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661.
随着城市能级的不断提高,城市生态环境问题也日益突出,二者间协调发展成为城市发展一致的追求。以皖江区域10个城市作为研究地域单元,构建了城市能级与生态环境的指标体系,并建立了城市能级与生态环境的协调度模型。在此基础上,对皖江区域2002~2011年的城市能级与生态环境协调度进行了测度,研究发现过去10a皖江区域城市能级与生态环境的协调度处于较低水平。根据测定的协调度数据,建立了协调度自回归预测模型,并运用该模型探究了未来10a皖江区域城市能级与生态环境协调度的发展趋势,结果表明皖江区域城市能级与生态环境的协调度发展水平经过拮抗期和基本协调期后不断提高,将于2019年前后趋近高质协调发展阶段,即城市能级与生态环境两个系统有序互动发展的态势。  相似文献   
662.
在原型观测的基础上,应用生态水力学法与生境模拟法,建立对考虑齐口裂腹鱼产卵需求的山区河流水电工程生态基流过程的确定方法,并以四川中型山区河流杂谷脑河薛城电站为背景,对所构建方法进行应用分析。通过原型观测,对生态水力学的齐口裂腹鱼生境水力参数标准在杂谷脑河应用的适宜性进行分析;应用生态水力学方法,对不同河道流量下薛城电站减水河段的齐口裂腹鱼生境水力参数进行数值模拟,根据模拟结果,结合齐口裂腹鱼生境水力参数标准,分析得到薛城电站满足其生存的最小下泄流量;应用生境模拟法,对齐口裂腹鱼产卵期不同河道流量下薛城电站减水河段集中产卵场的可利用生境面积进行计算,得到最大可利用生境面积对应的下泄流量。综合最小下泄流量值与最大可利用生境面积所对应的下泄流量值,考虑齐口裂腹鱼产卵对水文情势的要求,建立薛城电站考虑齐口裂腹鱼产卵需求的生态基流过程。采用所构建方法得到的考虑鱼类产卵需求的水电工程生态基流过程,由于考虑了鱼类生存对最低流量以及产卵对水文情势的要求,能更好地满足鱼类产卵需求,可作为电站运行调度的约束。  相似文献   
663.
于2014年10月至2015年1月采用样线调查法对黄河三角洲自然保护区秋季迁徙期和越冬期水鸟群落结构进行调查研究,调查共包括8条样线40个观测点.结果表明:(1)秋季迁徙期共记录水鸟6目14科54种,国家Ⅰ级保护鸟类5种,国家Ⅱ级保护鸟类8种;越冬期共记录水鸟5目7科31种,国家Ⅰ级保护鸟类1种,国家Ⅱ级保护鸟类4种.(2)2个时期雁形目水鸟种类和数量均占优势,豆雁(Anser fabalis)、斑嘴鸭(Anas poecilorhycha)、赤膀鸭(Anas strepera)和绿头鸭(Anas platyrhynchos)为优势物种,丹顶鹤(Grus japonensis)、东方白鹳(Ciconia boyciana)和大大鹅(Cygnus cygnus)等珍稀水鸟也有一定的种群数量.(3)秋季迁徙期水鸟种数、数量和ShannonWiener多样性指数多于或高于越冬期.(4)5种典型生境之间水鸟种类和数量存在差异,天然水域是水鸟群落的主要分布区.(5)自然生境内的水鸟种数、数量和Shannon-Wiener多样性指数一般多于或高于人工生境.相似性分析结果表明,自然生境之间水鸟群落结构相似程度高于人工生境.  相似文献   
664.
Water quality modelling of the river Yamuna (India) using QUAL2E-UNCAS   总被引:2,自引:0,他引:2  
This paper describes the utility of QUAL2E as a modelling package in the evaluation of a water quality improvement programme. In this study, QUAL2E was applied to determine the pollution loads in the river Yamuna during its course through the national capital territory of Delhi, India. The study aimed at examining the influence of different scenarios on river water quality. Four different pollution scenarios were analysed besides the 'business as usual' situation. The study revealed that it was necessary to treat the discharge from drains to the river Yamuna and diversion of a substantial load to the Agra canal for further treatment was also essential. It was also established through this study that maintaining a flow rate of more than 10 m(3)/s in the river could also help preserve the river's water quality. To clearly display the model outcomes and demarcate polluted zones in the river stretch, model results were interfaced with a Geographical Information System (GIS) to produce cartographic outputs. In addition, uncertainty analysis in the form of first-order error analysis and Monte Carlo analysis was performed, to realise the effect of each model parameter on DO and BOD predictions. The uncertainty analysis gave satisfactory results on simulated data.  相似文献   
665.
The integrated project "AquaTerra" with the full title "integrated modeling of the river-sediment-soil-groundwater system; advanced tools for the management of catchment areas and river basins in the context of global change" is among the first environmental projects within the sixth Framework Program of the European Union. Commencing in June 2004, it brought together a multidisciplinary team of 45 partner organizations from 12 EU countries, Romania, Switzerland, Serbia and Montenegro. AquaTerra is an ambitious project with the primary objective of laying the foundations for a better understanding of the behavior of environmental pollutants and their fluxes in the soil-sediment-water system with respect to climate and land use changes. The project performs research as well as modeling on river-sediment-soil-groundwater systems through quantification of deposition, sorption and turnover rates and the development of numerical models to reveal fluxes and trends in soil and sediment functioning. Scales ranging from the laboratory to river basins are addressed with the potential to provide improved river basin management, enhanced soil and groundwater monitoring as well as the early identification and forecasting of impacts on water quantity and quality. Study areas are the catchments of the Ebro, Meuse, Elbe and Danube Rivers and the Brévilles Spring. Here we outline the general structure of the project and the activities conducted within eleven existing sub-projects of AquaTerra.  相似文献   
666.
