基于CROPWAT模型水稻需水量及灌溉制度研究

为研究黑龙江松嫩平原南部地区气候变化对水稻需水量影响及水稻不同灌溉制度,基于黑龙江省庆安县1966～2015年气象、土壤数据和水稻作物参数,采用Mann-Kendall趋势检验法分析水稻生育期内需水量变化规律,利用CROPWAT模型计算水稻各生育期需水量、有效降雨和灌溉需水量,对不同典型年份水稻需水量和有效降雨作耦合度分析,制定水稻灌溉制度。结果表明,生育期内水稻需水量在气象因素共同作用下以13.68 mm·10年-1速率下降,变化范围为410.8～574.6 mm;该地区特枯水年、枯水年、平水年和丰水年水稻需水量分别为521.0、484.9、451.8、410.8 mm;水稻在拔节和抽穗期需水量较大,两个时期需水量在不同水文年下差异明显;不同水文年下6、7、8月主要需水时期,需水量与有效降雨耦合度均小于1;同一水文年下灌溉定额均为淹水灌溉>"浅、湿"灌溉>干湿交替灌溉>控制灌溉,淹水灌溉灌溉次数最多,干湿交替灌溉模式灌溉次数最少;不同水文年下与淹水灌溉灌溉定额相比水稻"浅、湿"灌溉、干湿交替灌溉和控制灌溉节水效果明显,分别可节水6.3%～13.4%、29.1%～39.4%、30.6%～42.6%。有效降雨量难以满足水稻需水要求,在水稻生育期内应根据不同典型年选择合适灌溉制度灌溉,并在拔节孕穗、抽穗开花两个高耗水时期加强灌溉。

Study on water requirement and irrigation schedule of rice base on CROPWAT model

In order to study the impact of climate change on rice water requirement and to formulate different irrigation schedules for rice in the southern Songnen plain of Heilongjiang Province.Using available data from 1966-2015, the CROPWAT model and the Mann-Kendall trend test method.The temporal change in meteorological factors, water requirement of the rice, effective rainfall, water requirement for irrigation, as well as their relationships in Qingan County of Heilongjiang Province were estimated. The relationship between the effective rainfall and water requirement of the rice, and calculated the associated irrigation schedule under different annual rainfalls was analyzed. The results showed that the water requirement of rice decreased at a rate of 13.68 mm/10 a under the combined action of meteorological factors, and the variation range was 410.8 ～ 666.3 mm. The water requirement of rice in special dry year, dry year, normal year and abundant year was 521, 484.9, 451.8 and 410.8 mm,respectively, the variation range was 410.8-574.6 mm. The water requirement in the two stages of jointing and heading was large, and the water requirement in the two stages was obviously different under different hydrological years. In June, July and August, the coupling degree of water demand and effective rainfall was less than 1. Under the same hydrological year, the irrigation quota was Flooded irrigation > "shallow and wet" irrigation, >alternating dry and wet irrigation, > controlled irrigation, and the maximum number of times of submerged irrigation was the minimum number of times of alternating dry and wet irrigation.Compared with flooded irrigation Compared with flooded irrigation under different hydrological years, "shallow" irrigation, "wet" irrigation, "dry and wet" alternate irrigation and control irrigation had obvious water-saving effects, respectively saving 6.3%-13.4%, 29.1%-39.4% and 30.6%-42.6%. It was difficult for effective rainfall to meet the water requirement of rice, so appropriate irrigation system should be selected according to different typical years, during the rice growth period, and irrigation should be strengthened in the two periods of high water requirement at jointing booting ear and ear flowering.