Desertification Change Research Articles

西南典型喀斯特地区石漠化时空演变特征——以贵州省普定县为例

PDF HTML阅读 XML下载 导出引用 引用提醒 西南典型喀斯特地区石漠化时空演变特征——以贵州省普定县为例 DOI: 10.5846/stxb201806011216 作者: 作者单位: 中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所,中国科学院地球化学研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划（2016YFC0502102）；中国科学院科技服务网络计划（KFJ-STS-ZDTP-036）；"西部之光"人才培养计划（A类）（〔2018〕X）；贵州省科技计划（2017-2966） Spatio-temporal characteristics of rocky desertification in typical Karst areas of Southwest China: A case study of Puding County, Guizhou Province Author: Affiliation: Institute of Geochemistry,,State Key Laboratory of environmental geochemistry,,,,,,,,,, Fund Project: National key research program of China (No. 2016YFC0502102 & 2016YFC0502300), 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为揭示我国西南典型喀斯特地区石漠化时空演变特征，选取贵州省普定县为研究对象，基于Landsat、DEM等影像数据，提取了坡度和4期植被覆盖度、岩石裸露率分布图，并利用地理探测器获得各自的贡献率，反演了1990-2015年4期石漠化空间分布信息，进而讨论了石漠化时空演变特征。结果表明：（1）在1990-2015年间，普定县石漠化演变复杂，经历了由好转到恶化再到好转的阶段，总体趋势在好转，局部恶化，石漠化治理仍需加大力度；（2）中度以上石漠化集中分布在三岔河沿岸附近，轻度以下石漠化则分布较散乱；（3）潜在和轻度石漠化演变方向复杂，潜在石漠化平均变化速率最大（2.75 km2/a），在1997-2006年间更是达到了16.5 km2/a；（4）植被覆盖度与岩石裸露率的变化主要呈负相关，前者的增加主导了石漠化的好转，而后者的增加则控制了石漠化的恶化；（5）石漠化演变存在突变，在三岔河沿岸附近，存在无/潜在石漠化突变为重度以上石漠化的现象；在靠近城乡居民地附近，存在重度以上石漠化突变为无/潜在石漠化的现象；（6）植被覆盖度、岩石裸露率、坡度能较准确反演石漠化，贡献率分别为44%、42%、14%。本文提供的石漠化反演方法快速高效，制作的图件、数据为同行提供了参考，得出的结论为石漠化治理提供了科学支撑。 Abstract:To reveal the spatiotemporal evolution characteristics of rocky desertification in the typical Karst region of Southwest China, we selected Puding County of Guizhou Province as the research subject. Based on Landsat and DEM image data, we extracted the Slope and the four-stage Fractional Vegetation Coverage and the Rock exposedness rate distribution map; then, we used geo-detectors to obtain their respective contribution rates, and retrieved the spatial distribution information for the four stages of rocky desertification in 1990-2015. Finally, we discussed the temporal and spatial evolution of characteristics of rocky desertification. The results showed that:(1) In the period of 1990-2015, the evolution of rocky desertification in Puding County was complex, it ranged from good to deterioration and then back to improvement, but the overall trend was improving with local deterioration, so the control of rocky desertification still needs to be intensified; (2) Moderate rocky desertification was concentrated in the vicinity of the Sancha River, and the light rocky desertification was distributed. (3) The evolution direction of potential and light rocky desertification were complex, the average change rate of potential rocky desertification was a maximum of 2.75 km2/a, reaching 16.5 km2/a in 1997-2006; (4) Fractional Vegetation Coverage was negatively correlated with the change in Rock exposedness. The increased Fractional Vegetation Coverage led to the improvement of rocky desertification, whereas the increased of Rock exposedness controlled the deterioration of rocky desertification;(5)There was a sudden change in the evolution of rocky desertification, and there was no/potential rocky desertification change to severe rocky desertification near the coast of the Sancha River. Near the urban and rural areas, there was a severe rocky desertification change to no/potential rocky desertification; (6) Fractional Vegetation Coverage, Rock exposedness, and Slope can be used to accurately retrieve rocky desertification, and the contribution rate was 44%, 42%, and 14%, respectively. The inversion method of rocky desertification provided in this paper is fast and efficient, the drawings or data are provided for reference, and the conclusions can provide scientific support for the control of rocky desertification. 参考文献 相似文献 引证文献

