Invisible Effect of Virtual Water Transfer on Water Quantity Conflict in Transboundary Rivers—Taking Ili River as a Case

Abstract

Water stress in countries within a drainage basin exacerbates the water quantity conflict in transboundary rivers. However, few studies considered the invisible effect of virtual water transfer on water quantity conflict by intensifying water stress. Therefore, this study, with Ili River as the case, collects data on Virtual Water Trade (VWT) from 1990 to 2015, uses water stress index (WSI) to assess water stress values under two scenarios (with or without virtual water transfer), and takes Grey Verhulst Model to predict two scenarios water stress values respectively. Next, based on the Levenberg—Marquardt (LM) Algorithm, this study compares the water quantity conflict intensity of the two scenarios, and further explores the invisible effect of virtual water transfer on the conflicts among transboundary rivers. Results show: (1) During the study period (1990–2015), water stress in China and Kazakhstan along the banks of Ili River increased in general. (2) China was basically a net exporter of virtual water during 1990–1995, and Kazakhstan became a net exporter after 1995. (3) During 2020–2025, water conflict value of Ili River without virtual water transfer is 0.458, while the value rises to 0.622 with virtual water transfer, indicating that virtual water transfer between China and Kazakhstan has an invisible enhancement on the water quantity conflict of Ili River. (4) The intensified water quantity conflict is mainly caused by the more and more serious water stress in Kazakhstan. On such basis, it is more urgent for Kazakhstan to restructure its economy and trade.

A Study of Initial Water Rights Allocation Coupled with Physical and Virtual Water Resources

“…Thus, VWT needs to be converted from the provincial level to the riparian level. However, a few studies that focus on this topic convert VWT using the water efficiency coefficient [50][51][52]. Therefore, this paper also employed the proportion of the riparian water efficiency coefficient to the provincial water efficiency coefficient to quantify and convert the provincial VWT.…”

A Study on Water Rights Allocation in Transboundary Rivers Based on the Transfer and Inequality Index of Virtual Water

“…In terms of methodology, this paper, drawing from previous studies, thus constructed an index system grounded in principles of status quo, equity, efficiency, sustainability, and macro regulation. Second, as for VWT methodology, many scholars found that the multiregional input-output approach can clarify the interdependence among sections of an entire supply chain in an economy [53][54][55][56][57][58][59][60]. It provides a clearer quantification of the amount of water deployed in trade and makes the virtual water calculation more intuitive and accurate [53][54][55][56][57][58][59][60].…”

“…Second, as for VWT methodology, many scholars found that the multiregional input-output approach can clarify the interdependence among sections of an entire supply chain in an economy [53][54][55][56][57][58][59][60]. It provides a clearer quantification of the amount of water deployed in trade and makes the virtual water calculation more intuitive and accurate [53][54][55][56][57][58][59][60]. Therefore, this paper drew an input-output tablet for modelling to calibrate water resources allocation in trade [35][36][37][38][39][40][41][42][43][44][45].…”