张掖国家级农业高新技术产业示范区规划研究   总被引：7，自引：1，他引：6  

徐建华  刘巧芹  藤丽 《中国沙漠》2000,20(3):283-285

以增长极理论、区位理论、技术创新理论等建设农业高新技术园区的理论为指导,简要论述了建立张掖国家级农业高新技术产业示范区的必要性、可行性,对其规划进行了详细陈述。立足张掖地区实际,体现示范区功能,张掖国家级农业高新技术产业示范区规划研究得出以下结果:①本示范区空间布局采用多核心空间结构;②按照示范区发展侧重点和技术层次高低之不同,提出了三个规划方案,并通过方案对比选择一个最优方案作为实施方案;③该方案把示范区分成中心园区和示范基地两个部分,中心园区依托张掖市东北郊开发区建设,示范基地在各县市条件适宜的位置选建,二者分工协作,共同完成示范区各项职能;④本规划体现了经济、社会和生态效益的有机统一。  相似文献   

土壤侵蚀预报研究中的标准小区问题论证   总被引：19，自引：2，他引：17  

张科利  刘宝元  蔡永明 《地理研究》2000,19(3):297-302

确定标准小区在土壤侵蚀预报中具有重要意义,也是进行土壤侵蚀规律研究的必要基础。文中根据我国的自然环境条件、土壤侵蚀特征、农业生产特点,通过分析土壤侵蚀发生的地形特点、已有资料的坡度变化范围,以及土壤流失量估算中的误差变化规律,提出并论证了我国土壤侵蚀研究中的标准小区应选定15°坡度、20m坡长、5m宽的清耕休闲地。小区每年按传统方法准备成苗床,并按当地农作习惯适时中耕,保证没有明显的杂草生长。  相似文献   

贵州喀斯特峡谷地区土地利用效果评价——以贵州花江峡谷地区为例   总被引：1，自引：0，他引：1  

李开忠  彭贤伟  熊康宁 《中国岩溶》2005,24(4):293-299

通过选取土地生产力、土地多样化程度指数、人均耕地面积、人均GDP等23个影响因子,并采用层次分析法对花江峡谷地区土地利用效果进行评价,以检验当前的土地利用模式是否适宜。测评结果表明,花江峡谷地区土地利用效果以查耳岩村最好,云洞湾、坝山、木工等次之,其它地区则较一般。与此同时,分析评价还证实了目前以经济林(草)种植为主的土地利用模式是适宜于花江峡谷地区的环境条件的。但是,花江峡谷地区土地利用效果很不均衡,有不少地区土地利用效果还比较差,仍需要进一步加强政策扶持与科技、资金及人才的投入。   相似文献   

Are spatial patterns of soil moisture at plot scales generalisable across catchments,climates, and other characteristics? A synthesis of synoptic soil moisture across the Mid-Atlantic     

Charles I. Scaife  Jonathan M. Duncan  Laurence Lin  Christina Tague  Colin D. Bell  Lawrence Band 《水文研究》2021,35(9):e14313

The spatial variation of soil moisture over very small areas (<100 m²) can have nonlinear impacts on cycling and flux rates resulting in bias if it is not considered, but measuring this variation is difficult over extensive temporal and spatial scales. Most studies examining spatial variation of soil moisture were conducted at hillslope (0.01 km²) to multi-catchment spatial scales (1000 km²). They found the greatest variation at mid wetness levels and the smallest variation at wet and dry wetness levels forming a concave down relationship. There is growing evidence that concave down relationships formed between spatial variation of soil moisture and average soil moisture are consistent across spatial scales spanning several orders of magnitude, but more research is needed at very small, plot scales (<100 m²). The goal of this study was to characterise spatial variation in shallow soil moisture at the plot scale by relating the mean of measurements collected in a plot to the standard deviation (SD). We combined data from a previous study with thousands of new soil moisture measurements from 212 plots in eight catchments distributed across the US Mid-Atlantic Region to (1) test for a generalisable mean–SD relationship at plot scales, (2) characterise how landcover, land use, season, and hillslope position contribute to differences in mean–SD relationships, and (3) use these generalised mean–SD relationships to quantify their impacts on catchment scale nitrification and denitrification potential. Our study found that 98% of all measurements formed a generalised mean–SD relationship like those observed at hillslope and catchment spatial scales. The remaining 2% of data comprised a mean–SD relationship with greater spatial variation that originated from two riparian plots reported in a previous study. Incorporating the generalised mean–SD relationship into estimates of nitrification and denitrification potential revealed strong bias that was even greater when incorporating mean–SD observations from the two riparian plots with significantly greater spatial variation.  相似文献   

