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近30年来北方农牧交错带沙质荒漠化动态变化 总被引：3，自引：0，他引：3
中国北方农牧交错带是沙质荒漠化发展最迅速的地区，随着自然环境变化和人类活动的加强，沙质荒漠化有愈演愈烈的趋势。为搞清沙质荒漠化的地质成因，采用以遥感为主要技术手段，结合地面，对其沙质荒漠化现状进行调查；并利用不同时期遥感数据对比，研究变化发展趋势。结果表明，全区共有沙质荒漠化土地290512．53km^2，占全区总面积的23．67％；近30多年来，中国北方沙质荒漠化土地面积增加了7369．71km^2，平均每年增加294．79km^2。就沙质荒漠化发生、发展而言，地质背景是内因，干旱大风气候是条件因素，人类活动是“催化剂”。 相似文献
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基于遥感技术的中国北方沙质荒漠化防治建议 总被引：3，自引：0，他引：3
根据中国北方地区人类活动对地表组成物质的扰动特征,将中国北方沙质荒漠化土地治理区划分为绿洲周缘农业型沙质荒漠化、农牧交错带农牧型沙质荒漠化、草原牧业型沙质荒漠化三种类型;利用1975年M SS卫星图像数据和2000年ETM卫星图像数据为信息源,在M APG IS软件支持下,采用人机交互方法对沙质荒漠化土地类型进行信息提取,编制研究区1975年和2000年沙质荒漠化土地类型分布图,在根据沙质荒漠化土地类型的变化幅度确定沙质荒漠化土地变化类型的基础上,通过1975年和2000年沙质荒漠化土地类型分布图的叠加分析,查明了中国北方近25年来沙质荒漠化土地的时空演化规律,结合中国北方不同沙质荒漠化土地治理区的自然条件和人类活动特征,提出了中国北方沙质荒漠化土地治理建议。 相似文献
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荒漠化目前已成为威胁全球生态环境的主要问题。我国北方地区风蚀作用强烈,是土地沙质荒漠化问题最为突出的地区。以沙漠、沙地分布较广的北方6省(区)为研究区,利用遥感技术获取2010—2018年研究区沙质荒漠化演化特征,并将气象、地质等因素进行综合分析,探讨毛乌素沙地、科尔沁沙地沙质荒漠化变化原因。遥感解译结果表明: 2018年北方地区沙质荒漠化土地共35.08万km2,其中重度沙质荒漠化面积11.92万km2,中度沙质荒漠化13.54万km2,轻度沙质荒漠化9.62万km2,主要分布于内蒙古自治区和新疆维吾尔自治区; 2010—2018年,北方地区沙质荒漠化土地面积减少0.73万km2,其中,新疆维吾尔自治区沙质荒漠化面积减少0.48万km2,内蒙古自治区减少0.19万km2,同时有2.78万km2沙质荒漠化土地程度减轻。以毛乌素沙地和科尔沁沙地为典型研究区,对比两沙地生态地质条件差异,总结了沙质荒漠化好转、加重的原因。研究认为,毛乌素沙地应降低人类活动干扰的影响,以自然恢复为主; 科尔沁沙地应加强地下水资源管理,优化植被结构,进一步推进退耕还林、退耕还草工作。研究成果为我国北方沙质荒漠化地区生态保护修复提供了科学参考。 相似文献
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根据影响沙漠、沙质荒漠化土地的地质地貌、植被、气候和人类活动等特征,通过确定地域分异、发生学、多级序列等区划原则,建立了以地质地貌类型组合、气候为沙漠、沙质荒漠化土地区(Ⅰ级区)划分和以沙质荒漠化土地类型空间分布特征为沙漠、沙质荒漠化土地亚区(Ⅱ级区)划分的指标体系。采用遥感方法,将中国北方沙漠、沙质荒漠化土地划分为贺兰山以西干旱沙漠、沙质荒漠化区;贺兰山-大兴安岭干旱、半干旱沙漠、沙质荒漠化区和大兴安岭以东半干旱、半湿润沙质荒漠化区等3个区和17个亚区。并对沙漠、沙质荒漠化土地区进行了现状分析。 相似文献
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中国三北地区荒漠化区域分类与发展趋势综合研究 总被引：8，自引：2，他引：8
中国北方土地荒漠化主要受青藏高原隆升以来形成的构造－沉积特征、水文地质条件、全球气候变化、尤其是亚洲季风等地质背景控制。本文仅对北方沙质荒漠化、水蚀荒漠化两种主要的荒漠化类型的区域地质分布、成因及其发展趋势进行探讨。三北地区沙质荒漠化依成因可分为：就地起沙型、风沙侵入型和土地粗粒化型等。就地起沙型沙质荒漠化主要分布在西部内陆盆地周缘冲洪积扇上，中东部高原、冲积平原上的沙漠边缘地带、沙地内部和流经这些沙漠和沙地的古河道，以及河湖相砂质沉积物和以砂质沉积物为母质的土壤分布区；风沙侵入型沙质荒漠化主要分布在上述沙漠、沙地边缘的下风地带，如巴丹吉林沙漠和腾格里沙漠的东南缘、毛乌素沙地以南的覆沙黄土区、科尔沁沙地以东的辽河平原等；土地粗化主要分布在西部盆地沙漠与戈壁的过渡地带、中东部高原砾质沙草原。