【作者】 刘桂芳；

【导师】 孙九林；

【作者基本信息】 河南大学 ， 人文地理学， 2009， 博士

【摘要】 土地利用是人与自然的最直接的对话,人地矛盾代表了人与环境间最大的利害冲突。20世纪60年代以来,伴随着全球经济迅猛发展,人口爆炸性地增长。人类面临着人口膨胀、资源匮乏和环境变化三大危机,人地矛盾日益激化,进而全球环境变化研究日益受到重视。大量的研究表明,土地利用/土地覆被变化(LUCC)是引起全球环境变化的最重要的原因之一,而土地的可持续利用是有效解决全球环境、资源等问题的有效途径。国内外关于LUCC开展了许多卓有成效的研究工作。这些工作对深化LUCC理论、指导区域实践及后续研究都具有非常大的意义。但在研究中仍存在着一些不足,如对非“热点”,但土地利用条件独特,人地关系复杂的特殊区域研究不够,不利于LUCC理论的进一步深化和通用模型的建立;土地利用变化作为仅次于化石燃料燃烧的影响人为二氧化碳排放的第二大因素,其碳汇效应在中、小区域尺度上的研究还很不深入,而土地利用具体调控大多和中小尺度尤其是县域尺度相一致;土地可持续利用评价的参照标准和评价依据不统一、可比性差,实践意义不强。因此,在一个土地利用条件较为独特的特殊区域内,系统地分析区域LUCC规律,揭示LUCC的驱动机制,采用统一标准评价LUCC的可持续性,指出土地利用中存在的不可持续因素,根据区域水土资源状况和社会经济发展水平,提出可持续土地利用的对策和建议,既具有重要的区域实践价值,又具有进一步深化LUCC研究的重要理论价值。黄河中下游过渡区位于我国第二级地貌台阶与第三级地貌台阶的接触部位,为黄土高原的后缘,系太行山前丘陵向黄河冲积平原过渡地带,黄河在该区河道逐渐展宽,泥沙开始大量沉积,因此,该区受黄河影响深刻,拥有较大面积的黄河滩地、湿地、另有较大面积的河谷冲积平原以及低山丘陵区,地形复杂,光、热、水等资源差异明显,区位特殊,土地利用条件独特。近些年,该区经济发展迅速,土地利用变化剧烈,导致人地关系紧张。本文以黄河中下游过渡区的孟州市为研究样区,以LUCC的方法、思想为依托,运用人地关系理论、土壤学理论、土地经济学理论、遥感和GIS学科等相关理论和方法,对这一LUCC特殊区域的土地利用变化及驱动力进行深入研究;对区域土地利用变化的资源环境效应和碳效应进行了分析评价;根据上述研究结果和区域土地利用实际,尝试构建了乡镇土地可持续利用的资源环境、社会和经济指标体系,并在此基础上,统一以某指标全市平均水平作为该指标评价的“阈值”,给出了各乡镇土地利用相对可持续性的空间和时间尺度上的评价,并指出了各乡镇土地利用过程中存在的不利因素;最后,提出黄河中下游过渡区土地可持续利用对策。得出了以下主要结论:1)黄河中下游过渡区的孟州市近20年的土地利用变化主要是:建设用地逐年增加;林地、园地面积有较大扩展;耕地面积总量变化不大,质量有所下降;水域、未利用地面积不断减少。耕地、林地和园地的变化主要发生在黄土丘陵向冲积平原过渡地带的乡镇;建设用地和水域滩地面积变化主要发生在黄河沿岸的乡镇;冲积平原上的乡镇,各土地利用类型的相对变化率均较大;耕地和建设用地分布较为均衡,其它地类集中分布在部分乡镇中,整体格局保持不变。土地利用程度综合指数值属中等偏上水平,土地利用由快速发展期开始走上稳定期。2)土地利用变化的驱动机制分析表明:本区土地利用变化主要受到了地貌、气候、水文、土壤、植被以及自然灾害等自然驱动力和人口、社会经济发展水平、技术进步、政策以及区域文化环境等人文驱动力的共同作用影响。3)农田排灌系统的不断完善,影响了水分在区域中的再分配与运行过程,陵区地下水位普遍上升2-3米,而在平原低洼易涝地,地下水位下降,使盐碱地得到改良;采取秸秆还田、引黄淤灌等多种土壤培肥、改良措施,区域水土资源环境得到了明显改观。另一方面,由于黄河流域近年来气候变干、降水量减少,农业灌溉用水的大幅增加,又导致了区域水资源不足,湿地面积减小,地下水采补失衡,部分地区形成大面积地下水降落漏斗,以及生活污水和工业废水污染农田等新的水土资源环境问题,严重影响了区域土地的可持续利用和社会经济的进一步发展,成为新时期区域土地利用研究和土地利用管理的重点。4)1987-2007年间,孟州市由于土地利用转类造成县域陆地生态系统总碳储量增加99.69×103MgC,这表明在近20年里,孟州市土地利用变化的碳效应总的表现为较弱的碳汇作用。其中林、园地尤其是林地由于具有较高的植被碳密度和土壤碳密度,其面积增加增强了区域陆地生态系统的固碳能力,起着碳汇作用;而水域滩涂的大量开垦及建设用地的大幅增加则是导致区域植被碳储量减少的重要原因。因此,未来在严格控制建设用地的同时,要加大植树造林力度,以增加区域陆地生态系统中的碳储量,减少碳排放。5)将土地利用系统可持续性评价指标体系分为目标层、子目标层、准则层、指标层四个层次,采用目标分解法构建框架结构;以孟州市为研究样区,从微观尺度出发,基于多源数据,并针对孟州市土地利用特点,从土地利用系统的资源环境、经济和社会等方面建立指标体系;在此基础上,统一以某指标全市平均水平作为该指标评价的“阈值”,给出了各乡镇土地利用相对可持续性的空间和时间尺度上的评价,指出了各乡镇土地利用过程中存在的不利因素。评价结果:土地利用系统相对可持续性较高的乡镇主要分布在孟州市的平原地区,较低的乡镇主要分布在丘陵区,且这种差距在不断拉大。从资源环境可持续性、经济可持续性和社会可持续性三个不同土地利用效应来看,不同乡镇之间互不相同,其中,资源环境相对可持续性差别较小,经济相对可持续性差别较大。同一乡镇土地利用不同方面的相对可持续性差别也较大,一些乡镇虽然资源环境和经济相对可持续性均较高,但社会相对可持续性较低,个别乡则土地利用各方面相对可持续性均十分低,这些落后地区在进行县域发展规划时应给予重点扶持。6)采用对地物光谱影响较大的地貌因素(高程、坡度及地表组成物质)对研究区进行分区解译,使得在同一区中的相同地物类型具有较为一致的光谱特征,不同的地物之间则有较大的光谱差异,可减少“同物异谱”现象,并同时使用多层次提取法,可在一定程度上提高遥感影像的解译精度。更多还原

【Abstract】 It is the most direct dialogue between people and the nature and human-land conflict represents the greatest conflict between people and environment. Since 1960s with global economy developing rapidly and population explosion mankind has faced three major crises of population expansion, resource shortage and environment changes. As a result of human-land conflict sharpening day by day studies on global environmental change are paid more attention. A large amount of research indicated that Land use-cover change (LUCC) is one of the most important reasons causing the global environment change, and sustainable land use is the effective way of solving problems such as global environment and resources,etc..Highly successful researches on LUCC have been launched home and abroad, making LUCC theory deeper and instructing follow-up studies. But some insufficient still existed. For example studies on special region of not-hot spot were not enough, causing shortages of deepening theory and constructing general model. As the second leading factor of carbon emission carbon effective on village and town area were shortage. Standards and reference of LUCC sustainability evaluation were not uniform and weak in practice. So, it not only had the practical