深圳市主要公园及道路绿地土壤重金属含量状况比较研究

对深圳城市主要公园和道路绿地土壤Cu、Zn、Pb、Cd含量状况进行取样调查分析。研究结果表明,绿地土壤重金属含量与土地利用类型有关,表现为道路绿地土壤Cu、Zn、Pb平均含量高于公园绿地土壤,而Cd平均含量则相反。采用不同土壤重金属污染评价方法对深圳城市绿地土壤进行的环境质量评价均表明深圳城市绿地土壤Cd污染现象显著。在考察的四种重金属元素中,Zn含量与土壤有机质、pH有关,其中pH对Zn含量的影响相对较大;土壤Cu与Pb、Zn呈直线相关,表现出相互依存的关系。     

日本横滨市土壤各形态铅和蚯蚓体内铅的含量关系研究

以日本横滨市国道两侧绿地土壤和横滨国立大学校内绿地土壤为研究区,采用连续浸提-ICP法分析了横滨市土壤环境中表层(0～5cm)和5～20cm处的Ph元素的水溶性、离子态、碳酸盐结合态、铁锰氧化物结合态、有机质结合态、和残渣态Pb的含量变化及其与土壤蚯蚓体内Pb含量的关系,结果表明:横滨市土壤表层全Ph含量在76.85～100.05 mg kg-1之间,5～20cm土层全Pb含量为40.83～57mg kg-1之间,远高于当地的土壤Pb背景值(17mg kg-1),受到不同程度的污染;并且横滨国立大学校内绿地土壤比围道两侧绿地土壤表层的全Ph含量显著提高,其污染原因有待于进一步研究.蚯蚓体内的Pb含量变化范围在在研究区各采样点中没有显著差异,统计分析结果表明,蚯蚓体内的Pb含量与土壤环境中各形态Pb之间并无线性相关关系.     

沈阳适应老年人身心健康的居住区景观设计调查分析

随着人口老龄化程度的加剧,居住小区是老年人日常生活的主要空间,居住小区景观设计应该更加关注老年人的生理与心 理状态。城市绿地设计关注老年人是人性化设计的一部分,城市居住区绿地设计是否关注老年人更是一个国家文明程度的实际体 现。在了解老年人对居住区绿地需求的基础上,以沈阳市有代表性小区为研究对象,通过问卷调查、现场访谈等研究方式,对沈阳 居住小区绿地进行前期调查发现,使用者在服务设施、地面状况、植物景观等方面不甚满意。为解决这些问题,在居住区的设计中 要注重安全性、生态性和人性化的设计理念。重视细节,为老年人提供一个舒适的户外活动空间。     

黄土区村级农田土壤养分空间变异特征研究

本研究选择黄土高原地区陕西省新集村为研究对象。在219hm2耕地上用网格法采集364个表层(0~20 cm)土壤,研究了该村土壤pH,有机质和速效养分(N,P,K,Ca,Mg,S)空间变异性。结果表明:该村98.9%耕地缺N,缺K,缺P比例占11.5%和4.4%。地统计学分析结果表明:土壤有机质、有效N、P、K、Mg、Ca、S具有中等的空间相关性,空间变异程度依次为:OM>P>Ca>K>Mg>N>S,土壤pH的空间相关性很弱。有机质、有效N、S最大相关距离大,达到1853m,pH值最小,为148m,K、Ca、P、Mg最大相关距离分别为717m、720m、1032m和1344m。施肥是导致该村土壤养分空间变异性的主要原因。基于土壤养分状况和空间分布特征,目前仅需要考虑对该村土壤K,P进行分区管理。     

基于GIS的杭州市居民区土壤重金属污染现状及空间分异研究

研究了杭州市50个代表性居民小区土壤重金属(Cd、Cr、Cu、Ni、Pb和Zn)的含量,按照国家《土壤环境质量标准》对该市居民区土壤重金属污染状况做出了评价,并在GIS技术支持下,研究了土壤重金属污染的空间变异性。结果表明,杭州市居民区土壤均受到了不同程度的污染。其中4%的土壤轻度污染,54%的土壤中度污染,42%的土壤严重污染。土壤重金属污染具有显著的空间分异特征,严重污染区域大致呈西北-东南走向,包括了城北的大部分地区、市中心和城东南一些地区。工业生产和居民区形成时间对居民区土壤重金属积累有较大的影响。     

