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The Evolution of Lop Nur and salt crusts. Stage I: wet period, prior to the lake's desiccation. Stage II: dry period, lake completely dried and
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Study region
Lop Nur, Xinjiang Province, China
Study focus
Lop Nur has been a vast playa which was a historic lake in eastern Tarim Basin, northwest China. The lake's catchment played a significant role in the development of oasis states in the early Common Era, such as the ancient Loulan Kingdom. However, the history of lake dynamics remains uncl...
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Context 1
... its width reaches 1 km. As shown by aerial photos taken in the 1950s and USA Corona photos taken in the 1960 s, West Lake occasionally received flood water and wet airflow, causing water to be randomly distributed within the West Lake area. Lop Nur became completely dry before 1972 (Xia, 2007). The wet-dry-wet-dry cycle of Lop Nur is depicted in Fig. 8 demonstrated based on the evolution of observed and modeled salt crusts. The analysis assumes that the different shapes and hardness of the salt crusts express their age. The harder the salt crusts, the older they are. Their evolution processes are illustrated in Fig. 8. ...
Context 2
... before 1972 (Xia, 2007). The wet-dry-wet-dry cycle of Lop Nur is depicted in Fig. 8 demonstrated based on the evolution of observed and modeled salt crusts. The analysis assumes that the different shapes and hardness of the salt crusts express their age. The harder the salt crusts, the older they are. Their evolution processes are illustrated in Fig. 8. ...
Citations
... The multi-proxy records of Lop Nur show that humid conditions between 2300 BP and 2100 BP, supported the ancient Loulan Kingdom until aridification began (Liu et al., 2016b(Liu et al., , 2016cYang et al., 2006). The historical changes in the lake level were coincided with the ancient Loulan Kingdom's collapse, showing that the dynamics of hydrological conditions in the catchment may have a direct influence on the fall of human settlement in drylands (Li et al., 2018;Shao et al., 2022). Scholars have actively debated the factors contributing to changes in water resources. ...
Endorheic river basins and their terminal lakes are highly sensitive to climate change and human activities. Based on chemical and pollen indicators, lake level, and erosion/accumulation rates of rivers, we explore the phasing of the evolution of the river system in the Hexi Corridor during the Holocene. The results suggest that climate change dominated the evolution of the river system during the early-Mid-Holocene. Entering the historical period, humans began to have an impact on runoff, water resources, and lake evolution, and since 1000 BP, anthropogenic perturbations recorded by regional proxies increased and humans dominated the migrations of river . In addition, we discuss the widespread erosion of rivers in the global endorheic zone and the impact of human activities in this context and found the timing of human influence on river evolution is not the same in different regions.
... Furthermore, Shao et al. (2022) used synthetic aperture radar (SAR) to explore the ancient shoreline of Lop Nur and combined it with OSL and 14 C age data from different lacustrine and Aeolian sediments to reconstruct the lake-level changes over the past 2000 years. The research results indicate that during the period of 360-470 CE, Lop Nur gradually dried up and subsequently formed salt crust (Fig. 4h). ...
... Li et al., 2021a); b) EM1 as an indicator of Lake size; c) Grain size of suspended lacustrine silt from Lake Bosten, as an indicator of lake hydrodynamic intensity (Xie et al., 2021); d); EM2 as an indicator of Water input. e) Fine sand fractions of Niya River section, as an indicator of Strong sand Storms (Zhong et al., 2007); f) EM3 as an indicator of exogenous sediment input; g) Uluu-2 stable oxygen isotope data, as an indicator of precipitation (Wolff et al., 2017); h) the era of construction and abandonment of Loulan, indicate by artifacts 14 C age ; i)The Stages of Lop Nur evolution revealed by synthetic aperture radar (SAR) data, optically stimulated luminescence (OSL) dating and radiocarbon ( 14 C) dating (Shao et al., 2022). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) ...
... This implies a decrease in the water available from meltwater and precipitation for agricultural and domestic consumption in the TB, which led to the shrinkage of oases, the deterioration of living conditions for humans, and the abandonment of settlements. This hypothesis is supported by records of hydroclimatic variations from Bosten Lake and Lop Nur, which demonstrate negative impacts on the evolution of the Loulan Kingdom in the TB during $420-600 CE [49][50][51]. Bosten Lake, the largest inland freshwater lake in China, and located on the northeastern margin of the TB, experienced a drastic decrease in lake level during this period, with an abrupt increase in the CaCO 3 content of the lake sediments and in the abundance of benthic diatoms (e.g., Staurosira construens) [49] (Fig. 3c). Lop Nur, a former lake which once covered an area of more than 11,600 km 2 in the eastern TB, began to shrink at $360 CE and Fig. 2. Comparison of climate proxy records from Shuanghu Lake. ...
