【作者】 张克斌；

【导师】 慈龙骏；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2003， 博士

【摘要】 随着全球环境问题的日益恶化，荒漠化越来越引起国际社会的关注。历经半个世纪的争议，以《联合国防治荒漠化公约》为代表的荒漠化定义已为多数人所接受。即：荒漠化是指包括气候变异和人类活动在内的种种因素造成的干旱、半干旱和干旱亚湿润区的土地退化。 本文采用理论与实践相结合研究方法。在深入系统研究荒漠化指标体系的基础上，在理论上提出了确定和选择荒漠化评价指标体系综合性、主导性和实用性相结合原则，即科学合理、小样本、可测且误差较小、反应敏感应用广泛且成本低、用途广泛且易于获得、综合性强并对生态系统无破坏等。在实际工作中，应遵循综合性、主导性和实用性原则，根据评价研究尺度、监测方法、技术手段、经费投入等因素，选择气候、土壤、地貌、植被、水文等自然因素以及人为因素和社会经济因素，尽可能简洁并易于获取、经济实用，切实可行。 就荒漠化监测技术和方法而言，一个在3S(GIS、GPS、RS)支持下荒漠化监测技术日臻成熟。利用计算机解译遥感图象-目视解译和数字卫星影像资料计算机屏幕勾绘方法，将是今后荒漠化监测的主要方法之一。 结合全国荒漠化典型监测，以盐池荒漠化定位监测研究为对象，在分析以往大量资料的基础上，结合典型调查数据，在图形图象处理方面，采用R2V数字化软件以及ArcView GIS系统，并利用马尔可夫链(Markov)模型和模糊模式识别(Fuzzy Pattern Recognition)数学方法对盐池荒漠化现状和动态变化进行分析。研究表明：过去40年盐池县土地荒漠化发展强烈，荒漠化土地面积已占北部总土地面积的89.04％，荒漠化土地平均年增长率4.03％。荒漠化主要原因是在脆弱生态环境(大量丰富、易于侵蚀的沙物质、干旱、大风、植被稀少等)和全球变化(温度升高、降水减少或季节性干旱)基础上，人为不合理经济活动所致。人口过快增长是造成盐池县土地荒漠化的根本原因；在此基础上过度放牧和过度垦荒是两大主要原因，其次是滥挖甘草和樵采等活动；管理不善、治理投入不足等进一步加剧了荒漠化。近期盐池县土地荒漠化防治重点应在转变观念(控制人口过快增长、增强可持续发展理念)、抓住“退耕还林”等生态治理工程机遇，加强管理(加大宣传力度、严格执法)、首先控制畜牧业过快增长，严格控制牲畜头数，作好禁牧和划区轮牧工作；其次，要杜绝新的滥垦，结合盐环定引黄工程，组织好移民工作，防止新的由于移民所导致的滥垦。第三，要通过加强管理，严格执法手段，杜绝滥挖甘草现象。 最后关于荒漠化评价存在的问题(评价基线、评价时空尺度、评价监测的指标体系、正确区分干旱与荒漠化对植被的影响)进行了讨论。同时就我国荒漠化定位监测网络建设和荒漠化定位监测技术规范提出了建议。更多还原

【Abstract】 As the global environment degradation, more and more attention is paid to desertification worldwide. After half century disputing and even there still some debating, the definition on desertification in the United Nations Convention to Combat Desertification in Countries Experiencing Serious Drought and/or Desertification, Particularly in Africa were accepted by most of people worldwide, namely, "desertification" means land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities.In this paper, through methods of theory with typical studies the author point out the guidelines for choice the desertification assessment system. Under guidance of integrated, dominant and practical, the indicators used for desertification assessment should be rational in science, use small sample, measurable with minimized error, sensitive and easily got with less cost and broadly used, integrated and without harm to ecosystem. While in practical desertification assessment, one should base on the research scale, monitoring & assessment method, technical measures and outlay investment to select climate factors, soil factors, topography factors, vegetation factors, hydrological factors and some social economic factors whivh including human factors.As development of computer science and for monitoring methods, 3S (GIS, GPS, RS) supported desertification monitoring method will be one of the most advanced and abroadly used methods in future. By images computer interpreting, artificial interpreting and images computer screen drawing methods will be the most used and popularized.Taking Yanchi County as case studies, by data collection & analysts with typical investigation data, and by using R2V digital method, Arc View GIS softare and the mathematical methods of Markov Chain model and Fuzzy Pattern Recognition, desertification pattern and trend were studied. The results show that in past 40 years, desertification has been seriously in Yanchi County. Desertified land has takes 89.04% in its north part and mean yearly increased rate was 4.03%. The main causes of desertification in Yanchi County are frangible ecological condition (rich erosive sandy soil materials, drought weather condition, strong wind in winter & early spring, thin plant covering) with global change (temperature increasing, rain fall reducing with seasonable drought) combined with un-rational human activities. Over-speeded population increment is the basic cause of desertification. It leads over grazing, over cultivation, un-rational Chinese medicine and fuel wood collection. Mis-management & small control investment speed up the desertification. For desertification combating in future, much attention should be paid to change idea (family planning & sustainable development), taking advantage of project of "Reversion of Farmland to Forest" and other policies, enhance management (massive propagation and strictly implementation of Desertification Law) and increase investment in desertification control. First, animal stock should be reduced as population control policy. Some pastureland should be enclosed & protected. Rotation grazing should be adopted. Second, over-cultivation should be stopped. Combined with Yan-Huan-Ding Water Transportation Project, immigration should well be organized to avoid over-cultivation. Third, massive propagation and strictly implementation law should stop un-rational Chinese medicine and fuel wood collection activities.At last some problems opinions on desertification as assessment baseline, time and space scale, indicators, drought and its effect to plant are discussed. And the regulation for desertification fixed monitoring should be made in near future.更多还原