scholarly journals Characterizing the Topographic Changes and Land Subsidence Associated with the Mountain Excavation and City Construction on the Chinese Loess Plateau

2021 ◽  
Vol 13 (8) ◽  
pp. 1556
Author(s):  
Chuanhao Pu ◽  
Qiang Xu ◽  
Kuanyao Zhao ◽  
Yanan Jiang ◽  
Lina Hao ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
Ground Deformation ◽  
Urban Expansion ◽  
Chinese Loess Plateau ◽  
Rapid Urbanization ◽  
Chinese Loess ◽  
City Construction ◽  
Large Scale Land ◽  
The Chinese Loess Plateau

A mega project, Mountain Excavation and City Construction (MECC), was launched in the hilly and gully region of the Chinese Loess Plateau in 2012, in order to address the shortage of available land and create new flat land for urban construction. However, large-scale land creation and urban expansion significantly alters the local geological environment, leading to severe ground deformation. This study investigated the topographic changes, ground deformation, and their interactions due to the MECC project in the Yan’an New District (YND). First, new surface elevations were generated using ZiYuan-3 (ZY-3) stereo images acquired after the construction in order to map the local topographic changes and the fill thickness associated with the MECC project. Then, the interferometric synthetic aperture radar (InSAR) time series and 32 Sentinel-1A images were used to assess the spatial patterns of the ground deformation in the YND during the postconstruction period (2017–2018). By combining the InSAR-derived results and topographic change features, the relationship between the ground deformation and large-scale land creation was further analyzed. The results indicated that the MECC project in the YND has created over 22 km2 of flat land, including 10.8 km2 of filled area, with a maximum fill thickness of ~110 m. Significant uneven ground deformation was detected in the land-creation area, with a maximum subsidence rate of approximately 121 mm/year, which was consistent with the field survey. The strong correlation between the observed subsidence patterns and the land creation project suggested that this recorded uneven subsidence was primarily related to the spatial distribution of the filling works, along with the changes in the thickness and geotechnical properties of the filled loess; moreover, rapid urbanization, such as road construction, can accelerate the subsidence process. These findings can guide improvements in urban planning and the mitigation of geohazards in regions experiencing large-scale land construction.

Using ecosystem service bundles to evaluate spatial and temporal impacts of large-scale landscape restoration on ecosystem services on the Chinese Loess Plateau

2021 ◽  
Author(s):  
Hao Chen ◽  
Luuk Fleskens ◽  
Johanna Schild ◽  
Simon Moolenaar ◽  
Fei Wang ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Loess Plateau ◽  
Large Scale ◽  
Chinese Loess Plateau ◽  
Water Yield ◽  
Timber Production ◽  
Sediment Retention ◽  
Chinese Loess ◽  
Trade Offs ◽  
The Chinese Loess Plateau

<p>From 1999 onwards, China has initiated a large-scale landscape restoration project on the Chinese Loess Plateau, which has had profound but variable impacts on the local ecosystem services supply. In this study, we evaluate the spatial and temporal dynamics in 11 ecosystem services in the Yan’an area on the Chinese Loess Plateau from 1990 to 2018 based on the InVEST model and statistical yearbook data. To consider trade-offs and synergies between ecosystem services, the concept of ecosystem service bundles was used to understand the dynamics of ecosystem services. A significant increase of fruit production, sediment retention, habitat quality, aesthetic landscape value as well as learning and inspiration value was found over time in Yan’an area, while a decrease of timber production and water yield was also observed. Synergistic relations were found between sediment retention, carbon sequestration, habitat quality and outdoor recreation, while trade-offs were observed between timber production and water yield. The majority of ecosystem services bundles of Yan’an area were transformed from having a focus on timber production to aesthetic landscape value. The dynamics of ecosystem services change by land restoration was discovered, to start with increasing regulating services at expense of provisioning services, cultural services exceeding regulating services and occupied the main proportion subsequently. The most obvious change was observed in 2000, coinciding with the start of large-scale restoration activities. The implementation of the large-scale restoration project is recognized as a key driving force inducing these changes. Based on the results, it is recommended that the Yan’an government pays attention to local water resource management and timber supply.</p>

scholarly journals Changes in soil water holding capacity and water availability following vegetation restoration on the Chinese Loess Plateau

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong-wang Zhang ◽  
Kai-bo Wang ◽  
Jun Wang ◽  
Changhai Liu ◽  
Zhou-ping Shangguan
Keyword(s):  
Land Use ◽  
Soil Water ◽  
Loess Plateau ◽  
Soil Layer ◽  
Soil Physical Properties ◽  
Chinese Loess Plateau ◽  
Land Use Type ◽  
Chinese Loess ◽  
Water Holding ◽  
The Chinese Loess Plateau

AbstractChanges in land use type can lead to variations in soil water characteristics. The objective of this study was to identify the responses of soil water holding capacity (SWHC) and soil water availability (SWA) to land use type (grassland, shrubland and forestland). The soil water characteristic curve describes the relationship between gravimetric water content and soil suction. We measured the soil water characteristic parameters representing SWHC and SWA, which we derived from soil water characteristic curves, in the 0–50 cm soil layer at sites representing three land use types in the Ziwuling forest region, located in the central part of the Loess Plateau, China. Our results showed that the SWHC was higher at the woodland site than the grassland and shrubland, and there was no significant difference between the latter two sites, the trend of SWA was similar to the SWHC. From grassland to woodland, the soil physical properties in the 0–50 cm soil layer partially improved, BD was significantly higher at the grassland site than at the shrubland and woodland sites, the clay and silt contents decreased significantly from grassland to shrubland to woodland and sand content showed the opposite pattern, the soil porosity was higher in the shrubland and woodland than that in the grassland, the soil physical properties across the 0–50 cm soil layer improved. Soil texture, porosity and bulk density were the key factors affecting SWHC and SWA. The results of this study provide insight into the effects of vegetation restoration on local hydrological resources and can inform soil water management and land use planning on the Chinese Loess Plateau.

Drought variation trends in different subregions of the Chinese Loess Plateau over the past four decades

2012 ◽  
Vol 115 ◽  
pp. 167-177 ◽  
Author(s):  
Baoqing Zhang ◽  
Pute Wu ◽  
Xining Zhao ◽  
Yubao Wang ◽  
Jiawen Wang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Chinese Loess Plateau ◽  
Chinese Loess ◽  
The Past ◽  
Variation Trends ◽  
The Chinese Loess Plateau
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