【作者】 陈芳淼；

【导师】 胡跃高； 曾昭海；

【作者基本信息】 中国农业大学 ， 作物栽培学与耕作学， 2013， 博士

【摘要】 从历史演变状况看,荒漠化问题区域特征明显,整体可归属于地理系统问题。因此,用地理系统方法衡量与评价荒漠化问题具有科学性。地理学是实践科学。使用地理系统方法在认识荒漠化演化机制的同时,可以为防治工作提供重要理论指导。依据地理学特征,可将区域荒漠化问题划分到耕地、草地、林地、湿地-水系、沙地、社区六元结构板块,进行基本状况、发展趋势、主要原因及演化机制认识(简称六元法)。我国西部地区地域辽阔、政治地位重要、文化结构多元,其可持续发展对我国乃至整个亚太地区建设具有重要意义。近半个多世纪以来,该区域社会经济发展迅速,但与此同时出现了区域荒漠化问题加重、生态环境恶化、地理系统变化剧烈等问题,严重影响区域协调发展。本研究用六元法,从村庄、县域、省域、区域尺度,对西部地区荒漠化问题进行逐级研究验证,分析认识区域荒漠化演化机制,探索防治对策,同时检验六元法的有效性。研究得出如下结论：1、我国西部地区荒漠化演化基本机制通过六元法多层次、多点、长历史时段考察,得出我国西部地区荒漠化演化机制为：耕地扩张,耕地质量下降；天然草地缩减、人工草场扩大,草地整体退化严重；天然林遭到严重破坏,近期人工林地面积稳步扩大,林地生态经济功能较弱；湿地-水系萎缩,地表水面积减少，河流径流不稳定性增加,地下水位下降,冰川融化加剧；沙地系统局部得到控制,整体扩张：社区扩张明显,城镇居民区和工矿区建设步伐快,大量占用郊区优质耕地。上述发展趋势反映出耕地、社区、人工林地扩张,草地、湿地-水系显著退化,沙地整体形势严峻,西部地区荒漠化形势不容乐观。进一步分析表明,导致西部荒漠化问题严峻化的基本因素为人为因素与自然因素。其中,人为因素占主导方面。2、我国西部地区防治荒漠化对策建议研究对未来西部地区防治荒漠化工作提出如下建议：1)加强区域防治荒漠化管理机构与机制建设；2)彻查全区资源环境状况,为防治工作提供依据；3)严格控制耕地、社区发展,其中包括工矿业经济发展,建立严格的草地、湿地-水系保护体系；4)将防治荒漠化措施落实到每一个村庄或嘎查；5)尊重民族区域防治荒漠化的传统经验,制定少数民族地区生态经济综合发展政策；6)采取措施,积极应对全球气候变暖在西部地区产生的荒漠化效应；7)全面加强防治荒漠化的科学技术体系建设,为防治工作提供理论指导与技术支撑。3、六元法应用认识对“六元法”的实际应用得出如下认识：1)利用“六元法”进行区域荒漠化研究可覆盖全地理区域,研究方法简洁,研究结果条理清晰,问题定位准确,容易得出明确结论；2)“六元法”适用于多尺度地理系统(从村庄到全球系统)研究,上下尺度间研究结果互为印证,利于原因诊断；3)可分别六单元进行纵向历史发展趋势演变研究,借以从历史角度清晰地判明各自的发展轨迹与彼此演替机制；4)可分别区域地理特征,判断单元荒漠化轻重关系与主次矛盾：5)县域及以下尺度的研究中,注意从主体地理单元把握荒漠化现状及其演化过程的细节,寻求针对性防治对策；县域以上尺度的研究中,注意对各地理单元变化趋势进行归纳总结,理清演变机制。更多还原

【Abstract】 Judging from historical evolvement, the desertification problems occur regionally and generally could be located in geographic systems. It is scientific to measure and assess the desertification problem by geographic methods. Geography is the science of practice. Geographic systematical method is helpful to understand the mechanism of desertification evolvement while provids important theoretical support for prevent. According to geographic features, the desertification area could be divided into six units as arable land, lawn, woodland, marsh and hydrographic net, sandlot and community area. The basic status, evolvement trend, main reasons, evolvement mechanism could be analyzed from these six respects, and the methodology is called the "Six-unit Method". The western China is large with important political position and various cultures, and the sustainable development of this area is very critical to China, even the whole Asia. In recent5decades, the regional economy is developing rapidly, at the same time, the desertification problem and ecological environment are becoming worse, geographic system is changing fiercely as well, which have severely influenced the regional development. This research studied the desertification in the western China, from village to large region scale, analyzing and discussing the regional desertification evolvement mechanism, probing the countermeasures, and verifying the "Six-unit Method".The conclusions are concluded as below:1The basic evolvement mechanism of desertification in the western ChinaThrough multi-level, multi-point and long historical period research by applying the "Six-unit Method", this research came to a conclusion of the desertification evolvement mechanisms of China’s western region:the expansion of arable land in parallel with quality decrease; natural lawn reduced and artificial lawn expended, with serious degradation of lawn in overall; natural woodland suffered severely destruction, the area of artificial woodland enlarged steadily in the recent period, the ecological economy function of woodland is weak; marsh and hydrographic net decreased, and surface water area is reduced, increased the instability of river and runoff, groundwater declined, melting glaciers aggravated; Sandlot system was partly controlled, but the entirety expanded in long period; community expanded obviously, the pace of construction of urban residential area and industrial and mining areas was fast, which threatens high quality farmlands nearby. These trends reflect the fact that arable land, community and artificial woodland expanded, while lawn, marsh and hydrographic net degenerated observably, sandlot situation is grim. The whole situation of desertification in western region is not optimistic. Further analysis showed that the fundamental factors lead to severe desertification in western area included human factors and natural factors. Among them, the human factors were dominant.2The suggestions for anti-desertification in the western chinaThe suggestions for anti-desertification in western china was presented as followed:1) To enhance the administration and the mechanism construction of regional desertification prevention and treatment.2) To completely investigate the situation of resources and environment in the whole area to provide the basis of the work of anti-desertification.3) To strictly control the development of arable land and community area, including the economic development of industry and mining industry, establishing strict protection system for lawn and hydrographic net.4) To implement the anti-desertification measures into every village.5) To respect the traditional experience of anti-desertification by ethnic people, building policies for comprehensive development of regional ecological economy.6) To implement measures for dealing with the desertification effect due to global warming in the western china.7) To comprehensively enhance the construction of the scientific technology system of desertification prevention and treatment, while provide the theoretical guidance and the technological support.3Application of the "Six-unit Method"Concluded from the practice of "Six-unit Method":1) Using the six-unit method to do the research of anti-desertification could coverage the whole geographic region. The method is simple, and the result is coherent. The location of the question was accurate, and could easily be concluded.2) This method could be applied to multi-scale geographic systems (from village to the whole world system), and results of the research between upper and lower scale could confirm each other, that is helpful to find out the causes.3) The research could be carried out from the vertically historical development point of view, that could ascertain the respective developing path and the mechanism of succession for each system.4)When apply this method, the geographic features and the primary or secondary contradiction between each unit should be considered.5) In county scale research(and below), should focus on key geographic systems to understand the details of desertification for finding targeted countermeasures. For the research above the county scale, each geographic unit should be discussed for clearly analyzing the evolvement mechanism.更多还原