首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
基于土地退化的甘肃省生态脆弱性评价研究   总被引:7,自引:2,他引:5  
生态脆弱性评价是区域生态综合评价的重要内容和生态规划的重要依据。采用甘肃省最主要和普遍的土地退化指标:土地沙漠化、土壤侵蚀(水蚀)、土壤盐渍化3项指标,以县为单元,对全省进行生态脆弱性综合评价。省内土地沙漠化和土壤盐渍化主要发生在河西地区,土壤侵蚀(水蚀)主要发生在中东部和南部地区。生态脆弱性综合评价结果为:全省发生土地退化的81个县(市、区),强度脆弱2个,高度脆弱4个,中度脆弱26个,轻度脆弱30个,微度脆弱19个。生态脆弱性呈现由南到北增加的趋势。  相似文献   

2.
中国陆地生态敏感性时空演变特征   总被引:5,自引:0,他引:5  
生态敏感性作为评价区域生态环境问题的重要指标之一,对区域的生态治理与管理工作具有重要意义。本文从自然生态系统、自然—社会复合生态系统、社会生态系统等视角选取生物多样性、水热环境、土壤盐渍化、土地荒漠化、土壤侵蚀和人类干扰6个指标,运用全排列多边形图示指标法对2000—2018年间中国陆地生态敏感性进行计算,并运用格网编码法对其时空演变特征进行分析。研究结果表明:① 2000—2018年间中国陆地生态敏感性总体稳定,生态敏感值稳定在0.33~0.34之间;但得益于21世纪以来中国实施了一系列生态环境治理与预防工作,敏感值在2000—2018年间持续下降,表明中国陆地生态敏感性状况正在逐渐好转。② 中国陆地生态敏感性空间异质性显著,呈现出“东低西高、南低北高”“城区高、郊区低”的空间分布格局。中国西部区域和北方区域自然环境恶劣,生态自我调节能力较差,易受外界因素的影响,而人类聚居区生态自我调节能力虽然较强,但由于人类活动强度较大,其敏感性反而较高。③ 中国陆地生态敏感性受土壤(地)环境因素影响较大,但人类干扰因素影响力也在逐年递增,这表明在经济快速发展的同时,中国的生态环境保护与治理工作仍然任重道远。  相似文献   

3.
西藏土壤侵蚀敏感性分布规律及其区划研究   总被引:3,自引:1,他引:3  
西藏土壤侵蚀类型多样,其中水土流失、土地沙漠化、冻融侵蚀以及崩塌、滑坡和泥石流等侵蚀类型广泛分布,危害严重。本文对前三种土壤侵蚀类型敏感性特点及其分布规律进行了评价,在此基础上,作出了西藏土壤侵蚀敏感性综合区划,并对各分区主要特点作了简要的描述。为土壤侵蚀防治和生态环境保护与建设提供依据。  相似文献   

4.
荒漠化是生态退化的极端表现形式,包括气候变异和人类活动在内的种种因素造成的干旱、半干旱和亚湿润干旱区的土地退化。快速和准确地识别中国荒漠化地区,是防范和治理荒漠化的关键。针对2000-2015年我国陆地生态系统NPP的变化趋势、稳定性和荒漠化敏感性进行了综合分析,构建了识别荒漠化土地的技术方法。结果表明:(1)近16 a以来,我国内蒙古阴山以南、新疆天山以北、西藏阿里地区、长江以南大部地区,植被净初级生产力均出现了不同程度的下降趋势,且一半以上的区域处于植被生态系统不稳定状况;在全国56.2%的国土属于荒漠化敏感区内,上述区域容易受气候、自然条件、人为干扰等影响而发生荒漠化。(2)2000年以来,我国土地荒漠化退化区域面积约20.74×104 km2,占国土总面积的2.16%。主要为五大分布区域,即内蒙古高原中部的典型草原和荒漠化草原区、新疆天山-阿尔泰山山地草原区、新疆塔里木河下游的温带荒漠和绿洲区、青藏高原的阿里-昆仑山高寒荒漠区、青海省的青南山高寒草原区。(3)荒漠化进程伴随有生产力下降、植被盖度降低和地表温度不断攀升的地表关键参数演变特征,荒漠化的形成受气候影响显著,降雨的减少是造成土地荒漠化进程突出的主要因素;人类活动、不合理的种植业、畜牧业等在一定程度上对土地荒漠化起到推动作用。  相似文献   

