关键词: 高山寒漠带, 水文循环, 蒸发, 凝结水, 径流系数

Abstract:

Alpine desert is the mainly runoff yield regions and headwater regions for most large river and inland river basins in China. However, due to lack of observation data and theoretical basis, there are few researches focusing on the hydrological process of alpine desert at home and abroad. In this paper, water cycle observation and experiment were done to analyze the hydrological characteristics in the alpine desert zone of Hulugou watershed in non-freezing period. Observations show that: (1) during the experimental period (2009.6.7-9.30), precipitation was 541.4 mm at the experimental site, pan evaporation was 256.9 mm, Micro-Lysimeter evaporation was 122.8 mm, mean evaporation was 1.1 mm·d^-1; (2) based on the experimental observation, condensation water was relatively abundant in the alpine desert zone. Although condensation water do not directly involve in the hydrological cycle of mountain runoff generation and confluence process, it consumed energy, offset part of solar radiation, indirectly involved in the runoff generation and confluence process; (3) runoff depth of the small watershed was 461.2 mm. Using elevation precipitation gradient, it was obtained that the average precipitation of the alpine desert watershed was 639.1 mm, with a runoff coefficient of 0.72.

Key words: alpine desert zone, hydrologic cycle, evaporation, condensation water, runoff coefficient