干旱区研究 ›› 2023, Vol. 40 ›› Issue (9): 1404-1413.doi: 10.13866/j.azr.2023.09.04 cstr: 32277.14.j.azr.2023.09.04

• 天气与气候 • 上一篇    下一篇

银川平原夏半年不同等级降雨水汽输送机制

王娜娜1(),韩磊1,2,3(),柳利利1,彭苓4,周鹏4,马云蕾1,马军4   

  1. 1.宁夏大学地理科学与规划学院,宁夏 银川 750021
    2.中阿旱区特色资源与环境治理国际合作联合实验室,宁夏 银川 750021
    3.宁夏旱区资源评价与环境调控重点实验室,宁夏 银川 750021
    4.宁夏大学农学院,宁夏 银川 750021
  • 收稿日期:2023-03-14 修回日期:2023-04-30 出版日期:2023-09-15 发布日期:2023-09-28
  • 作者简介:王娜娜(1998-),女,硕士研究生,主要研究方向为同位素水文学. E-mail: wangna5904@163.com
  • 基金资助:
    国家自然科学基金项目(31760236);宁夏自然科学基金项目(2023AAC03056)

Water vapor transport mechanisms for varied precipitation grades during the summer half-year in Yinchuan Plain

WANG Nana1(),HAN Lei1,2,3(),LIU Lili1,PENG Ling4,ZHOU Peng4,Ma Yunlei1,Ma Jun4   

  1. 1. School of Geography and Planning, Ningxia University, Yinchuan 750021, Ningxia, China
    2. China-Arab Joint International Research Laboratory for Featured Resources and Environmental Governance in Arid Regions, Yinchuan 750021, Ningxia, China
    3. Key Laboratory of Resource Evaluation and Environmental Regulation in Arid Region of Ningxia, Yinchuan 750021, Ningxia, China
    4. College of Agriculture, Ningxia University, Yinchuan 750021, Ningxia, China
  • Received:2023-03-14 Revised:2023-04-30 Published:2023-09-15 Online:2023-09-28

摘要:

全球气候变暖加速了区域水循环,改变了水汽的传输路径,了解不同等级降雨稳定同位素特征及水汽来源为水资源的利用及旱涝灾害的防治提供依据。基于2018—2020年夏半年(5—10月)采集的银川平原降雨样品,研究不同等级降雨中氢氧稳定同位素的变化特征及其二次蒸发效应,并利用后向轨迹模型及水汽通量等方法分析降雨的水汽来源及潜在蒸发源区。结果表明:银川平原夏半年不同等级降雨稳定同位素随着降雨等级的增加而偏负,小雨氘盈余(d-excess)值偏负而中雨和大雨偏正,大气降水线斜率和截距随着雨量级的增加呈现出递减的规律。二次蒸发作用的强弱随气温升高而增大,随降雨量、相对湿度和雨滴直径增大而减弱。西风水汽为银川平原夏半年降雨的主控水汽,同时小雨、中雨、大雨还分别受到陆地蒸发水汽、大西洋水汽及太平洋水汽的影响。潜在蒸发源区对小雨影响较大,主要位于研究区周边及北部、南部和东南部地区;中雨潜在蒸发源区主要分布在研究区周边地区及其西北部和东南部;大雨主要分布在研究区周边及东南部地区。

关键词: 降雨等级, 氢氧稳定同位素, 水汽来源, 水汽通量, 潜在贡献源区, 银川平原

Abstract:

Global warming intensifies regional water cycles and alters water vapor transport routes. Investigating stable isotope traits in diverse precipitation grades and identifying water vapor origins can offer insights for efficient water resource utilization and drought-flood management. By analyzing precipitation samples from Yinchuan Plain in the May-October summer half-years of 2018-2020, the hydrogen and oxygen isotope fluctuations across precipitation levels and their secondary evaporation effects were estimated in this study. Backward trajectory modeling and water vapor flux methods were applied to determine vapor sources and potential evaporation areas. The findings revealed that the stable isotope signature in Yinchuan Plain during the summer half-year decreased with increased rainfall levels; light rain exhibited negative d-excess values, whereas moderate and heavy rains showed positive values. The slope and intercept of the regional atmospheric precipitation line diminished as rainfall magnitude increased. Secondary evaporation intensified with higher air temperature, but decreased with increased precipitation, air relative humidity, and raindrop diameter. Distinct water vapor origins existed across precipitation levels: westerly vapor dominated light rain, whereas moderate and heavy rains originated not only from westerly vapor but also from high latitude land evaporation vapor and southeast ocean vapor, respectively. Potential evaporative vapor source areas predominantly influenced light and moderate rainfall, encompassing the study area’s vicinity as well as northwest and southeast regions. Moderate rainfall events were largely observed in the study area’s vicinity, as well as northwest and southeast regions, whereas heavy rainfall clustered around the study area and the southeastern region.

Key words: precipitation level, stable hydrogen and oxygen isotopes, water vapor source, vapor flux, potential contribution source area, Yinchuan Plain