沙质荒漠化在毛乌素、科尔沁和浑善达克等沙地、河西走廊的局部地区有所逆转，但三北地区总体上仍呈恶化趋势，尤其是以地表土壤粗化为主的沙质荒漠化的发展更应引起人们的关注。水蚀荒漠化依地质背景之不同可分为土漠化和岩漠化两类，前者主要分布在北方中部黄土高原地区、内蒙古科尔沁沙地南侧的黄土分布区等；后者主要分布于太行山北部、辽宁西北部的基岩山区。晋陕蒙交界地带、甘肃平凉北部、定西地区和科尔沁沙地东南的蒙辽交界处等地水蚀荒漠化形势严峻；以小流域水土流失为主的治理工程使陕西的吴旗、延安、洛川等地和朝阳河中上游地区水蚀荒漠化有所好转。总之，第四纪以来的构造－沉积特征控制着不同类型荒漠化的区域分布，气候变化和水文地质条件控制着漠化的进程，人类不合理的经济活动则更是荒漠化过程的催化剂，尽管在局部、在一定的时间段内可使这一过程得以缓解甚至逆转。 相似文献
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中国北方东部沙质荒漠化的地学观 总被引：8，自引：2，他引：8
中国北方东部的土地荒漠化主要受新构造运动以来的权造－沉积特征、青藏高原隆升所引起的全球气候变化、尤其是亚洲季风等地质背景控制。北方东部沙质荒漠化区域地质分类，按其成因可分为就地起沙型、风沙型和土地粗粒化型等3种类型。其中，就地起沙型沙质荒漠化主要分布在东部毛乌素、科尔沁、浑善达克、呼伦贝尔等沙地内，流经这些沙地的古河道，广泛发育河湖相砂质沉积物以及以砂质沉积物为母质的土壤分布区。风沙型沙质荒漠化主要分布在上述沙地的边缘地带，如毛乌素沙地以南的覆沙黄土区等。土地粗化主要分布在内蒙古锡林郭勒草原－河北坝上草原－河北坝上草原，其土壤类型多为含砾沙土，其土壤母质为基岩风化壳、残坡积或冲洪积物。荒漠化发展趋势上，尽管就地起沙型沙质荒漠化在毛乌素、科尔沁和浑善达达沙地的局部地区均有所逆转，但总体上，在北方广大地区，主要以地表土壤粗化为主的荒漠化和风沙型荒漠化等均有不同程度的扩大。上述不同类型的沙质荒漠化，总体上受地背景控制。其中，第四纪以来的构造－沉积特征控制着不同类型荒漠化的区域分布，气候变化控制着荒漠化的进程，人类活动则是在上述背景的基础上进行。 相似文献
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呼伦贝尔地区土地荒漠化动态变化 总被引：6，自引：0，他引：6
呼伦贝尔地区是中国重要的天然草原和畜牧基地, 随着该地区经济和社会的发展及人类对资源的不合理利用, 土地荒漠化现象加重。笔者应用RS和GIS技术, 以1970 年MSS、2000 年ETM和 2007年CBERS数据为数据源, 主要采用人工目视解译方法, 并辅助野外调查验证, 获得三期解译数据, 并利用空间分析、网格剖分方法, 对呼伦贝尔地区荒漠化的时空变化情况进行研究。结果表明: 近40年来, 该地区土地荒漠化总面积不断增加, 1970 年该地区土地荒漠化面积为7408.76 km2 , 2000年为7 539.52 km2 , 2007年增加到7 852.12 km2 , 共增加面积443.36 km2。1970-2000年间, 沙漠化减轻、盐碱化加重的面积为134.09 km2 , 沙漠化加重、盐碱化减轻的面积为53.35 km2 ; 2000- 2007年间, 沙漠化减轻、盐碱化加重的面积为41.71 km2 , 沙漠化加重、盐碱化减轻的面积为172.8 km2。 相似文献
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本文根据类似荒漠境况的出现是判断荒漠化发生与否的重要标志这一原则,并结合在中国南方开展的一些研究,对湿润地区的荒漠化进行了初步的探讨。研究表明,湿润地区的荒漠化并不包含所有存在侵蚀作用的退化土地,而专指人为侵蚀作用导致的出现了具类似荒漠境况的退化土地。中国南方湿润地区土地荒漠化分布最显著的特征为斑点状分布于丘陵山区或河、湖、海滨的冲积平原,面积为1．98×105km2,其中流水作用导致的荒漠化面积为1．78×105km2,风力作用的为0．11×105km2,其它0．09×105km2。自然因素,特别是气候和地貌因素对荒漠化的形成和发展起着积极的影响作用,但不是决定作用。人为不合理的经济活动,才是造成荒漠化的主要原因。文章最后还简要介绍了湿润地区荒漠化的防治问题。 相似文献
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中国沙漠化研究的理论与实践 总被引：43，自引：2，他引：43
中国的沙漠化研究的理论与实践在过去的十多年里取得了一些成果。据此,本文对沙漠化的概念、成因、过程、指征、后果、发展趋势及其治理等方面进行扼要的介绍。研究表明,沙漠化是一种人为活动与自然资源、环境不相协调所产生的以风沙活动为主要标志的土地退化过程。我国北方沙漠化土地的蔓延速率从50年代末期至70年代中期的年均1560km2发展到近十多年来的年均2100km2;实践证明,沙漠化土地作为一种土地资源可以通过合理的整治过程而恢复其原有的生产潜力。 相似文献
