【作者】 陈峰云；

【导师】 蔡崇法； 吴宜进；

【作者基本信息】 华中农业大学 ， 资源环境信息工程， 2009， 博士

【摘要】 土地利用/覆被变化是人类活动作用于自然环境的具体表现形式,是全球环境变化的重要组成部分和主要原因,是自然环境变化的主要驱动因素之一。人类活动通过土地利用/覆被变化改变自然环境的空间格局和过程,影响了自然环境形成与变化的复杂性。湖北武汉历来有“九省通衢”之称,随着国家“中部崛起”战略的逐渐推进,武汉城市圈“两型”社会建设综合配套改革试验总体方案获国家批准并实施,区域内土地覆被格局将发生显著的变化,对该区域的土壤环境、水环境和气候环境等自然环境要素也将产生深远的影响。因此,开展土地利用/覆被变化及其对自然环境要素影响的研究对本区水土资源优化配置、社会经济可持续发展及自然生态环境改善都有着十分重要的意义。本研究以80年代中期、90年代中期和21世纪初期的TM卫星影像资料和相关的社会经济统计资料等为数据源,结合野外调查,运用3S集成技术,对各种数据和信息进行科学的校正和处理。通过室内分析、模式识别、模型模拟、空间演算等多种手段,分析了湖北省过去二十年间土地利用/覆被变化的动态过程、驱动因子,提出了典型性分区模式,针对11个典型县市的土地利用覆被变化进行聚类分析,在此基础上,对湖北省土地利用变化最活跃的耕地、林地和建设用地进行了预测分析。本研究结合湖北省土壤侵蚀遥感资料和土壤养分资料,探讨了土地利用/覆被变化对土壤侵蚀和土壤质量的影响;结合水文水质资料,探讨了土地利用/覆被变化对水文环境的影响;结合多年气象气候资料,探讨了土地利用/覆被变化所产生的气候效应。主要研究结果如下:(1)在过去二十年间,湖北省土地利用/覆被发生了显著的变化。从数量上来看,1985-1995年间变化幅度从大到小依次是:耕地、林地、水域、居民建设用地、未利用土地、草地;1996-2005年则为未利用地、水域、耕地、林地、交通设施及建设用地、园地、草地。二十年间土地利用/覆被变化的主要趋势表现为耕地面积不断减少,林地面积总体呈增加趋势,建设用地呈逐年增加趋势。(2)湖北省土地利用/覆被变化是多种因素交织在一起共同作用造成的。人口增加、国民经济的发展、耕地效益比较低下及洪涝灾害是耕地减少、以鱼塘增加为主要特征的水域增加及建设用地扩张的主要原因。(3)根据社会-经济-生态现状将湖北省划分为四个一级区划,14个二级区划。通过对丹江口等11个典型县市近五年的土地利用变化聚类分析发现以大冶为首的六个市(县),建设用地增长显著;洪湖市充分发挥其湖泊资源优势,水域面积增加较大;秭归县受大型水利工程影响,水域面积也大幅增加;丹江口等三个市(县)耕地猛减,林地剧增,两者成此消彼长的趋势。根据遥感解译和统计资料显示,湖北省土地利用变化最活跃的是耕、林、建三类用地。选用灰色预测GM(1,1)模型,预测湖北省至2010年的情况呈现:耕地下降曲线应该更为平稳,林地面积将稳步上升,建设用地也将不断在增加。(4)湖北省土壤侵蚀总体呈下降趋势,中度侵蚀和强度侵蚀面积下降变幅较大。土地利用类型改变,一定程度上影响了土壤侵蚀速度和侵蚀强度。从地类上看,耕地、林地的土壤侵蚀面积最大,占流域侵蚀总面积的95.9%;从地域分布上看西部山区最为严重,中南部次之。土壤侵蚀主要分布在15°以上的陡坡地。(5)土地利用类型的改变严重影响了土壤质量要素的空间异质性。不同土壤质量要素在不同深度的差异较大,0-20 cm的高低顺序依次为:有效磷、速效钾、TP、水解性氮、TN、有机质、TK、pH值;20-100 cm的高低顺序是:有效磷、有机质、速效钾、TP、水解性氮、TN、TK、pH值;表层土壤pH均值为6.23,深层土壤均值为6.83,全区域呈弱酸性;全省有机质平均含量较高,表层达1.926%。说明湖北农业基础条件较好,种植业比较发达。从块金值与基台值之比来看,表层土壤的pH值最小,为19.8%,其他的土壤要素都没有大于50%,说明影响pH值分布的结构性因素控制导致样点之间的空间自相关作用强,而其他各土壤要素为中等强度的空间自相关。(6)湖北水资源相当丰富,但城市化使湖泊河塘面积剧减,尤其是经济发展较快地区,水资源利用形势严峻。通过计算,21世纪初湖北省以武汉市为首的鄂东一带和以襄樊为首的鄂北地区存在较为严重的水量紧张状态和安全问题;21世纪前50年生产生活用水增加101.6亿m3,增长幅度非常明显,而后50年仅增长10.4亿m3,且增长趋势渐缓。土地利用/覆被的变化是湖北水灾的主要诱因之一,城市化使地表径流系数增大,使洪水的洪峰变窄,峰线提前;城市现有排水方式造成雨水资源的浪费和污染等;城市化使江河近岸、湖泊富营养化污染严重;农业土地利用对水质的影响主要表现在化肥、农药污染,畜禽养殖、居民生活垃圾污染等多方面。(7)湖北省近45年年平均气温为15.9℃,上升了0.54℃,上升速率为0.12℃/10a。上世纪80年代以来极端最高气温呈现较明显的上升趋势。武汉市最近23年城市热岛增温强度在不同季节均有所增加;近45年平均降水量为1145.8mm,年降雨量增加速率为6.9mm/10a,呈现出明显的年际和年代际变化;年平均日照时数为1749.9h,呈现明显的下降趋势,其下降速率为-68.6h/10a;近年来的强降水的增加直接导致了洪涝灾害的增加。(8)江汉平原湿地的退化与恢复导致局地气候变化。江汉平原自1958年后年平均气温呈上升趋势,气温增加为0.246℃/10a,但1998年之后气温出现了明显下降趋势,年平均气温从1998年的17.92℃下降到现在的16.96℃,平均为0.4℃/a;在降水量的变化方面,20世纪90年代以来年降水量以平均4.9mm/a的速率增加,并以夏、冬季降水增加为主。(9)城市化所带来的土地利用变化对城市气候产生了较大影响,城市环境温度与下垫面温度、下垫面结构、水体、植被等因素密切相关。随着城市化进程加快,武汉市城市热岛效应愈强。1961-2000年的平均气温、最高气温和最低气温增温速率的季节差异明显,冬季增温速率非常显著;对同一季节,最低气温的增温速率最大,最高气温的增温速率最小,平均气温居中,非对称性明显;近20年无论是城区还是郊区,3项气温的增温速率在不同的季节都得以加强;近20年热岛增温速率明显增加,尤其是夏季的最高气温和冬季的最低气温。由于城市热岛的存在,产生了武汉的城市风场,武汉市城市风场与武汉市城市热岛中心位置非常吻合。更多还原

【Abstract】 The land use/cover change, as the concrete forms that human activities affected the natural environment,is the key component and the main reason of global environmental change. It is also one of the main driving forces of natural environment change. Human activities affect the spatial pattern and process of natural environment through changing land use/cover. Wuhan is called "the Centre of Nine Provinces" in the history. With the process of gradually promoting of "the rising of the central China" and the authorized and implementing of Wuhan city circle as "the reform testing areas of national resources-saving and environment-neighboring social constructions with synthesis and whole set", significant variations will be taken place to land cover pattern. And it will have an profound influence on the regional natural environmental factors such as soil environment, water environment and climate environment. Thus, it is very important of study on land use/land cover change and its impacts on natural environment to the optimal allocation of soil and water resources, social economic sustainable development and natural eco-environment improvement.Based on the TM images of Mid of Eighties, mid of Nineties and early 21st Century and socio-economic statistic data etc., combination of field investigation, using 3S integration technique, the various data and information are corrected and handled scientifically. Using various means such as laboratory analysis, pattern recognition, model simulation and spatial calculation etc., we study on the