Supporting USLE‐MM reliability by analyzing soil loss measurement errors          下载免费PDF全文

Vincenzo Bagarello  Vito Ferro 《水文研究》2017,31(4):847-853

Sampling the collected suspension in a storage tank is a common procedure to obtain soil loss data. A calibration curve of the tank has to be used to obtain actual concentration values from those measured by sampling. However, literature suggests that using a tank calibration curve was not a common procedure in the past. For the clay soil of the Sparacia (Italy) experimental station, this investigation aimed to establish a link between the relative performances of the USLE‐M and USLE‐MM models, usable to predict plot soil loss at the event temporal scale, and soil loss measurement errors. Using all available soil loss data, lower soil loss prediction errors were obtained with the USLE‐MM (exponent of the erosivity term, b₁ > 1) than the USLE‐M (b₁ = 1). A systematic error of the soil loss data is unexpected for the Sparacia soil because the calibration curve does not depend on the water level in the tank. In any case, this type of error does not have any effect on the b₁ exponent. Instead, this exponent decreases as the level of underestimation increases for increasing soil loss values. This type of error can occur at Sparacia if it is assumed that a soil loss measurement can be obtained by a bottle sampler dipped close to the bottom of the tank after mixing the suspension and assuming that the measured concentration coincides with the actual one. In this case, the risk is to obtain a lower b₁ value than the actual one. In conclusion, additional investigations on the factors determining errors in soil loss data collected by a sampling procedure are advisable because these errors can have a noticeable effect on the calibrated empirical models for soil loss prediction.  相似文献   

Potential and Suitability Evaluation of CO2 Geological Storage in Major Sedimentary Basins of China, and the Demonstration Project in Ordos Basin     

GUO Jianqiang  WEN Dongguang  ZHANG Senqi  XU Tianfu  LI Xufeng  DIAO Yujie  JIA Xiaofeng 《《地质学报》英文版》2015,89(4):1319-1332

From 2010 to 2012, the China Geological Survey Center for Hydrogeology and Environmental Geology Survey (CHEGS) carried out the project “Potential evaluation and demonstration project of CO2 Geological Storage in China”. During this project, we developed an evaluation index system and technical methods for the potential and suitability of CO2 geological storage based on China’s geological conditions, and evaluated the potential and suitability of the primary basins for CO2 geological storage, in order to draw a series of regional scale maps (at a scale of 1:5000000) and develop an atlas of the main sedimentary basins in China. By using these tools, we delineated many potential targets for CO2 storage. We also built techniques and methods for site selection and the exploration and assessment of CO2 geological storage in deep saline aquifers. Furthermore, through cooperation with the China Shenhua Coal to Liquid and Chemical Co., Ltd., we successfully constructed the first coal-based demonstration project for CO2 geological storage in deep saline aquifers in the Yijinhuoluo Banner of Ordos in the Inner Mongolia Autonomous Region, which brought about the basic preliminary theories, techniques, and methods of geological CO2 storage in deep saline aquifers under China’s geological conditions.  相似文献   

露天矿虚拟采场模型的构建与应用     

宋伟东  耿春雨  于国栋  李兰勇 《测绘科学》2011,36(1):81-83

本文针对我国矿山地质情况及短(中)期生产计划编制方法,以AutoCAD2009为开发平台,提出了一种能够反映矿山工程发展状态及几何约束关系的虚拟采场模型,并利用此模型建立采场时空数据库模型,实现采矿过程的回放及超前演示.  相似文献   

全站仪在森林生态系统大样地定位中的应用     

林观土  王长委  韩锡君  徐庆华  陈军 《测绘科学》2011,36(4):242-243,207

本文介绍全站仪在森林大样地内进行放样测量、树高测量及胸径测量的原理与方法,通过误差传播定律分析其测量的精度,结果表明:全站仪在森林生态调查定位中是可行的.放样距控制点300m的方格顶点的精度可达到1/100,树高测量的精度可达到1/250,胸径测量的精度可达到1/50,可满足林业调查规范的要求.对于日后森林生态系统大样...  相似文献   