value of special region but also had the value of LUCC theory through adopting uniform LUCC standard, pointing out the unsustainable factor in LUCC and putting forward countermeasure and suggestion according to the regional water and soil resources and social economic development level in a given region.The middle-lower transition region of the Yellow River located in the contact of the second landscape step and the third landscape step, being the trailing edge of Loess Plateau and the transition area between the front hills of Taihang Mountain and the alluvial plain of Yellow River. This district is influenced by the Yellow River deeply. The Yellow River opens up gradually and a large amount of silt begins to deposit. Here is large beach, wetland, and valley alluvial plain and low hill area. The special topography are with different resources of light, heat, water,etc. and unique LUCC conditions. In recent years, the economy grown fast, the land use changed violently and human-land conflict relation was nervous. In this paper Mengzhou City was chosen as the study city. LUCC and driving mechanism were studied deeply through human-land theory, soil theory, land economy theory and GIS and RS technology and resource environmental effect and carbon effect were evaluated. Based on above result land use relative sustainability evaluation of villages and towns was gained and relative land use obstacle factors were given regarding average level of the whole county as "Threshold". Finally, sustainable land use countermeasures and suggestions on middle-lower transition region of the Yellow River were given. The results showed:1) The main land use change in Mengzhou City for the past 20 years was that building area increased year by year, forest and garden area expanded greatly, farm area did not change generally bur with quality dropping, water and un-used area reduced constantly. Changes of the farm land, forest land and garden land mainly located in the town of transition area from loess hills to alluvial plain. Change of building and water beach mainly located in villages and towns along the Yellow River. The relative change rate of every land use pattern in the alluvial plain was great. Farm and building land distributed evenly and other kind of land concentrated in some villages, showing intact pattern for the past 20 years. Comprehensive index of land use belonged to medium and above grade, showing that land use stepped into steady period from developing fast period.2)The analysis on driving mechanism of land use change showed that land use change mainly influenced synthetically by natural driving forces such as landscape, climate, hydrology, soil, vegetation, natural calamity and humane driving force such as population social economic development, technological progress, policy, regional cultural environment.3)The constant completion of farmland drains and irrigates influenced water reallocation and operation courses. In this area water level in hills generally rose by 2-3 meters, but that in the low-lying area in plain dropped, making the salt-alkaline area to be better. Soil improvement methods such as straw returning and basin irrigation from the Yellow River made the water and soil resources environment obviously change better. On the other hand, climate becoming dry in recent years, precipitation in the Yellow River Basin reducing and great incensement on agricultural irrigation water produced new environmental problems like that regional water resource became insufficient, wetland area reduced, groundwater level dropped and sanitary sewage and industry waste water polluted farmland. This seriously influenced the sustainable land use and social economy further development, and became the key point of land use research and management in new period.4) From 1987 to 2007, because