水稻需水量包括叶面腾发量和棵间水面蒸发量,需水量加稻田渗漏量称耗水量。据江苏省水稻需水量等值线图的研究,全生长期多年平均需水量的低值区在灌溉总渠至射阳河北一带,为525mm;苏北的其它大部地区为550mm;575mm的等值线在泗洪、盱眙、仪征、镇江、靖江、南通、崇明一线;镇、宁山区和苏、锡、常则为600mm的高值区。中等干旱年型(P=75%),上述各地的水稻需水量值都要增加50mm左右;特旱年型(P=90%),苏北地区的水稻需水量都要再增加25mm,苏南地区则要再增加50mm。水稻各生育期的日需水强度:前期在3～5mm,中期(7月下旬到8月中旬)为最高值,达6～8 mm,后期一般在4mm左右。稻田渗漏量受土壤质地砂粘、淹灌水层深浅、地下水位高低和边界排水条件等的影响,各地差别很大,过大或过小,都不利于水稻丰产,一般在有水层的情况下,日 Paddy water demand includes the amount of leaf surface evapotranspiration and forest water surface evaporation, water demand plus paddy field leakage is called water consumption. According to the study of paddy water demand contour map of Jiangsu Province, the low-value area for multi-year average water requirement during the whole growth period was 525mm from the irrigation canal to Sheyang Hebei; the other parts of northern Jiangsu were 550mm; the 575mm The value line in Sihong, 盱 眙, Yizheng, Zhenjiang, Jingjiang, Nantong, Chongming line; town, Ning Shan and Su, tin, often 600mm high value area. In middle-drought type (P = 75%), the water requirement of rice in all the above places should be increased by about 50mm; for the special drought type (P = 90%), the water requirement of paddy in North Jiangsu should be increased by 25mm, The area will have to increase 50mm. The daily water requirement of rice in each growth period was 3 ~ 5mm in the early period, the highest value in the middle period (late July to mid-August), reaching 6 ~ 8 mm, and the latter was generally about 4mm. The amount of seepage in paddy fields is affected by soil texture such as sand sticking, water depth of submerged aquifer, water table height and boundary drainage conditions, and the difference is very large and too large or too small, which is unfavorable to the high yield of rice. Generally, Next, day