节点文献

经济发达地区城镇化对土壤质量的影响分析

Influence of Urbanization on the Soil Quality in Developed Regions

【作者】 严世光

【导师】 廖铁军;

【作者基本信息】 西南大学 , 土壤学, 2010, 硕士

【副题名】以富阳市为例

【摘要】 城镇化是人类社会发展的必然趋势,已经成为重要的社会、经济现象。然而城镇化在改变人们生活方式的同时,也对城镇及其周边地区的资源、生态、环境产生巨大的挑战,特别是作为人类生存基础的土壤和耕地资源,在城镇化进程中面临着前所未有的压力。富阳市位于经济发达的长江三角洲地区,是杭州未来大都市的重要组成部分,作为城镇化快速发展的地区之一,由城镇化引发的土壤和耕地资源、质量、环境等方面的问题十分突出。本研究以富阳市为例,利用1996年、2004年和2009年三个时期的富阳市土地利用现状数据以及2006年采集的富阳市土壤样点数据,分析了富阳市1996-2009年的城镇扩张格局及其对土壤资源的影响;运用GIS和地统计学对土壤各肥力因子和土壤重金属元素进行了空间变异分析,在此基础上用土壤肥力质量综合指数(IFI)和内梅罗综合指数法分别评价了土壤肥力质量和环境质量,并阐述了在城镇化过程中,不同的土地利用方式对土壤肥力质量和环境质量的影响;最后探讨了城镇扩张对基本农田和耕地占补的影响。主要结果如下:(1)1996年以来,富阳市的城镇扩张呈加速发展态势,相应地也导致了土壤资源数量的不断缩减。富阳市的城镇用地面积在过去的13年间增加了3.7倍。其中,1996-2004年期间,城镇用地的年扩张速率达到了惊人的23.00%,这个时期富阳市乡镇的扩张速度是城区的2倍,发展速度明显快于城区;2004-2009年期间,城镇用地速度开始放缓,年扩张速率下降到6.03%,而这一时期城区的扩张速度要快于乡镇,是乡镇扩张的3.2倍。从城镇扩张的空间上看,城镇的主要扩张区域都位于富春江沿岸的两侧,并以富阳城区为中心、以辐射状向周围城镇扩张,另外富阳市西南部的新登镇和北部的万市镇城镇扩张速度也比较快。从1996年到2009年,富阳市城镇扩展88.15%占用的是质地优良的水稻土类,可见城镇化的发展已经对富阳市的土壤质量及耕地质量产生不利影响。(2)土壤肥力和环境质量空间变化特征:研究区域内土壤pH、有效P及速效K的空间变异明显,尤其是有效P及速效K受人为因素的影响比较大。富阳市土壤肥力质量总体较高,而且发展潜力较大,主要以Ⅲ类土壤为主,其次是Ⅱ土壤、Ⅳ类土壤和Ⅰ类土壤。Ⅰ类土壤和Ⅱ类土壤主要分布于富阳市主要的三大农业发展带,Ⅲ类土壤分布最广,Ⅳ类土壤则呈零星分布。研究发现,不同的土地利用方式已经使富阳市的土壤肥力质量有下降的趋势。研究区域内的土壤重金属已经在土壤中富集积累,但是大部分土壤还没有受到重金属污染。土壤Cu、Ni、Pb和Zn的空间变异较为明显,土壤Cd的空间相关性较好。从土壤环境质量评价上看,土地利用方式是导致土壤重金属污染的主要因素,富阳市各区域的重金属污染程度从轻到重的顺序依次是:建制镇、城区、城郊、其他用地区、村庄、采矿用地。建制镇和城区的土壤环境质量相对较好,范围内无污染的土壤,但重金属已经在土壤中累积;其他区域受工业“三废”的排放或者农业长期施用化肥和农药的影响都已经不同程度的受到了土壤重金属的污染。(3)城镇扩张与基本农田、耕地占补平衡政策的关系:经过基本农田调整后,富阳市2009年的基本农田面积比1996年的基本农田面积增加了76.59hm2,而且布局更加集中连片,土壤质量也比1996年有所提高,但是土壤环境质量相对于1996年有所下降,需要引起有关方面的重视。富阳市在1996-2009年的城镇化过程中,耕地占补平衡。但是从耕地占补的空间上看,占用耕地主要为富春江和320国道的两侧低丘和平原的耕地,并呈一定的带状对称分布,而补充耕地则较为零散,主要在富阳市西北部的山地和丘陵地区;从高程和坡度上看,富阳市的耕地质量有下降的趋势,而在坡向上这一趋势并不明显;从土壤肥力质量上看,主要占用的是高等级的土壤,补充的则是低等级的土壤,耕地质量有所下降;从土壤环境质量上看,补充耕地的环境质量虽然比占用耕地情况要好,但是补充耕地中属于警戒级的土壤数量要大于占用耕地,补充耕地中土壤重金属已经开始富集,土壤环境质量有下降的趋势。