Historical grassland desertification changes in the Horqin Sandy Land, Northern China (1985\u20132013)

Since rural reforms in the 1980s, both the state and local governments of China have devoted great efforts to combating desertification through a number of eco-environmental restoration campaigns, resulting in burgeoning contention at all levels of government and sparking public concern. Monitoring and accurately assessing the statuses and trends of grassland desertification are important for developing effective restoration strategies. The Horqin Sandy Land (HSL), a very typical desertified grassland (DG) with better hydrothermal conditions among sandy lands in north China, was recently selected (1985–2013) to assess the spatiotemporal dynamic performances of grassland desertification before and after implementing restoration projects. Landsat images (TM/ETM+/OLI), field investigations and expert review were integrated to form a classification scheme for the HSL. Then, spectral mixture analysis and the decision-tree method were used to extract bare-sand ratios and vegetation cover fraction dynamics. A favourable phenomenon of DG was seen to be reversed in an accelerated pace during 2001–2013, despite challenge from both climatic and anthropogenic factors. However, overexploitation of grassland (especially for farming) and ground water for irrigation has led to remarkable decreases in the ground water level in recent decades, which should be highly concerning regarding the formulation of restoration campaigns in the sandy land.

The relationship between consumer shopping stress and purchase abandonment in task-oriented and recreation-oriented consumers

Shopping is sometimes a source of stress, leading to avoidance coping behavior by consumers. Prior research suggests that store-induced stress makes shopping an adverse experience and thus negatively affects consumers’ purchase likelihood. We propose that consumers’ response to shopping stress depends on their motivational orientation. The greater the in-store stress, the more likely task-oriented consumers are to abandon the trip without making purchases. However, recreation-oriented consumers will be, up to a point, less likely to end the trip. The results of four studies show that the functional relationship between shopping stress and purchase abandonment changes from monotonic and positive for task-oriented consumers to an inverted U-shape for recreation-oriented consumers. Evidence of goal changes provides a process explanation for the differing functional relationships. The results offer an alternative explanation for why people buy or not and suggest approaches to structuring the shopping environment to appeal to both types of consumers.

Assessment and forecasting the desertification changes in the east and south of Isfahan by CA-Markov model

Assessment and forecasting the desertification changes in the east and south of Isfahan by CA-Markov model

A qualitative assessment of desertification change in the Tarfaya basin (Morocco) using panchromatic data of Landsat ETM+ and oli: sand encroachment approach

The purpose of the present work is to assess desertification change in the Tarfaya basin (Morocco) based on quantifying sand dunes mass change at the corridor scale using two Panchromatic bands of Landsat ETM + and OLI with 15 m of resolution covering the study area for ten years (2005–2016). In this work, the sand dunes quantification is qualitative and is based on automatic extraction and classification of sand dunes shape using co-occurence texture filters and Support Vector Machine (SVM) classifier. The statistical results show that the area covered by sand was increased during the last ten years, which reveal that desertification becomes more intense.

Changes in precipitation from 1958 to 2012 in arid and semiarid regions of northern China

We used a precipitation dataset from 1958 to 2012 in arid and semiarid regions of northern China, to look for monotonic trends and 'steps' (abrupt changes) in the trends for annual and seasonal precipitation. We found that annual precipitation during the study period had decreased in semiarid regions, mainly caused by decreasing precipitation during the rainy season, versus increases in eastern arid and western arid regions, mainly caused by increasing precipitation in the pre-rainy season and winter. An abrupt increase in the pre-rainy season precipitation occurred in the semiarid, eastern arid, and western arid regions in the early to mid-1980s, which was consistent with the period when rehabilitation of aeolian desertified land began in these regions. Therefore, the change in pre-rainy season precipitation may have been the key factor responsible for changes in aeolian desertification in arid and semiarid regions of northern China.