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Change trends for desertified lands in the Horqin Sandy Land at the beginning of the twenty-first century 总被引：2，自引：1，他引：1
Zhiwen Han Tao Wang Changzhen Yan Yubin Liu Lichao Liu Aimin Li Heqiang Du 《Environmental Earth Sciences》2010,59(8):1749-1757
The dynamics of desertification in the Horqin Sandy Land between 2000 and 2005 were analyzed using Landsat TM/ETM images and
the data-processing function of geographical information software. The results showed that the extent of desertified land
decreased at a rate of slightly more than 0.1 km2 year−1, from 22,423.1 km2 in 2000 to 22,422.4 km2 in 2005, indicating that desertification has been controlled in this area and that desert areas may be approaching a steady
state. The dynamics of desertification differed among land types. Desertification decreased most obviously in areas of previous
desert land. The area in which desertification was ameliorated was higher than the area that underwent further degradation,
but non-desertified land (113.3 km2) deteriorated at a rate of 22.7 km2 year−1 during this period. This significant change requires careful attention by managers in the study area. 相似文献
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Rocky desertification and its causes in karst areas: a case study in Yongshun County,Hunan Province,China 总被引：9，自引：0，他引：9
Rocky desertification, a process of land degradation characterized by soil erosion and bedrock exposure, is one of the most
serious land degradation problems in karst areas, and is regarded as an obstacle to local sustainable development. It is well
known that human activities can accelerate rocky desertification; however, the effects of climate change on rocky desertification
in karst areas are still unclear. This study focused on the effects of temperature and precipitation changes and human activities
on rocky desertification in karst areas to determine the impacts of climate change and human disturbances on rocky desertification.
