scholarly journals Assessing Controversial Desertification Prevention Policies in Ecologically Fragile and Deeply Impoverished Areas: A Case Study of Marginal Parts of the Taklimakan Desert, China

Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 641
Author(s):  
Shidong Liu ◽  
Jianjun Zhang ◽  
Jie Zhang ◽  
Zheng Li ◽  
Yuhuan Geng ◽  
...  
Keyword(s):  
Sustainability Assessment ◽  
Control Policy ◽  
Site Investigation ◽  
Northwest China ◽  
Rangeland Management ◽  
Taklimakan Desert ◽  
Land Resource ◽  
Prevention Policy ◽  
Ecological Compensation ◽  
Desertification Control

Overgrazing plays an important role in the grassland desertification in global drylands. The effectiveness of policies related to grazing directly affects efforts to combat desertification and sustainable rangeland management. However, there remain questions around how the interplay of grassland desertification and poverty affects the implementation of policies. To reveal the effectiveness of the desertification prevention policy that delineates national key ecological function areas (NKEFAs), the main objective was to perform a sustainability assessment and on-site investigation in Northwest China. A parallel index system, which integrates the indices for economic input–output and material supply–demand to represent sustainability, and the indices for interview records from managers and questionnaires from residents to represent the effectiveness of NKEFA policy, was proposed to comprehensively judge the performance of NKEFA policy, and the underlying causes behind undesirable effects were further analyzed. The results indicate that (1) the performance of desertification control policy is related to socioeconomic conditions—a few counties with increased socioeconomic and land resource sustainability (SLS) are peri-urban or resource-rich; (2) the fact that the socioeconomic benefits of the NKEFA policy are not obvious to impoverished farmers greatly reduces their enthusiasm for preventing desertification; and (3) the livelihood needs and defective ecological compensation force residents with underdeveloped comprehensive quality to overdevelop or use grassland resources even though they have received subsidies for conserving grassland. It is concluded that poverty and grassland desertification interact to influence potential policy performance. Our analysis can help decision makers to formulate desertification control policies with multiple goals to achieve sustainable performance in an economy–ecology system.

Temporal and spatial variations of sandstorm and the related meteorological influences over northern China in the 21st century

2021 ◽  
Author(s):  
Jie Yang ◽  
Tianliang Zhao
Keyword(s):  
Land Surface ◽  
Source Region ◽  
Northern China ◽  
Northwest China ◽  
Gobi Desert ◽  
Taklimakan Desert ◽  
Observation Data ◽  
Average Wind Speed ◽  
Modis Ndvi ◽  
Temporal And Spatial

<p>In this study, we used the sandstorm data of 233 meteorological stations in northern China, conventional meteorological observation data and MODIS-NDVI data in the 40 years from 1980 to 2019 to analyze the spatio-temporal variation of sandstorms in northern China and its related meteorological effects in this century.</p><p>The results show that: 1) The average number of sandstorm days in northern China has been fluctuating and decreasing since the beginning of this century, and increasing from 2017 to 2019. Spring is the main season of dust storm, and the springtime proportion of sandstorm days decreases year by year. 2) In the 1980s and 1990s, sandstorms covered almost covered the whole northwest region; Since the beginning of this century, the range of sandstorm days in the whole Northwest China has shown an obvious decadal downward trend. The spatial pattern of sandstorm days in northern China has been shrinking and moving westward since 2000, and the dominant position of the Gobi Desert in the Asian dust source region has been decreasing year by year. The high sandstorm days were located in the Taklimakan Desert with the increasing trend of sandstorm days year by year. 3) The temporal and spatial variation of sandstorm days in northern China is closely related to the increase of vegetation cover with the greenness and wetness of the land surface, the decreases of average wind speed and gale days, and the significant increase of annual precipitation in northern China after 2000.</p>

scholarly journals The Impacts of Taklimakan Dust Events on Chinese Urban Air Quality in 2015

Atmosphere ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 281 ◽  
Author(s):  
Xiaoyu Li ◽  
Xiaodong Liu ◽  
Zhi-Yong Yin
Keyword(s):  
Air Quality ◽  
Dust Storm ◽  
Northwest China ◽  
Urban Air Quality ◽  
Urban Air ◽  
Taklimakan Desert ◽  
The Taklimakan Desert ◽  
Pm10 And Pm2.5 ◽  
Dust Events ◽  
Mass Concentrations