Changes in precipitation from 1958 to 2012 in arid and semiarid regions of northern China

We used a precipitation dataset from 1958 to 2012 in arid and semiarid regions of northern China, to look for monotonic trends and 'steps' (abrupt changes) in the trends for annual and seasonal precipitation. We found that annual precipitation during the study period had decreased in semiarid regions, mainly caused by decreasing precipitation during the rainy season, versus increases in eastern arid and western arid regions, mainly caused by increasing precipitation in the pre-rainy season and winter. An abrupt increase in the pre-rainy season precipitation occurred in the semiarid, eastern arid, and western arid regions in the early to mid-1980s, which was consistent with the period when rehabilitation of aeolian desertified land began in these regions. Therefore, the change in pre-rainy season precipitation may have been the key factor responsible for changes in aeolian desertification in arid and semiarid regions of northern China.

Climate Change, Desertification, and Societal Responses along the Mu Us Desert Margin during the Ming Dynasty

Abstract Historical records for the Mu Us Desert margin during the Ming dynasty (1368–1644) and corresponding high-resolution climate proxy records have prompted studies on societal responses to climatic changes in this region. The Mu Us Desert margin is highly sensitive to changes in desertification and biological productivity controlled in part by Asian monsoon variations. Here the existing historical temperature and precipitation records are examined to understand spatiotemporal climate variations and to identify potential mechanisms that have driven desertification in the region over the past 500 years. The focus here is on three severe desertification events that occurred in 1529–46, the 1570s, and 1601–50. The relationships among temperature, precipitation, and desertification indicate that a cold/drought-prone climate drives the desertification process. During the Ming dynasty, this region was one of nine important military districts, where the frontier wall (the Great Wall) and other fortifications were constructed. To maintain the defense system, military officers made a valiant effort to decrease the influence of desertification. However, the human-waged war against nature was largely futile, and local rebellions in the stricken region were spawned by the inability of the government to cope with the severe environmental stresses associated with rapid desertification.

Spatial and temporal changes in desertification in the southern region of the Tengger Desert from 1973 to 2009

The sandy land in the southern region of the Tengger Desert is adjacent to cities and towns, and land desertification poses a threat to the livelihood and production of local residents. To determine dynamic changes in local desertification, five periods (1973, 1987, 1992, 2001, and 2009) of remote sensing data are studied by remote sensing (RS) and geographic information system (GIS). The desert contraction area is primarily centered around three units (Wuwei, Gulang, and Jingtai) and nearby regions of Zhongwei City. The primary desert expansion areas include the west side of Helan Mountain (WSHM), the Central Mountainous Area (CMA), and the eastern and western Zhongwei units far from towns. From 1973 to 2009, the degree of change in the contracting part of the primary desert expansion unit showed an increasing trend; in brief, most of the desert (especially after 2001) has been developing in a direction in which desertification has been gradually controlled. The primary desert expansion areas are less affected by human activity, but they are primarily controlled by natural factors (especially wind and terrain). The desert contraction areas occur around the towns and nearby regions with frequent human activity; desertification is primarily controlled by human factors. With rapid economic development (especially after 2000), the scale of the cultivated area, town, and ecological protection engineering has gradually expanded, and the latter two are primarily built on a previous desert, which is the root cause of the reduction in the desert areas around the towns and the shrinkage toward north of border. Therefore, reasonable and effective human activity in the southern region of the Tengger Desert is playing a crucial role in preventing desertification.

QUANTITATIVE METHODS OF PEDOLOGICAL DROUGHT ANALYSIS IN THE NORTHEASTERN PART OF ROMANIA (1961 – 2006)

In the context of desertification and climate changes, under the pressure of a growing need for food all over the world, the increasing frequency and severity of droughts becomes an intensely debated subject by a great number of stakeholders, scientists, planners and decision makers. The aims of this study are to establish a good correlation between the atmospheric and soil pedological within the northeastern part of Romania, by modeling the role of different soil properties on drought propagation. Here, the authors present the results of Standardized Precipitation Index, Palfai Aridity Index and Palmer Drought Severity Index, indices that were computed using data of temperature and precipitation from four meteorological stations, evenly spread within the study area. Significant correlations were found between the above mentioned indices, hence the Palmer Drought Severity Index was modified by replacing the standard soil available water content with the real value obtained from 7 soil profiles (Chernozem, Phaeozem, Luvisol, Preluvisol, Vertisol and Gleysol) situated within the study area. Finally, based on a diagram between the water content and the wilting point the results of the study led to the identification of the most susceptible soil to drought, as an important preliminary step to drought risk management.

