灌溉规划中，参考作物蒸散量ET₀为什么采用FAO-56 Penman-Monteith公式估算？
In irrigation planning, why is reference crop evapotranspiration ET₀ estimated with the FAO-56 Penman-Monteith equation?
ET₀指假想参考植被的蒸散速率——株高12厘米、叶面阻力70 s/m、反照率0.23、水分充足——先剥离作物差异，仅由气象驱动。Penman-Monteith式将能量平衡与空气动力学输送耦合，以冠层阻力刻画气孔调控，物理机理明确、参数全球统一，免去Hargreaves等经验法逐地率定之弊；实际作物需水再乘系数Kc求得。
ET₀ is the evapotranspiration rate of a hypothetical reference vegetation-0.12 m tall, surface resistance 70 s/m, albedo 0.23, well watered-so crop differences are stripped out and weather alone drives it. Penman-Monteith couples the energy balance with aerodynamic transport and expresses stomatal control through canopy resistance; parameters stay consistent worldwide, sparing users the site-by-site calibration empirical formulas such as Hargreaves demand. Actual crop water need is then ET₀ times the crop coefficient Kc.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
R.G. Allen 等，《作物蒸散：作物需水量计算指南》，FAO灌溉与排水论文第56号，1998
R.G. Allen et al., Crop Evapotranspiration: Guidelines for Computing Crop Water Requirements, FAO Irrigation and Drainage Paper 56, 1998
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL6430721W：Crop Evapotranspiration
#灌溉 #蒸散量 #FAO-56
与传统地面漫灌相比，滴灌为什么更省水？
Compared with surface flood irrigation, why does drip irrigation save more water?
滴灌通过滴头以小流量把水直接送到根区，湿润范围只限根层，基本没有全田面蒸发、深层渗漏和尾水弃水这三类漫灌的主要损失；滴灌还能高频少量供水，使根区含水率长期接近田间持水量、水分张力低而稳定，根系吸水省力，灌溉水的有效利用率显著高于漫灌。
Drip emitters deliver small flows directly into the root zone, wetting only the soil volume the roots actually occupy, so the main losses of flood irrigation—whole-field surface evaporation, deep percolation below the root layer, and tailwater runoff—are largely avoided. Frequent, low-volume applications also keep root-zone moisture near field capacity at low, stable matric suction, so roots take up water easily and effective water-use efficiency rises markedly.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Keller J. & Bliesner R.D.著《Sprinkle and Trickle Irrigation》，Van Nostrand Reinhold，1990年版
Keller, J. & Bliesner, R.D., "Sprinkle and Trickle Irrigation", Van Nostrand Reinhold, New York, 1990
独立核验依据 · Independent verification: 核验依据 1 ISBN 9781930665194 (1990)
#灌溉工程 #节水灌溉 #滴灌
波涌（间歇）灌溉与连续畦沟灌相比，为什么往往能取得更高的灌水均匀度？
Compared with continuous furrow or border irrigation, why does surge (intermittent) irrigation often achieve better distribution uniformity?
波涌灌溉以脉冲方式分几次向沟畦供水：首次放水推进时表土被浸润、细颗粒沉降密实，土壤入渗率随之下降；停水片刻再放水时，水流在已预湿的上段快速推进，头部深层渗漏减少，节余水量被推向田尾，首尾受水差缩小。于是灌水均匀度与田间水利用系数同时提高，对渗透性强的轻质土壤和长沟长畦尤为有效。
Surge irrigation delivers water to furrows or borders in alternating on-off pulses rather than one continuous run. The first pulse wets and consolidates the soil surface, lowering infiltration; when flow resumes, water races over the pre-wetted upper reach, so less soaks away near the head end and more reaches the tail. Head-to-tail application becomes more even, lifting distribution uniformity and application efficiency, especially on long runs of permeable light soils.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
W.R. Walker、G.V. Skogerboe《Surface Irrigation: Theory and Practice》，Prentice-Hall，1987年
W.R. Walker & G.V. Skogerboe, Surface Irrigation: Theory and Practice, Prentice-Hall, 1987
独立核验依据 · Independent verification: 核验依据 1 ISBN 9780138779290 (1987)
#波涌灌溉 #地面灌溉 #灌水均匀度