双氰胺对土壤酶活性的影响

本文选用沈阳市东陵区天拄山耕作棕壤,采用室内培养试验研究了双氰胺对土壤酶活性的影响情况。双氰胺对土壤中性磷酸酶活性的影响主要在培养的前20天,表现为显著的抑制作用;对土壤脲酶活性的影响主要在培养的第20、30天时表现为显著的抑制作用;对土壤过氧化氢酶活性的影响在培养的第30天时表现为显著的激活作用;对土壤转化酶活性影响不大。     

论资源节约型高速公路绿地规划设计

高速公路绿地由于跨度大、功能特殊、绿化宽度窄、环境差、养护不方便,虽然前期建设和后期养护投入很大,但是难以达到理想 的效果,造成资源的浪费与破坏。因此,资源节约型高速公路绿地成为高速公路规划设计的主流理念。高速公路绿地具有大跨度狭长 线型性、植物生存环境差和景观环境多样性等特点,也具有生态防护、引导防眩和景观绿化功能,资源节约型高速公路绿地具有粗放 养护、节约水资源和节省土地资源的特征,资源节约型高速公路绿地设计思路坚持保护和利用现有景观资源,遵循乡土性、抗污染性、 抗旱性和土壤适应性原则,优化选择景观植物,构建地带性植物群落,实现资源节约型高速公路的可持续发展目标。     

不同频率激励信号下土壤水分传感器性能试验

激励信号频率是影响高频电容式土壤水分传感器性能的重要因素。利用去离子水和2—异丙氧基乙醇(2—isoproxyethanol)或二氧六环(dioxane)2种溶液混合,配制了一系列等效土壤体积含水率为0.9%~51.8%的待测介电溶液来替代土样。从与土壤含水率的函数关系、温度变异性2个方面,分别对激励信号频率为40,50,60,70,80,90,100 MHz的7种土壤水分传感器进行了性能测试与分析。结果表明:7种频率的传感器的输出电压均与土壤体积含水率呈线性负相关,其相关系数R2均大于0.94;激励信号频率不影响传感器输出电压的温度变异性,温差是影响温度变异性的主要因素,其最大变异率均小于4%。试验结果可为设计高频电容式土壤水分传感器时选择激励信号频率提供依据。     

苏南典型地区土壤颗粒的空间变异特征

在地统计学和GIS的支持下,以半方差函数为基本工具,分析了苏南典型地区耕层土壤颗粒的空间变异特征,并运用块段普通克立格法(BlockKriging)进行最优无偏线性插值,制作了不同粒径土壤颗粒的空间分布图。结果表明,研究区域不同粒径土壤颗粒在较大的范围内存在着空间相关性,砂粒和粉砂的空间相关距离达到243km,粘粒也达到81km;不同粒径土壤颗粒由结构性因素引起的空间变异性达到70%以上,反映了土壤颗粒在研究区域内具有较强的空间自相关性。Kriging插值结果更直观地反映了研究区域土壤颗粒的空间变异特征。     

海伦县土壤重金属含量的空间变异性研究

兼顾土壤类型和相对均匀性的前提下,在黑龙江省海伦县中部地区采集黑土土壤样品60个(0-20cm),在GIS的支持下,采用经典统计学与地统计学相结合的方法研究了土壤铜、铬、铅、镉、汞、砷含量的空间变异性及分异规律。结果表明,就空间相关域而言,铜含量的空间变异性比铬要大;铅、镉、汞、砷含量存在很好的空间结构性,趋势项可用一次趋势面方程分离,一次趋势面方程代表了这四种元素的宏观分布趋势;铜、铬、铅含量的空间分异表现为起伏变化较大,岛状区域分布较多;铅、镉、汞含量以靠近海伦县县城处相对较高,砷含量不同空间位置上变化相对比较平缓。     

