Influence of climate change and anthropogenic factors on the Ile River basin streamflow, Kazakhstan

The article considers modern change in the streamflow resources of the Ile River basin that conjugates territories of the two countries, China and Kazakhstan, with the account of climatic and anthropogenic influences. The main goal of the authors is to study long-term trends of changes in the streamflow with the account of climatic and anthropogenic load in order to develop scientifically based strategies for sustainable management and protection of the Ile-Balkhash basin water resources. The current change in streamflow with the account of climate change was estimated using the linear trend coefficient, the Mann-Kendall test, and Sen slope estimator. The results show that intense warming occurs unevenly and most of all, it became warmer at the meteorological stations located in the Ile River delta at the Kuygan, Bakanas stations for more than 0.40 °С/10 years (1974–2015), and also at the Almaty MS, the maximum warming was noted at the rate of 0.04 °С/10 years (before 1973) up to 0.52 °С/10 years (1974–2015), and therefore since 1973, there has been a phase of increased water content in the region, in addition to some stations located in the flat part of the basin. This is possibly connected with an intense increase in the air temperature. To assess the impact of economic activities on the streamflow, the authors used the method of channel way water balance and the statistical data coefficient of water intake of irretrievable water consumption. In general, the assessment of the anthropogenic impact in the Ile River basin shows reduction of the total streamflow by 6.0 km3, i.e., by 28% of the climatic streamflow (21.4 km3). © 2021, Saudi Society for Geosciences.