安徽省淮北麦茬稻水分供需差的气候分析

安徽淮北5～9月多年(1959～1989年)平均降水量为566～640毫米,占全年降水量的74%左右,利于发展麦茬稻生产。但旱涝频繁,6～8月平均降水相对变率虽为全年最小,仍在50%左右,麦茬稻本田期(6～9月)平均需水量为572～628毫米,80%保证率降水量的水分供需差仍为105～180毫米左右,泡田还需水150毫米。泡田和水层灌溉期间稻田渗漏量最少为200毫米,有效雨量系数若以0.5计,常年麦茬稻本田每亩需灌400～500方。从水分供需差分析,淮北东部较适于发展水稻生产。淮北发展水稻生产还必须根据水利和能源条件,科学规划,合理布局,并大力推广节水栽培。

Studies on Difference between Water Supply and Need of Rice Following wheat in Huaibei Plain of Anhui Province.

A rain capacity of 566—640mm from May to September accounted for about 74% of mean annual precipitation in Huaibei plain of Anhui Province over 31 years(1959—1989),thus benefiting the development of rice following wheat. On the other hand ,dry damage happened frequently because of higher relative deviation (deviation from mean/mean)of rain capacity from June to August, which was about 50%,being the least in a year. The water requirement of rice following wheat was 570—630mm after being transplanted (from June to September). The difference between need and water supply from rain at 80% level of confidence was 105—180mm,excluding 150mm for soaking field and 200mm for seepage loss. Rice following wheat should be irrigated 400—500 cubic metre of water per mu according as the coefficient of useful rain capacity was 50%. From above analysis,the eastern Huaibei was suitable for production of rice following wheat. The development of rice following wheat should be based on water and energy resources with scientific plan,rational distribution and cultural practices of saving on water.