dynamic process and driving factors of Hubei’s land use / cover change in the past 20 years and put forward a typical partitioned mode, and apply cluster analysis to the land use/cover change of 11 typical cities (counties).Some predictions were done to analysis the most active land use change land category such as cultivated land, woodland and construction land. At the same time, this study discussed the effect of land use / cover change to soil erosion and soil quality combining with soil nutrient data and the remote sensing data of soil erosion. Using hydrology and water quality data, this study analysised the effect of land use/cover change to hydrological environment. And in this study we also discuss the climatic effects of land use/cover change combining with many years of meteorological and climate data. The main results are as follows:(1) In the past 20 years, significant changes were observed in the land use/cover of Hubei Province. During the years of 1985-1995, the order of the change range, from maximum to minimum, is cultivated land, woodland, waters, residential land, unutilized land, grassland. Cultivated land area obviously reduced among them. The order in the year 1996 to 2005 is unutilized land, waters, cultivated land, woodland, construction land, garden plot, grassland. The main tendency for the changes of land use/cover change in the past two decades is that cultivated land decreases gradually, while woodland shows an increasing trend, and construction land has a year-by-year-increasing trend.(2) It is apparent that the land use/cover change are caused by the interaction of various factors. The main reason of the decrease of cultivated land, the increase of waters owing to of fish pond, and the construction land expansion, is the explosion of population, the development of national economic, the low comparative benefit of cultivated land and flood disaster.(3) Hubei is divided into 4 class-1 regionalization, according to the present situation of society-economy-ecology, and 14 class-2 regionalization. Cluster analysis is employed to analysis the land use/cover change of 11 typical cities (counties) including Danjiangkou. The results showed that the Daye-led 6 cities (counties) has a increasing trend of construction land; Honghu which gives full play to its advantage of lake resource, as well as Zigui which is influenced by "large dams"in the area duing to increasing of waters; there is a leap of woodland and rapid reduction of cultivated land with a trend of one-falls-the-other-rises in Danjiangkou-led 3 cities (counties).As the remote sensing interpretation and statistical data say that the most actively change is the three categories of land as follows: cultivated land, woodland, construction land. The situation of Hubei (to 2010) is predicted by the application of grey forecasting model GM (1, 1). The result shows that the decreasing curve of cultivated land will much more stable while woodland will rise steadily and construction land will increase continuously.(4) Soil erosion displays a general downward trend in Hubei. The decrease rate of middle degree erosion and serious erosion is maximum. The change of land use type worsens the speed and intensity of soil erosion, furthermore, increases the amount of soil erosion. In the view of land category, the erosion area of cultivated land and woodland is the most, covering the 95.9 percent of total watershed erosion area.According to regional distribution, erosion intensity of West Mountain areas are the most, the next is central south areas. There was a good correlation between soil erosion and slope, most erosion are steep sloping field which 15 degree upwards.