The constraints and driving forces of oasis development in arid region: a case study of the Hexi Corridor in northwest China

Abstract The oasis, a special landscape with the integration of nature and humanity in the arid region, has undergone an enormous transformation during the past decades. To gain a better understanding of the tradeoff between economic growth and oases stability in the arid land, we took the oases in the Hexi Corridor as a case to explore the constraints of oases development and the driving factors of oases expansion. The dynamic changes and spatial distribution patterns underwent by the oases were examined using multispectral remote sensing imagery. The constraints of oasis development in arid land were investigated by the grid-transformed model, as well as the index system of driving forces was analyzed using the grey incidence model based on the data from statistics yearbooks. The oasis area in the Hexi Corridor had tremendous changes expanded 40% from 1986 to 2015, the stable oasis area was 9062 km2, while the maximum area reached 16,374 km2. The constraints for oases of topography, hydrology and heat condition are as follow: The elevation of oasis ranged from 1000 to 1800 m, peaked in 1500 m; the slope of oasis distribution was flatter than 3 degrees; the aspect of oases on slope land concentrated in northeast and north, accounting for more than 60%. The main driving forces of oasis spatial expansion in the arid region were population, water resource, economy, policies, and other factors. These results are expected to (1) improve the rationality of oasis development, and (2) promote the sustainable planning and management of oases in the arid land.

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Biodiversity of wild alfalfa pollinators and their temporal foraging characters in Hexi Corridor, Northwest China

Entomologica Fennica ◽

10.33338/ef.84561 ◽

2019 ◽

Vol 23 (1) ◽

pp. 4-12 ◽

Cited By ~ 2

Author(s):

Xiaojuan Wang ◽

Hongping Liu ◽

Lichun Huang ◽

Shuzhen Zhang ◽

Zhigang Deng ◽

...

Keyword(s):

Distribution Patterns ◽

Northwest China ◽

Hexi Corridor ◽

Wild Bees ◽

Community Function ◽

Native Bee ◽

Diurnal Distribution ◽

Medicago Sativa L ◽

Insect Visitors ◽

Effective Distribution

Seed production of alfalfa (Medicago sativa L.) is important in determining the effective distribution of new cultivars to farmers. However, little is known about the biodiversity and their community function of native wild pollinators of alfalfa in agronomic systems. We investigated the biodiversity of insects which visited alfalfa flowers and their temporal foraging characters in Hexi Corridor, China. A high biodiversity of insect visitors was discovered, 20 insect taxa in all, including 13 species of Hymenoptera, 3 species of Coleoptera, 3 species of Lepidoptera and 1 species of Diptera. Three native bee species, Andrena squamata, Anthophora melanognatha and Megachile abluta,were validated as the principal pollinators. They showed significant variations in tripping mode and their diurnal distribution patterns. Our results indicated that the native wild bees are diverse and they complement each other. This means they have developed a more complex system for the pollination of alfalfa than has been previously found out.

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Shielding effect of oasis-protection systems composed of various forms of wind break on sand fixation in an arid region: A case study in the Hexi Corridor, northwest China

Ecological Engineering ◽

10.1016/j.ecoleng.2008.02.010 ◽

2008 ◽

Vol 33 (2) ◽

pp. 119-125 ◽

Cited By ~ 44

Author(s):

Wenzhi Zhao ◽

Guanglu Hu ◽

Zhihui Zhang ◽

Zhibin He

Keyword(s):

Arid Region ◽

Northwest China ◽

Hexi Corridor ◽

Shielding Effect ◽

Protection Systems

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Ecological effects of desertification control and desertified land reclamation in an oasis–desert ecotone in an arid region: A case study in Hexi Corridor, northwest China

Ecological Engineering ◽

10.1016/j.ecoleng.2005.10.015 ◽

2007 ◽

Vol 29 (2) ◽

pp. 117-124 ◽

Cited By ~ 120

Author(s):

Yong Zhong Su ◽

Wen Zhi Zhao ◽

Pei Xi Su ◽

Zhi Hui Zhang ◽

Tao Wang ◽

...

Keyword(s):

Arid Region ◽

Land Reclamation ◽

Northwest China ◽

Hexi Corridor ◽

Ecological Effects ◽

Desertification Control

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Vegetation Change and Its Response to Climate Extremes in the Arid Region of Northwest China

Remote Sensing ◽

10.3390/rs13071230 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1230

Author(s):

Simeng Wang ◽

Qihang Liu ◽

Chang Huang

Keyword(s):

Arid Region ◽

Vegetation Change ◽

Vegetation Index ◽

Pearson Correlation ◽

Time Lag ◽

Climate Extremes ◽

Northwest China ◽

Precipitation Extremes ◽

Temperature Extremes ◽

Increasing Trend

Changes in climate extremes have a profound impact on vegetation growth. In this study, we employed the Moderate Resolution Imaging Spectroradiometer (MODIS) and a recently published climate extremes dataset (HadEX3) to study the temporal and spatial evolution of vegetation cover, and its responses to climate extremes in the arid region of northwest China (ARNC). Mann-Kendall test, Anomaly analysis, Pearson correlation analysis, Time lag cross-correlation method, and Least absolute shrinkage and selection operator logistic regression (Lasso) were conducted to quantitatively analyze the response characteristics between Normalized Difference Vegetation Index (NDVI) and climate extremes from 2000 to 2018. The results showed that: (1) The vegetation in the ARNC had a fluctuating upward trend, with vegetation significantly increasing in Xinjiang Tianshan, Altai Mountain, and Tarim Basin, and decreasing in the central inland desert. (2) Temperature extremes showed an increasing trend, with extremely high-temperature events increasing and extremely low-temperature events decreasing. Precipitation extremes events also exhibited a slightly increasing trend. (3) NDVI was overall positively correlated with the climate extremes indices (CEIs), although both positive and negative correlations spatially coexisted. (4) The responses of NDVI and climate extremes showed time lag effects and spatial differences in the growing period. (5) Precipitation extremes were closely related to NDVI than temperature extremes according to Lasso modeling results. This study provides a reference for understanding vegetation variations and their response to climate extremes in arid regions.

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Diversity and Spatiotemporal Dynamics of Fungal Communities in the Rhizosphere Soil of Cotton in the Arid Region of Northwest China

Microbial Ecology ◽

10.1007/s00248-020-01646-y ◽

2021 ◽

Author(s):

YingWu Shi ◽

HongMei Yang ◽

Ming Chu ◽

XinXiang Niu ◽

XiangDong Huo ◽

...

Keyword(s):

Arid Region ◽

Rhizosphere Soil ◽

Northwest China ◽

Spatiotemporal Dynamics ◽

Fungal Communities

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High-Resolution Monitoring and Assessment of Evapotranspiration and Gross Primary Production Using Remote Sensing in a Typical Arid Region

Land ◽

10.3390/land10040396 ◽

2021 ◽

Vol 10 (4) ◽

pp. 396

Author(s):

Junxia Yan ◽

Yanfei Ma ◽

Dongyun Zhang ◽

Zechen Li ◽

Weike Zhang ◽

...

Keyword(s):

