The Shrinkage of Lake Lop Nur in the Twentieth Century: A Comprehensive Ecohydrological Analysis

Abstract

Abstract A comprehensive ecohydrological analysis is designed to understand the formation and evolution of lake Lop Nur and the environmental change over the Tarim River basin. Three temporal scales from century-based climatological mean to decade-based quasi-steady state change and to annual-scale-based abrupt change test are included. Combining the Budyko and Tomer–Schilling framework, this research first analyzes hydroclimatic and ecohydrological resistance/resilience conditions, then attributes observed changes to external/climate impact or to internal/anthropogenic activities, and finally diagnoses the possible tipping point on ecohydrological dynamics. (i) The arid regions reveal less sensitivity in terms of low variabilities of excess water W and energy U and show high resilience, which will more likely stay the same pattern in the future. (ii) Present towns situated in the semiarid regions with a natural hydraulic linkage with the mainstream of the Tarim River show a higher sensitivity and likelihood to be affected if drier scenarios occurred in the future. (iii) The attribution from two subsequent quasi-steady states indicates increasing effects of the anthropogenic activities increase (1961–80 versus 1981–2000) and provides climatical evidence that the central Tarim River basin was getting wetter before 1960 and then kept drying afterward. (iv) In the Kongqi subcatchment, the excess water reveals a significant decrease-then-increase evolution, from which the years with abrupt changes are observed in the 1960s. Generally, both points iii and iv are in agreement with that the closed-basin lake Lop Nur desiccation until the 1970s and its connection with the eastern part of the Taklamakan Sand Sea.