Monitoring spatial-temporal change of land desertification in a fragile subalpine rangeland eco-environment

Zoige County (China) represents a typical fragile subalpine rangeland eco-environment with a severe land desertification problem. This paper aims at detecting land desertification change in Zoige County between 15 years by quantified remote sensing techniques with multispectral imagery. Landsat images acquired in 1994 and 2009 were analyzed by this methodology: 1) image preprocessing 2) using Spectral Mixture Analysis (SMA) to obtain precise sub-pixel classification results of land cover; 3) then using Change Vector Analysis (CVA) to conduct a multi-temporal comparison process. Change detection results indicated the land desertification conditions and vegetation re-growing conditions which represent the spatial-temporal change pattern of land desertification at Zoige County. After dividing out ecological regions based on change detection results, analyzing the driving factors of both land desertification conditions and vegetation re-growing conditions, specific suggestions for each ecological region are proposed, which can assist the development of environmental restoration measures and environmental protection measures at Zoige County in an effective way.

Monitoring the recent trend of aeolian desertification using Landsat TM and Landsat 8 imagery on the north-east Qinghai–Tibet Plateau in the Qinghai Lake basin

As an important part of Qinghai Plateau, the Qinghai Lake is a sensitive and fragile zone for global change impacts. It is one of the most strongly desertified regions on the Qinghai Plateau. Based on remote sensing, a geographic information system and using Thematic Mapper imagery for the years 1987, 2000, 2009 and Landsat 8 images for the year 2014 as data sources, we extracted information regarding the dynamic changes of aeolian desertification in the study area over the last 28 years. The spatio-temporal evolutions of the landscape patterns of regional aeolian desertified land (ADL) are discussed. Our objective is to provide references for desertification control and eco-environmental restoration in the Qinghai Lake basin (QLB). Results elicit an aeolian desertified area which has increased by 96.74 km2 over the past 28 years. ADL mainly experienced processes of increasing stable to decreasing trends, before 2000, the area of aeolian desertification increased by 338.03 km2. After 2000, desertification remains stable, but as we speak desertification decreases and a moderate and slight ADL took the lead. The dynamics of aeolian desertification in QLB is mainly determined by climate change, human activities and management.

Monitoring Spatial-Temporal Change of Land Desertification in a Fragile Sub-Alpine Rangeland Eco-Environment: A Case Study from China

Zoige County, China, represents a fragile sub-alpine rangeland eco-environment with a severe land desertification problem. This paper aims at detecting land desertification change in Zoige County over 15 years with quantitative remote-sensing techniques using multi-spectral imagery. Landsat images acquired in 1994 and 2009 were analyzed using the following methodology: (1) image pre-processing; (2) spectral mixture analysis (SMA) to obtain precise sub-pixel classification results of land cover; and (3) change vector analysis (CVA) to conduct a multi-temporal comparison process. Change detection results depict the land desertification conditions and vegetation re-growth conditions. In this way, we characterized the spatial-temporal change pattern of land desertification in Zoige County between 1994 and 2009. After categorizing ecological regions based on change detection results, we analyzed the driving factors of both land desertification conditions and vegetation re-growth conditions, finding out that grasslands under intense grazing pressure tend to suffer severe desertification, while topographic relief has an obvious influence on vegetation re-growth. Specific suggestions for each ecological region are proposed, which can assist the development of environmental restoration measures and environmental protection measures in Zoige County in an effective way. Furthermore, this methodology for monitoring land desertification could be carried out across neighboring counties or in other regions with similar sub-alpine rangeland and land desertification problems.

