State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China.
State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China; College of Agronomy, Inner Mongolia Agricultural University, Hohhot 010019, China.
Sci Total Environ. 2024 Nov 1;949:175114. doi: 10.1016/j.scitotenv.2024.175114. Epub 2024 Jul 29.
Drought is one of the vital meteorological disasters that influence crop growth. Timely and accurately estimating the drought dynamics of crops is valuable for decision-maker to formulate scientific management measures of agricultural drought risk. In this study, the evapotranspiration and drought dynamics of winter wheat from 1981 to 2020 in the Huang-Huai-Hai (HHH) region of China were evaluated based on long-term multi-source observation data. Four key developmental stages of winter wheat were given attentions: growth before winter stage, overwintering stage, stage of greening-heading, and stage of filling-maturity. The crop water deficit index (CWDI) on a daily scale was established for quantitatively appraising the impacts of drought on winter wheat. Our results indicated that interannual variation in reference crop evapotranspiration (ET) during the growth season of winter wheat from 1981 to 2020 in the HHH region showed a slight increase trend, with an average of 602.4 mm and obvious spatial differences of decreasing from the Northeast to the Southwest. Over the past forty years, the winter wheat in the HHH region was most severely affected by severe drought, followed by moderate drought, and finally mild drought. In addition, the impacts of drought on winter wheat at different critical growth stages varied greatly. For the growth before winter stage, the winter wheat was mainly threatened by mild, moderate, and severe droughts. For the overwintering stage, the winter wheat was mainly threatened by moderate, severe, and extreme droughts. For the greening-heading stage, the winter wheat was mainly threatened by mild, moderate, severe, and extreme droughts. For the filling-maturity stage, the winter wheat was mainly threatened by mild and moderate droughts. Finally, the impacts of drought on winter wheat during 1981-2020 in the HHH region were revealed to differ extraordinarily in space. In particular, the areas of winter wheat affected by severe drought significantly decreased. However, the areas of winter wheat affected by moderate drought clearly expanded. Our findings provide new insights for further improving climate change impact studies and agricultural drought defense capabilities adapting to continuous environmental change.
干旱是影响作物生长的重要气象灾害之一。及时准确地估计作物干旱动态，对于决策者制定农业干旱风险的科学管理措施具有重要价值。本研究基于长期多源观测数据，评估了 1981 年至 2020 年中国黄淮海地区冬小麦的蒸散和干旱动态。关注了冬小麦的四个关键发育期：越冬前阶段、越冬阶段、拔节-孕穗阶段和灌浆-成熟阶段。建立了基于日尺度的作物水分亏缺指数（CWDI），定量评价干旱对冬小麦的影响。结果表明，1981 年至 2020 年冬小麦生长季参考作物蒸散量（ET）的年际变化呈微弱增加趋势，平均为 602.4mm，空间分布从东北向西南递减。在过去的四十年中，黄淮海地区的冬小麦受严重干旱的影响最为严重，其次是中度干旱，最后是轻度干旱。此外，干旱对冬小麦不同关键生长阶段的影响差异很大。对于越冬前阶段，冬小麦主要受到轻度、中度和重度干旱的威胁。对于越冬阶段，冬小麦主要受到中度、重度和极端干旱的威胁。对于拔节-孕穗阶段，冬小麦主要受到轻度、中度、重度和极端干旱的威胁。对于灌浆-成熟阶段，冬小麦主要受到轻度和中度干旱的威胁。最后，揭示了 1981-2020 年黄淮海地区冬小麦受干旱影响在空间上存在显著差异。特别是受严重干旱影响的冬小麦面积显著减少。然而，受中度干旱影响的冬小麦面积明显扩大。本研究结果为进一步提高气候变化影响研究和适应不断变化的环境的农业干旱防御能力提供了新的见解。