Aerosols are an important factor affecting air quality. As the largest source of dust aerosol of East Asia, the Taklimakan Desert in Northwest China witnesses frequent dust storm events, which bring about significant impacts on the downstream air quality. However, the scope and timing of the impacts of Taklimakan dust events on Chinese urban air quality have not yet been fully investigated. In this paper, based on multi-source dust data including ground observations, satellite monitoring, and reanalysis products, as well as air quality index (AQI) and the mass concentrations of PM10 and PM2.5 at 367 urban stations in China for 2015, we examined the temporal and spatial characteristics of the impacts of the Taklimakan dust events on downstream urban air quality in China. The results show that the Taklimakan dust events severely affected the air quality of most cities in Northwest China including eastern Xinjiang, Hexi Corridor and Guanzhong Basin, and even northern Southwest China, leading to significant increases in mass concentrations of PM10 and PM2.5 in these cities correlating with the occurrence of dust events. The mass concentrations of PM10 on dust days increased by 11–173% compared with the non-dust days, while the mass concentration of PM2.5 increased by 21–172%. The increments of the mass concentrations of PM10 and PM2.5 on dust days decreased as the distances increased between the cities and the Taklimakan Desert. The influence of the Taklimakan dust events on the air quality in the downstream cities usually persisted for up to four days. The mass concentrations of PM10 and PM2.5 increased successively and the impact duration shortened gradually with increasing distances to the source area as a strong dust storm progressed toward the southeast from the Taklimakan Desert. The peaks of the PM10 concentrations in the downstream cities of eastern Xinjiang, the Hexi Corridor and the Guanzhong Basin occurred on the second, third and fourth days, respectively, after the initiation of the Taklimakan dust storm.

Petri Net Channelized-Based Deadlock Prevention Policy for Flexible Manufacturing Systems

2011 ◽  
Vol 317-319 ◽  
pp. 552-555
Author(s):  
Yi Sheng Huang ◽  
Ter Chan Row
Keyword(s):  
Control System ◽  
Petri Net ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Original Model ◽  
Deadlock Prevention ◽  
Prevention Policy ◽  
Maximal Permissiveness

Petri nets are employed to model flexible manufacturing systems (FMSs). However, the system deadlocked are possible happened. The conventional deadlock prevention policies are always to forbid the system entering the deadlock by using the control places. To obtain a live system, some dead markings must be sacrificed in the traditional policies. Therefore, the original reachability states of the original model can not be conserved. However, this paper is able to maintain all the reachability states of the original net and guaranty the control system live. Under our control policy, all number of reachability states of the original net will be preserved. Finally, two examples are performed that can reach the maximal permissiveness for FMSs using Petri net models (PNMs).

Land take in the Italian Alps

2014 ◽  
Vol 25 (4) ◽  
pp. 407-420 ◽  
Author(s):  
Stefano Salata
Keyword(s):  
Decision Making ◽  
Land Use ◽  
Land Use Changes ◽  
Local Scale ◽  
Land Resource ◽  
Ecological Compensation ◽  
Content Type ◽  
Soil Sealing ◽  
Alpine Regions ◽  
Land Use Decisions

Purpose – Land use change in the Alpine Regions is dominated by two main factors: a process of re-naturalization and a process of expansion for settlements with the relevant occupation of low-valley areas. The purpose of this paper is to present an overview of land take measures in the Lombardy Alpine context and the recent proposals of spatial planning instruments for land resource management. New solutions to limit soil sealing have to be confronted with qualitative proposals at local scale. Design/methodology/approach – The paper collects different research outputs regarding land take in the Italian Alpine context and carried out by GIS software and tries to show the new methodologies available for limiting and mitigating soil sealing, in accordance with DIAMONT aims. Findings – The paper argues that the data are now available to analyze the problem and new operative methods have to be settled in the recent context of European Union (Soil Sealing Guidelines) to support decision making in planning, suggesting land use allocation and possible ecological compensation. Research limitations/implications – The new qualitative decision models have to be assessed for a better ecological integration in supporting land use decisions. Practical implications – An evaluation of land take at local scale caused by land use changes is a good support in the decision-making process of planning. Originality/value – In this paper a method based on a local scale is reported, which can be used for the specific assessment of land take in order to support land-use decisions.

scholarly journals The challenge and future of rocky desertification control in karst areas in southwest China

Solid Earth ◽  
2016 ◽  
Vol 7 (1) ◽  
pp. 83-91 ◽  
Author(s):  
J. Y. Zhang ◽  
M. H. Dai ◽  
L. C. Wang ◽  
C. F. Zeng ◽  
W. C. Su
Keyword(s):  
Southwest China ◽  
Scientific Research ◽  
Lessons Learned ◽  
Dynamic Monitoring ◽  
Chinese Government ◽  
Second Phase ◽  
Karst Rocky Desertification ◽  
Ecological Compensation ◽  
Rocky Desertification ◽  
Desertification Control

Abstract. Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. Karst rocky desertification is found in humid areas in southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarise the lessons learned over the last 10 years of the first phase. In this paper, we analyse the driving social and economic factors behind rocky desertification, summarise the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, scientific research, and China's economic development and urbanisation process. These suggestions include promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies.

