多.豫东平原各地冬小麦逐日需水量10-2月均值随ET0频率增大而下降,3月往后上升,其均值为4.31 mm/d.ET0频率25％～50％范围对10-3月逐日需水量影响较大.     

北京地区草坪耗水量测定方法及需水量浅析

根据多年蒸发耗水量观测和研究的经验 ,针对首都绿地建设中草坪耗水问题 ,提出了采用供水式蒸发器和注水式蒸发器最适合草坪耗水量的测定的结论。同时 ,分析得出 ,北京地区草坪全年的需水量为 772 .0mm。根据该地区多年平均降水量和草坪需水量分析 ,年平均缺水量为 12 3 .0mm。     

风沙区参考作物需水量的计算

根据国内外相关的研究成果 ,分析选择并确定了适宜于风沙区参考作物需水量 (ET0 )的计算模式。利用典型风沙区的气象资料 ,对多年逐旬参考作物需水量及 2 0 0 1年春小麦与春玉米生育时段内逐日参考作物需水量进行了分析计算。结果表明 ,FAO最新修正的 Penman-Moteith公式可较好地用于风沙区参考作物需水量的估算 ,一般 ET0 值在年内与年际间变化较大 ,最高值发生在 6月上旬左右 ,多年平均为 5 .82 mm/ d,最低值发生在 1月上旬 ,多年平均 0 .43 mm/ d左右 ,年内各日 ET0 值受气象因素的影响变幅很大 ,因此 ,精确灌溉应设法提高短期天气预报和灌溉预报的精度     

基于遥感修正作物系数的冬小麦需水量预测

作物需水量是确定灌溉制度和灌溉用水的重要依据。为准确预测冬小麦的需水量，以河北邯郸漳滏河灌区为例，利用sentinel-1A雷达影像反演灌区的土壤墒情以修正作物系数，并结合未来15 d的气象预报数据计算的参考蒸散发(ET₀)，预测漳滏河灌区重要灌水期的冬小麦需水量。结果表明：通过遥感反演的土壤含水量与实测值相近，平均相对误差为4.60%；经气象预报数据预测研究区12月11-25日ET₀预测值为15.32 mm；结合土壤水分修正系数与预测ET₀数据，计算冬小麦平均需水量预测值为12.64 mm，其中，磁县需水量最大，为14.23 mm，广平县冬小麦需水量最小，为12.04 mm；由MOD16A2产品计算研究期平均需水量为10.65 mm，较预测值相对误差为18.69%。该方法可以有效地预测作物需水量及其空间分布，可为灌区作物生育期用水预测与管理提供理论参考。     

北疆地区棉花生育期需水量变化特征及成因分析

探讨北疆地区棉花生育期需水量和灌溉需水量的变化趋势进而分析了变化趋势与气象因子的关系.选用北疆26个气象站1961-2016年的逐日气象数据,参考作物蒸散量计算方法和相关作物系数,计算北疆棉花56 a来的作物需水量和灌溉需水量,并分析了对气候变化的响应.结果表明:近56 a北疆地区棉花需水量和灌溉需水量都呈下降趋势,尤其是花铃期下降趋势很显著,气候倾向率依次为-0.635、-0.643 mm/a;棉花花铃期平均需水量为305.02 mm,灌溉需水量平均值为289.95 mm.气象因子与棉花各生育期作物需水量和灌溉需水量相关,其中,降雨对灌溉需水量的影响最大.从气候变化来看,北疆地区棉花作物需要水量呈减少趋势,随着降雨量的增加,灌溉需水量也呈减少趋势.     

泾惠渠灌区作物需水量特征及影响因素分析

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.     

高产条件下夏玉米需水量与需水规律研究

依据2009-2010年田间试验资料,利用农田水量平衡方程计算高产条件下夏玉米各生育阶段需水量和全生育期需水量.结果表明,高产条件下,夏玉米全生育期土壤水分维持在田间持水量的80%左右;全生育期需水量为417.30～507.45 mm.各生育阶段需水量分别为:苗期16.80～33.75 mm,占全生育期需水量3.31%...     