杭州市城市土壤有机碳的积累和特性

杭州市城市土壤有机碳具明显的积累并具较大的空间变异性,城区土壤表土(0~10 cm)和0~100 cm深度土壤平均有机碳贮量约为远郊区土壤的4.3和5.7倍。城市土壤有机碳中含较高比例的碳黑、颗粒态碳和较低比例的易氧化态碳,表明城市土壤有机碳较为稳定。随着人为影响程度的增加,土壤碳黑、颗粒状碳量增加,易氧化态碳的数量减少。     

Quantifying urban land use and impact on soils in Egypt using diurnal satellite imagery of the Earth surface

Conversion of agricultural land to urban use represents a potential loss of agricultural productivity, especially in areas where arable land is in short supply. Using derived products from both daytime (Landsat sensor data) and night-time imaging systems (U.S. Air Force Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS)) we examined the impacts of urbanization on soils in Egypt; a country with very limited agricultural land. We concluded that urban land cover types to occupy 3.7% of the total area of Egypt and that over 30% of the soils most suitable for agriculture are under urban land cover. Analysis of multiyear historical DMSP/OLS data sets (digitized from paper images) proved unreliable for long-term urban growth estimates.     

长期施肥对城市边缘区不同作物土壤酶活性的影响

以开封市为例,探讨了长期施肥条件下城市边缘区不同作物土壤酶活性的变化及其与土壤养分的关系。结果表明,土壤酶活性受施肥处理影响明显,其中蛋白酶、过氧化氢酶、转化酶和脲酶活性在化肥处理中均受到抑制,在有机肥中却得到大幅提升,碱性磷酸酶活性变化与之正好相反;在混施处理中各酶活性均有不同程度的增强,其中以脲酶活性增强尤为突出。土壤酶活性在各作物之间表现出一定的差异,但总的来说差异不显著。土壤各酶之间及酶与土壤肥力因素之间存在显著或极显著相关关系,因此土壤酶活性可以作为城市边缘区土壤环境质量评价的生物肥力指标之一。     

南京城市土壤磷的形态和吸附-解吸特征

研究了南京城市土壤有机磷、各形态无机磷的含量和比例以及磷的吸附 -解吸特性。结果表明 :随着土壤全磷含量的增加 ,Al-P、Fe -P、O -P、Ca -P含量、Al-P占全磷的比例增加 ,但有机磷占全磷的比例、Fe -P占全磷的比例减少 ;与非城区土壤相比较 ,城市土壤磷的吸附量低 ,磷的解吸量和解吸率高 ;城市土壤中Al -P的含量及其在全磷中的比例较高 ,而磷的吸附量低、解吸率高是导致城市地下水磷浓度偏高的重要原因之一。     

Mapping the land-cover distribution in arid and semiarid urban landscapes with Landsat Thematic Mapper imagery

Mapping the land-cover distribution in arid and semiarid urban landscapes using medium spatial resolution imagery is especially difficult due to the mixed-pixel problem in remotely sensed data and the confusion of spectral signatures among bare soils, sparse density shrub lands, and impervious surface areas (ISAs hereafter). This article explores a hybrid method consisting of linear spectral mixture analysis (LSMA), decision tree classifier, and cluster analysis for mapping land-cover distribution in two arid and semiarid urban landscapes: Urumqi, China, and Phoenix, USA. The Landsat Thematic Mapper (TM) imagery was unmixed into four endmember fraction images (i.e. high-albedo object, low-albedo object, green vegetation (GV), and soil) using the LSMA approach. New variables from these fraction images and TM spectral bands were used to map seven land-cover classes (i.e. forest, shrub, grass, crop, bare soil, ISA, and water) using the decision tree classifier. The cluster analysis was further used to modify the classification results. QuickBird imagery in Urumqi and aerial photographs in Phoenix were used to assess classification accuracy. Overall classification accuracies of 86.0% for Urumqi and 88.7% for Phoenix were obtained, much higher accuracies than those utilizing the traditional maximum likelihood classifier (MLC). This research demonstrates the necessity of using new variables from fraction images to distinguish between ISA and bare soils and between shrub and other vegetation types. It also indicates the different effects of spatial patterns of land-cover composition in arid and semiarid landscapes on urban land-cover classification.     

