Runoff response to the glacier shrinkage in the Karatal river basin, Kazakhstan

Abstract

The fresh water lack in Central Asian countries with fast-growing population is one of the most critical problems in this region, where runoff of most rivers closely depends on supply of glaciers melting water. However, the impact of glacier shrinkage on the river runoff remains poorly understood. In this paper, we took the Karatal river basin, Tien Shan, as a model for investigation interrelation between dramatic decreasing of glaciers (−1 % annually) and river runoff. We investigated long-term observed climatic and runoff data for different sub-basins of the river, having various glaciated area and used non-parametric Mann-Kendall test for our analyses. Analyzing weather station climatic data, we found a significant increase in temperature and quite stable trends for precipitation during study period. Positive trends in annual discharge were detected in almost all glacierized tributaries of Karatal river. This obvious upward trend in river runoff is likely connected with a general trend of increasing temperatures and intensive melting of glaciers in Tien Shan.

Spatiotemporal Variation of Snow Cover in Tianshan Mountains, Central Asia, Based on Cloud-Free MODIS Fractional Snow Cover Product, 2001–2015

“…These may imply an early snowmelt and early arrival of spring peak runoff along with the global warming and the state of high variability in temperature of the Tianshan Mountains. Changes of runoff and peaks moving forward are already detected in Central Asian rivers that are mainly supplied by glacier and snowmelt water from Tianshan Mountains [49][50][51]. Changes in SCA may also change the future runoff regimes and water availability in high-altitude catchments [55], thus impacting ecosystem, irrigation and agriculture, and water resources in the densely populated downstream areas [16,26].…”

“…The climate characteristics and cryosphere change showed obvious differences in these four subregions [10,13,20]. The total area of the study area is 135.5 × 10 4 km 2 ; and the areas of these subregions are accounted for 13.9% (Central Tianshan), 34 increased the runoff in the Tianshan Mountains due to the accelerated glacier/snowmelt [44,[49][50][51]. Therefore, it is very necessary to examine the possible linkages between the snow cover and the climatic parameters (precipitation and temperature) in the Tianshan Mountains.…”

“…They have relatively stable and with a small increase [44]. The state of high variability in temperature of the Tianshan Mountains has led to changes in mountainous hydrological processes and water resources, and increased the runoff in the Tianshan Mountains due to the accelerated glacier/snowmelt [44,[49][50][51]. Therefore, it is very necessary to examine the possible linkages between the snow cover and the climatic parameters (precipitation and temperature) in the Tianshan Mountains.…”

Review article: Hydrological modeling in glacierized catchments of central Asia – status and challenges

“…They suggested that the mismatch between decreasing trends in snow indicators and the increasing river runoff could be the result of enhanced glacier melting. Heavily glacierized river basins showed mainly positive runoff trends in the past few decades (simulated under different scenarios in the head rivers of the Tarim River basin), while those with less or no glacierization exhibited wide variations in runoff Kaldybayev et al, 2016).…”

Large Hydrological Processes Changes in the Transboundary Rivers of Central Asia

“…Moreover, the higher the glacierization of a catchment, the greater was the increment in runoff (Duethmann et al, ; Kaldybayev et al, ). Another example is the Aksu River, which originates in the southern flank of the Tienshan Mountains and is the largest headwater of the Tarim River Basin (providing 74% of water to the mainstream).…”