5.
西藏冻融侵蚀的分级和评价   总被引:4,自引:0,他引:4  
Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion. Restricted by many factors, few researches on freeze-thaw erosion have so far been done at home and abroad, especially those on the assessment method of freeze-thaw erosion. Based on the comprehensive analysis of impact factors of free-thaw erosion, this paper chooses six indexes, including the annual temperature range, annual precipitation, slope, aspect, vegetation and soil, to build the model for relative classification of freeze-thaw erosion using weighted and additive methods, and realizes the relative classification of the freeze-thaw erosion in Tibet with the support of GIS software. Then a synthetic assessment of freeze-thaw erosion in Tibet has been carried out according to the relative classification result. The result shows that the distribution of freeze-thaw eroded area is very extensive in Tibet, accounting for 55.3% of the total local land area; the spatial differentiation of freeze-thaw erosion with different intensities is obvious; and the difference in distribution among different regions is also obvious.  相似文献   

6.
闫虎  王玉杰  张会兰 《干旱区地理》2015,38(6):1226-1233
生态环境敏感性分析对于生态环境功能得到保护和恢复,资源得到高效利用,生态安全得到保障,区域可持续发展能力得到增强具有重要作用。本文根据巴音郭楞蒙古自治州自然地理特征,采用GIS分析和专家集成方法,分别进行了巴州土壤侵蚀敏感性、土地沙漠化敏感性、土壤盐渍化敏感性和生物多样性及生境敏感性评价,最后展开生态环境敏感性综合研究。结果表明:巴州生态环境敏感性共分为极敏感、高度敏感、敏感、轻度敏感以及不敏感5个等级。生态环境极敏感区面积为2.7×104 km2,占全州面积5.7%;高度敏感区为12.7×104 km2,占26.4%;敏感区面积为14.8×104 km2,占30.8%;轻度敏感地区为7.9×104 km2,占16.4%;不敏感区面积为10.0×104 km2,占20.7%。  相似文献   

7.
Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion. Restricted by many factors, few researches on freeze-thaw erosion have so far been done at home and abroad, especially those on the assessment method of freeze-thaw erosion. Based on the comprehensive analysis of impact factors of free-thaw erosion, this paper chooses six indexes, including the annual temperature range, annual precipitation, slope, aspect, vegetation and soil, to build the model for relative classification of freeze-thaw erosion using weighted and additive methods, and realizes the relative classification of the freeze-thaw erosion in Tibet with the support of GIS software. Then a synthetic assessment of freeze-thaw erosion in Tibet has been carried out according to the relative classification result. The result shows that the distribution of freeze-thaw eroded area is very extensive in Tibet, accounting for 55.3% of the total local land area; the spatial differentiation of freeze-thaw erosion with different intensities is obvious; and the difference in distribution among different regions is also obvious.  相似文献   