Changes in wind activity from 1957 to 2011 and their possible influence on aeolian desertification in northern China

Wind activity is proved to have significant impacts on aeolian desertification. Clarifying the fluctuations and change trend of wind velocity is important for understanding their influence on aeolian desertification. In this study, we used a dataset of wind velocities collected from 93 meteorological stations across northern China from 1957 to 2011 to analyze the changes in wind activity during this period. We tested the monotonic and step (abrupt) trends for annual and seasonal data of mean wind velocity by using Mann-Kendall and Mann-Whitney tests, respectively. The results indicated that the annual mean wind velocity decreased by 0.83 m/s from 1957 to 2011. The decreasing trends were also significant (P<0.01) for each season. The magnitude of the decrease was smallest in the east of northern China and largest in the west of northern China, and the most remarkable decrease occurred in the northwest of northern China. Abrupt decreases in annual and seasonal mean wind velocities occurred in the mid-1980s, which was consistent with the changes in aeolian desertification since the mid-1980s in northern China. As revealed by our study, although both modern aeolian desertification and ecosystem rehabilitation are affected by human activities to some extent, they are also likely to be strongly controlled by climate change, especially by wind activity.

Characterizing changes in grassland desertification based on Landsat images of the Ongniud and Naiman Banners, Inner Mongolia

Desertification is treated as an important and critical environmental hazard. In the face of increasingly serious grassland desertification, China has made great efforts to combat desertification and a series of key national ecological projects has been launched. However, accurate, timely, and effective monitoring and assessment are required to determine whether these projects work well. The Horqin sandy land represents the largest area of sandy land in China. In this article, the Naiman and Ongniud Banners were studied because these contain the main desertified grassland in Horqin. Next, a desertification classification and grading system was designed for the Horqin sandy land after conducting fieldwork. Based on spectral mixture analysis (SMA) and decision-tree methods, we interpreted Landsat Thematic Mapper/Enhanced Thematic Mapper Plus/Operational Land Imager (TM/ETM+/OLI) images of the study area from four years: 1985, 1992, 2001, and 2013. Overall, the following results were obtained. The total area of desertified grassland in the Naiman and Ongniud Banners increased from 5979 km2 in 1985 to 9195 km2 in 1992 (an increase of 53.79%) and then decreased to 7828 km2 in 2001 and to 6023 km2 in 2013. The changes in the areas of desertified grassland with various degrees of desertification displayed the same trends as that of the total desertified grassland area. The severely desertified grassland expanded from 1872 km2 in 1985 to 3723 km2 in 1992 before shrinking to 2189 km2 in 2013. The annual rates of expansion of desertified grassland during the periods 1985–1992, 1992–2001, and 2001–2013 were 7.68%, −1.65%, and −1.92%, respectively, and the corresponding expansion rates of severely desertified grassland were 14.12%, −3.48%, and −1.19%, respectively. Both the desertified grasslands and the areas with various degrees of desertification displayed significant expansion during the period 1985–1992. Since 1992, this trend has reduced. During the study period, the changes in temperature and precipitation did not benefit the reversal of grassland sandy desertification. Furthermore, the growing population and expansion of livestock production and farming inhibited such reversal. However, the results presented in this article suggest that a reversal in grassland sandy desertification has been occurring since 1992. The results indicate that ecological engineering measures have helped reverse desertification and have promoted the restoration of grassland vegetation.

The developmental trend and influencing factors of aeolian desertification in the Zoige Basin, eastern Qinghai–Tibet Plateau

Abstract The Zoige Basin is located in the northeastern region of the Qinghai–Tibet Plateau and covers an area of 19,400 km 2 . At a mean altitude of 3500 m, the basin is highly sensitive to global environmental change and human disturbance due to its high elevation and fragile cold environment. The process of aeolian desertification in the basin can be clearly recognized in Landsat images that show the development of sand sheets and dunes over time. To monitor the spatial and temporal changes of aeolian desertification in the Zoige Basin, we analyzed Landsat images recorded in 1975, 1990, 2000, 2005, and 2010. Results showed that aeolian desertification increased rapidly from 1975 to 1990, was stable from 1990 to 2000, decreased slightly from 2000 to 2005, and decreased sharply from 2005 to 2010. Increasing temperature, overgrazing, rodent damage, and drainage of wetlands were considered the key driving factors of the expansion of aeolian desertification. A number of political measures were initiated in the 1990s to slow desertification, but the countermeasures of grazing prohibition, enclosures, and paving straw checkerboard barriers were not implemented until around 2005. These measures resulted in a dramatic recovery of aeolian desertified land between 2005 and 2010. Based on the cause analysis, anthropogenic factors were identified as the dominant driving force for both development and recovery of aeolian desertified land.