1960—2015年黑龙江省水稻需水量时空分布特征

基于黑龙江省26个气象站1960—2015年逐日气象数据和29个水稻灌溉试验站的作物系数,利用Penman-Monteith方法和Arcmap空间分析功能计算并绘制了1960—1979年、1980—1999年和2000—2015年3个阶段水稻生长季参考作物蒸散量(ET0)、水稻生育期天数、需水量、有效降雨量和需水量与有效降雨量耦合度及相应的气候倾向率分布图。结果表明：水稻生长季ET0平均值为620mm,自西向东总体表现为先减小后增大趋势,风速、湿度、日照时数的减小和温度的升高共同作用导致水稻生长季ET0以-3.90mm/(10a)的平均速度下降;生育期平均天数为115d,自北向南总体表现为增加趋势,温度升高引起了水稻生育期天数以2.68d/(10a)的平均速度增加;水稻生育期有效降雨量平均值为297.03mm,自西向东总体表现为先增大后减小的趋势,生育期天数的增加也弥补了降雨量减小的影响,使有效降雨量以0.62mm/(10a)的平均速度增加;需水量平均值为490.52mm,自西向东总体表现为先减小后增加的趋势,生育期天数的增加弥补了ET0减小对需水量的影响,使研究区内水稻需水量以6.66mm/(10a)的平均速度增加;需水量与有效降雨量耦合度平均值为0.64,自西向东表现为先增加后减小的趋势,需水量增幅大于有效降雨量增幅,使需水量与有效降雨量耦合度总体以-0.009/(10a)速度下降。本研究可为黑龙江省合理分配灌溉水资源和优化水稻品种布局提供依据。     

泾惠渠灌区作物需水量特征及影响因素

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.     

不同ET_0频率夏玉米需水特性分析

以豫东地区安阳、西华、信阳、许昌、郑州、驻马店等地夏玉米为研究对象,采用Penman-Monteith法计算了ET0频率25%、50%和75%条件下夏玉米需水量并进行分析。结果表明,安阳、信阳、郑州、驻马店夏玉米全生育期需水量呈现出湿润年较低、干旱年较高的趋势,最大值介于450.3~477.7mm。各地夏玉米需水量最大的生育阶段均为拔节和灌浆期,信阳、许昌灌浆期需水量平均占全生育期29.2%、37.0%,信阳该生育阶段需水量占全生育期百分比随ET0频率增大而上升,呈现为相对干旱年份需水更多。7月中旬至8月的日需水均值随频率的增大而增大,平均5.52mm/d;9月往后日需水均值随ET0频率的增大而下降,平均3.69mm/d。     

利用地下水动态观测资料估算芦苇耗水量

分析了绿洲内农区非农区水分转化的机理及绿洲内非农区地下水动态规律。荒地和洼地作为绿洲内自然生态 ,其耗水属于生态用水的范畴。绿洲内部非农区地下水动态属侧渗蒸发型。根据非农区地下水动态监测资料 ,通过计算潜水蒸发 ,估算得绿洲内部非农区依靠潜水生长的天然芦苇全生育期耗水量为 14 4～ 188m m。该结果可为确定干旱区平原绿洲生态需水量 ,实现其水资源合理利用提供科学依据。     

气候变化对长江流域早稻灌溉需水量的影响

选用长江流域种植早稻的35个站点1961-2003年气象数据,分析气候变化对长江流域早稻灌溉需水量的影响.结果表明,长江流域大部分地区早稻需水量、灌溉需水量均有减少的趋势.需水量、灌溉需水量同生育期年降雨量、日平均相对湿度呈负相关关系,同生育期日平均气温、日平均风速、年日照时数呈正相关关系,其中灌溉需水量与年降雨量呈极...     

Simulation of water harvesting potential in rainfed ricelands using water balance model

Using daily water balance simulation in rainfed ricelands, the study estimates the probable supplemental irrigation (SI) requirement to meet the water deficits during the reproductive stage of rice and surface runoff (SR) generated that can be harvested in OFR for meeting the aforesaid SI. Value of SI of rice during reproductive stage at 25% probability of exceedence (PE) was found to be 144 mm, neglecting distribution and application losses. Water harvesting potential of the study area indicates that at 50% PE, 85% of SI of rice can be met from the SR generated from the ricelands and stored in OFR. Rest amount of SI can be met from the direct conservation of rainfall in a lined OFR of 2 m depth with 1:1 side slope occupying 9% ricelands. Economic analysis of OFR irrigation system reveals that OFR of 9% ricelands gives net profit (NP) of Indian Rupees (Rs.) 13445 (US $295.49) for 1 ha sown with dry seeded rainfed upland rice with benefit–cost ratio (BCR) of 1.25. Values of NP and BCR indicate that investment in OFR irrigation system is profitable in the study region.     

地下水埋深与土壤含水率对应关系和最优灌溉模式的试验研究

节水高产的浅湿灌溉技术较适合南太湖地区的水稻生产。试验选用苏南太湖地区水稻土中有代表性的粘土和重壤土作试验载体 ,系统地探讨了浅湿灌溉对水稻生理、生态及稻田生态环境的影响 ,水稻平均比浅水勤灌增产 6.1 %。经对降水利用率、稻田耗水量、灌水量测定 ,浅湿灌溉比浅水勤灌分别增加 1 4 .6%和减少 1 9.2 %和 30 % ,收到了节水高产的效果。对地下水埋深和土壤含水率对应关系的测定 ,得出 ,稻田落干时地下水埋深以 30 cm为宜 (烤田期除外 )。在此范围内 ,地下水埋深每下降 1 0 cm,土壤含水率下降 1 %～ 5%。据此大田试验 ,得出了水稻的最优灌溉模式     

覆膜旱作水稻需水规律试验研究

依据覆膜旱作水稻需水量试验资料 ,分析了节水高产技术条件下水稻各生育阶段和月旬的需水量、需水强度、模比系数及其变化规律。结果表明 :与浅湿晒灌溉 ( CK)相比 ,覆膜旱作水稻蒸发蒸腾量减少 1 95.9mm( 2 9.94 %) ,需水强度减少 1 .7mm/d,比现有水稻节水灌溉技术更节水。模比系数变化更符合水稻高产特点 ,水分利用更趋合理。成果为水稻覆膜旱作节水高产技术的推广提供了科学依据     

两熟制杂交中稻超稀旱育秧迟栽产量及节水效应研究

为了探索川西北丘陵区两熟制杂交中稻的抗旱节水栽培途径,以2个杂交水稻品种进行了超稀旱育秧分期移栽试验,研究了不同秧龄处理下水稻的生长发育、产量状况和节水效应。结果表明,秧龄处理对水稻同一品种的见穗期、完全齐穗和抽穗持续的时间长短有一定的影响,但对成熟期的影响很小;在采用旱稀育壮秧和良好管理条件下,适度范围内的推迟移栽,杂交稻仍然能保持正常的本田分蘖能力,保持良好的穗粒结构,达到较高的产量水平;推迟水稻的移栽期可以大幅度地减少本田前期灌溉用水量,提高灌溉水的生产效率,取得明显的节水效果。     

Groundwater uptake and sustainability of Acacia and Prosopis plantations in Southern Pakistan

Farm woodlots or plantations of salt tolerant trees may provide an economic use or reclamation treatment for salt-affected farmland within the irrigation regions of the Indus Valley, but the hydrological impact and sustainability of such plantations are unknown. Detailed measurements of plantation water use, watertable depth and soil conditions were recorded over 2 years in two small plantations with contrasting soil and groundwater salinity at Tando Jam in the Sindh province of Pakistan. The species monitored were Acacia nilotica, A. ampliceps and Prosopis pallida. Annual water use by 3- to 5-year old A. nilotica was 1248 mm on the severely saline site and 2225 mm on the mildly saline site. Water use by the other species was less than 25% of these rates, but this difference is largely explained by their lower density in terms of sapwood area per hectare. Water use by A. nilotica was considerably greater than annual rainfall, implying uptake of groundwater which was confirmed both by piezometric observations and chloride balance modelling to predict vertical water movement through the root zone. Plantation watertables fell from 1.7 m below surface in March to over 2.9 m in September, then rose again during irrigation of the surrounding farmland. Root zone salt concentrations remained high at the more saline site throughout the monitoring period, but at the less saline site there was evidence of increasing root zone salinity as salt accumulated in areas of the profile subject to root water uptake. Salt concentration in the upper profile decreased as the soil dried and water was absorbed from greater depth. Plantations using saline groundwater may be sustainable if occasional leaching and other salt-removing processes are sufficient to maintain root zone salinity at a level which does not excessively reduce tree growth.     