8.
新疆克拉玛依市生态敏感性研究(英文)   总被引:1,自引:1,他引:1  
Karamay City is a typical mining city, relying on oilfield exploration and development. After 60 years of construction and development, Karamay has become the first large oilfield and an important base of the national petroleum and petrochemical industry in China. Based on spatial analysis, and Geographic Information Systems (GIS) grid computing and overlay techniques, whilst considering the effect of oilfield development and aimed at the ecological problems of Karamay City in the Xinjiang Uygur Autonomous Region of China, we conducted research on the spatial characteristics of the comprehensive ecological sensitivity of Karamay. The ecological problems of natural environment evolution include soil erosion, land deserti-fication, soil salinization, and biodiversity reduction. The most significant disturbance factor from the activities of humans in this area is oilfield exploitation. This study carries out an analysis of single factor ecological problem sensitivity and integrated ecological sensitivity. The results of the research are as follows: (1) Soil erosion is relatively sensitive, especially in Karamay district, Dushanzi district, north of Urho district and west of Baijiantan district, which is mainly a result of the vertical dropping slopes, serious rainfall erosion and the distribution of scattered woodland. (2) The main types of land desertification are represented by high and moderate grade sensitivities, and high and extremely high sensitive areas are distributed in the intersection of Karamay and Baijiantan districts. This is due to evaporation exceeding rainfall in these areas, and the soil mainly consists of sand and is seldom covered by vegetation. (3) The soil salinizatiion sensitivity grades are mainly moderate, high and extremely high. The highly sensitive areas are mainly distributed in southeast of Baijiantan district, north and east of Karamay district and east of Urho district. The primary causes are evaporation exceeding rainfall and extreme human activities. (4) The main types of biodiversity sensitivity are light and moderate grade. Highly sensitive areas are located in the east and south of Karamay district, north of the Baiyang River basin and parts of the wetland areas. (5) Oil fields development areas are highly ecologically sensitive, which are located in the northern oilfields of Urho district, western oilfields of Baijiantan district, northwestern oilfields of Karamay district and central oilfields of Dushanzi district. (6) The main types of integrated ecological sen-sitivity are high and moderate. The high and extremely highly sensitive areas are located in the central and northern parts of Karamay district, and southwest of Baijiantan district. The evaluation results will provide guidance for the future planning and development, the protection of the ecological environment and the realization of harmonious social, economic, and ecological development in Karamay City.  相似文献   

9.
Intense freezing and thawing actions occur in the Qinghai–Tibet Plateau because of its high elevation and cold temperature. The plateau's unique environment makes it easy to generate wind erosion under dry, windy weather conditions, resulting in the emergence of desertification. As a major form of freeze–thaw erosion, freeze–thaw and wind erosion is displayed prominently on the Qinghai–Tibet Plateau. Therefore, in this study, soil samples were collected from the surface of the plateau to undergo freeze–thaw and wind erosion simulation experiments. Results show that wind erosion strength increases with an increasing number of freeze–thaw cycles, water content in the freezing–thawing process, and the difference in freeze–thaw temperatures. Therefore, in the conditions of water participation, the main reason for the freeze–thaw and wind erosion in the Qinghai–Tibet Plateau is the damage to the soil structure by repeated, fierce freeze–thaw actions, and the sand-bearing wind is the main driving force for this process. The research results have theoretical significance for exploring the formation mechanism of freeze–thaw and wind erosion in the Qinghai–Tibet Plateau, and provide a scientific basis for freeze–thaw desertification control in the plateau.  相似文献   

10.
张智全  张军  黄高宝 《中国沙漠》2010,30(3):614-619
可持续发展理念已经深入人心,而生态环境与社会经济的协调发展成为研究热点之一。而干旱、半干旱区更是面临生态环境恶化与社会经济发展的双重压力,为促进生态环境保护与建设,加强不同生态敏感区的生态环境管理对策,以庆阳市为例,对土壤侵蚀敏感性、土壤沙漠化敏感性、水环境敏感性和生境敏感性进行了评价,并计算了生态敏感性综合指数,将庆阳市划分为生态环境不敏感区、中度敏感区、高度敏感区和极敏感区4个等级。并提出了不同敏感性区域的环境保护对策和产业调整方向,以作为庆阳市可持续发展规划决策的依据。  相似文献   

11.
新疆克拉玛依市生态敏感性研究   总被引:21,自引:2,他引:19  
潘峰  田长彦  邵峰  周伟  陈飞 《地理学报》2011,66(11):1497-1507
基于地理信息系统空间分析、栅格运算与叠加方法,针对克拉玛依市土壤侵蚀、土地沙漠化、土壤盐渍化和生物多样性减少等区域自然环境演变过程中出现的生态问题,考虑油田开发这一人类活动影响因素,定量研究克拉玛依市综合生态敏感性空间特征.研究结果表明:(1)土壤侵蚀敏感性以中、高和极高敏感性为主,高和极高敏感性分布在克拉玛依区和独山...  相似文献   

