Soil quality changes in land degradation as indicated by soil chemical, biochemical and microbiological properties in a karst area of southwest Guizhou, China   总被引：7，自引：0，他引：7  

Pingjiu Zhang  Lianqing Li  Genxing Pan  Jingchen Ren 《Environmental Geology》2006,51(4):609-619

Not only the nutritional status and biological activity but also the soil ecological functioning or soil health has been impacted profoundly by land degradation in the karst area of southwest China where the karst ecosystems are generally considered as extremely vulnerable to land degradation under intensified land-use changes. The objectives of this study are to elucidate the changes in overall soil quality by a holistic approach of soil nutritional, biological activity, and soil health indicators in the karst area as impacted by intense cultivation and vegetation degradation. Topsoil samples were collected on selected eco-tesserae in a sequence of land degradation in a karst area of southwest Guizhou in 2004. The soil nutrient pools of organic carbon (C_org), extractable extracellular carbon (C_ext), total soil nitrogen (N_t), alkali-hydrolyzable nitrogen (N_ah), total phosphorus (P_t), available phosphorus (P_a) were analyzed by wet soil chemistry. The soil biological properties were studied by means of measurements of microbial biomass carbon (both by fumigation–extraction, FE-C_mic, and by calculation from substrate-incubation respiration, SIR-C_mic) of respiration [respiration without addition of substrates, basal respiration (BR), and potential respiration (PR) with substrate-incubation] and of soil enzyme activities (invertase, urease, and alkaline phosphatase). Soil health status was assessed by simple indices of C_mic/C_org and BR/C_mic in conjunction with bacterial community structures determined by polymerase chain reaction and denaturing gradient gel electrophoresis. While the nutritional pool parameters, such as C_org and C_ext, described basically the changes in soil life-supporting capacity with cultivation interference and vegetation declined, those parameters of biological activity such as FE-C_mic, SIR, and SIR-C_mic as well as bacterial community structures measured by molecular method evidenced well the changes in soil functioning for ecosystem health with the land degradation.  相似文献   

Will the river Irtysh survive the year 2030? Impact of long-term unsuitable land use and water management of the upper stretch of the river catchment (North Kazakhstan)     

Zbyněk Hrkal  Alain Gadalia  Pierre Rigaudiere 《Environmental Geology》2006,50(5):717-723

The Irtysh river basin all the way from river spring in China across Kazakhstan as far as the Russian part of Siberia is among the most ecologically endangered and affected regions on our planet. The study provides a summary of the historical reasons for anthropological interventions in this area, which began with the construction of plants of the military—industrial complexes in the forties of the last century during World War II. These plants have a major share in extreme high concentrations of heavy metals in surface as well in groundwaters locally. The Semipalatinsk nuclear polygon plays a specific role as a source of contamination of local waters. The release of top secret data enabled us to gain knowledge about serious problems related to high radioactivity of groundwaters, which should spread uncontrollably through a system of secondary fissures activated by nuclear blasts. Another serious problem in this region is the quantitative aspect of contamination. Model simulations of water balance indicate that large industrial development in the spring area in China and continuously increasing water consumption in Kazakhstan may lead to desiccation of the lower stretch of this large river in Siberia during the summer months of 2030.  相似文献   

Identification and evaluation of hydrogeochemical processes in the groundwater environment of Delhi, India   总被引：10，自引：0，他引：10  

Manish Kumar  AL. Ramanathan  M. S. Rao  Bhishm Kumar 《Environmental Geology》2006,50(7):1025-1039

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全数字摄影测量系统DEM生产的质量控制     

戴腾  童忠富  祁信舒  陈春华 《地理空间信息》2005,3(1):51-52,56

目前,数字高程模型(DEM)在理论研究和实践应用方面都有了很大的进展,已在测绘、地质、农业、工程、建筑、军事、导航等多个领域得到了广泛应用,因此高效快捷地生产高精度的DEM是十分必要和迫切的。全数字摄影测量系统DEM生产方案是解决这一问题的有效途径,文章针对该系统的特点,提出了加强质量控制的策略和方法,并阐述了对一些实践问题的解决。  相似文献   

区域大气环境质量灰关联评价方法探讨   总被引：7，自引：0，他引：7  

姚焕玫  黄仁涛  蒋文凯 《武汉大学学报(信息科学版)》2005,30(4):326-328

针对区域中大气环境质量的特点，采用对数主成分分析方法获得各环境指标的权重及各监测点的横向排名，再用适宜的灰度关联方法进行了评价。整个过程在MATLAB6．5中实现，计算简便易行，与传统的综合指数法相比较，其评价结果更符合客观实际。  相似文献   

矢量数字地图数据质量的综合评估   总被引：1，自引：0，他引：1  

王华  陈星 《测绘学院学报》2005,22(4):278-280

研究和确定了矢量数字地图数据的质量评估因子和评估标准,介绍了利用模糊综合评估方法进行质量评估的过程和做法,并给出了实例.  相似文献   

非等截面桩超声波成孔质量检测     

韩亮 《物探与化探》2005,29(2):185-188

分析了非等截面超声波成孔质量检测的几个主要影响因素,给出了相应得改进措施。用工程实例说明超声波反射技术是一种保证非等截面桩成孔质量和成桩质量必不可少的检测方法。  相似文献   

隧道锚杆锚固质量无损检测技术   总被引：2，自引：0，他引：2  

黄华林  朱自强  杨天春  王齐仁  鲁光银 《物探与化探》2005,29(6):551-553

采用声波检测仪,应用声频应力波在不同波阻抗面反射的能量和相位的变化原理,对隧道的锚杆锚固质量进行了无损检测试验研究,并对检测技术进行了探讨.结果表明,作为一种工程质量管理辅助手段,采用应力波对锚杆锚固质量进行无损检测,丰富了隧道围岩锚固质量检测方法,为隧道工程建设提供更好的质量保障.  相似文献   

永城煤矿区矿井经济环境价值综合评价     

刘金平张幼蒂  王明明 《中国煤田地质》2005,17(2):40-42

在初步估算永城煤矿区的环境成本的基础上，对该矿区某矿井经济环境综合价值进行了评价和分析。当考虑矿区煤炭环境成本时，煤炭资源开采的净现值变小，该矿井煤炭资源开采的经济环境综合价值变小。进一步计算了不同环境成本和贴现率时的净现值，为动态决策服务。  相似文献   

浅析混凝土质量通病防治的措施     

钱新泽 《中国煤田地质》2005,17(3):56-58

在混凝土工程施工时，经常会发现诸如蜂窝、麻面、孔洞、露筋、缝隙、夹层、缺棱掉角、表面不平整。混凝土强度不够，均质性差等质量通病。在分析产生混凝土施工质量问题原因的基础上，有针对性地提出了各种防治措施。  相似文献