4 results on '"Ning, Kai"'
Search Results
2. A grain size and n-alkanes record of Holocene environmental evolution from a groundwater recharge lake in Badain Jaran Desert, Northwestern China
- Author
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Wang Naiang, Sun Jiaqi, An Ran, Ning Kai, Lv Xiaonan, Zhang Lvlv, and LI Zhuolun
- Subjects
Environmental evolution ,Archeology ,Global and Planetary Change ,Water transport ,Ecology ,Earth science ,Desert (particle physics) ,Paleontology ,Groundwater recharge ,Arid ,Grain size ,Environmental science ,China ,Holocene ,Earth-Surface Processes - Abstract
Vertical water transport plays an important role in the development and maintenance of lakes in arid zones. However, previous study of this phenomenon has focused mainly on the effects of regional precipitation, rather than effects of groundwater recharge, on arid-zone environmental change. We selected a sedimentary profile from a seasonal lake basin located in the hinterland of the Badain Jaran Desert, northwestern China, to assess the Holocene environmental evolution of this region and its response to climate change. Our results show that peat deposition from 11 to 10 ka indicates humidification after Younger Dryas (YD) event; the lake sediment and lower EM2 and lower principal component analysis (PCA)-1 scores indicate relative more humid environment from 10 to 7.8 ka; the lake sediment and higher EM2 and higher PCA-1 scores indicate most humid environment from 7.8 to 5.8 ka; the transition from lacustrine facies to limnetic facies and increasing salinity indicate drying trend from 5.8 to 2.5 ka; the aeolian sand sediment and lowest EM2 and lowest PCA-1 scores indicate driest environment from 2.5 to 0.8 ka; and lacustrine facies and finest grain size indicate relative humid environment during the ‘Little Ice Age’ period. The environment was relative humid in early Holocene, most Humid in mid-Holocene, and dry in mid-late Holocene. The moisture pattern in the hinterland of the Badain Jaran Desert was synchronous with that in the northeastern of Tibetan Plateau, which implies that the groundwater recharge lake was dominated by the intensity of groundwater recharge from monsoon margin area, especially the northeastern of Tibetan Plateau. As a record from groundwater recharge lake without runoff, our study provides the groundwater output quantity record from northeastern of Tibetan Plateau and would benefit the environment change research and regional water resources allocation around the Tibetan Plateau.
- Published
- 2019
3. Formation and environmental significance of late Quaternary calcareous root tubes in the deserts of the Alashan Plateau, northwest China.
- Author
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Li, Zhuolun, Wang, Nai'ang, Cheng, Hongyi, Ning, Kai, Zhao, Liqiang, and Li, Ruolan
- Subjects
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ENVIRONMENTAL engineering , *HOLOCENE Epoch , *CALCAREOUS soils , *MARINE ecology , *CARBON isotopes - Abstract
Calcareous root tubes are widely distributed across the Badain Jaran Desert and the Tengger Desert of the Alashan Plateau in northwest China. However, the reliability of their 14 C dating results and their environmental significance remain unclear. In this study, the conventional 14 C ages of 31 calcareous root tube samples and one aquatic mollusc shell sample, which were all collected from the Badain Jaran Desert and the Tengger Desert, were measured. The results reveal that nine of the 14 calcareous root tube samples from the Badain Jaran Desert were from Marine Isotope Stage (MIS) 3, while two samples were from MIS 2. The other three samples were dated to the mid-Holocene, one of which is consistent with the aquatic mollusc shell sample collected from the shoreline of Zhunzhahanjilin Lake in the Badain Jaran Desert. Moreover, the 17 calcareous root tube samples from the Tengger Desert were all dated to the mid- and late-Holocene, most of which were from the mid-Holocene. The results demonstrate that calcareous root tubes can be used as 14 C dating materials and that the accuracy of their 14 C dating depends on the time scale. The dating results were reliable at the millennial scale. However, the reliability of the ages from MIS 3a is lower than that of the Holocene ages, though the ages were reliable in tens of thousands years. Based on the statistical analysis, the overwhelming majority of calcareous root tubes collected from the deserts of the Alashan Plateau were formed during MIS 3a and the mid-Holocene. The concentrated emergence of calcareous root tubes in phases implies that they were formed during periods of relatively humid environments in desert areas, arid regions. Moreover, the results indicate that the effectivity of the moisture level probably affects the formation of calcareous root tubes, and the presence of calcareous root tubes indicates the occurrence of periods of relatively humid environments in the study area. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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4. Quantitative reconstruction of consecutive paleolake-level fluctuations by the groundwater recharged lake in the desert hinterland: A case study in the Badain Jaran Desert, Northwestern China.
- Author
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Dong, Shipei, Li, Zhuolun, Li, Meng, Lu, Chen'ao, Wang, Nai'ang, and Ning, Kai
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GROUNDWATER recharge , *MELTWATER , *HINTERLAND , *DUST , *SAND dunes , *LAKE sediments , *LAKES - Abstract
• New methods to quantitatively reconstruct consecutive lake level changes in desert. • The highest lake levels occurred at the early Holocene in BJD hinterland. • Increase in meltwater resulted in high lake levels during the early Holocene. Quantitative reconstruction of consecutive paleolake-level fluctuations may help reconstruct lake evolution during the Holocene. However, the reconstruction of a groundwater recharged lake in a desert hinterland is challenging. In this study, 23 samples of lake bottom sediments were obtained from eight groundwater recharged lakes in the hinterland of the Badian Jaran Desert in northwest China to establish models between the grain size component and lake level. Our results showed that the four grain size components of the sediments could be separated using the Weibull function. The first two fine grain components (W1 and W2) were deposited in the atmospheric dust. The two coarser components (W3 and W4) could be interpreted as sediments transported by wind from the surrounding sand dunes, while W3 was subsequently redistributed by lake waves. Changes in the lake water depth could be expressed by the W1 and W2 component contents, as well as the modal size of W3. Using the above models, unmixing grain size components of the lake sediment obtained from the ZZH section located in a seasonal lake (Zhunzhahan Jaran Lake) in the desert hinterland were used to quantitatively reconstruct the lake-level fluctuations during the Holocene. The lake level frequently fluctuated between 3.82 and 9.21 m during 10.6–8.6 cal kyr BP, slightly fluctuated between 3.41 and 5.26 m during 8.6–4.7 cal kyr BP, and markedly declined from 6.09 m to 4.46 m during 4.7–3.5 cal kyr BP. Lake-level changes in the hinterland of the Badian Jaran Desert did not correspond to the effective moisture changes during the early Holocene. Instead, the rise in lake level during the early Holocene would have resulted from the input of groundwater from the meltwater in the mountains of the recharge area. The data reveal new methods for quantitatively reconstructing consecutive paleolake-level fluctuations by groundwater recharged lakes in the desert hinterland. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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