Japan Geoscience Union Meeting 2018

Presentation information

[EE] Oral

A (Atmospheric and Hydrospheric Sciences) » A-HW Hydrology & Water Environment

[A-HW20] Materials transport and nutrient cycles in watersheds; Human and climate impacts

Mon. May 21, 2018 10:45 AM - 12:15 PM Convention Hall B (CH-B) (2F International Conference Hall, Makuhari Messe)

convener:Mitsuyo Saito(Graduate School of Environmental and Life Science, Okayama University), Shin-ichi Onodera(Graduate School of Integrated and Arts Sciences, Hiroshima University), Takahiro Hosono(熊本大学大学院先導機構, 共同), Adina Paytan(University of California Santa Cruz), Chairperson:Onodera Shin-ichi(Graduate School of Integrated Arts and Sciences, Hiroshima University)

11:15 AM - 11:30 AM

[AHW20-20] Estimation of dissolved chemical loading flowing into Lake Issyk-Kul

*Kei Saitoh1, Hideaki Maemoku2, Koji Kodera2, Kenji Okubo3 (1.Graduate School of Humanities , Major in Geography , Hosei University, 2.Department of Geography, Hosei Univ., 3.Graduate School of Environmental and Life Science, Okayama University)

Keywords:Saline Lake, Arid Region, Major Chemical Compornent, Central Asia

For Lake Issyk-Kul, the rise in salt concentration has been confirmed before 1998, when water level declined due to evaporation condensation, but as for the factor that the salt concentration continues to rise even after 1998 when the water level turned to rise It is still unknown. The water quality formation mechanism of the saline lake is important in balancing the supply amount of each chemical component from the inflow river and groundwater and the amount that they are removed from the water, and the water quality of the inflow river and groundwater and the salinity concentration of the lake It is necessary to grasp the relationship with the rise. Therefore, in this research, major chemical components of samples sampled from Lake Issyk-Kul and its river water and groundwater during the summer of 2012 to 2015 were analyzed. In addition, the load amount of dissolved chemical components was calculated using weather data of the past 11 years and water quality data of river water.

River water in the Lake Issyk-Kul catchment area shows Ca-HCO3 type. In this area, wastewater treatment facilities are inadequate, and Na, Cl, SO4 and NO3 concentrations are relatively higher in other river waters in areas where urban areas and upland fields concentrate. Groundwater shows different water quality types depending on the area, and there are Ca-HCO3 type, Na-SO4 type and Na-Cl type. The Na-SO4 type and Na-Cl type are hot spring water, which are found in hot spring facilities in the southern part of Lake Issyk-Kul and east well. In particular, the Na-Cl type is three times the ion concentration of Lake Issyk-Kul, and it is thought that it influences the water quality formation of Lake Issyk-Kul. For loading from river water and groundwater, the TDS is 493×106 kg/y, which is required in 24758 years to reach the current water quality of Lake Issyk-Kul. In the future, considering the process of water quality formation of Lake Issyk-Kul, it is necessary to verify the load amount for each ion.