Areas of different level of rocky desertification were obtained from Landsat TM (1987) and Landsat ETM+ (2000) images. The
results show that, although the total desertification area increased by only 1.27% between 1987 and 2000, 17.73% of the slightly
desertified land had degraded to a moderate or intense level, 2.01 and 15.71%, respectively. Meanwhile, between 1987 and 2000,
the air temperature increased by 0.7°C, and precipitation increased by 170 mm. Statistical results indicate that the increase
in precipitation was caused by heavy rainfall. In addition, under the interactive influences of heavy rainfall and temperature,
the average karst dissolution rate was about 87 m3 km−2 a−1 during the 14 years in the study area. Further analysis indicated that rocky desertification was positively related with
the increase in temperature and precipitation and especially with the heavy rainfall events. Climate change accelerated rocky
desertification in the karst areas.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Relationships between rocky desertification and spatial pattern of land use in typical karst area,Southwest China 总被引：7，自引：4，他引：3
Yongjun Jiang Linli Li Chris Groves Daoxian Yuan Pat Kambesis 《Environmental Earth Sciences》2009,59(4):881-890
Karst rocky desertification is a typical type of land degradation in the Southwest China. An attempt was made to study quantitatively
the relationships between rocky desertification and spatial pattern of land use through applying spatial analysis of Geographical
Information System in Nandong underground river system, a typical karst area, Southwest China. The spatial distribution of
rocky desertification and spatial pattern of land use were obtained from interpreting Landsat Images in Nandong area in 2007
by supervised classifications, and verified and rectified through field survey. The results indicate that: (1) the total land
deserted area covers 378.3 km2, or 23.4% of the total area, of which intense, moderate and slight rocky desertification covers 269.46, 54.2, and 54.63 km2, respectively, in Nandong area. (2) There is an obvious effect of spatial pattern of land use on rocky desertification. With
the increase of elevation and slope, there is a higher occurrence ratio of rocky desertification in the cultivated land and
grass land. Also, more than half of total rocky desertification was dominated within the areas of 4 km from the construction
land, and 97% of total rocky desertification was dominated within the areas of 10 km from the construction land in Nandong
area. And what can be known from the data is that the primary effect distance of human on rocky desertification from the construction
land is 4 km, and the farthest effect distance of human on rocky desertification from the construction land is 10 km in Nandong
area. 相似文献
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Spatial pattern of Karst rock desertification in the Middle of Guizhou Province,Southwestern China 总被引：13，自引：0，他引：13
Karst rocky desertification is a typical type of land degradation in the Southwestern China. It has great ecological and economical
implications for the local people. Landsat images from the middle of Guizhou Province collected in 1974, 1993 and 2001 were
used for change detection of the pattern of Karst rocky desertification. The results show the following findings: (1) Desertification
area expanded drastically in 27 years, at an increasing rate about 116.2 km2/year. (2) High areas (900–1,500 m) are the most affected. (3) Areas with the slope <5° or >25° are also easily tend to be
Karst rocky deserted. (4) The process of Karst rocky desertification is nearly irreversible. Few areas of Karst rocky desertification
could be meliorated to non-desertification land. (5) Most of the degraded lands are located in the south and the central of
the study region, and the meliorated land areas are sparsely located in the east and the west part of the region. All these
findings would provide bases for the decision-making of the local government to improve the Karst rocky desertification 相似文献
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Fang Zhang Benzhen Zhu Jing Zheng Zhiwen Xiong Fuqiang Jiang Longwu Han Tao Wang Min Wang 《Environmental Earth Sciences》2013,70(1):249-258
The objective of this study was to examine the variation of time and space and the effects of alpine meadow desertification, and the study area was selected at the Qinghai–Tibet Plateau of China. The sampling locations were categorized as the top, middle, bottom of the slope and flat in front of the slope, and the sites were classified as alpine meadow, light desertified land, moderate desertified land, serious desertified land, and very serious desertified land according to the level of alpine meadow desertification. This study examined spatial and temporal variability in soil organic carbon (SOC), total nitrogen (TN), pH, and soil bulk density due to wind erosion and documents the relationship between soil properties and desertification of alpine meadows. Desertification caused decreases to soil organic carbon and total nitrogen and increases to pH and soil bulk density. Soil properties were greatly affected by the level of alpine meadow desertification with the changes being attributed to overgrazing. The middle portion of slopes was identified as being the most susceptible to desertification. Carbon and nitrogen stocks were found to decrease as desertification progressed, the SOC stocks were 274.70, 273.81, 285.26, 196.20, and 144.36 g m?2 in the alpine meadow, light desertified land, moderate desertified land, serious desertified land and very serious desertified land, respectively; and the TN stocks were 27.23, 27.11, 28.35, 20.97, and 17.09 g m?2 at the top 30 cm soil layer, respectively. To alleviate desertification of alpine meadow, conservative grazing practices should be implemented. 相似文献
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基于RS和GIS的沙漠-黄土过渡带土地沙漠化分布与变化研究--以陕北榆林地区为例 总被引：3，自引：0，他引：3
选择毛乌素沙漠和黄土高原过渡带——陕北榆林地区作为研究区域,在地理信息系统支持下,对两个不同时期的遥感影像进行了解译,总结了该区10余年来沙漠化土地景观特征,分析了土地沙漠化空间格局的动态变化规律。结果表明,研究区内沙漠化土地形势仍十分严峻,沙漠化土地面积占土地总面积的67．7％,其空间分布具有明显的不平衡性,表现为西北部和中部区域沙漠化程度较为严重,土地沙漠化空间分布的不平衡性与该区自然因素和土地利用方式的空间差异有关。经过几十年的积极治理与改造,该区土地沙漠化过程逐渐趋于稳定。通过探讨土地沙漠化的成因,认为自然环境与人类行为的相互作用及在时间尺度上的矛盾造成了该区持续的土地沙漠化过程。 相似文献