关键词: 塔里木河下游, 干旱区湖泊, 风成湖, 湖泊演变

Abstract:

The study on environmental protection and ecological restoration in the lower reaches of the Tarim River has aroused widespread concern in the community and government at all levels. For those studies, the observation of the various forms of water resources is very important, because almost all natural processes and human activities are directly or indirectly restricted by lackage of water resources in the Tarim River Basin. In this research, the lakes in lower reaches of Tarim River were selected as an object, water body information was extracted from historical maps, topographic maps and satellite images, over the past century. Based on water body information and some other ancillary data, evolution of those lakes was analyzed, and the following results were summarized. (1) According to location, wate rbody and their change trends, evolution of the lakes could be divided to three time segments of the study period. Before the 1960s, hydrological conditions of the lower Tarim River were better than in recent 50 years, the number of the lakes was large, and most of the lakes were larger. For example, from the end of the 19th century to beginning of the 20th century, the total water body of the lakes were more than 2000 km². From the 1960s-1970s to the end of 20th century, along with the construction of water conservancy facilities, hydrological conditions in this region tended to be worse, water bodies were reduced or completely dried up in many lakes. In this century, as an one of important results of Ecological Water Transfusion Project, hydrological conditions were improved, some lakes were refilled with water, and they were dried up over the decades. For example, in 2013, the total water area of the lakes in this region reached 760 km². (2) The lakes of the lower Tarim River can be categorized into three main classes, in terms of types of lake basins. The lakes are distributed west of national highway and the right side of the mainstream is typical eolic (wind-formed) lakes; The lakes distributed on the east side of the mainstream and among the river network are riverine (fluvial) lakes; Tetima Lake can be identified as a tectonic lake. (3) Evolution of eolic lakes in this region has been summarized, and compared with riverine lakes in the same region. And we found that, there are great differences between eolic lakes and riverine lakes, in the aspects of shape, depth, water quality, formation time, etc. (4) In modern days, human factors exert more effects on the lake changes of this region than natural factors.

Key words: lower Tarim River, lakes in arid land, eolic lakes, lake evolution