A Channelized Deadlock Prevention Policy for Flexible Manufacturing Systems Using Petri Net Models

2011 ◽  
Vol 284-286 ◽  
pp. 1498-1501
Author(s):  
Yi Sheng Huang ◽  
Ter Chan Row
Keyword(s):  
Petri Net ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Deadlock Avoidance ◽  
Deadlock Prevention ◽  
Deadlock Detection ◽  
Prevention Policy ◽  
Maximal Permissiveness

Deadlock prevention, deadlock detection and deadlock avoidance strategies are used to solve the deadlock problems of flexible manufacturing systems (FMSs). The conventional prevention policies were always attempt to prevent the system entering the deadlocked situation by using a few control places. On can know that one prohibits the deadlocked markings, some dead markings will be sacrificed. Therefore, the reachability states will become less than the initial net. However, our goal is to preserve all the reachability states of the initial net. Under our control policy, the deadlocks or deadlock zone will be channelized to live markings such that all the dead markings in reachability states will be conserved. Finally, an example is performed and can obtain the maximal permissiveness of a Petri net model. The other examples are all getting the same result. To our knowledge, this is the first work that employs the channelized method to prevent the deadlock problem for FMSs.

Duststorm-Facilitated Improvement of the Photosynthetic Efficiency of Tamarix ramosissima L. in the Oasis-Desert Ecotone, Northwest China

2012 ◽  
Vol 518-523 ◽  
pp. 5035-5039
Author(s):  
Wei Han ◽  
Ling Cao ◽  
Haimid Yimit
Keyword(s):  
Photosynthetic Efficiency ◽  
Weather Conditions ◽  
Northwest China ◽  
Tamarix Ramosissima ◽  
Taklimakan Desert ◽  
Chl A ◽  
Fluorescence Parameters ◽  
Mature Leaves ◽  
Chl A Fluorescence ◽  
Maximum Period

The photosynthetic efficiency of Tamarix ramosissima Ledeb., one of the major natural plants in the southern oasis-desert ecotone of the Taklimakan Desert, was investigated to assess the ecological effects of duststorms on T ramosissima Ledeb. We measured daily chlorophyll a (Chl a) fluorescence parameters of mature leaves of healthy 10-years old T. ramosissima L. during months of July and August in 2008, using a portable modulated Chl a fluorometer PAM-2100 and three duststorm days were singled out to assess the affects of duststorms on the photosynthetic efficiency. Our results showed that duststorms increased the energy absorption and the increased absorption then enhanced the photosynthetic efficiency of T. ramosissima L. under duststorm weather conditions. Our results also showed that the qP (quenching coefficients for photosynthesis) was significantly decreased and qN (quenching coefficients for non-photosynthesis) was significantly increased during the maximum period of solar readiation between 14:00 and 16:00 under normal conditions, implying that stress might occur in normal weather conditions, but lowered stress to T ramosissima Ledeb. during duststorm weather conditions. In a word, duststorm-facilitated might provide favorable opportunities for constructing and expansing oasis-desert ecotone.

scholarly journals The Performance of a Scale-Aware Nonlocal PBL Scheme for the Subkilometer Simulation of a Deep CBL over the Taklimakan Desert

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hongxiong Xu ◽  
Yinjun Wang ◽  
Minzhong Wang
Keyword(s):  
Boundary Layer ◽  
Wrf Model ◽  
Northwest China ◽  
Taklimakan Desert ◽  
Convective Boundary ◽  
Eddy Simulation ◽  
The Taklimakan Desert ◽  
Realistic Representation ◽  
Pbl Scheme ◽  
Convective Cells

Although realistic representation of the convective boundary layer (CBL) in the desert region in Northwest China is important for weather forecasts and climate simulations, evaluations of the performance of various planetary boundary layer (PBL) schemes in simulating the CBL in the region are rare. In this study, the performance of a scale-aware PBL scheme newly implemented into the Weather Research and Forecasting (WRF) model in simulating the CBL in the Taklimakan desert is evaluated based on a comparison with both the WRF-LES simulations and observations, with the focus on scale dependencies of the simulations compared to the conventional PBL scheme. A series of simulations are performed with a scale-aware PBL scheme (Shin-Hong) and the conventional PBL scheme (YSU) for a deep CBL observed at Tazhong station in the central Taklimakan on 1 July 2016. The CBL was over 5000 m deep with wider and deeper rolls than in a shallow boundary layer. The results showed that the vertical structure simulated with the Shin-Hong scheme was closer to that in both the WRF-LES (large-eddy-simulation) and observations than that simulated with the YSU. The simulation with the scale-aware scheme reproduced cellular rolls similar to those in the WRF-LES, while the conventional PBL scheme struggled to trigger intense convective cells rather than cellular rolls. The results strongly suggest that the scale-aware nonlocal PBL scheme can be used to adequately reproduce the scale and evolution of the observed rolls in the deep CBL in Taklimakan desert at subkilometer resolutions.

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