yuan liu

Dr. yuan liu

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
KQkaixuan Qian
kaixuan Qian
Xiaofei MaXiaofei Ma
Xiaofei Ma
YongHui WangYongHui Wang
YongHui Wang
XYXiuliang Yuan
Xiuliang Yuan
Wei YanWei Yan
Wei Yan
JLJiaxin Li
Jiaxin Li
The uncertainties in soil erosion (SE) are further intensified by various factors, such as global warming, regional warming and humidification, and vegetation cover changes. Moreover, quantitative evaluations of SE in major basins of Central Asia (CA) under changing environments have rarely been conducted. This study conducted quantitative evaluation of SE in four major basins (Syr Darya Basin (SDB), Amu Darya Basin (ADB), Ili River Basin (IRB) and Tarim River Basin (TRB) using the Revised Universal Soil Loss Equation (RUSLE) and analyzed the main driving factors. SE quantities in the basins presented relatively consistent upward fluctuating trends from 1982 to 2017. Vegetation cover variation fluctuated significantly from 1982 to 2017. Specifically, vegetation cover decreased continuously in SDB, ADB, and IRB, but increased gradually in TRB. Pixels with positive spatial variation of vegetation mainly occurred around lakes and oases near rivers. The Normalized Difference Vegetation Index (NDVI) showed higher correlation with precipitation (80.5%) than with temperature (48.3%). During the study period, the area of arable land (AL) exhibited the largest change among all land use types in CA. Under long-term human activities, the proportion of NDVI of other land types converting to AL was the highest. In the structural equation model (SEM), precipitation, temperature, Shannon Diversity Index (SHDI), and NDVI strongly influenced SE. Overall, the major basins in CA were jointly affected by climate, human activities, and vegetation. Specifically, climatic factors exerted the strongest influence, followed by SHDI (human activities). SE was found to be relatively serious in ADB, SDB, and IRB, with SE in SDB even approaching that in the Loess Plateau. Under the background of global changes, appropriate water and land resource management and optimization configurations should be implemented in CA with reference to TRB in order to relieve local SE problems.

28 September 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Wei YanWei Yan
Wei Yan
Xiaofei MaXiaofei Ma
Xiaofei Ma
YLyuan liu
yuan liu
KQkaixuan Qian
kaixuan Qian
Xiuyun YangXiuyun Yang
Xiuyun Yang
YWYifan Wang
Yifan Wang
Climate change and anthropogenic activities drive the shrinkage of terminal lakes in arid areas to varying degrees. Ecological water conveyance (EWC) projects have emerged globally to restore the ecology of terminal lakes. However, there remains a lack of qualitative evaluation of the benefits of EWC on terminal lakes. This study compared the Taitema Lake Basin with the Aral Sea Basin in Central Asia, representative of terminal lake basins with and without EWC, respectively. The results show that the water area of Taitema Lake increased by 7.23 km2/year due to EWC (2000–2019), whereas that of the Aral Sea Basin decreased by 98.21% over the entire process of natural evolution (1972–2019). Land use changes before and after the EWC (1990–2019) included an increase and decrease in desert land and water bodies in the Aral Sea Basin, and a decrease and increase in desert land and arable land in the Tarim River Basin, respectively. The normalized difference vegetation index (NDVI) and actual evaporation (ETa) are the main factors influencing the change in the water area of the Aral Sea Basin with the changing environment, while EWC is the main factor influencing the change in the water area of Taitema Lake. The results confirm that EWC is a feasible measure for achieving ecological restoration of a terminal lake watershed in an arid area.

