横断山区南部干湿坝子降水特征差异与成因分析

Analysis of precipitation characteristic differences and their causes between dry and wet basins on the southern section of the Hengduan Mountains

摘要

横断山区南部地形复杂，“地近雨异”现象突出，为揭示该区域降水分布特征的差异与成因，基于 2019—2023 年横断山区南部 213 个区域气象观测站和 12 个国家气象观测站以及 2004—2023 年宾川、大理两个国家气象观测站的小时降水数据，以宾川站和大理站为代表对比分析了干、湿坝子的降水特征差异，并结合 2019—2023 年大理天气雷达观测资料探讨了 2 个代表站共有降水事件降水差异的成因。结果表明：(1) 横断山区南段年降水量、降水频次分布呈现东少西多而降水强度差异较小的特征。湿坝子的年、月、日降水量及降水频次均高于干坝子。湿坝子降水集中于 8 月，而干坝子在 7 月达到峰值。(2) 湿坝子降水日变化呈单峰型，降水峰值出现在 05 时 (北京时，下同)，干坝子则呈双峰型，峰值出现在 05 时和 15 时。湿坝子的降水频次和强度夜间明显高于白天，干坝子则相反。(3) 干、湿坝子降水类型均以短历时降水为主，但湿坝子的平均降水时长比干坝子多 2 h，是区域降水的主要来源。共有降水事件中湿坝子主要表现为高频次、中长历时降水，而干坝子则以午后短历时强对流降水为主。(4) 共有降水事件的雷达回波多呈自西向东传播，传播过程中降水强度减弱，难以到达干坝子，导致湿坝子降水频次与持续时间普遍高于干坝子。研究成果可为横断山区南段精细化天气预报和区域水资源管理提供参考。

Abstract

The southern section of the Hengduan Mountains is characterized by complex terrain and frequent meteorological disasters, with distinct local heterogeneity in precipitation distribution being frequently observed. To reveal the characteristics and causes of precipitation distribution in this region, this study utilized hourly precipitation data from 213 regional automatic weather stations and 12 national meteorological stations during 2019-2023, as well as two national stations (Binchuan and Dali) during 2004-2023. The differences in precipitation characteristics between typical dry and wet basins, represented by the Binchuan and Dali stations, were analyzed. The causes of these differences of joint precipitation event were further examined using Dali Doppler weather radar data during 2019-2023. The results are as follows. (1) The annual precipitation amount and frequency in the southern Hengduan Mountains generally displayed a trend of lower values in the east and higher values in the west, but the difference in precipitation intensity was relatively small. The annual, monthly, and daily precipitation amount and frequency of the wet basin were all higher than those of the dry basin. The precipitation in the wet basin peaked in August, while that in the dry basin reached its peak in July. (2) The diurnal variation of precipitation in the wet basin showed a single-peak pattern, with the peak occurring at 05:00 (BT, the same below). In the dry basin, it presented a bimodal pattern, with peaks occurring at 05:00 BT and 15:00 BT. The frequency and intensity of precipitation in the wet basin were significantly higher during nighttime than during the daytime, while an opposite diurnal distribution was observed in the dry basin. (3) Short-duration precipitation events dominated both the dry and wet basins. However, the average precipitation duration in the wet basin was 2 h longer than that in the dry basin, making it the primary contributor to regional precipitation. During regional coincident precipitation events, the wet basin was characterized by high-frequency, medium- to long-duration precipitation, whereas in the dry basin, precipitation was mainly contributed by short-duration convective precipitation occurring in the afternoon. (4) The diurnal variation of radar reflectivity factor during coincident precipitation events indicated that precipitation systems generally propagated from west to east. During the propagation, the intensity tended to weaken, making it difficult to reach the dry basin. This resulted in the higher frequency and duration of precipitation in the wet basin compared to the dry basin. These findings provide a reference for refined weather forecasting and regional water resources management in the southern section of the Hengduan Mountains.

关键词

横断山区 / 干湿坝子 / 降水特征 / 降水事件差异

Key words

Hengduan Mountains / dry and wet basins / precipitation characteristics / differences in precipitation events

参考文献

[1] 董新宁,吴遥,黄安宁,等. 2023.川渝地区夏季极端降水日变化特征分析[J].大气科学,47(2):259-272.

[2] Dong X N, Wu Y, Huang A N, et al. 2023. Analysis of diurnal variation characteristics of summer extreme precipitation in Sichuan and Chongqing [J].Chinese Journal of Atmospheric Sciences,47(2):259-272 (in Chinese). doi:10.3878/j.issn.1006-9895.2108.21032

[3] 冯亮亮, 詹正杰, 刘雨润, 等. 2026.昆明市夏季夜间冰雹天气分型及其环境参数特征[J].暴雨灾害,45(4):513-522.

