scholarly journals Stratigraphic Division of Holocene Loess in China

Radiocarbon ◽  
1994 ◽  
Vol 36 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Weijian Zhou ◽  
Zhisheng An ◽  
M. J. Head
Keyword(s):  
Environmental Change ◽  
Loess Plateau ◽  
Engineering Geology ◽  
Global Climate ◽  
The Loess Plateau ◽  
Human Occupation ◽  
South West ◽  
Stratigraphic Division ◽  
History Of ◽  
Loess Deposition

Loess deposition within the Loess Plateau of China records the history of environmental change over the last 2.5 Myr. Loess-paleosol sequences of the last 10 ka, which have preserved information of global climate change, relate closely to human occupation of the area. Hence, studies of the deposition and development of Holocene loess are significant for studying environmental change and problems associated with engineering geology. We present here stratigraphic relations among four profiles from the south, west and center of the Loess Plateau. On the basis of 14C radiometric and AMS dates of organic material extracted from the paleosols, together with magnetic susceptibility measurements down each profile, we discuss Holocene stratigraphic divisions within the Loess Plateau, and suggest that the Holocene optimum, characterized by paleosol complexes, occurred between 10 and 5 ka bp. From 5 ka BP to the present, neoglacial activity is characterized by recently deposited loess.

The response of extreme rainstorm to global climate pattern changes in the loess plateau

2020 ◽  
Author(s):  
shaobo long
Keyword(s):  
Water Resources ◽  
Soil Erosion ◽  
Loess Plateau ◽  
Water Conservation ◽  
Global Climate ◽  
Soil And Water Conservation ◽  
The Loess Plateau ◽  
Sst Anomaly ◽  
Academy Of Sciences ◽  
Soil And Water

<p><strong>The response of extreme rainstorm to global </strong><strong>climate pattern changes in the loess plateau</strong></p><p>Shaobo Long<sup>1,3</sup>、Jianen Gao<sup>1,2,3*</sup>、Huijuan Li<sup>5</sup>、Zhe Gao<sup>4</sup>、minmin Qiang<sup>1,3</sup>、Sixuan Liu<sup>1,3</sup></p><ol><li>Institute of Soil and Water Conservation, Northwest Agriculture and Forestry University, 712100, Yangling, Shaanxi, China.</li> <li>Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, Shaanxi, China.</li> <li>Research Center on Soil and Water Conservation, Ministry of Water Resources, 712100, Yangling, Shannxi, China.</li> <li>College of Water Resources and Architectural Engineering, Northwest Agriculture and Forestry University, 712100, Yangling, Shaanxi, China.</li> <li>Institute of Geographic Sciences and Natural Research, CAS, 100101, Beijing, China.</li> </ol><p><strong>Abstract: </strong>The loess plateau is the region with the most serious soil and water problems in the world, the soil erosion mainly occurs in the season of rainfall, especially the extreme rainstorm has great influence on soil erosion. In recent years, under the background of global climate change, extreme rainstorm occurs frequently in the loess plateau, causes a series of soil damage, was difficult to predict. Therefore, it is a great significance to study the rule of extreme rainstorm for the soil erosion in the loess plateau. Based on the daily rainfall data of 56 meteorological stations and global sea surface temperatures (SST) data in the last 60 years, the effects of El Niño on extreme rainstorm were studied by using empirical orthogonal function (EOF), wavelet transform, and other statistical methods. The results show:</p><ul><li>(1) The extreme rainstorm has obvious spatial distribution characteristics, which decreases gradually from the south to the north of the loess plateau; Temporal variation of extreme rainstorm has obvious decadal oscillation, showing a decreasing trend from 1982 to 2012 and an increasing trend after 2012.</li> <li>(2) There was a significant positive correlation between the time coefficient of EOF1 for SST and the extreme rainstorm (P < 0.05). Wavelet analysis shows that Both extreme rainstorm and SST anomaly have a 30-year cycle, with the time change becoming more dramatic after 2012.</li> <li>(3) El Niño has obvious influence on the extreme rainstorm in the loess plateau region. Extreme rainstorm can be predicted about 1 year in advance by the change of SST anomaly. This is of great significance to the study of extreme rainfall erosion in the loess plateau.</li> </ul><p><strong>Keywords: The loess plateau; Extreme rainstorm; El Niño</strong></p><p><strong>Funding:</strong></p><ol><li>The National key Research and Development Program of China (No.2017YFC0504703).</li> <li>National Natural Science Foundation of China (No. 41877078, 41371276).</li> <li>Knowledge Innovation Program of the Chinese Academy of Sciences (No.A315021615).</li> </ol>

scholarly journals Subsoiling during summer fallow in rainfed winter-wheat fields enhances soil organic carbon sequestration on the Loess Plateau in China

