摘要
首次利用GIS技术并结合沉积学研究结果 ,计算全新世两个时段石羊河流域终闾湖泊的面积 ,建立石羊河流域水热平衡模型 ,进而恢复全新世两个时期的降水量。
The study of lake evolution is one of the important aspects of study of global change. Inland lakes are influenced by climatic change more sensitively than lakes in humid area. It is significant to study the evolution of inland lakes. Gansu Corridor is located in the regional edge of the Eastern Asia Monsoon. Because it is sensitive to climatic change due to its fragile eco environment, it is an ideal regied for studying global change. In the prehistoric period a large terminal lake——Zhuyeze Lake once existed in the studied area——Shiyang River drainage that is located in the eastern Gansu Corridor. Since the historic period it has gradually shrunk into many small lakes, and these small lakes dried up and disappeared in succession. This article first tries to inquire into terminal lake evolution in this studied area by combining techniques of GIS with the results of deposit study.Digital Terrain Model(DTM) of lake area in the lower reaches of the Shiyang River is built. Space time evolution of terminal lakes was analyzed and the lake area of different periods in Holocene was calculated according DTM. The precipitation of two periods during Holocene was calculated by a mathematical model which applies to an ideal situation of terminal lake in the Shiyang River drainage, following the water and energy budget principle under the situation that no lake exists now.Preliminary results indicate that water levels reached 1320?m and 1314?m in 5000?a?B.P. and 3600?a?B.P. during Holocene, and terminal lake areas are 2130?km 2 and 870?km 2. Landforms around the basin reflected in the DTM suggest that if the water level reaches 1320-1330m, the Shiyang River drainage will become an outflow drainage. The lake of 2130?km 2 maybe is the largest lake in this drainage. During late Holocene after 3600?aB.P., the large terminal lake broke into two parts. According to the model of water and energy budget in the Shiyang River drainage, precipitation of above two periods was 250-256?mm and 186-188?mm, more than that of mode
出处
《地理科学》
CSCD
北大核心
2000年第5期422-426,共5页
Scientia Geographica Sinica
基金
国家自然科学基金!重点资助项目 (编号 497310 10 )
关键词
石羊河流域
GIS技术
水热平衡模型
古湖泊
水文
Shiyang river drainage
Terminal lakes
Digital terrain model
Holocene
Precipitation
