四湖流域水稻耗水与降雨匹配度及水稻旱涝易损特征分析

水稻是中国主要粮食作物之一，研究气候变化环境下降雨特征及其与水稻耗水之间的匹配关系，明晰水稻水分盈亏状况及旱涝易损特征，可为区域水资源配置规划与灌溉排水管理等提供重要依据。该研究以湖北江汉平原四湖流域为研究区域，基于5个气象站点1961—2020年逐日气象资料，利用Penman-Monteith公式、Mann-Kendall趋势检验、气候倾向率、空间插值分析等方法，分析了降雨量、水稻田间耗水量及水分盈亏指数时空分布特征，基于水分盈亏指数分析了水稻旱涝易损特征。结果表明：四湖流域多年平均降雨量为1209.2mm，且以35.1 mm/10a的平均速度显著上升，东南部降雨量及上升趋势均高于西北部；1）早、中、晚稻生育期多年平均降雨量分别为492.0、509.9和269.1 mm，早、中稻生育期降雨量分别以17.9 mm/10a和18.4 mm/10a的平均速度呈不显著上升趋势，晚稻生育期降雨量以-10.7 mm/10a的平均速度呈不显著下降趋势；2）早、中、晚稻多年平均田间耗水量分别为411.4、595.5和401.4 mm，中稻田间耗水量远大于早稻和晚稻，早、中稻田间耗水量分别以-5.54 mm/10a和-11.43mm/10a的平均速度显著下降，晚稻田间耗水量以-1.52 mm/10a的平均速度呈不显著下降趋势；3）早、中、晚稻多年平均水分盈亏指数分别为0.22、-0.12和-0.31，早、中稻水分盈亏指数以0.06/10a和0.04/10a的平均速度呈不显著上升趋势，晚稻水分盈亏指数以-0.03/10a的平均速度呈不显著下降趋势，早、中稻水分盈余程度在增加，晚稻水分亏缺加剧；4）四湖流域早、中、晚稻干旱频率分别在10.0%～16.7%、28.3%～40.0%和51.8%～60.0%之间，晚稻最容易受干旱威胁。早、中、晚稻雨涝频率分别在1.7%～15.0%、1.7%～3.3%和0～1.7%之间，早稻更容易受雨涝威胁。总体上，四湖流域早稻发生旱涝灾害的频率较小（20.7%），中稻次之（37%），晚稻最容易受旱涝威胁（56%），水稻耗水与降雨匹配程度为：早稻＞中稻＞晚稻，要特别注意晚稻干旱缺水问题。

Matching degree of precipitation and rice water consumption and analysis of drought and waterlogging vulnerable characteristics of rice in Sihu Basin, Hubei of China

Rice is one of the main food crops in the paddy field. The regional water resources can be allocated to manage the irrigation and drainage. This study aims to determine the matching relationship between precipitation and rice water consumption, the crop water surplus and deficit Index (CWSDI) and the vulnerability of rice in drought and waterlogging in climate change environment. Taking the Sihu basin of Jianghan Plain in Hubei Province as the research area, the daily meteorological data was collected from five meteorological stations from 1961 to 2020. The spatiotemporal distribution of precipitation, water consumption, CWSDI and the rice vulnerability in the drought and waterlogging were analyzed by Penman-Monteith formula, Mann-Kendall trend test, climate tendency rate and spatial interpolation analysis. Results showed that the multi-year average precipitation was 1209.2mm. There was a significant increase at an average rate of 35.1mm/10a. Both the precipitation and increase rate in the southeast were higher than that in the northwest. The multi-year average precipitation was 492.0, 509.9, and 269.1mm, respectively, in the growth periods of early, middle and late rice. There was an insignificant increase in the precipitation at an average rate of 17.9 and 18.4mm/10a, respectively, in the early and middle rice growth periods. By contrast, an insignificant downward trend of precipitation was found at an average rate of -10.7mm/10a in the late rice growth periods. The multi-year average water consumption was 411.4, 595.5, and 401.4mm, respectively, for the early, middle and late rice. The water consumption of the middle rice was much greater than that of the early and late rice. The water consumption of early and middle rice decreased significantly at an average rate of -5.54 and -11.43mm/10a, respectively. While the water consumption of late rice showed an insignificant downward trend at an average rate of -1.52mm/10a. The multi-year average CWSDI values were 0.22, -0.12 and -0.31, respectively, for the early, middle and late rice. The CWSDI values of early and middle rice showed an insignificant upward trend at an average rate of 0.06/10a and 0.04/10a, respectively, whereas, there was an insignificant downward trend of late rice at an average rate of -0.03/10a. Therefore, the water surplus degree of early and middle rice increased, while the water deficit of late rice was intensified. The drought frequencies of early, middle and late rice ranged from 10.0% to 16.7%, 28.3% to 40.0%, and 51.8% to 60.0%, respectively, where the late rice was the most vulnerable to drought. The frequencies of flood in the early, middle and late rice ranged from 1.7% to 15.0%, 1.7% to 3.3%, and 0 to 1.7%, respectively, where the early rice was more vulnerable to waterlogging. In general, the frequencies of drought and flood disasters for early rice were less (20.7%), followed by the middle rice (37%), and the late rice was the most vulnerable to drought and flood threats (56%). The matching degree of water consumption of rice and precipitation was ranked in the descending order of early rice > middle rice > late rice. Much attention should be paid to the drought and water shortages in the late rice.