... Science Bulletin xxx (xxxx) xxx eventually disappeared at $500 CE [50] (Fig. 3d). These events coincided with the decline of the ancient Loulan Kingdom [51]. ...
... Thus, it is likely that the depression of the trade along the TB route Fig. 3. Paleoclimate records compared with the history of the route shift of the SR and geopolitical conflicts in the TB. (a) Chironomid-inferred temperature change in Shuanghu Lake based on PC1 sample scores and a quantitative reconstruction (this study, the dashed line indicates the period without reconstructed values due to the insufficient number of chironomid head capsules); (b) precipitation change in the TB recorded by the net accumulation of the Guliya ice core [48]; (c) variations in water depth of Bosten Lake based on the sedimentary CaCO 3 content and the abundance of Staurosira construens [49]; (d) evolution of Lop Nur inferred from sediment dating [50]; (e) frequencies of wars along the TB route [35][36][37][38][39]; (f) key historical events in the TB [40,41]; (g) concentrations of titanium (Ti) in sediments from Jiang Co that were used to reflect precipitation variations on the central Tibetan Plateau [57], with a 50-point Fast Fourier Transform smoothing; and (h) population size of the Tibetan Plateau (in units of 1 million) [42]. Chinese dynasties during 420-850 CE are shown at the top. ...
Although climate change has convincingly been linked to the evolution of human civilization on different temporal scales, its role in influencing the spatial patterns of ancient civilizations has rarely been investigated. The northward shift of the ancient Silk Road (SR) route from the Tarim Basin (TB) to the Dzungarian Basin during ∼420–850 CE provides the opportunity to investigate the relationship between climate change and the spatial evolution of human societies. Here, we use a new high-resolution chironomid-based temperature reconstruction from arid China, combined with hydroclimatic and historical datasets, to assess the possible effects of climate fluctuations on the shift of the ancient SR route. We found that a cooling/drying climate in the TB triggered the SR route shift during ∼420–600 CE. However, a warming/wetting climate during ∼600–850 CE did not inhibit this shift, but instead promoted it, because of the favorable climate-induced geopolitical conflicts between the Tubo Kingdom and the Tang Dynasty in the TB. Our findings reveal two distinct ways in which climate change drove the spatial evolution of human civilization, and they demonstrate the flexibility of societal responses to climate change.
... Similarly, another study based on remote-sensing image interpretation and stratigraphic dating also found a persistent decrease in the water level of Lop Nur, located in the lower reaches of Bosten Lake, during AD 360-470, and its disappearance at~AD 500. However, contrary to the former study, the decline in the lake level of Lop Nur and the temporary demise of the Loulan Kingdom were attributed to increased evaporation resulting from high temperatures and a dry climate (Shao et al., 2022). Evidently, as an important aspect of hydroclimatic changes in the Tarim Basin, the water level fluctuations of Bosten Lake and its downstream Lop Nor showed similar patterns of decline during the 3rd-5th centuries AD, but which were ascribed to opposing temperature trends. ...