[4] Feng L L, Zhan Z J, Liu Y R, et al. 2026. Characteristics of environment parameters and weather type of nighttime hail weather in Kunming City from June to August [J].Torrential Rain and Disasters,45(4):513-522 (in Chinese). doi:10.12406/byzh.2025-046

[5] 付双喜,张洪芬,杨丽杰,等. 2021.地形影响下祁连山北麓不同类型降水特征对比分析[J].干旱区研究,38(5):1226-1234.

[6] Fu S X, Zhang H F, Yang L J, et al. 2021. Comparative analysis of different types of precipitation characteristics in the northern foot of Qilian Mountain under the influence of topography [J].Arid Zone Research,38(5):1226-1234 (in Chinese). doi:10.13866/j.azr.2021.05.04

[7] 季宗虎,孙栋元,牛最荣,等. 2023.疏勒河流域降水变化特征研究[J].干旱区研究,40(10):1583-1594.

[8] Ji Z H, Sun D Y, Niu Z R, et al. 2023. Characteristics of precipitation changes in the Shule River Basin [J].Arid Zone Research,40(10):1583-1594 (in Chinese). doi:10.13866/j.azr.2023.10.05

[9] 李君,李妍,贾瑞,等. 2022.两个相似路径台风引发的东部沿海地区降水分布特征及成因对比分析[J].海洋预报,39(3):25-36.

[10] Li J, Li Y, Jia R, et al. 2022. A comparison analysis of precipitation distribution over the eastern coastal area and their causes between two typhoons with similar paths [J].Marine Forecasts,39(3):25-36 (in Chinese). doi:10.11737/j.issn.1003-0239.2022.03.003

[11] 李强, 夏蘩, 周盈颖, 等. 2026. 2023 年重庆长滩镇“7.4”局地特大暴雨的中尺度对流系统特征和成因[J].暴雨灾害,45(2):159-170.

[12] Li Q, Xia F, Zhou Y Y, et al. 2026. Characteristics and causes of mesoscale convective system induced the "7.4" local extremely heavy rainstorm event in Changtan Town, Chongqing in 2023 [J].Torrential Rain and Disasters,45(2):159-170 (in Chinese) doi:10.12406/byzh.2024-185

[13] 李生辰,张青梅,沈晓燕,等. 2022.青海高原暴雨的形成条件与基本特征分析[J].高原气象,41(2):526-540.

[14] Li S C, Zhang Q M, Shen X Y, et al. 2022. Torrential rain in Qinghai Plateau: Forming conditions and characteristics [J].Plateau Meteorology,41(2):526-540 (in Chinese). doi:10.7522/j.issn.1000-0534.2021.00009

[15] 王灏,胡泽勇,杨耀先,等. 2023.近 60 年青藏高原季风期降水的南北变化特征及机理研究[J].高原气象,42(4):848-857.

[16] Wang H, Hu Z Y, Yang Y X, et al. 2023. The changing features and the mechanism of the precipitation in southern-northern Qinghai-Xizang Plateau during monsoon period in last 60 years [J].Plateau Meteorology,42(4):848-857 (in Chinese). doi:10.7522/j.issn.1000-0534.2023.00034

[17] 王灵芝,李茂善,吕钊,等. 2022.藏东南峡谷地区不同下垫面地表通量变化特征及其与降水的关系[J].高原气象,41(1):177-189.

[18] Wang L Z, Li M S, Lyu Z, et al. 2022. Variation characteristics of surface fluxes on different underlying surfaces and their relationship with precipitation in the canyon area of southeast Tibet [J].Plateau Meteorology,41(1):177-189 (in Chinese). doi:10.7522/j.issn.1000-0534.2020.00107

[19] 吴天贻,周玉淑,王咏青,等. 2021.两次不同季风强度背景下的西行台风登陆过程降水特征对比分析[J].大气科学,45(6):1173-1186.

[20] Wu T Y, Zhou Y S, Wang Y Q, et al. 2021. Comparative analysis of precipitation characteristics of the westward typhoon cases “Bilis” and “Sepat” during landfall under different monsoon intensities [J].Chinese Journal of Atmospheric Sciences,45(6):1173-1186 (in Chinese). doi:10.3878/j.issn.1006-9895.2009.20101

[21] 杨萍,肖子牛,石文静. 2017.基于小时降水资料研究北京地区降水的精细化特征[J].大气科学,41(3):475-489.

[22] Yang P, Xiao Z N, Shi W J. 2017. Fine-scale characteristics of rainfall in Beijing urban area based on a high-density autonomous weather stations (AWS) dataset [J].Chinese Journal of Atmospheric Sciences,41(3):475-489 (in Chinese). doi:10.3878/j.issn.1006-9895.1606.16134

[23] 杨霞,周鸿奎,赵克明,等. 2020. 1991-2018 年新疆夏季小时极端强降水特征[J].高原气象,39(4):762-773.