Xiuyun YangXiuyun Yang
Xiuyun Yang
EZIZ MamattursunEZIZ Mamattursun
EZIZ Mamattursun
AHAdila Hayrat
Adila Hayrat
Xiaofei MaXiaofei Ma
Xiaofei Ma
Wei YanWei Yan
Wei Yan
YWYifan Wang
Yifan Wang
High concentrations of heavy metals (HMs) in urban surface dust (USD) can be extremely hazardous to urban ecology and human health. Oasis cities are located at the edge of deserts and are more exposed to salt/sandstorms, and they face a significantly higher accumulation of USD than wet or semi-humid areas. However, systematic studies on the pollution and risk assessment of HMs in USD in oasis cities have rarely been conducted. This study systematically analyzed the enrichment status, spatial distribution, pollution levels, health risks, and sources of HMs in USD in a typical oasis city (Changji city). The results showed that the average concentrations of Pb, Ni, As, Cd, Hg, and Cu in the USD of Changji city were 46.83, 26.35, 9.92, 0.21, 0.047, and 59.33 mg/kg, respectively, and the results of the pollution index evaluation showed moderate Pb, Hg, and Cu pollution, mild Cd pollution, and no Ni or As pollution. The spatial distribution of HM concentrations in the USD was substantially heterogeneous. High values of Pb, Hg, and Cu concentrations were mainly observed in areas with relatively intensive transportation and commercial activities, and high values of Cd and Ni were observed in industrial areas. The health risk assessment showed that HMs do not pose non-carcinogenic risks to humans at their current level, but they pose a carcinogenic risk to children, with As contributing the largest carcinogenic and non-carcinogenic risks. The source identification of HMs showed that the main pollution of HMs were traffic sources for Pb and Cu, industrial sources for Ni and Cd, natural sources for As, and coal-fired sources for Hg. According to the results of the quantitative analysis with the positive matrix factorization, the contribution of pollution sources followed this order: industrial sources (31.08%) > traffic sources (26.80%) > coal-fired sources (23.31%) > natural sources (18.81%).

12 July 2023 in Remote Sensing
Verified
Journal Article
Open access
PDF file
SXShixian Xu
Shixian Xu
原苏原 苏
原 苏
Wei YanWei Yan
Wei Yan
YLyuan liu
yuan liu
YongHui WangYongHui Wang
YongHui Wang
Xiaofei MaXiaofei Ma
Xiaofei Ma
Ecosystem services (ESs) are important for supporting human development. However, a changing climate and anthropogenic impacts are resulting in the degradation of dryland ecosystems to varying degrees. While there has been the global implementation of Ecological Restoration Programs (ERPs) to restore degraded ecosystems, there remains limited comprehensive assessment of their impacts on ESs of drylands. In this study, the sandy areas of northern China were used as the study area. The RUSLE, RWEQ, CASA, and InVEST models were used to simulate four major ESs: soil conservation (SC), sand fixation (SF), carbon sequestration (CS), and water yield (WY). The study aimed to evaluate the influences of various ERPs on major ESs. The dominant factors affecting the overall benefits provided by ESs were also identified. Since ERPs were implemented, forest areas have increased by 2.8 × 104 km2, whereas the areas of cropland, shrubland, and grassland have decreased. There were generally increasing trends in SF, SC, and CS, whereas there was a decreasing trend in WY. We then used a scenario-based simulation approach to eliminate the influence of climate variability on ESs. The results showed increasing trends in SF, SC, and CS, whereas there were minimal changes in WY. The results suggested that although ERPs can significantly increase regional ESs, unregulated expansion in vegetation can result in a water crisis and affect regional water security.

6 March 2024 in Sustainability
Verified
Journal Article
Open access
PDF file
YLyuan liu
yuan liu
SLSihai Liu
Sihai Liu
KXKun Xing
Kun Xing
This research focuses on the Kriya River Basin and analyzes the spatiotemporal variability of ecosystem services (ESs) and their trade-offs and synergies, which are vital for regional ecosystem conservation and socio-economic sustainability. Utilizing land use data from 1990 to 2020 and predictive models for 2030 (PLUS for land use and InVEST for ESs), the study assesses four key ESs: water yield (WY), soil conservation (SC), habitat quality (HQ), and carbon storage (CS). The findings indicate that land use changes from 1990 to 2020 have significantly impacted these services. WY showed a negative trend because of a reduction in precipitation, while increased grasslands enhanced SC, HQ, and CS. Projections for 2030 suggest increases in WY and SC, with increases of 10.27 × 108 m3 in WY and 0.216 × 108 t in SC, but slight decreases in HQ and CS due to urban land expansion. Therefore, land types that provide important ESs should be protected in future planning, and the expansion of construction land should be controlled in order to realize the goal of ecological conservation. Our study also reveals that while WY and CS share a subtle trade-off, they both synergize with SC and HQ. Strong synergies exist between SC and HQ as well as between SC and CS, indicating lesser concerns for trade-offs in future planning. This research provides valuable data support and scientific insight for sustainable development and ecological governance policies in the watershed.