上海市区公园土壤重金属含量及其污染评价

通过对上海市区44个公园土壤重金属含量的调查,发现市区公园表层土壤Pb、Zn、Cu和Cr的平均含量分别为55.1mg kg-1,198.5 mg kg-1、44.6 mg kg-1、77.0 mg kg-1。以上海土壤背景值为标准,用内梅罗指数法综合评价上海市区公园土壤重金属污染状况为:绝大部分公园为轻污染,9个为中度污染,7个达重度污染。通过对公园土壤重金属含量的空间分析发现:内环线附近公园土壤Pb、Zn和Cu的平均含量最高,Cr的平均含量以内外环线之间公园为最高。上海市区公园较严重的重金属污染可能来源于交通和工业污染,与公园建成时间无显著性相关。     

土壤重金属污染的熵权模糊综合评价

利用2011年全国大学生数学建模竞赛A题所给数据,通过MAPGIS软件的空间分析功能分别绘制了各重金属的空间分布等值线和表面图。为对该城区不同区域的重金属污染程度进行综合评价,将污染等级分为A,B,C,D,E五级,利用熵值法确定了8种污染物的权重,利用模糊综合评价法对不同区域的的重金属污染程度进行了评价,通过实证分析表明该方法是合理、可行的。     

Analysis of land use/cover changes and urban expansion of Nairobi city using remote sensing and GIS

We used three Landsat images together with socio‐economic data in a post‐classification analysis to map the spatial dynamics of land use/cover changes and identify the urbanization process in Nairobi city. Land use/cover statistics, extracted from Landsat Multi‐spectral Scanner (MSS), Thematic Mapper (TM) and Enhanced Thematic Mapper plus (ETM+) images for 1976, 1988 and 2000 respectively, revealed that the built‐up area has expanded by about 47?km². The road network has influenced the spatial patterns and structure of urban development, so that the expansion of the built‐up areas has assumed an accretive as well as linear growth along the major roads. The urban expansion has been accompanied by loss of forests and urban sprawl. Integration of demographic and socio‐economic data with land use/cover change revealed that economic growth and proximity to transportation routes have been the major factors promoting urban expansion. Topography, geology and soils were also analysed as possible factors influencing expansion. The integration of remote sensing and Geographical Information System (GIS) was found to be effective in monitoring land use/cover changes and providing valuable information necessary for planning and research. A better understanding of the spatial and temporal dynamics of the city's growth, provided by this study, forms a basis for better planning and effective spatial organization of urban activities for future development of Nairobi city.     

A GIS AND WEB-BASED DECISION SUPPORT TOOL FOR THE MANAGEMENT OF URBAN SOILS

Soils are fundamental to urban environmental quality. They have aesthetic and recreational functions in parks and gardens and contribute to the preservation of biodiversity. They also directly influence citizens' health. This paper describes the initial development of a decision support tool (DST) to appraise the urban soil resource and its valuable functions within a wide range of urban environments. It is aimed to provide assistance to local, national, and European authorities in the optimum planning and sustainable management of their soils resources. The DST is an integrated information technology system based on a spatially distributed environmental database management system of soil quality parameters and soil characteristics together with broader environmental factors. The integration is achieved through the implementation of the DST within the framework of a geographical information system coupled with risk assessment, pollution decay, and other models including the handling of “soft” data. The DST will be web-based, allowing wide access to all stakeholders and citizens, providing on-line forums for consultations, and exchange of information and feedback among stakeholders. It is designed to support true transparency in decision making at the local and international levels. The paper focuses specifically on the development of the system architecture of the DST.