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245484
Author(s):  
Huiyu Zhang ◽  
Zhiqiang Gao ◽  
Jianfu Xue ◽  
Wen Lin ◽  
Min Sun
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Winter Wheat ◽  
Loess Plateau ◽  
Global Climate ◽  
Scientific Management ◽  
The Loess Plateau ◽  
Fallow Period ◽  
Tillage Practices ◽  
Summer Fallow

Scientific management of the soil organic carbon (SOC) pool, e.g., through a reasonable tillage system, is a potential way to mitigate global climate change. There is scarce information about the effect of tillage during the summer fallow period on the SOC pool in rainfed winter-wheat fields. The present study was designed to evaluate the effects of tillage practices, i.e., plow tillage (PTF), subsoiling (STF) and no tillage (NTF), during the summer fallow period on SOC sequestration in winter-wheat fields in the rainfed area of the eastern Loess Plateau of China. The SOC, mineral-associated organic carbon (MOC), permanganate-oxidizable organic carbon (POxC) and particulate organic carbon (POC) concentrations were determined after four years of tillage implementation during the summer fallow period. Our results showed that in comparison to the adoption of NTF, the adoption of STF significantly increased POxC, POC and MOC concentrations by 56.6–111.2%, 45.7–118.7% and 26.2–29.4%, respectively, at the 10–20 and 30–40 cm soil depths before sowing (P < 0.05). The POxC and MOC concentrations under STF at depths of 0–10, 10–20, 20–30 and 30–50 cm were significantly greater than those under PTF and NTF after harvesting (P < 0.05). In addition, the SOC concentration and SOC stock under STF were significantly greater than those under NTF at the 0–10, 10–20, 20–30 and 30–40 cm soil depths before sowing and after harvesting (P < 0.05). Furthermore, in comparison to PTF and NTF, STF resulted in significantly higher SOC stocks by 12.0–25.3% and 7.1–19.2% than PTF and NTF, respectively, in the 0–10, 0–20, 0–30, 0–40 and 0–50 cm soil profiles at harvesting (P < 0.05). In summary, the adoption of STF could be beneficial to the management of the SOC pool in the 0–50 cm soil profile in the rainfed area of winter-wheat on the Loess Plateau of China.

scholarly journals Impact of environmental change on runoff in a transitional basin: Tao River Basin from the Tibetan Plateau to the Loess Plateau, China

2019 ◽  
Vol 10 (4) ◽  
pp. 214-224
Author(s):  
Long Sun ◽  
Yue-Yang Wang ◽  
Jian-Yun Zhang ◽  
Qin-Li Yang ◽  
Zhen-Xin Bao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Environmental Change ◽  
River Basin ◽  
Loess Plateau ◽  
The Tibetan Plateau ◽  
The Loess Plateau

scholarly journals Unique traditional villages on the Loess Plateau of China: historic evolution and challenges to sustainable development of silo-caves

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Li Zhang ◽  
Peng Lu ◽  
Raymond Lau ◽  
Lijie Yan ◽  
Xiang Li ◽  
...  
Keyword(s):  
Sustainable Development ◽  
Economic Development ◽  
Loess Plateau ◽  
Morphological Evolution ◽  
Morphological Characteristics ◽  
Northern China ◽  
The Loess Plateau ◽  
Industrial Transformation ◽  
History Of ◽  
Inner Parts

AbstractSilo-cave is a unique human habitation form on the Loess Plateau in northern China, which consists of an excavated 6–7 m deep pit as the courtyard and cave dwellings in the surrounding four walls. This architecture has had a history of more than 7000 years, and yet such “living fossils for the history of dwellings” are now facing great crises and challenges during rapid social and economic development. In this paper, remote sensing and GIS techniques are used to comprehensively and systematically investigate the spatial distributions and morphological characteristics of silo-caves at both the macro and micro scales. The research shows that silo-cave villages are mainly distributed in economically underdeveloped areas, such as West Henan (Yuxi), South Shanxi (Jinnan), Central Shaanxi (Guanzhong), and East Gansu (Longdong). The morphological evolution patterns of typical silo-cave villages are identified, including: (1) retaining the periphery and rebuilding the inner parts of the villages, (2) retaining the inner parts and expanding the periphery of the villages, and (3) rebuilding the inner parts and expanding the periphery of the villages. These patterns are demonstrated to be influenced by many factors, including landforms, traffic conditions, economic development, population growth, and administrative division adjustment. Sustainable development of these traditional silo-cave villages relies on administrative policy and planning, people’s awareness of cultural heritage protection, culture inheritance, industrial transformation, and public services.