Expansion of irrigation in the Yellow River (Huang He in Chinese) Basin of China is a major accomplishment of the post-revolutionary period in China. Irrigation reliance on the Yellow River was anticipated to not only supply greater reliability of water for crops, but also to improve the productivity of aeolian, saline and alkali soils because of the high sediment loads in the river. Irrigation expansion also was a significant factor in affecting human modification of the landscape ecosystem in the lower reaches of the Yellow River. Based on field investigation and sampling of the amount and distribution of used suspended sediment load in irrigated areas, this paper analyzes the impact of the suspended sediment on soil texture, fertility and salinity and the consequences to the landscape ecosystem. Results indicate that soil quality has indeed been improved through irrigation and related deposition of sediment, but some local problems created by long periods of irrigation should not be ignored in the future.  相似文献   
667.
Criteria for the Assessment of Sustainable Water Management   总被引:2,自引:1,他引:1  
Pressure on the world’s water resources is increasing, restraining social and economic development in many countries, and threatening ecological values in others. In order to manage water resources in a more sustainable manner, new planning methodologies/processes for river basin management need to be developed. This study attempts to construct a set of useable normative criteria for the analysis and evaluation of such processes. The criteria were designed as a response to the lack of deductive approaches in the evaluation of methodologies and working procedures used in the context of river basin management, making it possible to highlight their potential for sustainable development. The criteria are based on the twin concepts of participation and integration. These concepts function as well-established dimensions of both sustainable development and sustainable river basin management, and they are of significant methodological relevance. A synthesis of the key aspects connected to the two concepts is undertaken, based on a broad literature review. Focus is laid on how in methodological terms, and in relation to regional water management, to achieve participation and integration in a decision-making or planning process. The criteria are concerned with how knowledge and values are integrated into the planning process and how commitment, legitimacy, or acceptance for the resulting plan is generated.  相似文献   
668.
一体化深化背景下,准确把握城市群创新互动关系,对于推动高质量发展具有重要现实意义。空间溢出是创新发展互动关系重要体现之一,基于城市尺度数据、空间计量方法,对长江三角洲创新发展空间溢出效应进行多角度研究。主要结论如下:(1)城市创新发展存在显著为正的空间溢出效应,创新人才、资金投入、经济发展、交通设施和对外开放等都是创新发展重要驱动因素,但不同因素空间溢出效应存在差异。(2)不同区域、不同时期对比发现,创新发展空间溢出效应存在显著差异,如区域对比核心区时间演变明显增强等。(3)空间溢出效应随距离增加呈现“倒U型”演变趋势,且这一效应在325 km处最大,而后空间溢出效应的缓慢波动下降与中心城市相对均衡分布有关。本文为识别城市创新发展互动关系提供了新视角,对推动城市群创新发展、一体化深化等具有现实指导意义。  相似文献   
669.
刘欣宇  卢江  孟璇  刘铮  宋鹏  李季  田光明 《环境科学》2023,44(8):4647-4654
收集整理1992年1月至2022年5月长江经济带地区长期定位施肥试验文献,提取并整合了其中农田土壤有机碳的资料.采用归一化处理和变化速率的分析方法,研究长期不同施肥措施下长江经济带地区农田土壤有机碳含量的总体变化,并比较3种耕作模式及不同土壤类型下土壤有机碳含量的变化差异,判断分析试验持续年限长短对土壤有机碳动态的影响.结果表明,在长期不同施肥措施下,我国长江经济带地区农田土壤有机碳含量整体呈上升趋势,无机氮肥磷肥配施(NP)、无机氮磷钾肥配施(NPK)、单独施用有机肥(O)和有机无机肥配施(NPKO)处理均能增加农田土壤的有机碳含量,其中以NPKO处理为最大,而单独施用无机氮肥(N)则会降低土壤有机碳含量.旱田、水田和水旱轮作农田土壤有机碳含量变化速率分别为0.22、 0.24和0.16g·(kg·a)-1,3种耕作模式在土壤固碳效果方面并无显著性差异.O和NPKO处理下所带来的有机碳相对快速增加效应在旱田土壤中的持续年限最高不超过28 a,而在水田及水旱轮作土壤中依然可以持续到28 a以上.在不同的土壤类型下,土壤有机碳含量的变化速率存在着一定的差异,平均有机...  相似文献   
670.
雅砻江锦屏二级水电站减水河段生态需水量研究   总被引:1,自引:0,他引:1  
针对雅砻江锦屏二级水电站减水河段面临的水生生物生态需水问题,提出了计算河道最小生态基流量的生态水力学法,考虑了水力生境参数的全河段变化情况,计算结果避免了单凭最低值进行判断所造成的判断失误。确定了锦屏二级水电站减水河段鱼类对流速、水深、水面宽等水力生境的需求。通过河道水力模拟,得出为满足减水河段鱼类的生存及繁衍,必须保证枯水季节猫猫滩闸址下泄45 m3/s流量,在该流量下,锦屏二级水电站减水河段中95%左右河段水力因子可满足研究中提出的河道内鱼类的生存条件;水温的变化不会影响河道内鱼类产卵;鱼类适应的缓流水、急流水、浅滩、深潭等水力形态的位置虽然发生变化,但数量保持不变。  相似文献   
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