Reconstructing temperature changes along the Silk Road (SR) over the last two millennia can provide insights into past global changes and their impact on the rise and fall of ancient civilizations in this region. Numerous high-quality single-site paleotemperature records have been produced for the eastern part of the SR (mainly for the Xinjiang region and its surrounding areas), which provide the data basis for a comprehensive synthesis. In this study, we used objective criteria to select 10 high-quality ones from 30 temperature reconstructions derived from various geological archives including lacustrine sediments, ice cores, and tree rings in this region. Our aims are to summarize the pattern of temperature change over the past 2000 years, to provide a long-term viewpoint on the present warming, and to evaluate the impact of climate change on civilizations along the SR. The principal results are as follows: (1) The temperature variations over the last millennium are mutually consistent within these records. The study area experienced typical climate anomalies during the Medieval Warm Period (MWP, AD 1000-1250), the Little Ice Age (LIA, AD 1450-1850), and the Current Warm Period (CWP, AD 1850 to present); however, contrary to previous knowledge, the amplitude of climatic warming during the CWP did not exceed that during the MWP. (2) Fewer temperature records were available for the interval AD 1-1000, and there were large differences between them. For example, the reconstructed climate during both the Han Dynasty and the Sui-Tang Dynasties was either warm or cold, without prevailing consensus. (3) The warming during the MWP favored the rapid development of the SR route along the northern slopes of the Tianshan Mountains, and the cooling during the LIA contributed to the decline of the SR marked by the closure of the Jiayuguan Pass. Notably, the scarcity of temperature records and the discrepancies between them during AD 1-1000 in the eastern part of the SR have hindered our understanding of the hydroclimatic changes and their influence on the development of civilizations along the SR. Thus, it is important to obtain an increased number of high-quality reliable records spanning the past 2000 year, and to examine the occurrence of local signals of temperature changes during the period of AD 1-1000. On the other hand, the paleotemperature investigation on the western part of the SR over the last two millennia is wholly insufficient, and thus more high-quality single-site and integrated studies are needed, to facilitate more comprehensive insights into the coupled relationship between climate change and the rise and fall of civilizations along the entire length of the Silk Road.
... Moreover, using multitemporal Landsat 5-TM, 7-ETM+, and 8-OLI images to construct multiple satellite-derived indices for extracting surface water, identify and simulate temporal and spatial changes in Lake Urmia's surface water area (Rokni et al., 2014). In China, the remote sensing application of salt lake study began in the 1990s and has yielded several results, including estimation of soil salt content, identification of salt lake information Wang et al., 2020), detection of salt lake water surface changes (Xu et al., 2017;Yao et al., 2018;Hu et al., 2021;Shao et al., 2022), and detection of ecosystem environmental changes Yang et al., 2020). The low-altitude unmanned aerial vehicles remote sensing system (UAVRSS) solves the shortcomings of space and aerial remote sensing systems in resolution, revisit duration, cloud cover, and cost, resulting in a unique technique for salt lake mesoscale investigation (Sun et al., 2017). ...
... However, the evaporation capacity exceeds 3 000 mm. During the Loulan Epoch, the elevation of the lake may seldom surpassed 790.0 m, and the lake once covered an area of more than 11 602 km 2 (Zhang et al., 2021;Shao et al., 2022). Lop Nur vanished in 1972 due to human activity of diversion and the shortage of water recharge from Tarim River, the major source. ...
The change in the ecological environment in the arid core area is a critical issue in the context of global warming. To study the paleoclimate evolution, precise identification of minerals deposited in Asia’s arid hinterland, Lop Nur Salt Lake, NW China was conducted. The hyperspectral data of the salt crust was sampled to identify the species and content of sedimentary minerals, and the multispectral photos were used to reconstruct the salt crust morphology using the unmanned aerial vehicles platform. The SUnSAL (sparse unmixing by variable splitting and augmented Lagrangian) method was employed to inverse the sedimentary mineral components along the shoreline. The heterogeneity of salt and clay minerals in bright and dark ear-shaped strips was evaluated. The paleoclimatic environment associated with salt lake extinction was reconstructed by analyzing paleoclimate records of sediments, spectral reflectance and morphology of the salt crust. Results show that: (1) the variations in the micro-geomorphology of the salt crust are obviously the reason for the formation of bright and dark ear-shaped strips and the differences in the species and relative content of the sedimentary minerals are the microscopic reason. The high ratio of sedimentary salt minerals to clay minerals (RS/C) contributes to the high reflectivity, and the salt crust presents a bright texture. The low RS/C results in the low reflectivity, salt crust presents a dark texture; (2) the bright and dark ear-shaped strips represent warm-arid and cold-humid climates. The shape of the Lop Nur Lake shoreline evolved due to alternating warm-dry and cold-humid paleoclimate changes.
... The higher temperatures during warm periods resulted in increased river discharge and the expansion of lakes, and the stable oasis environment at these times promoted the development of the Bronze Age Xiaohe and Gumugou cultures, during 4-2.2 ka BP Xie et al., 2021). The lower temperatures during colder intervals reduced the melting of snow and glacier ice, which resulted in the shrinking of lakes and the consequent abandonment of numerous cities during the 3rd to 6th centuries, including the well-documented Loulan Kingdom Shao et al., 2022). In contrast, cultures flourished in the Baiyang River Basin during the Bronze Age (4-2.2 ka BP) and after the Tang Dynasty (post-1.6 ka BP), when temperatures were relatively low (Fig. 7a, b). ...