Spatial and temporal trends of water productivity in the lower Mekong River Basin

We estimate the physical and economic water productivities of rice and upland crops grown in the Lower Mekong River Basin and we examine their spatial and temporal trends. We discuss the constraints to low productivity, suggest measures for improvement and show the future productivity requirements for food security for increased population. Both the physical and economic water productivities of rice are higher in Vietnam, moderate in Laos, and lower in Thailand and Cambodia. In contrast, the physical water productivities of upland crops such as sugarcane and maize are highest in Thailand. The economic water productivity of upland crops is higher in Laos followed by Vietnam, Cambodia and Thailand, and is much higher than that of rice. However, the economic productivity of all crops is dominated by the productivity of rice, particularly lowland rainfed rice, which is the dominant crop in the Lower Basin. The intra-regional variation (among the provinces within a country) of productivity is not substantial. There is an increasing trend of both physical and economic water productivity in all four riparian countries; however, the increase is more prominent in Laos and Vietnam. The economic productivity of upland crops is much higher than that of rice and therefore cultivation of more upland crops can significantly increase farm-level incomes, with positive impacts on reducing poverty. Increasing upland crops areas is unlikely to have any impact on the food security of the basin. The current rate of increase of both production and productivity of rice is considerably greater than the rate required to feed the expected extra population by 2050, suggesting that food security is not threatened by the population increase. There appears to be considerable scope to increase productivity and maintain the export potential of the basin.     

Exploring options for water savings in lowland rice using a modelling approach

Water-saving irrigation regimes are needed to deal with a reduced availability of water for rice production. Two important water-saving technologies at field scale are alternately submerged–nonsubmerged (SNS) and flush irrigated (FI) rice. SNS allows dry periods between submerged soil conditions, whereas FI resembles the irrigation regime of an upland crop. The effects of these regimes on the water balance and water savings were compared with continuously submerged (CS) and rainfed (RF) regimes.The crop growth model ORYZA2000 was used to calculate seasonal water balances of CS, SNS, FI, and RF regimes for two locations: Tuanlin in Hubei province in China from 1999 to 2002 during summer seasons and Los Baños in the Philippines in 2002–2003 during dry seasons. The model was first parameterized for site-specific soil conditions and cultivar traits and then evaluated using a combination of statistical and visual comparisons of observed and simulated variables. ORYZA2000 accurately simulated the crop variables leaf area index, biomass, and yield, and the soil water balance variables field water level and soil water tension in the root zone.Next, a scenario study was done to analyse the effect of water regime, soil permeability, and groundwater table depth on irrigation requirement and associated rice yield. For this study historical weather data for both sites were used.Within seasons, the amount of irrigation water application was higher for CS than for any of the water-saving regimes. It was found that groundwater table depth strongly affected the water-yield relationship for the water-saving regimes. Rainfed rice did not lead to significant yield reductions at Tuanlin as long as the groundwater table depth was less than 20 cm. Simulations at Los Baños with a more drought tolerant cultivar showed that FI resulted in higher yields than RF thereby requiring only 420 mm of irrigation.The soil type determined the irrigation water requirement in CS and SNS regimes. A more permeable soil requires around 2000 mm of irrigation water whereas less permeable, heavy soil types require less than half of this amount. We conclude that water savings can be considerable when water regimes are adapted to soil characteristics and rainfall dynamics. To further optimize water-saving regimes in lowland rice, groundwater table dynamics and soil permeability should be taken into account.     

鲜食甜玉米需水规律及节水灌溉制度研究

【目的】研究鲜食甜玉米需水量、需水规律及节水灌溉制度,指导其科学合理灌溉。【方法】连续开展2 a鲜食甜玉米田间灌溉试验,以群众高产种植经验为试验处理,在试验小区内安装智墒和云智能气象站采集土壤墒情、气象数据。分析了甜玉米全生育期土壤水分动态变化规律;计算了甜玉米逐日需水量和作物系数,分析了其需水量规律;针对实际灌溉中存在的问题,对甜玉米灌溉过程中土壤含水率上下限进行了优化。【结果】甜玉米土壤水分变化主要集中在10～30 cm之间,根系最大吸水深度为50 cm;2016—2017年甜玉米全生育期需水量分别为197.7 mm和212.9 mm,平均需水强度分别为3.0 mm/d和3.1 mm/d;需水强度呈现抽雄吐丝期灌浆乳熟期拔节期苗期的规律;甜玉米作物系数(Kc)苗期最小,抽雄吐丝期最大,2 a全生育期Kc平均值分别为0.63和0.67;经过灌溉制度优化,甜玉米全生育期灌水4次,净灌溉用水量较实际分别减少31.87%和33.97%。【结论】甜玉米需水量较小,需水规律和普通玉米相似,农业生产中应根据降雨情况适时补充灌溉。