• 论文 •

冰川作用流域能水平衡的径流模拟计算

1. 中国科学院兰州冰川冻土研究所, 兰州 730000
• 收稿日期:1993-09-01 修回日期:1995-04-01 出版日期:1995-11-15 发布日期:1995-11-15

RUNOFF MODELLING BASED ON ENERGY AND WATER BALANCE IN A GLACIERIZED BASIN

Kang Ersi

1. Lanzhou Institute of Glaciology and Geocryology. Chinese Academy of Sciences. Lanzhou 730000 China
• Received:1993-09-01 Revised:1995-04-01 Online:1995-11-15 Published:1995-11-15

Abstract: Based on the field measurement on energy and water fluxes in a Tianshan glacierized basin. this paper is aimed at simulating the runoff formation and transformation processes by using an energy and water balance model taking the standard meteorological elements as the foremost inputs. The purpose is to understand the processes of energy and water exchange between mountain glacierized areas and atmosphere and their relation to the runoff formation.The glacierized basin which is chosen for runoff simulation in this paper is situated at the sourcearea of the Urumqi River. The basin is located at 43°06’N and 86°50’E. Its catchment area is 28. 9km2, of which 5. 74km2 is covered by glaciers. The altitude of the basin ranges from 3408m to 4479m.The runoff consists mainly of the water from melted ices and snows, and of some efficient liquid precipitation. A glacierized basin can be divided into glacierized area and non-glacierized area. Snow cover is approximated to the solid precipitation. The precipitation of the basin is determined by the systematic error corrected precipitation and its altitude gradient. The ratio of solid precipitation to the total precipitation is determined by the temperature criteria for precipitation to form, the daily maximum and minimum temperatures and the daily mean temperature. The runoff from the ice and snow covered area is calculated by an energy and water balance model, while that from the ice and snow free area is obtained by a water balance model. The calculated results indicate that the runoff coefficient of the glacierized basin is 0- 72, and the runoff from melted glaciers is 13/00, the melted snows from the non-glacierized area makes up 57/60, and liquid precipitation accounts for only 8/00.The total amount of melted snows and ices from the glacierized area makes up 35/00.Under the climate conditions on the Tianshan Mountain, the ablation season can be divided into the weak melting period and intense melting period. The weak melting period is mainly for the melt of seasonal snow cover- and the runoff transformation occurs mainly on the surface. The intense melting period is mainly for glacier to melt, and a large amount of water is produced during this period. The intra-and subglacial drainage system and the active layer of the permafrost develop welland play an important role in the runoff transformation. The runoff transformation processes are simulated by a tank model, which is constructed with two vertically connected tanks. The simulation shows that, during the weak melting period, the runoff transformation processes are rather unitary with the characteristics of a linear reservoir, while during the intense melting period, the discharge increases with the water storage which has the nonlinear characteristics.The present study links the climate variables to the energy and water balance, and to the runoff formation in a glacierized basin. The discharge hydrographs at the basin outlet are well simulated.This is significant in the studies on the relationship of the changes of mountain glaciers, permafrost.snow cover and runoff to the climate change and its simulation.

• P333.1