【Abstract】 Urbanization is an inevitable trend of development of human society, have become important social and economic phenomena. However, Urbanization is changing lifestyles, but it also has posed enormous amount of challenges to many aspects of environment of cities and its periphery, e.g. resources, ecology, environment, etc. Among them, soil and land resources, the bases of human survivals, are facing unprecedented pressure.Fuyang City, located in the developed Yangtze River Delta region, is an important part of the future metropolis in Hangzhou, has astonishingly prominent issues of soil and land resources, quality, environment, which are brought about by rapid urbanization. In this study, the urban sprawl pattern of Fuyang City from 1996-2009 and its influences on soil resources were analysed, with the database of land use in 1996,2004 and 2009 and the data of soil samples collected in 2006 in Fuyang City; Meanwhile, the research analyzed spatial variability of soil fertility factors and heavy metals by GIS and geostatistics, as a consequence, soil fertility and environmental quality were assessed respectively, with the Soil Fertility Index (IFI) method and the Nemerow Comprehensive Index method; analysis the impacts of different land management policy on soil fertility quality and environmental quality in the process of urbanization; Finally, based on results got from processes above, the impacts of urban expansion on basic farmland and requitision-compensation of arable land have been conducted. The results are as follows:(1) Since 1996, Fuyang City, was to accelerate the development trend of urban expansion, a corresponding amount of resources has also led to the continuous reduction in the soil.Urbanization has been posing impacts on the quality of soil and arable land. To be specific, area of urban land in Fuyang City increased by 3.7 times in the past 13 years. Among them, in the period of 1996-2004, the annual expansion rate of urban land achieved 23.00% astonishingly, and the rate of township expansion doubled that of urban areas; and from 2004 to 2009, urban land expansion rate started to slow down, specifically, the annual expansion rate dropped to 6.03%, and urban areas sprawled faster than township (3.7 times). Space for urban expansion from the point of view, the major expansion of urban areas are located along both sides of Fuchun River, and to Fuyang City as the center and radial expansion of the surrounding cities and towns, while the southwestern Xindeng town and northern Wanshi town sprawled fast as well. In addition,88.15% of urban expansion occupied high quality paddy soil types in Fuyang City from 1996 to 2009, the development of urbanization in Fuyang City has been adverse effects impacted on the soil quality and land quality.(2) Spatial variation of soil fertility and environmental quality characteristics:In the study area, there are obvious spatial variability of soil pH, available P, and available K, especially available P and available K influenced by anthropogenic factors is relatively large. The soil fertility quality in Fuyang City is high as a whole and is full of potential, which comprises mainly soil type III soil, followed by soil typeⅡ,Ⅳ,ⅠType I andⅡare mainly distributed in the three major agricultural development zones of Fuyang City, and typeⅣis distributed sporadically, while type III is of wide distribution. As illustrated in this dissertation, different land use patterns have influenced the soil fertility quality of Fuyang City, which will pose challenges to reasonable configuration and scientific management of soil resources.As far as soil in the study area, in spite of the accumulated heavy metals within it, most of it is not affected. Soil Cu, Ni, Pb and Zn have obvious spatial variability, whereas soil Cd has good spatial correlation. Judging from the evaluation of soil environmental quality, land use is the main factor leading to soil heavy metal pollution in Fuyang City. It is reported that the heavy metal pollution in the region can be ranked from light to heavy as follows:towns, urban, suburban, other land, village, mining lease. Towns and urban areas is relatively better soil environmental quality, without pollution but heavy metal has accumulated in the soil; other regions have been polluted by soil heavy metal due to discharge of industrial waste and long-term application of chemical fertilizers and pesticides.(3) The relationship between the urbanization and basic farmland, requisition-compensation of arable land:After basic farmland adjustment, area of basic farmland in 2009 has increased 76.59hm2 than that of 1996 in Fuyang City, and more focused contiguous layout, soil quality is also improved over 1996, however, the decline of soil environmental quality should be given enough attention.Requisition-compensation of arable land has been achieved in the process of urbanization of Fuyang City in the period of 1996-2009. However, the space from Requisition-compensation of arable land point of view, requisition of farmland mainly distributed in hilly and plain land along Fuchun River and State Highway 320, whereas the compensation of arable land is relatively dispersed, mainly distributed in the mountain and hilly regions in the northwest part of Fuyang City; from the elevation and slope point of view, the quality of cultivated land in Fuyang City has declined, while the upward trend in the slope is not obvious; from soil fertility quality point of view, requisition is mainly constituted of high-grade soil, while low level soil is compensated, the quality of cultivated land has declined; from the soil environmental quality perspective, although the environmental quality of compensational arable land is better than the cultivated land requisitioned, heavy metals has begun enriching in soil of compensational arable land, i.e., soil quality tends to declined.

  • 【网络出版投稿人】 西南大学
  • 【网络出版年期】2010年 08期
节点文献中: