【作者】 李秀花；

【导师】 齐家国；

【作者基本信息】 新疆大学 ， 自然地理学， 2009， 博士

【摘要】 土地利用/土地覆被变化影响着能量交换、水分循环、土壤侵蚀与堆积、生物地球化学循环和作物生产等陆地主要生态过程的结构和功能。特别是对于直接依赖于土地资源而进行生产的农业生态经济复合系统来说,土地利用/土地覆被变化影响着系统内能量和资源的输入、利用和输出,从而对农业复合系统的生产功能和可持续性产生巨大而深远的影响。因此,土地利用/土地覆被变化下农业复合系统发展的可持续性研究应当成为LUCC研究的主要内容之一。在国家西部大开发的基本国策下,如何保护好生态环境、实现土地资源持续利用和农业系统可持续发展,对整个西北干旱区的发展来说至关重要。论文以土地资源学、景观生态学、生态经济学、可持续发展理论和社会-经济-自然复合系统论为理论框架,以遥感(RS)、地理信息系统(GIS)和全球定位系统(GPS)为主要技术支持,以马尔科夫转移矩阵、克里格插值和相图法以及数理统计方法等为主要分析方法,选取新疆维吾尔自治区的精河县为典型研究区,开展土地利用/土地覆被变化与农业系统可持续发展评价研究,以期为我国西北干旱区土地可持续利用管理和农业发展科学决策提供有力依据。循此目标,论文核心内容包括:1.以1990、1999和2007年的TM影像数据为主要遥感信息源,将遥感定量分析方法和马尔科夫转移矩阵相结合,全面开展精河县土地利用/土地覆被变化特征研究。结果着重表现在土地利用的变化速度、时空状态转移、土地利用程度和趋势以及植被覆盖指数变化等方面:(1)整个研究时段内农田的面积先是增加,到2001年以后又逐渐减小,城乡建设用地比例虽然很小,但处于增加趋势,其它土地利用类型的面积处于一定程度的波动变化中,但波动幅度不大;(2) 1990~1999年,农田面积增加的速度最快,为13.75%/a,未利用地以小于单位动态度的速度增加,此间的城乡建设用地增速较小,而林地、草地和盐碱地/沼泽处于减小的动态变化中;(3) 1999~2007年,城乡建设用地增速迅猛,达到18.15%/a,其次是盐碱地/沼泽的动态度超过了5%/a,草地则以每年2.82%的速度减少,水域面积的减少也超过了单位动态度,另外还有农田也处于减少的动态过程中;(4)土地利用/覆被变化过程中,林地、草地和未利用地三种土地利用类型的状态转移特征相对于其它几种类型更加明显,其中未利用地面积持续上升,而草地面积持续下降;(5)研究区土地利用/覆被变化过程是马尔柯夫状态转移过程,且在9年、8年和17年三种步长下均能达到稳态概率,并且土地利用/覆被变化的马尔柯夫过程的收敛情况与步长和初始状态的选取密切相关;(6) 1990~2007年研究区的平均NDVI逐渐下降,且下降幅度明显高于土地利用程度降低的幅度,表明土地利用程度的降低对NDVI的减小具有放大作用,说明人类活动对NDVI变化的影响正逐渐增大。2.基于三期TM遥感影像的分类结果,借助于地理信息系统中的地统计学模块,分析研究区农业系统能值产出在相应土地利用类型上的空间分布特征。从1990~2007年精河县农业系统能值投入和产出入手,着重对系统能值可持续发展性能进行分析和评价。发现1990~2007年精河县农业系统的能值投入总量在波动中增加,能值产出逐渐上升。农业用地的能值集约水平持续提高。能值产出的空间分布差异显著,能值高值区主要在种植棉花、枸杞等的农田用地类型上。3.从能值分析的角度出发,选取有效评价指标,在研究区土地利用/土地覆被变化背景下,分析其农业系统的可持续发展性能。虽然1990~2007年精河县农业系统的发展是可持续的,但是,其发展的能值可持续性指数是逐渐下降的,说明系统的可持续发展性能在逐渐降低。通过分析研究区农业系统发展的持续性指标ESI分别与土地利用程度La以及土地覆被指数NDVI之间的关系分析发现:三个指数在1990、1999和2007年都在逐步下降,其中以NDVI的下降速度最快,ESI与La之间变化的相似性高达0.964。另外,从理论和实践两个方面分别对系统可持续发展的能值指标ESI的有效性加以分析和验证。结果表明运用系统可持续发展的能值指标ESI来评价精河县农业系统的可持续发展状况是符合当地实际的,同时也是合理和有效的。4.依据以上对研究区农业系统可持续发展性能的评价结果,选取精河县农业系统未来发展的四种情景进行分析,从中优选出适宜研究区的、相对高效的可持续发展模式。借助于人工神经网络(ANN)方法,对系统的能值利用情况进行预测,并基于预测结果提出自然发展情景、农业系统能值总产出与总投入的比值EmY/EmT最大情景、农业系统能值利用边际效益ΔEmY/ΔEmT最大情景和能值投入比例调节8%*EmT情景,并分别得到四种情景下的系统能值产出率和系统能值产出结构的稳定性S和优势度D。选取S/D、EYR、ESI三种能值利用的综合指标,对上述四种情景模式进行优选,系统能值投入比例调节情景模式EmR2+8EmF-8为研究区农业系统2008~2013年六年中较为适宜的、相对高效的能值可持续发展模式。5.为精河县农业系统未来的可持续发展提出决策参考与建议,在土地资源合理利用政策的制定及策略的调整方面提出科学依据。建议精河县在未来的农业发展中应当多借鉴国内外在发展可持续农业或生态农业方面的先进经验,学习其成功做法,为本地农业的可持续发展所用;在农业发展中,注意利用新能源和当地的优势资源,如太阳能、风能等,提高农业系统能值利用的可更新资源投入比例。同时,要善于挖掘本地特色资源潜力,像棉花、枸杞和卤虫等;立足当地区位优势,大力发展农、林、牧、渔一体,种养结合及粮、棉、林、果、畜、禽、水产结合的立体发展模式。在具体发展过程中,需要采取的发展对策有:提高农民各方面的素质;在农业节水方面花大气力,做实、做好;对农业产业结构的调整,本着“一业为主,多种经营”的思路,在稳定原有基础产业的前提下,坚持走枸杞种植和水产养殖等多种经营的发展路子。为保证对策措施的有效实施,各部门必须积极协调与支持,建立一个保障体系。为我国西北干旱区的土地可持续利用和农业的可持续发展树立起一个光辉典范。更多还原

【Abstract】 Land use/land cover change affects the energy exchange, water cycle, soil erosion and accumulation, biogeochemical cycles and crop production such as land-based structure of the main ecological processes and functions. Especially for the direct dependence on land resources in the production of agricultural eco-economic complex systems, land use/land cover change impacts on system resources, energy input and output, therefore, complex system of agricultural production functions can have a great sustained and far-reaching impact. Therefore, land use/land cover change of the development