Policy incentives for carbon capture and storage technologies in Europe: A qualitative multi-criteria analysis     

Christoph von Stechow  Jim Watson  Barbara Praetorius 《Global Environmental Change》2011,21(2):346-357

In this paper, we compare different policy incentives for overcoming investment uncertainties that are typical for low-carbon technologies prior to their commercialisation, some of which may be attributable to market failures. The paper focuses on the particular case of carbon capture and storage (CCS) technologies and conducts a qualitative multi-criteria analysis of different public policy support schemes for CCS demonstration to evaluate their suitability. The assessed schemes include mandatory CCS, emission performance standards and several different financial incentives (in addition to the European Union Emission Trading Scheme). Based on the available literature and on experience in the UK and Germany with promotion instruments for low-carbon technologies, the results of our analysis suggest that two alternative schemes, a CCS bonus incentive or a carbon dioxide (CO₂) price guarantee, perform best in comparison with the other assessed instruments. While they reduce the uncertainty of CCS investments in the face of low European Union Allowance prices, they also avoid significant adverse impacts on operational and investment decisions in electricity markets.  相似文献   

Applying the box plot to the recognition of footwall alteration zones related to VMS deposits in a high-grade metamorphic terrain, South Africa, a lithogeochemical exploration application     

H.F.J. Theart  R. Ghavami-Riabi  H. Mouri  P. Gräser 《Chemie der Erde / Geochemistry》2011,(2):143-154

Alteration zones (more commonly foot wall alteration zones) are related to volcanic-hosted massive sulfide (VMS) deposits and represent unique features that may be targeted during exploration. Of these, the chloritic foot wall alteration pipe is the most extensive and characteristic of VMS deposits. This feature is geochemically identified by a strong relative enrichment in aluminium and magnesium and a coupled depletion in calcium and sodium, giving rise to chloritic rocks in the primary environment of formation. During high grade regional metamorphism such chloritic precursor rock types are replaced by an unusual mineral paragenesis, typically containing magnesium rich cordierite, phlogopite, orthoamphiboles or orthopyroxenes and aluminium rich minerals such as sillimanite and corundum. This suggests that the unusual geochemical features of the alteration zone, retained during the deformation and metamorphism, should be recognisable in lithogeochemical exploration.The massive sulfide deposit in the eastern part of the metamorphic Namaqua Province, South Africa, at Areachap, Kantienpan and the defunct Prieska Cu–Zn Mine are hosted by a Mid-Proterozoic volcano sedimentary succession known as the Areachap Group. These deposits were affected by a complex deformation and metamorphic history and represent examples of upper amphibolite to granulite grade metamorphosed VMS deposits.The application of the known lithogeochemical methods is especially complicated where the geology is not well understood, due to the poor rock exposure of complexly deformed and metamorphosed areas, such as in the eastern part of the Namaqua Province.The box plot presents a more readily applicable lithogeochemical method to characterize and identify the alteration process, but it was designed for relatively un-metamorphosed environments. It is demonstrated here that the box plot may also be applied to high-grade metamorphic terrains and that the mineral phases used in defining the boxplot in low grade metamorphic environments may be replaced by their equivalents in high grade metamorphic terrains. The compositional trends of the metamorphic minerals themselves may be used in defining the boxplot for high grade metamorphic terrains. These include the transition of: annite to phlogopite; grossular to almandine or pyrope, augite to enstatite or clinoenstatite, and hornblende to gedrite or cummingtonite. Close to the ore zone, the relative Mg content of pyroxene, cordierite and biotite are higher than further away from this zone. It could be demonstrated that the changes in the mineral compositions are gradational when comparing unaffected rocks with progressively more altered wall rocks.Conclusions based on an application of the isocon method demonstrate that primary footwall alteration zones in the Areachap Group's VMS deposits are characterized by elemental depletion of Na₂O, CaO, Sr, Ni, V and La and enrichment of MgO, Fe₂O_3(total), S, Zn, SiO₂, Co and F. It is shown that the whole rock compositions of rocks that were independently identified as the metamorphic equivalents of altered rocks, using the isocon method, plot in the correct place in the box plot for high grade regionally metamorphosed terrains. This establishes the box plot as an effective and practical tool for lithogeochemical exploration for VMS deposits in complexly deformed high grade metamorphosed terrains.  相似文献