Some Physicogeographic Facts

The Khaidik Gol and Lake Baghrash Kol.

In its lower reaches the Khaidik Gol follows a southeasterly course. It discharges into Lake Baghrash Kol, which is located in the Karashahr basin (see Figure 4). The surplus water from Baghrash Kol flows into the Tarim basin via the Konche Dar'ya, which exits from the southwestern part of the lake. Thus, Baghrash Kol is part of a circulating system: it is fed by a surface and subsurface flow coming in general from the north, and its surplus flows out southward via the Konche Dar'ya. Somewhat downstream from the city of Karashahr, the present-day delta of the Khaidik Gol begins. Here the river divides into two branches, the left one flowing directly into Baghrash Kol, and the right one, which actually bypasses the lake, flowing through a system of small overflow lakes to the Konche Darya.

During the third cold period (late Middle Ages), the Khaidik Gol deviated to the right (equatorward) and flowed southward, bypassing what is now Baghrash Kol, directly to the Konche Dar'ya. The lake then had little water in it, since it was fed principally by the subsurface flow and by the small rivers to the north of it. The total discharge in the direction of the Tarim basin was relatively large.

During the third (present) warm period, the river tends to deviate to the left (poleward). The left branch has developed and now carries the main bulk of the Khaidik Gol to Lake Baghrash Kol, after which the flow is along the Konche Darya to the Tarim basin. The level of Baghrash Kol is at present rising.

As Kuznetsov and Murzaev (1960) have pointed out, Roborovskii and Kozlov (1896) made no mention of the presence of the left branch of the Khaidik Gol, and they did not indicate it on their map. Apparently, this branch formed after these travelers visited the lake. The observations of Kozlov, Kuznetsov, and Murzaev make it clear that during the last 70 or 80 years the channel of the Khaidik Gol has been shifting toward the northeast in the vicinity of its mouth. The same tendency is observed further upstream, after the river has debouched from the mountains and entered the plain.

The Manass River and Lakes Ayran Kol and Ikhe Kh&k.

In its lower reaches the Manass follows a northwesterly course. It discharges into an inland basin located in the western part of the Dzhungarian plain, near the southeastern foothills of the Chingiz Mountains. The basin extends toward the northeast and is divided into two parts, a southwestern part containing the Ayran Kol solonchak [salt marsh] and a northeastern part containing the Ikhe Khak solonchak.

"The Manass River, which supplies the present-day lake, divides into a number of distributaries when it enters the basin. Some of these

flow into the western half, to the Ayran Kol solonchak, while the others go eastward, to the Ikhe Khak solonchak. Therefore, the lake actually does not have a definite location, and it may be in either the Ayran Kol region or the Ikhe Khak region, depending on the distribution of water in its distributary channels ... " (Sinitsyn, 1959).

During the third cold period (late Middle Ages), the Manass deviated to the left (equatorward). At this time it discharged into the Ayran Kol solonchak, the present site of the lake. The right-hand distributaries were then insufficiently supplied with water and the Ikhe Khak depression became a solonchak.

During the third (present) warm period, the river has a tendency to deviate to the right (poleward). Consequently, the Ikhe Khak depression has become supplied with water and Lake Ayran Kol has dried up.

Murzaev (1939) cites the Manass River as an example of a recent migration of distributary channels. This river used to discharge into Lake Ayran Kol, which is now dry. The main channel of the present Manass delta shifted to the northeast and formed the large but shallow and salty Lake Ikhe Khak, in the ancient lake- solonchak basin. Certain facts make it clear that this is not the first time that the Manass has migrated toward the northeast.

The Ili River and Lake Balkhash.

In its lower reaches the Ili flows northwest, until finally it discharges into Lake Balkhash. At the beginning of its delta the river divides into two large distributary systems: the Ili system proper on the left, and the Bakanas system on the right. At present the flow is along the Ili system of distributaries, the largest of which are the Topar (left), the Ili (middle), and the Dzhideli (right).

During the third cold period (late Middle Ages) the Ili deviated to the left (equatorward). At this time Lake Balkhash also moved toward the south. The main flow of the Ili was then along the left branch, the Topar, while part of the flow was along the middle branch, the Ili. The level of Balkhash was relatively low in the northeastern part of the lake and relatively high in the southwestern part. During the third (present) warm period the river tends to deviate to the right (poleward). Therefore the right distributary, the Dzhideli, is now quite developed and well supplied with water, whereas in the left distributary, the Topar, the flow has practically stopped. The level of Balkhash has become higher in the northeastern part of the lake and lower in the southwestern part.