Remote Sensing ◽

High Resolution ◽

Land Surface ◽

Arid Region ◽

Management Practices ◽

Gross Primary Production ◽

Irrigation District ◽

Heihe River ◽

Freshwater Resource ◽

Oasis Area

Land surface evapotranspiration (ET) and gross primary productivity (GPP) are critical components in terrestrial ecosystems with water and carbon cycles. Large-scale, high-resolution, and accurately quantified ET and GPP values are important fundamental data for freshwater resource management and help in understanding terrestrial carbon and water cycles in an arid region. In this study, the revised surface energy balance system (SEBS) model and MOD17 GPP algorithm were used to estimate daily ET and GPP at 100 m resolution based on multi-source satellite remote sensing data to obtain surface biophysical parameters and meteorological forcing data as input variables for the model in the midstream oasis area of the Heihe River Basin (HRB) from 2010 to 2016. Then, we further calculated the ecosystem water-use efficiency (WUE). We validated the daily ET, GPP, and WUE from ground observations at a crop oasis station and conducted spatial intercomparisons of monthly and annual ET, GPP, and WUE at the irrigation district and cropland oasis scales. The site-level evaluation results show that ET and GPP had better performance than WUE at the daily time scale. Specifically, the deviations in the daily ET, GPP, and WUE data compared with ground observations were small, with a root mean square error (RMSE) and mean absolute percent error (MAPE) of 0.75 mm/day and 26.59%, 1.13 gC/m2 and 36.62%, and 0.50 gC/kgH2O and 39.83%, respectively. The regional annual ET, GPP, and WUE varied from 300 to 700 mm, 200 to 650 gC/m2, and 0.5 to 1.0 gC/kgH2O, respectively, over the entire irrigation oasis area. It was found that annual ET and GPP were greater than 550 mm and 500 gC/m2, and annual oasis cropland WUE had strong invariability and was maintained at approximately 0.85 gC/kgH2O. The spatial intercomparisons from 2010 to 2016 revealed that ET had similar spatial patterns to GPP due to tightly coupled carbon and water fluxes. However, the WUE spatiotemporal patterns were slightly different from both ET and GPP, particularly in the early and late growing seasons for the oasis area. Our results demonstrate that spatial full coverage and reasonably fine spatiotemporal variation and variability could significantly improve our understanding of water-saving irrigation strategies and oasis agricultural water management practices in the face of water shortage issues.

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Climatic Warming and Humidification in the Arid Region of Northwest China: Multi-Scale Characteristics and Impacts on Ecological Vegetation

Journal of Meteorological Research ◽

10.1007/s13351-021-0105-3 ◽

2021 ◽

Vol 35 (1) ◽

pp. 113-127

Author(s):

Qiang Zhang ◽

Jinhu Yang ◽

Wei Wang ◽

Pengli Ma ◽

Guoyang Lu ◽

...

Keyword(s):

Arid Region ◽

Northwest China ◽

Climatic Warming ◽

Multi Scale ◽

Scale Characteristics

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Multi-Temporal Arable Land Monitoring in Arid Region of Northwest China Using a New Extraction Index

Sustainability ◽

10.3390/su13095274 ◽

2021 ◽

Vol 13 (9) ◽

pp. 5274

Author(s):

Xinyang Yu ◽

Younggu Her ◽

Xicun Zhu ◽

Changhe Lu ◽

Xuefei Li

Keyword(s):

Arable Land ◽

Ground Truth ◽

Northwest China ◽

Hexi Corridor ◽

Ground Truth Data ◽

Land Protection ◽

Promising Tool ◽

Study Results ◽

Multi Temporal ◽

The Mean

Development of a high-accuracy method to extract arable land using effective data sources is crucial to detect and monitor arable land dynamics, servicing land protection and sustainable development. In this study, a new arable land extraction index (ALEI) based on spectral analysis was proposed, examined by ground truth data, and then applied to the Hexi Corridor in northwest China. The arable land and its change patterns during 1990–2020 were extracted and identified using 40 Landsat TM/OLI images acquired in 1990, 2000, 2010, and 2020. The results demonstrated that the proposed method can distinguish arable land areas accurately, with the User’s (Producer’s) accuracy and overall accuracy (kappa coefficient) exceeding 0.90 (0.88) and 0.89 (0.87), respectively. The mean relative error calculated using field survey data obtained in 2012 and 2020 was 0.169 and 0.191, respectively, indicating the feasibility of the ALEI method in arable land extracting. The study found that arable land area in the Hexi Corridor was 13217.58 km2 in 2020, significantly increased by 25.33% compared to that in 1990. At 10-year intervals, the arable land experienced different change patterns. The study results indicate that ALEI index is a promising tool used to effectively extract arable land in the arid area.

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