How Forestry in the Southern Hemisphere Can Help Address Desertification and Global Climate Change

How Forestry in the Southern Hemisphere Can Help Address Desertification and Global Climate Change

Study on Karst Rock Desertification by Human-Nature Interaction: A Case Study of Fengshan County of Guangxi, China

Abstract. Rocky desertification is a process of soil erosion leading to the bareness of bedrock, and is a kind of typical natural disaster in karst areas, which seriously constrains the developments of local society and economy. This paper studies the impact of human activities on the changes of rocky desertification. With the interpretation of remote sensing images of Fengshan County, GuangXi, China covering 1990, 1995 and 2005, this paper analyzes the relationship of the changes of social and economic index (including population density, agricultural population, rural per capital net income, and farmland) and the changes of rocky desertification in recent 15 years. The results indicate that: in recent 15 years, the average annual growth rate of rocky desertification, rate of change of population density, agricultural population, rural per capita net income, and farmland area are 8.7375 km2 /year, 0.7 person/km2.year, 1153 person/year, 85 Yuan/year, and −269.1 ha/year, respectively. The first three of social and economic indicators at different degrees of growth, show a positive correlation with rocky desertification change. However, farmland area, which has been diminishing, shows a negative correlation with rocky desertification. The influence of human activities for karst rocky desertification can be regarded as population growth – steep slope reclamation – the destruction of vegetation – erosion – rocky desertification – poverty.

Desertification Change Analysis in Siwalik Hills of Haryana Using Geo-informatics

Abstract. Desertification constitutes one of the international environment problems whose global importance has been recognized by the international community. Desertification is a problem that affects a number of regions of the world in the developed and developing countries. Desertification is even more closely associated with the development process insofar as it impacts on peoples livelihoods much more directly than other environmental problem. One of the central challenges of environment management in the coming years, the loss of productive land is of major concern in a world where hundreds millions of individuals already go hungry today. Availability of remote sensing data from earth observation satellite and GIS techniques has made it convenient to map and monitor land use /land cover of desertification areas. In the present study Desertification Change analysis in Panchkula district Haryana was carried out by using LISS-III satellite data of 2002 and 2011. The main objective of the study was to monitor the changes in degraded lands in the district. Onscreen digitization technique was followed to interpret the satellite data. The two dates maps were overlaid and changes in area under various degraded lands were calculated. It was observed that Total geographical area of under investigation is 1021.86 sq. km.

Evaluation of land desertification from 1990 to 2010 and its causes in Ebinur Lake region, Xinjiang China

Desertification is a threat to human survival and has a major sustainability development impact on environment and socio-economic society. The study area where oasis desertification occurred is located east of the Ebinur Lake region, just west of Junggar Basin in Xinjiang, China. The ecological and environmental issues in the study area are vulnerable and sensitive. The authors of this paper discuss the changes in land desertification that occurred between 1990 and 2010. In the past 20 years, because of the human activities, such as population growth and agricultural development, desertification occurred rapidly in the study area. Remote sensing images were classified into eight categories: light desertification, moderate desertification, severe desertification, extremely severe desertification, bare rock, farmland, water body, and salt desert. To evaluate the evolution and status of land desertification as well as its causes, the authors interpreted and analyzed Landsat Thematic Mapper images (acquired in 1990, 2007, 2010) and Enhanced Landsat Thematic Mapper images (acquired in 2001) as well as meteorological and socio-economic data. Results revealed that 4,426.49, 3,713.25, 3,713.95 and 3,789.16 km2 of the total area is desertified land during these four periods (1990, 2001, 2007, and 2010). The factors controlling desertified land dynamics were analyzed from the perspectives of two groups: climatic variations and human activities. The results indicated that the climate-dominated natural factors contribute greatly to the occurrence and development desertified land. However, they are not the fundamental causes of its development. The human factors are the primary and direct driving forces responsible for the increase in desertification area. More thorough quantitative analysis, with more frequent remotely sensed data is needed to assess the driving forces in more detail.