of complex system of agricultural research should be continued. And LUCC research should be one of the main contents.Development of western region is a major strategic decision-making at the beginning of the new century in order to reach the great rejuvenation of China. It’s very critical to achieve such a goal that land resources use and agricultural system are both sustainable on condition of better protecting ecological environment in arid and semi-arid area of northwest China.With the help of“3S”tecnology, ternary diagram and statistics etc., the analysis of LUCC and the evaluation on agricultural-system sustainability are processed taking Jinghe county of Xinjiang as a case study on the base of land resource science, landscape ecology, ecological economics, emergy theory, social-economic-natural complex system theory as theoretical framework and sustainable development theory. The information of LUCC in this dissertation is obtained from TM image of 1990, 1999 and 2007. With it the landscape patterns both land use and emergy distribution are spatially showed out. Acts on these objectives the core contents of thesis include:First, three TM remote sensing images act as the main source of information. Quantitative analysis of remote sensing methods combining Markov transition matrix is applied to comprehensive change research. The results focus on the change speed, the temporal-spatial transfer of status, the extent and trends of land use/land cover change and some indices of land cover:The farmland area increases then minishes gradually. From 1990 to 1999 its up speed is 13.75%/a. Land area of urban & rural construction is small in ratio. Its trend is going up at 18.15% per year from 1999 to 2007. And at the same time, the salty land & marsh is adding at more than 5%/a. However, grassland area decreases at a speed of 2.82% per year. Other types vary also, but their variable extents are not very obvious like farmland, urban and rural construction land and salty land & marsh.In landuse type transition, forest land, grassland and unused land are more obvious than others. There are all steady status in Markov transition with steps of 9-year, 8-year and 17-year. And their Markov-transition convergence closely relate to the step and initial state.From 1990 to 2007, the average NDVI of the studied area decrease with a degree higher than the landuse extent. It shows that the reducment of landuse extent can amplify the minishing NDVI, and human activities affect NDVI more and more greatly.Second, the emergy analysis is carried out on agricultural system. By means of the geostatistics module in geographic information systems, this thesis analyzes the emergy output of agricultural systems and the characteristics of the spatial distribution on it’s correspond land-use types based on the classification results from TM remote sensing images.Starting from the emergy input and output in Jinghe County from 1990 to 2007, the key points are the evaluation on emergy sustainability of agricultural system. By cotrast, it is found that the tatal emergy input increase in fluctuation and the output ascend gradually. The intensive level continues