(5) The category change of land use effect the spatial heterogeneity of soil quality characteristics greatly. The different soil quality factors have different statistical variation in different depth. The order of these factors in the layer of 0～20 cm deep is available phosphorus, available potassium, TP,, TN, organic matter, TK, pH. The order in the layer of 20～100 cm deep, from max to min, is available phosphorus, organic matter, available potassium, TP, hydrolyzable nitrogen, TN, TK, pH. The pH of the whole region of Hubei Province appeared a little acidic, with the average being at 6.23 in the surface soil and 6.83 in the deep. The more sample depth increase, the more pH rise. The average content of organic matter of the whole province is relatively high; even surface soil can reach 1.926%. It show that the basic condition of Hubei’s agriculture is a relatively good, the planting is comparatively developed. In the view of nugget-sill ratios, the pH of surface soil is the minimum 19.8%, others are no more than 50%. The results showed that the structural factor controlling of pH distribution leaded to the high intensity of spatial autocorrelation between sample points, while other factors showed medium intensity spatial autocorrelation.(6) The water resource is abundant in Hubei, but area of lakes and ponds declines sharply because of urbanization. Especially in regions with rapid economic development, water resources utilization is facing a serious situation. It’s found by calculation that, there are quite serious problems about quantity of water and security in the east area of Hubei leading by Wuhan and the north area leading by Xiangfan at begin of 21st century. In the previous fifty years of 21st century, the consumption of living and production water will increase 10.16 billion stereos, which the rate is quite obvious, and only 1.04 billion stereos in posterior 50 years, which the rate slows down gradually. Land use/cover change is a main factor of floods in Hubei because of the following reasons. The urbanization process leads to increasing of surface runoff coefficient, blood becoming narrow and earlier. The existing mode of water discharge bring about waste and pollution of rain water. The urbanization process also causes eutrophication of lakes and river. And the influences of agriculture land use on water quality are as follows, chemical, fertilizer and pesticide pollution, livestock and poultry raising, living garbage pollution etc.(7) In recent 45 years, Hubei annual mean temperature is 15.9℃, which has rise 0.54℃and the rising speed is 0.12℃/10a. And the extreme maximum temperature showed a significant rising trend since 1980s. The urban heat island warming intension in capital Wuhan has strengthened in different season in recent 23 years. The annual mean precipitation is 1145.8mm in recent 45 years, which has a rising trend of 6.9mm/10a. The annual mean sunshine duration is 1749.9h, which has a obvious decreasing trend of -68.6H/10a. The increasing of heavy rainfall in recent years results in more flooding disaster.(8) The degeneration and recovering of the Jianghan plain wetland lead to local climate change. Since 1958, the annual mean temperature of the Jianghan plain has shown a trend of rising and the rising rate is 0.246℃/10a. But the temperature has begun to decrease obviously after 1998. The annual mean temperature decreased from 17.92℃in 1998 to 16.96℃nowadays and the rate is 0.4℃/a. Referring to the change of precipitation, it increased 4.9mm/a average since 1990s, especially in Sumer and Winter.(9) The urban environment temperature is closely related to such factors as underlying surface temperature, underlying surface structure difference, water body, vegetation cover and so on. As the change of land use due to the urbanization have extended great influence on the urban climate, the rapid acceleration of urbanization process lead to urban heat island effect of Wuhan increasingly. The seasonal difference about the rate of warming of the mean temperature, the maximum temperature and the minimum temperature from 1961 to 2000 was significant. Such conclusion was draw that a remarkable warming rate occurred in winter and the warming rate showed nonsymmetry in same season, which the warming rate of minimum temperature was highest, maximum temperature lowest and mean temperature between them. In recent two decades, the warming rate of mean, minimum and maximum temperature is raised in both urban and suburban in different season, and the warming rate due to the heat island obviously increased, especially maximum temperature in summer and minimum temperature in winter. The existing of urban heat island leads to the generation of the urban winds. And the urban winds is quite fit with the center of urban heat island in Wuhan.更多还原