... Moreover, using multitemporal Landsat 5-TM, 7-ETM+, and 8-OLI images to construct multiple satellite-derived indices for extracting surface water, identify and simulate temporal and spatial changes in Lake Urmia's surface water area (Rokni et al., 2014). In China, the remote sensing application of salt lake study began in the 1990s and has yielded several results, including estimation of soil salt content, identification of salt lake information Wang et al., 2020), detection of salt lake water surface changes (Xu et al., 2017;Yao et al., 2018;Hu et al., 2021;Shao et al., 2022), and detection of ecosystem environmental changes Yang et al., 2020). The low-altitude unmanned aerial vehicles remote sensing system (UAVRSS) solves the shortcomings of space and aerial remote sensing systems in resolution, revisit duration, cloud cover, and cost, resulting in a unique technique for salt lake mesoscale investigation (Sun et al., 2017). ...
... However, the evaporation capacity exceeds 3 000 mm. During the Loulan Epoch, the elevation of the lake may seldom surpassed 790.0 m, and the lake once covered an area of more than 11 602 km 2 (Zhang et al., 2021;Shao et al., 2022). Lop Nur vanished in 1972 due to human activity of diversion and the shortage of water recharge from Tarim River, the major source. ...
Lop Sea, located at the east end of the Tarim Basin, Northwest China, dried up permanently, which is the terminal lake of the Tarim River. Lop Sea was considered as the lake basin of Lop Nor since Quaternary. However, the possibility that Lop Nor was away from the Lop Sea in historical time is crucial to be discussed to interpret the proxy records in sediment profiles. To obtain a general view of the evolution of Lop Nor and Lop Sea in a historical period, several approaches were adopted in this paper. First, the Qianlong Thirteen-Row Atlas, an ancient imperial atlas of the Qing Dynasty, which was completed around 1760, indicated that the Tarim River formed a relatively large lake at its modern upstream region. Second, a Digital Elevation Model (DEM) with a 10-m spatial resolution and a relative precision of 0.42 m was derived from TanDEM-X/TerraSAR-X satellite image pairs using the interferometry method, which was verified using ICESat-GLAS laser footprints and a local DEM acquired by a drone. Finally, based on the spatial analysis of historical documents, expedition reports, sediment profiles and archaeological evidence, it can be deduced that the lacustrine deposition was discontinued in the Lop Sea. Six episodes in the evolutionary history of the drainage system in eastern Tarim Basin were summarized. The proved depositional condition variations could be used for future interpretation of proxy records in sediment. The high-accurate DEM provided a reference for the location of further fieldwork in the Lop Sea. The method proposed in this paper may be efficient for the research of inland lakes or rivers in global arid regions.
Lake Chany is the largest endorheic lake in Siberia whose catchment is entirely on the territory of Russia. Its geographical location on the climate-sensitive boundary of wet and dry landscapes provides an opportunity to gain more knowledge about environmental changes in the West Siberian interior during the Holocene and about the evolution of the lake itself. Sediment cores obtained from the Yarkov sub-basin of the lake in 2008 have been comprehensively studied by a number of approaches including sedimentology and AMS dating, pollen, diatom and chironomid analyses (with statistical interpretation of the results), mineralogy of authigenic minerals and geochemistry of plant lipids (biomarker analysis.). Synthesis of new results presented here and published data provides a good justification for our hypothesis that Lake Chany is very young, no older than 3.6 ka BP. Before that, between 9 and 3.6 ka BP, the Chany basin was a swampy landscape with a very low sedimentation rate; it could not be identified as a water body. In the early lake phase, between 3.6 and 1.5 ka BP, the lake was shallow, 1.2—3.5 m in depth, and it rose to its modern size, up to 6.5 m in depth, during the last millennium. Our data reveal important changes in the understanding of the history of this large endorheic lake, as before it was envisioned as a large lake with significant changes in water level since ca. 14 ka BP. In addition to hydrology, our proxies provide updates and details of the regional vegetation and climate change since ca. 4 ka BP in the West-Siberian forest-steppe and steppe. As evolution of the Chany basin is dependent on hydroclimatic changes in a large region of southern West Siberia, we compare lake-level change and climate-change proxies from the other recently and most comprehensively studied lakes of the region.
