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21.
荒漠生态系统是地球上最大的陆地生态系统,全球四分之一的人口生活在这一区域。清晰地定义荒漠生态系统生态质量,制定反映生态质量优劣的关键监测指标,集成"星–空–地"一体化监测技术、构建综合评价模型可为干旱区生态质量监测、促进区域可持续发展提供技术支撑。荒漠生态质量是指一定时空范围内荒漠生态系统要素、结构和功能的综合特征。该研究通过集成卫星、无人机和地面传感器网络的"星–空–地"一体化监测技术,在区域和站点两个尺度上对荒漠生态系统的生态要素、生物多样性和生态功能进行连续监测,通过标准化生态质量指标数值、厘定其阈值范围,构造判断矩阵建立生态质量综合评价模型,评价荒漠生态系统质量状况。本论文阐明了构建荒漠生态质量动态综合监测技术规范与评价方法的概念框架,为实现我国荒漠生态系统生态质量综合监测、科学诊断和定量评估提供理论基础。  相似文献   
22.
The dryland ecosystem is the dominant component of the global terrestrial ecosystem since arid regions occupy 45% of the earth’s land area and feed 38% of the world's population. The stability and sustainable development of the dryland ecosystem are critical for achieving the millennium development goal (MDG) in the arid and semiarid areas. However, there is still no scientific guideline for measuring and conserving the health and productivity of dryland ecosystems. Therefore, the purpose of this study is to develop the scientific conceptual framework of defining, monitoring and evaluating the ecological quality of dryland ecosystems. The ecological quality of dryland ecosystems is represented by a system of comprehensive indicators that are each extracted from the ecological elements, and structural and functional indices of the ecosystem. These indicators can be monitored by integrating satellites and unmanned aerial vehicles with ground-based sensor networks at the scale of either observational sites or regional scales. Finally, the ecological quality can be evaluated by evaluation models based on the normalized index values and their thresholds. This paper presents a conceptual framework for monitoring and evaluating the ecological quality of drylands, which provides a way of advancing the monitoring, diagnosis, and evaluation of the ecological quality of the dryland ecosystems.  相似文献   
23.
旨在剖析我国《开发区土地集约利用评价规程》中指标体系存在的问题并提出改进建议。在界定开发区土地集约利用内涵基础上,从要素特征(W维)、利用目标(R维)和评价过程(S维)等3个维度阐述了开发区土地集约利用评价的系统要求,构建关联分析矩阵,对《规程》中评价指标体系的特征差异化、层次完整性和目标关联性等3个方面进行了分析讨论。针对当前《规程》中存在的评价对象混杂、开发区类型需要细化、指标体系不完整、计算方法需修正等问题提出了相应修改建议。  相似文献   
24.
选取2018—2021年汛期短时强降水天气过程,利用相关性分析、箱线图法和极值统计法,尝试研究FY-4A卫星产品在短时强降水天气过程中的监测预警指标。研究表明:(1)FY-4A卫星多通道数据可以作为短时强降水监测预警的定量化指标予以应用。(2)筛选出相关性较好的13项产品统计出短时强降水的监测预警指标,其中赋值类指标4项,数值判别类指标9项(含辅助指标3项);初步设定13项指标中有9项达标时,短时强降水会发生。(3)在评估基础上完善了指标,监测预警效果有所提高,TS评分提高5.4%,空报率降低2.7%,漏报率降低1.9%。  相似文献   
25.
Validation of the AZTI's Fish Index (AFI), proposed for the Basque Country (northern Spain), in assessing fish quality within the Water Framework Directive (WFD), is undertaken. The response to anthropogenic pressure is investigated, in setting the boundaries between the different quality status classes. Hence, 12 estuaries were sampled, at different frequencies, between 1989 and 2007, by means of a beam trawl. Significant (p < 0.0001) correlations were found between the AFI and oxygen saturation and ammonia. Oxygen quality standards are used to set boundaries between quality classes. Then, the AFIs obtained are compared with different anthropogenic pressures, including urban and industrial discharges, engineering works and dredging. The effects of the removal of some of these pressures are also studied. The total number of pressures within an estuary shows significant (p < 0.009) negative correlation with AFI, explaining between 51 and 62% of the variability in fish quality. The impact of pressures upon fish and demersal assemblages is detected as required by the WFD. Nonetheless, further investigation and intercalibration of the methods used, are necessary.  相似文献   
26.