scholarly journals Relationship between tectonism and desertification inferred from provenance and lithofacies changes in the Cenozoic terrestrial sequence of the southwestern Tarim Basin

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Aki Sakuma ◽  
Ryuji Tada ◽  
Tomohiro Yoshida ◽  
Hitoshi Hasegawa ◽  
Naomi Sugiura ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Global Climate ◽  
Crystallinity Index ◽  
Late Eocene ◽  
Global Climate Changes ◽  
Tectonic Events ◽  
First Occurrence ◽  
History Of ◽  
Age Model ◽  
Loess Deposition

AbstractThe modern-day Tarim Basin is covered almost entirely by the Taklimakan sand desert and is one of the most arid regions in the world. Unraveling the aridification history of the desert is important for understanding global climate changes during the Cenozoic, yet the timing and mechanisms driving its formation remain controversial. One of the leading hypotheses is that the uplift of the Pamir, located to the west of the Tarim Basin, blocked the intrusion of moist air and induced the aridification in the Tarim Basin. In this study, we explore the linkage between the uplift of the Pamir and the desertification in the Tarim Basin from the late Eocene to the middle Miocene in the Aertashi section, which is located at the southwestern edge of the Tarim Basin and offers the longest sedimentary record with a reliable age model. Provenance changes in fluvial deposits along the Aertashi section were examined using electron spin resonance (ESR) signal intensity and crystallinity index (CI) of quartz in the sand fraction of fluvial sandstones and clast counting based on the identification of clast types by thin section observation to identify timings of tectonic events in the Pamir, from which clastic materials were supplied to the Aertashi section by rivers. Our results suggest that major provenance changes in the drainage of the paleo-Yarkand river delivering clasts to the Aertashi section occurred at ca. 27, 20, and 15 Ma. These timings are mostly consistent with those observed in previous provenance studies in the Aertashi section and probably reflect tectonic events in the Pamir. On the other hand, according to the previous studies, the first occurrence of sand dune deposits indicates that the Tarim Basin was relatively arid after ca. 34 Ma. Hence, our result does not support the hypothesis that the initial aridification in the Tarim Basin was triggered by the uplift of the Pamir and the resultant blocking of moisture supply from the Paratethys Sea, although the subsequent intensification of tectonic events at ca. 27 Ma in the Pamir might have caused aridification indicated by the initiation of loess deposition.

scholarly journals Will Human-Induced Vegetation Regreening Continually Decrease Runoff in the Loess Plateau of China?

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 906 ◽  
Author(s):  
Yanzhong Li ◽  
Dehua Mao ◽  
Aiqing Feng ◽  
Tayler Schillerberg
Keyword(s):  
Loess Plateau ◽  
Vegetation Change ◽  
Climate Models ◽  
Global Climate ◽  
Temporal Trends ◽  
Global Climate Models ◽  
The Loess Plateau ◽  
Runoff Variation ◽  
The Future ◽  
Grain For Green Project

China has become the largest contributing country to global vegetation regreening. However, the regreening pattern and subsequent impact on arid areas have not been comprehensively evaluated. Therefore, we selected the Loess Plateau, a representative arid region that has undergone evident vegetation restoration, to investigate the spatial patterns and temporal trends, as well as the drivers of vegetation change. This study primarily focused on 12 afforested watersheds during 2000–2018. Furthermore, both the impacts of vegetation regreening on runoff for the past two decades and the future projections were quantified based on the fraction of photosynthetically active radiation (fPAR), the Budyko model, and the global climate models (GCMs). fPAR for the last two decades indicates that vegetation in the Loess Plateau has experienced a continuous increasing trend during the growing season, primarily in response to the implementation of the Grain for Green Project (GFGP). Of the 12 watersheds, 9 experienced significant fPAR change with a change rate above 50%, and 11 exhibited a significant increase (p < 0.05) in runoff sensitivity to vegetation regreening, which indicates that vegetation regreening plays an increasingly important role in controlling runoff variation. The decline in runoff caused by vegetation regreening was particularly noticeable before 2011 or 2012; afterwards, runoff tended to vary with precipitation. In the future (2020–2049 and 2050–2099), decrease in runoff by regreening will be limited, as runoff is anticipated to decrease by 3.5% in 2020–2049 and 4.1% in 2050–2099 with a 20% increase in fPAR. These results indicate that runoff tends to be stable even with continuous vegetation regreening. While the reduction of runoff by regreening will be limited in the future, rapid human-induced vegetation regreening may aggravate water scarcity when flash droughts occur and may result in disasters in water-limited regions to the socio-economic stability and agriculture. Our study will provide an applicable theoretical foundation for water resources decision-making and ecological restoration.

