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生态学杂志 ›› 2021, Vol. 40 ›› Issue (8): 2388-2399.doi: 10.13292/j.1000-4890.202108.029

• 研究报告 • 上一篇    下一篇

青藏高原色林错流域高寒草原坡面产流特征及其影响因素

刘志伟1,李胜男2*,郭燕红3,马宁4,张寅生3   

  1. (1国家林业和草原局昆明勘察设计院, 国家林业和草原局国家公园规划研究中心, 昆明 650031; 2中国林业科学研究院湿地研究所, 湿地生态功能与恢复北京市重点实验室, 北京 100091;3中国科学院青藏高原研究所, 环境变化与地表过程重点实验室, 北京 100101;4中国科学院地理科学与资源研究所, 陆地水循环及地表过程重点实验室, 北京 100101)
  • 出版日期:2021-08-10 发布日期:2021-08-16

Characteristics of hillslope runoff generation and its controlling factors on an alpine grassland in the Silin Co basin of the Tibetan Plateau.

LIU Zhi-wei1, LI Sheng-nan2*, GUO Yan-hong3, MA Ning4, ZHANG Yin-sheng3   

  1. (1Kunming Survey and Design Institute of National Forestry and Grassland Administration, National Park Planning and Research Center of National Forestry and Grassland Administration, Kunming 650031, China; 2Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China; 3Key Laboratory of Tibetan Environmental Changes and the Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; 4Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China).
  • Online:2021-08-10 Published:2021-08-16

摘要: 研究坡面产流与降雨之间的关系是揭示降雨径流产生机制以及土壤水分时空变化的关键。受特殊的地理条件限制,在青藏高原的典型高寒草原缺乏坡面产流的相关实测数据,限制了学术界对该区坡面产流特征及机制的理解。本研究选取色林错流域的典型高寒草原坡面为对象,通过开展坡面降雨、土壤水分和产流过程观测,探讨高寒草原坡面产流特征,诠释坡面降水-下渗-储存-产流机制;并结合土壤含水量、下垫面性质以及降雨强度、降雨量等特征的观测,分析影响坡面径流的主要因素。结果表明:6—10月色林错流域坡面产流的模式主要为超渗产流;在小雨时,降雨量为7.6 mm,径流深为0.23 mm,水分入渗量为2.63 mm;在中雨时,降雨量为18.8 mm,径流深为0.68 mm,水分入渗量为14.65 mm;在大雨时,降雨量为32.4 mm,径流深为0.78 mm,水分入渗量为30.49 mm;在暴雨时,降雨量为55.4 mm,径流深为0.89 mm,水分入渗量为47.59 mm,小雨、中雨、大雨和暴雨水分入渗分别发生于土壤0~5 cm、0~80 cm、0~10 cm和0~80 cm;厘清了研究区产流形成的最小降雨量和径流系数,率定了径流系数的主要影响因子,在低含水量(5%左右)时,产流形成的最低降雨量为5 mm;而在高含水量(8%左右)时,产流形成的最低降雨量为1.8 mm,径流系数大约为0.016,最大10 min降雨强度和土壤初始含水量是影响径流系数的主要因子。

关键词: 色林错, 高寒草原, 坡面径流, 径流系数, 最大10 min降雨强度

Abstract: Quantifying the relationship between precipitation and hillslope runoff is of great importance for understanding the rainfall runoff generation mechanism and the temporal and spatial dynamics of soil moisture. However, the hillslope runoff characteristics and its controlling factors in the central Tibetan Plateau remains poorly understood because of limited in situ observations, which impedes the understanding of land surface hydrological processes in this region with complex terrain. Based on a wide range of in situ observations of hillslope runoff, soil water and precipitation from a typical alpine grassland in the Silin Co Basin in the Tibetan Plateau, we investigated the hillslope runoff dynamics and elucidated the precipitation infiltration soil water storage runoff generation processes. By measuring soil water, land cover and precipitation, we quantified the runoff generation under different precipitation levels. The results showed that infiltration excess runoff was the main way for the generation of runoff in Silin Co Basin. For the light rain event of 7.6 mm, the runoff depth was 0.23 mm, and the water infiltration was 2.63 mm. For the medium rain event of 18.8 mm, the runoff depth was 0.68 mm and the water infiltration was14.65 mm. For the heavy rain event of 32.4 mm, the runoff depth was 0.78 mm and the water infiltration was 30.49 mm. For the rainstorm with rainfall of 55.4 mm, the runoff depth was 0.89 mm and the water infiltration was 47.59 mm. For those four sorts of rain events, the water infiltration occurred in the soil depth of 0-5 cm, 0-80 cm, 0-10 cm, and 0-80 cm, respectively. With a low soil water content (about 5%), the minimum rainfall that could generate runoff was 5 mm. However, with the relatively high soil water content (about 8%), the minimum rainfall that could generate runoff became 1.8 mm, and the runoff coefficient was approximately 0.016. The main factors controlling runoff coefficient were the maximum 10-min rainfall intensity and the initial soil water content.

Key words: Silin Co, alpine grassland, hillslope runoff, runoff coefficient, the maximum 10 min rainfall intensity.