12.
山地生态系统的土壤侵蚀和水源供给变化对评估区域生态环境质量有重要意义。基于2000-2015年四期土地利用数据,借助InVEST模型对淇河流域近16年间山地生态系统的土壤侵蚀和水源供给变化进行评估。结果表明:① 研究区主要土地利用类型为耕地、草地和林地,共占流域总面积的90%以上。近16年间淇河流域的耕地面积显著减少,草地和水域面积大幅增加,建设用地扩张明显。② 平均土壤侵蚀模数显著降低,2000年土壤侵蚀模数为154.27 t/(hm2·a),2015年减少到32.09 t/(hm2·a);强度侵蚀、极强侵蚀和剧烈侵蚀由9.03%、12.19%和25.96%分别减少到7.17%、6.36%和4.21%,微度侵蚀、轻度侵蚀和中度侵蚀由24.31%、16.96%和11.57%增加到41.89%、27.71%和12.68%;退耕还林、还草措施优化了土地利用格局,促进植被恢复,对治理土壤侵蚀起到了显著效果。③ 水源供给量整体呈现先增加后减少的趋势,2005年达到峰值(1.79亿m3)。相邻两期水源供给量增减变化不一,2000-2005年水源供给量增加的面积大于减少的面积,其水源供给的量值也呈增加趋势,水源供给能力整体增强;而2005-2010年、2010-2015年的水源供给能力随之减弱,其中,2010-2015年水源供给减少的较小;林地和草地面积的增加造成水源供给量降低,土壤水源涵养能力增强。土壤侵蚀和水源供给是山地生态脆弱性响应的重要指标,制定合理的水土保持措施对增强山区生态系统的服务能力具有重要意义。  相似文献   

13.
西藏冻融侵蚀分级评价   总被引:21,自引:1,他引:20  
冻融侵蚀是仅次于水蚀和风蚀的第三大土壤侵蚀类型,由于受诸多因素限制,到目前为止,国内外对其研究甚少,有关其强度分级评价方面的研究则更为鲜见。本文在综合分析冻融侵蚀影响因子的基础上,选取气温年较差、坡度、坡向、植被、年降水量、土壤等六个因子作为西藏冻融侵蚀分级评价指标,用加权加和的方法建立了适合西藏自治区的冻融侵蚀相对分级评价模型,并在地理信息系统软件的支持下实现了西藏自治区冻融侵蚀相对分级。最后,利用分级结果对西藏自治区冻融侵蚀进行了综合评价。结果表明,西藏冻融侵蚀具有分布范围广,不同强度冻融侵蚀空间分异明显,冻融侵蚀地区分布差异明显等特点。  相似文献   

14.
中国南方岩溶区土地石漠化的成因与过程   总被引:18,自引:2,他引:16  
中国南方岩溶区是石漠化广为发展的脆弱生态区域。南方岩溶区土地石漠化的起因既有自然因素,也有人为因素。在地质历史时期其自身环境孕育和存在着自然石漠化过程,在历史时期—现代自然石漠化过程又叠加了人为石漠化过程,人为活动加速、加剧了石漠化的发展。清朝初、中期是人为活动影响石漠化的重要转折时期,此后人为因素作用比重逐渐超过自然因素的作用比重。岩溶区土地石漠化过程是由植被退化丧失过程、土壤侵蚀过程、地表水流失过程、基岩溶蚀侵蚀过程、土地生物生产力退化过程合成的地表生态过程,其实质是形成石质荒漠的土地退化过程。  相似文献   