Evolution Characteristics and Simulation Prediction of Forest and Grass Landscape Fragmentation Based on the “Grain for Green” Projects on the Loess Plateau, P.R. China

2021 ◽  
Author(s):  
Li Gu ◽  
Zhiwen Gong ◽  
Yuankun Bu
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Loess Plateau ◽  
Global Climate Change ◽  
Global Climate ◽  
Landscape Fragmentation ◽  
The Loess Plateau ◽  
Grain For Green ◽  
Grain For Green Project ◽  
The Impact

Abstract Forest fragmentation is one of the major environmental issues that the international community is generally concerned about under the background of global climate change. Studying the impact and the interaction mechanism of land use change processes on landscape fragmentation is important to gaining a comprehensive understanding of the ecosystem response to human activities and global climate change. Based on the implementation background for the “Grain for Green” Project, we selected the Loess Plateau as the research area and used the coupled future land use simulation (FLUS) model and landscape fragmentation model to explore the temporal and spatial changes in forest and grass landscape fragmentation. The results showed that (1) Woodland, grassland, and cropland are the main landscape types, accounting for about 90% of the total area. In addition, the area of cropland initially increased and then decreased, while the area of woodland and grassland exhibited the opposite trend Oover the last 35 years. In particular, the period from 2000 to 2015 was a forest and grass restoration stage, and the average annual rate of forest and grass restoration reached 0.56%. (2) The FLUS model was used to predict the land use on the Loess Plateau in 2030. The kappa coefficient was 0.85, and the figure of merit coefficient (FOM) was 0.11 for a 1% random sampling, which are within a reasonable range, and the simulation results are also consistent with the objective change in the current social and economic development. (3) The fragmentation of woodland and grassland were dominated by edge type and core type. The core type had a concentrated distribution and an absolute advantage, accounting for more than 75% of the total area. It is predicted that the landscape fragmentation will gradually slowdown in 2030 under different intensities of the “Grain for Green” project. The dynamics of landscape fragmentation based on land use changes are conducive to the reasonable planning and objective evaluation of woodland and grassland spatial allocation and quality improvement, and provide an important basis for the formulation of ecological protection and land management policies.

Sap flow dynamics of xerophytic shrubs differ significantly among rainfall categories in the Loess Plateau of China

2020 ◽  
Author(s):  
Di Wang ◽  
Guangyao Gao ◽  
Junran Li ◽  
Chuan Yuan ◽  
Yihe Lü ◽  
...  
Keyword(s):  
Climate Change ◽  
Loess Plateau ◽  
Global Climate Change ◽  
Sap Flow ◽  
Global Climate ◽  
Weather Condition ◽  
Daily Rainfall ◽  
The Loess Plateau ◽  
Rainfall Events ◽  
Caragana Korshinskii

&lt;p&gt;Global climate change is likely to change the timing, frequency and magnitude of precipitation events, studying the response of sap flow (SF) of plants to rainfall events is thus important for understanding the response of ecosystems to global climate change. Here, we conducted a comprehensive study on the SF, rainfall events, meteorological factors and soil water for two typical xerophytic shrub stands (&lt;em&gt;Caragana korshinskii&lt;/em&gt; and &lt;em&gt;Salix psammophila&lt;/em&gt;) on the Loess Plateau of China for two rainy seasons (from June-September) in 2015 and 2016. The rainfall events were classified into three rainfall categories using the K-means clustering based on the rainfall amount (RA), rainfall duration (RD) and rainfall intensity (RI) (category I: lowest mean RA, RD and RI, category II: moderate mean RA, RI and highest mean RD and category III: highest mean RA, RI and moderate mean RD). The results showed that the response of SF at both&lt;em&gt; C. korshinskii&lt;/em&gt; and &lt;em&gt;S. psammophila&lt;/em&gt; stands to rainfall events differed under the three categories. The occurrence of rainfall events significantly decreased daily SF of &lt;em&gt;C. korshinskii&lt;/em&gt; in three rainfall categories, whereas the daily SF of &lt;em&gt;S. psammophila&lt;/em&gt; is more strongly influenced by rainfall category II. Maximum decreases in daily SF between the pre-rainfall and the rainfall weather condition of the two stands both occurred in rainfall category II. Daily rainfall SF at both stands was strongly correlated with daily SR, RH and VPD, regardless of the rainfall categories. Diurnal variation of hourly SF at both stands also differed among the days with similar RA and RD in the same rainfall category. It can be inferred that SF of&lt;em&gt; C. korshinskii&lt;/em&gt; is more susceptible to rainfall events than &lt;em&gt;S. psammophila&lt;/em&gt;. Rainfall characteristics (RA, RD and RI) and rainfall distribution should be fully considered when assessing the response of SF of shrubs to rainfall events.&lt;/p&gt;

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