[24] Yang X, Zhou H K, Zhao K M, et al. 2020. Variation features of hourly precipitation in Xinjiang Province during 1991-2018 [J].Plateau Meteorology,39(4):762-773 (in Chinese). doi:10.7522/j.issn.1000-0534.2019.00114

[25] 张述清,王爱华,王宇新,等. 2012.云贵高原地区坝子划定技术与方法研究-以云南省为例[J].地矿测绘,28(4):1-4.

[26] Zhang S Q, Wang A H, Wang Y X, et al. 2012. Study on techniques and methods in demarcation of bazi in Yunnan-Guizhou Plateau-Taking Yunnan Province as an example [J].Surveying and Mapping of Geology and Mineral Resources,28(4):1-4 (in Chinese). doi:10.3969/j.issn.1007-9394.2012.04.001

[27] 张涛,李亮亮,李建. 2022.云贵高原两个国家基准站降水特性比较[J].暴雨灾害,41(1):50-57.

[28] Zhang T, Li L L, Li J. 2022. Comparison of rainfall characteristics of two national reference stations in Yunnan-Guizhou plateau [J].Torrential Rain and Disasters,41(1):50-57 (in Chinese). doi:10.3969/j.issn.1004-9045.2022.01.006

[29] 赵玮,郝翠,曹洁,等. 2022.近 40 年北京地区夏季降水日变化及不同持续时间降水事件的特征[J].大气科学,46(5):1167-1176.

[30] Zhao W, Hao C, Cao J, et al. 2022. Diurnal variation characteristics of summer precipitation and precipitation events with different durations in Beijing in the past 40 years [J].Chinese Journal of Atmospheric Sciences,46(5):1167-1176 (in Chinese). doi:10.3878/j.issn.1006-9895.2204.22028

[31] Li J, Yu R C, Wang J J. 2008. Diurnal variations of summer precipitation in Beijing [J].Chinese Science Bulletin,53(12):1933-1936. doi:10.1007/s11434-008-0195-7

[32] Li J, Zhao Y, Wang G L, et al. 2026. The Cangshan Mountain Precipitation Experiment (CAMPEX): Modulation of precipitation by typical steep mesoscale terrain over Southeast China [J].Journal of Meteorological Research,40(4):1008-1026. doi:10.1007/s13351-026-6047-z

[33] Li Z X, He Y Q, Wang C F, et al. 2011. Spatial and temporal trends of temperature and precipitation during 1960-2008 at the Hengduan Mountains, China [J].Quaternary International, 236(1-2): 127-142. doi:10.1016/j.quaint.2010.05.017

[34] Ning B Y, Yang X M, Chang L. 2012. Changes of temperature and precipitation extremes in Hengduan Mountains, Qinghai-Tibet Plateau in 1961-2008 [J].Chinese Geographical Science,22(4):422-436. doi:10.1007/s11769-012-0549-6

[35] Xiang R L, Steger C R, Li S P, et al. 2024. Assessing the regional climate response to different Hengduan Mountains geometries with a high‐resolution regional climate model [J].Journal of Geophysical Research: Atmospheres,129(6):e2023JD040208. doi:10.1029/2023jd040208

[36] Yu H, Wang L, Yang R, et al. 2020. Temporal and spatial distribution of maximum daily precipitation in Hengduan Mountainous region of China and its probability characteristics [J].Journal of Hydrologic Engineering,25(11):05020039. doi:10.1061/(asce)he.1943-5584.0002009

[37] Yu R C, Chen H M, Sun W. 2015. The definition and characteristics of regional rainfall events demonstrated by warm season precipitation over the Beijing plain [J].Journal of Hydrometeorology,16(1):396-406. doi:10.1175/JHM-D-14-0086.1

[38] Zhang K X, Pan S M, Cao L G, et al. 2014. Spatial distribution and temporal trends in precipitation extremes over the Hengduan Mountains region, China, from 1961 to 2012 [J].Quaternary International,349:346-356. doi:10.1016/j.quaint.2014.04.050

[39] Zhang M K, Li J, Li N N. 2021. Fine-scale characteristics of summer precipitation over Cang Mountain [J].Journal of Applied Meteorology and Climatology,21(9):1285-1300. doi:10.1175/JAMC-D-20-0220.1

[40] Zhao Y, Li J, Wang G L, et al. 2026. Influence of low-level winds and topography on nocturnal convection initiation over Cangshan Mountain in Southwest China [J].Journal of Meteorological Research,40(4):1199-1215. doi:10.1007/s13351-026-5281-8

[41] Zhu G F, He Y Q, Pu T, et al. 2012. Spatial distribution and temporal trends in potential evapotranspiration over Hengduan Mountains region from 1960 to 2009 [J].Journal of Geographical Sciences,22:71-85. doi:10.1007/s11442-012-0912-7

基金资助

云南省气象局科研基金项目(YZ202429)

国家自然科学基金项目(42275163)

中国气象局创新发展专项(CXFZ2025J147)

云南省科技计划项目(202505AW340002)