Long-Term Hydro–Climatic Trends in the Mountainous Kofarnihon River Basin in Central Asia

Abstract

Hydro–climatic variables play an essential role in assessing the long-term changes in streamflow in the snow-fed and glacier-fed rivers that are extremely vulnerable to climatic variations in the alpine mountainous regions. The trend and magnitudinal changes of hydro–climatic variables, such as temperature, precipitation, and streamflow, were determined by applying the non-parametric Mann–Kendall, modified Mann–Kendall, and Sen’s slope tests in the Kofarnihon River Basin in Central Asia. We also used Pettitt’s test to analyze the changes during the 1951–2012 and 1979–2012 time periods. This study revealed that the variations of climate variables have their significant spatial patterns and are strongly regulated by the altitude. From mountainous regions down to plain regions, the decadal temperature trends varied from −0.18 to 0.36 °C/decade and the variation of precipitation from −4.76 to −14.63 mm yr−1 per decade. Considering the temporal variation, the temperature trends decreased in winter and significantly increased in spring, and the precipitation trends significantly decreased in spring but significantly increased in winter in the high-altitude areas. As consequence, total streamflow in headwater regions shows the obvious increase and clear seasonal variations. The mean monthly streamflow decreased in fall and winter and significantly increased in the spring and summer seasons which can be attributed to the influence of global warming on the rapid melting of snow and ice. Although the abrupt change points in air temperature and precipitation occurred around the 1970s and 1990s in the low-altitude areas and 2000s in the high-altitude areas during the 1951–2012 and 1979–2012 periods, the general trends of hydro–climatic variables keep consistent. This study benefits water resource management, socio–economic development, and sustainable agricultural planning in Tajikistan and its downstream countries.

Quantifying the Relative Contribution of Climate Change and Anthropogenic Activities on Runoff Variations in the Central Part of Tajikistan in Central Asia

“…In our previous study, we demonstrated the seasonal trend analysis of temperature, precipitation, and streamflow upstream of the KRB. Those results were compared with the fifth assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) [79]. The results of the annual temperature, annual precipitation, and annual potential evapotranspiration during the 1950-2016 time period are shown in Table 3.…”

“…In our previous study, we demonstrated the seasonal trend analysis of temperature, precipitation, and streamflow upstream of the KRB. Those results were compared with the fifth assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) [79].…”

Evaluation of the CRU TS3.1, APHRODITE_V1101, and CFSR Datasets in Assessing Water Balance Components in the Upper Vakhsh River Basin in Central Asia

“…River flow is mainly influenced by snowmelt, since a major part of the annual precipitation falls during the winter months, in higher areas, as snow. A seasonal and annual temperature and precipitation trend analysis of the flat and mountainous areas of Tajikistan can be found in our previous study [40]. In the upstream reaches of the Vakhsh River, due to limitations in the availability of suitable land, irrigation is rather limited.…”

Spatiotemporal Sensitivity Characteristics of Water Resources in Huai River Ecological–Economic Belt, China

“…Mountains rich in biodiversity and ecosystem services contribute considerably to economic activities, for example, through hydroelectricity generation and through tourism, agriculture, and animal husbandry. (20)(21)(22) These essential ecosystem services also characterize regional climates. However, these ecosystems face anthropogenic pressures caused by high population growth and global warming, which further lead to changes in the hydrological cycle and the retreat of glaciers.…”