to be improved. There is significant difference in spatial distribution of emergy output. And its high-value areas are mainly in the cotton and wolfberry plant field.From the emergy point of view, energy flow, material flow even information flow can all be transferred into solar energy uniformly to express. Then, some indices are inducted into evaluation on the sustainability of agricultural system. By means of the emergy evaluation results, four scenarios of agriculture development are analyzed on condition that a forecast method of artificial neural network (ANN) is choosed. They are natural development scenario, the largest ratio between input and output (EmY/ EmT) one, the maximum of marginal benefit (ΔEmY/ΔEmT) scenario and the adjustment on the ratio of 8% * EmT one. Furthermore, two indices S and D are induced into the analysis on stability of the agricultural system. Then, three general indices such as S/D, EYR and ESI are carefully analyzed. At last the most efficient one (EmR2+8EmF-8) that fits to the study area is selected out from them.Last, the results including both LUCC and emergy analysis on the agricultural system can help the sustainable development of agricultural system in Jinghe County and give some scientific basis to policy-making and stratigy-adjustment in rational use of land resources in the future.In Jinghe County it is proposed that the agricultural development in the future should learn advanced experience and successful practices on the development of sustainable agriculture or eco-agriculture from the domestic and abroad for the sustainable development of local agricultural use. Pay attention to the use of new energy and the advantages of local resources such as solar, wind, etc., improve the value of the use of renewable resources into the ratio of the agricultural systems. At the same time, we should be good at mining the resource potential of the local characteristics, such as cotton, Chinese wolfberry and artemia; based on advantage when the region to develop agriculture, forestry, animal husbandry and fishery together and grain farming, cotton, forestry, fruit, livestock, poultry , three-dimensional combination of aquaculture development.In the specific process of agricultural development, some countermeasures should be taken to improve its sustainability. The first one is to improve the farmer quality of all aspects; the second one is that lots of efforts should be spent on the agricultural water-saving for good efficicncy; the third one is to adjust the agricultural structure with the spirit of "one industry-based, diversified economy". And under the premise of basic industries in the stability of the original, insists on wolfberry plant, aquaculture operators and others such as the development of a variety of ways are nacessary. In order to ensure the effective implementation of response measures, all of the departments must actively coordinate and support the establishment of a security system for the sustainable development of agriculture in studied area. And then an excellent sample can be set for our whole northwest arid area with good agriculture development sustainability.更多还原