贵州水稻有效降水量和需水量特征分析

为了分析贵州水稻生育期内有效降水量和需水量等水资源的变化特征,研究基于贵州80个气象站点1961—2015年的逐日气象资料,采用美国农业部(USDA)土壤保持局推荐的有效降水量和联合国粮食及农业组织(FAO)推荐的参考作物蒸散量计算方法,计算贵州水稻不同生育期内的有效降水量和需水量,并分析水稻不同生育阶段缺水量和灌溉需求指数的变化特征。结果表明:1961—2015年,贵州水稻全生育期有效降水量为324 mm,呈递减趋势,其中,移栽—抽穗期是有效降水量最大的阶段,呈递增趋势,其他生育期有效降水量均为递减趋势;水稻全生育期需水量为737 mm,呈递减趋势,其中,移栽—抽穗期、抽穗—灌浆期需水量呈递减趋势,其他生育期需水量呈递增趋势;水稻全生育期多年平均缺水量为413 mm,呈递增趋势,其中,移栽—抽穗期缺水量呈递减趋势,其他生育期呈递增趋势。全生育期作物水分盈亏指数为0.56,其中,抽穗—灌浆期对灌溉依赖程度最高。

Characteristics of effective precipitation and water requirement of rice in Guizhou

In order to analyze the characteristics of rice effective precipitation and irrigation water requirement in Guizhou, the daily meteorological data of 80 meteorological stations in Guizhou during 1961-2015 were collected, and the effective precipitation and water requirement in different growth stages of rice in Guizhou were calculated by effective precipitation recommended by the United States Department of Agriculture (USDA) Soil Conservation Agency and reference crop evapotranspiration recommended by the United Nations Food and Agriculture Organization (FAO). The variation characteristics of irrigation amount and irrigation demand index at different rice growth stages were also analyzed. It was shown that the effective precipitation in the whole rice growth season in Guizhou was 324 mm, and presented a decreasing trend. The transplanting-heading period showed the highest effective precipitation along with an increasing trend, yet the effective precipitation in other growth periods showed a decline trend. The total water requirement of the whole rice growth season was 737 mm, and showed a decline trend. Specifically, the water requirement in rice transplanting-heading and heading-filling stage showed a decline trend, yet the water requirement in other growth period showed an increasing trend. The average water shortage during the whole rice growth season was 413 mm along with an increasing trend. The water shortage in rice transplanting-heading stage exhibited a decline trend, yet the water shortage in other growth period showed an increasing trend. The water budget index of the whole rice growht season was 0.56. Within the whole growth season, the rice heading-filling stage was most dependent on irrigation.