15.
This article analyzes the territorial disparities in the level of land vulnerability (TDLV) to soil degradation caused by five processes (soil erosion, salinization, sealing, contamination, and compaction) as well as by climate variations in Italy in 1990 and 2000. The analysis reveals, for each soil degradation process, a typical spatial distribution across Italy. Three processes (soil salinization, compaction, and sealing) contribute significantly to the increase in land vulnerability, which is mainly concentrated in risky areas. The observed disparities highlight a growing environmental divide between northern Italy (an economically developed region, not at risk of desertification) and southern Italy and the two main islands (dry, disadvantaged regions at risk of desertification). The knowledge of such a territorial divide and of the underlying soil degradation processes is regarded as important for environmental policies at the country and regional scales aimed at sustaining the economic and socioenvironmental cohesion between areas that are either vulnerable or nonvulnerable to soil degradation. The proposed approach should be seen as part of a decision-making tool informing policies and supporting the design of management solutions, hopefully reversing disparities in land vulnerability to soil degradation.  相似文献   

16.
青藏高原高寒区生态脆弱性评价   总被引:25,自引:3,他引:22  
于伯华  吕昌河 《地理研究》2011,30(12):2289-2295
在分析青藏高原高寒生态系统形成机制的基础上,构筑了3个层次、10个指标的脆弱性评价指标体系,系统评估了青藏高原生态脆弱性及其区域差异。研究结果表明:青藏高原中、重度以上脆弱区的面积较大,占区域总面积的74.79%。微度、轻度脆弱区主要分布在雅鲁藏布江大拐弯处、藏东南海拔3000m以下的山地、祁连山南坡的西北段和昆仑山北...  相似文献   

17.
云南元谋土地荒漠化特征及原因分析   总被引:22,自引:1,他引:22  
元谋地区由于青藏高原隆起而产生的气候变化和人类活动强烈干扰而形成的土壤加速侵蚀,使土地荒漠化加速发展,主要表现在土地资源不断被蚕食和土壤退化而导致的土地质量下降,最终使土地荒废.因此,控制人口增长,调整区域农林牧结构布局,增加地表覆盖度,是控制区域土地荒漠化发展的主要措施。  相似文献   

18.
以USLE方程为理论指导,遥感影像为主要数据源,基于ArcGIS 进行水土流失敏感性空间分析。选择降雨侵蚀力、土地利用类型、坡度、植被覆盖度等影响因子构建水土流失敏感性评价指标体系,在考虑不同因子影响作用大小的情况下,运用空间分析的方法按标准将水土流失敏感性分为五级;并以河北太行山区为例进行研究,利用危险性指数表征研究区水土流失敏感性大小,分析研究区在不同地理背景下的水土流失敏感区的空间分布特征。研究表明:河北太行山区的水土流失敏感性危险性指数为3.97;空间上水土流失敏感性分等级呈现明显的条带状分布;中度敏感区所占面积比例最大,为39.2%;整体水土流失敏感性中度偏重。  相似文献   

19.
郑兴年  王乃斌 《地理学报》1993,48(2):161-170
本文利用遥感技术通过典型区的分析,对黄土高原土地退化现状及其成因过程进行了深入研究。结果表明,黄土高原地区由于特殊的自然条件,加以长期人类活动影响,土地退化十分严重,并处于不断发展之中,主要表现为水土流失和土地沙化等。  相似文献   

20.
基于GIS的黄河上游龙羊峡库区生态环境遥感监测研究   总被引:8,自引:0,他引:8  
本项研究以黄河上游生态环境严重退化的龙羊峡库区为研究区,应用遥感与GIS一体化的方法,建立了库区生态环境动态监测信息系统。在系统的支持下,利用多时相、多波段TM遥感数据,对库区近十年来生态环境变化进行监测分析,揭示了库区土地沙漠化、水土流失、土地利用/土地覆盖的现状,以及建库近十年来生态环境时空演化的过程与发展趋势,为库区生态环境治理提供科学依据。本项研究利用遥感和GIS技术,采用生态环境综合分类系统,在一次分类处理中通过多层次不同级别的组合获得了基于同一信息源的土地沙漠化、草场盖度、土地利用处地覆盖等多种环境类型信息,并利用环境信息模型对库区的土壤侵蚀进行了评价。基于GIS的分类后再处理使遥感分类精度有了一定程度的提高。研究表明,在GIS的支持下充分利用遥感信息监测与评价生态环境,是区域生态环境定量化研究的有效途径。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号