Interannual variations and decrease of the river runoff in the Lake Balkhash basin, in Central Asia

KEZER, Kader

[ABSTRACT] The Interannual variations and decrease of river runoff draining into the lake Balkhash basin, in Central Asia are investigated by using meteorological and hydrological data over long term period. At first, it is found that an apparent increase of decrease trend is not seen in the interannual variability of the meteorological elements in the basin. Next, interannual variations of the annual mean runoff in the rivers are investigated by the difference integral curves. From this analysis, it is determined that a low flow period begins in 1970 in the Ili-river and in 1973 in the eastern rivers, respectively. Finally, the Characteristics of the integral curves of runoff in the runoff growing season (from Apr. to Sep.) and non-growing season (from Oct. to Mar.) of entire period are investigated concerning the 3 sections of the upper, middle and lower reach of the Ili-river. The following results are obtained. (1) The mean runoff of the non-growing season at the 3 section has remained virtually unchanged entire period. (2) The largest decrease of runoff growing period of the Ili-river has occurred in the middle and lower reaches, respectively. These amounting to 44%, 45% of mean runoff of the growing season before 1969, respectively. Also the effect of human activity is responsible for 58%, 60%, respectively. This study has quantitatively made clear that the main reason of the apparent decrease of the runoff of the Ili-river is derived from the human activity.

https://opac.ll.chiba-u.jp/da/curator/900022280/

https://opac.ll.chiba-u.jp/da/curator/900022280/C-19_49.pdf

Chiba University. Center for Environmental Remote Sensing

千葉大学環境リモートセンシング研究センター

Presentation

BA40903676

Proceedings of the CEReS international symposium = CEReS国際シンポジウム資料集

3

285

292

1997-11-05

eng

publisher

Proceedings of the symposium on environmental remote sensing