of land use change carbon storage in Mengzhou City increased by 99.69* 103 MgC. This showed that carbon effect in Mengzhou City was a weak sink. Because of forest land having high vegetation carbon density and soil carbon density, its area increase played a key role in enhancing carbon sink ability. Large reducing water areas and the increase of building land was the main reason of regional vegetation carbon reducing. So in order to increase the carbon storage of the local land ecosystem and reduce carbon emission policy such as planting trees should be enhanced while controlling building area strictly in the future.5) Land use relative sustainability evaluation of villages and towns was constructed from micro angle through considering spatial heterogeneity of villages and towns, and combining index scheme of natural - economy - safety with that of production - safety - protection - economy - society. The land use high relative sustainability area in Meng town mainly located in the plain area, the low one in the northwestern hills. Spatial distribution of resources and environment shown that northeast area was better and west and south hills areas was worse; spatial distribution of production shown that east plain area was strong and west hills areas was weak; spatial distribution of stability shown that east plain area was good, and west hills areas was bad and south Yellow river beach was the worst; spatial distribution of protective shown that south area was strong, north area was weak and east plain area of high population density was weaker. The economic structure and benefits in the western hills area were generally relatively bad, social structure and benefit were relatively better. And the fact was just opposite in the eastern plain area. From 1986 to 2004 spatial distribution of land use relative sustainability was unchangeable generally, showing that east and south area was good and west and north area was bad. The gap between the highest and the lowest was 0.624 in 1986 and increased to 0.889 in 2004, showing a obvious polarization.6) It was a trend that image was classified under combining multi-source remote sensing data with non-remote sensing data by GIS technology. This was because that multi-source data can overcome the lost or error of series data. Meanwhile land use classification accuracy could be effectively improved using background database or expert knowledge database based upon quantitative data of natural and human factors processed by GIS. In this paper, technological framework of land use information extraction was established using multi-source remote sensing data (TM and CBERS-02B), DEM, slope data, land use map and other geographic auxiliary data. The method of multi-level supervised classification was adopted. First urban building and water were extracted on TM 1-4-5 image. Then TM 3-4-5 image was masked by above classified land for remnant land use information extraction. As to CBERS it was 1-2-4 and 4-3-2 respectively. Finally above each classification was overlapped by ERDAS in order to obtain overall land use map. Interpretation accuracy was improved by establishing background database through GIS technology. First, non-remote sensing information, such as topographic map, soil map, land-use map, transportation map, etc, was integrated as background database. Then land use classifications were overlapped with above database. In the study area dry land spectrums in plain area, hilly area and the Yellow River flood plain were very different and spectrums of habitation in plain and the Yellow River land wash were the same. As for above phenomenon of“same object with different spectrums”and“different objects with same spectrum”, expert knowledge database was established based upon correlation between remote sensing image and geographical environment.更多还原