青岛即墨温泉盆地热水沉积指示物及其标识性意义   总被引:2,自引:0,他引:2  
经野外取样和XRD测试技术,在即墨温泉盆地发现硅质沉淀物、盐华、石膏、自然硫等温泉热水沉积指示物.根据热水沉积指示物的空间分布和含量的变化,阐述温泉热水沉积指示物的标识性意义:(1) 热水沉积指示物是划分第四纪沉积物层系的依据;(2) 是温泉地下热储温度的指示剂;(3) 依据热水沉积指示物百分含量的空间变化,可圈定温泉地热中心,指导地热资源开发;(4) 是寻找地下盲温泉和古地热水活动的标志;(5) 温泉热水沉积模式对现代海底热水沉积作用、成矿作用环境的模拟研究具有重要参考作用.  相似文献   
27.
地下水是孔雀河流域农业灌溉的主要水源之一,其对本地区经济发展的支撑作用日益增强.为实现孔雀河流域水资源合理开发和生态保护,采用环境同位素和水化学方法,研究了孔雀河流域地下水与地表水关系.结果表明:地下水的主要补给来源为河水.含水层成因类型和现代河道分布共同控制着孔雀河流域地下咸淡水的空间分布格局;氢氧稳定同位素对不同水...  相似文献   
28.
The variability of water chemistry on a daily scale is rarely addressed due to the lack of records. Appropriate tools, such as typologies and dimensionless indicators, which permit comparisons between stations and between river materials, are missing. Such tools are developed here for daily concentrations (C), specific fluxes or yields (Y) and specific river flow (q). The data set includes 128 long‐term daily records, for suspended particulate matter (SPM), total dissolved solids (TDS), dissolved and total nutrients, totalling 1236 years of records. These 86 river basins (103–106 km2) cover a wide range of environmental conditions in semi‐arid and temperate regions. The segmentation—truncation of Cq rating curves into two parts at median flows (q50) generates two exponents (b50inf and b50sup) that are different for 66% of the analysed rating curves. After segmentation, the analysis of records results in the definition of nine major Cq types combining concentrating, diluting or stable patterns, showing inflexions, chevron and U shapes. SPM and TDS are preferentially distributed among a few types, while dissolved and total nutrients are more widely distributed. Four dimensionless indicators of daily variability combine median (C50, Y50), extreme (C99, Y99) and flow‐weighted (C*, Y*) concentrations and yields (e.g. C99/C50, Y*/Y50). They vary over two to four orders of magnitude in the analysed records, discriminating stations and river material. A second set of four indicators of relative variability [e.g. (Y*/Y50)/(q*/q50)], takes into account the daily flow variability, as expressed by q*/q50 and q99/q50, which also vary over multiple orders of magnitude. The truncated exponent b50sup is used to describe fluxes at higher flows accounting for 75% (TDS) to 97% (SPM) of interannual fluxes. It ranges from ? 0·61 to + 1·86 in the database. It can be regarded as the key amplificator (positive b50sup) or reductor (negative b50sup) of concentrations or yields variability. C50, Y50, b50sup can also be estimated in discrete surveys, which provides a new perspective for quantifying and mapping water quality variability at daily scale. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
29.
Using the logic for quantitative inversion of present-day downhole thermal indicators, the inversion procedure can be used to determine unknown, or poorly known, chemical and physical parameters as well as other geological quantities of interest which impact on burial history and thermal history of an evolving sedimentary basin. Some such quantities are: amount of erosion and timing of unconformities, paleo-overpressuring, stratigraphic age, timing of igneous intrusion and insertion temperature, overthrust timing and frictional heating, fault and slump timing, effects due to emplacement of a radiocative layer, and salt emplacement and dissolution timing. Combining a priori unknown values of these chemical/physical and geological parameters with unknown (a priori) paleoheat flux variations, a theoretical scheme, called thermal indicator tomography, is developed for the systematic determination of all parameters at the same time and on the same footing. Case histories will be discussed in subsequent papers in this series.  相似文献   
30.
闽粤台沿海北西西向最新构造带与大震构造背景   总被引:3,自引:0,他引:3       下载免费PDF全文
毕福志  袁又申 《地震地质》1990,12(2):183-192,T001
闽粤台沿海自台湾运动以来逐渐形成了多条北西西向隆起—拗陷的最新活动构造带,与已知的北东—北北东向隆起、拗陷带构成了区域性镶嵌构造格局。 研究区内除板块相互碰撞、俯冲及上地幔物质上涌形成大震构造背景外,莫霍面隆起或隆起断距大、低速层厚、地壳变薄、近两、三千年地表抬升差异活动显著以及台东近海有北西西向构造活动等,也都是发生大震的重要构造背景  相似文献   
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