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1.
辽河三角洲的自然资源与区域开发   总被引:23,自引:0,他引:23  
辽河三角洲有丰富的地上和地下资源,是农业综合开发和油田建设的重点地区。其区域资源开发以油田、稻田、苇田和虾田开发为核心,在土地利用主要做到全面规划与统筹兼顾;对淡水资源不足的问题要从开源与节流两方面来进行解决;对河口湿地景观生态系统要注意保护,发挥业已建立的自然保护区的功能;对河口湾水产资源更要加强保护与培育。  相似文献   

2.
Land use changes and landscape processes are interrelated and influenced by multiple bio-physical and socio-economic driving factors, resulting in a complex, multi-scale system. Consequently in landscapes with active landscape processes such as erosion, land use changes should not be analysed in isolation without accounting for both on-site and off-site effects on landscape processes. To investigate the interactions between land use, land use change and landscape processes, a case study for the Álora region in southern Spain is carried out, coupling a land use change model (CLUE) and a landscape process model simulating water and tillage erosion and sedimentation (LAPSUS). First, both models are run independently for a baseline scenario of land use change. Secondly, different feedbacks are added to the coupled model framework as ‘interaction scenarios’. Firstly effects of land use change on landscape processes are introduced by means of a ‘changed erodibility feedback’. Secondly effects of landscape processes on land use are introduced stepwise: (i) an ‘observed erosion feedback’ where reallocation of land use results from farmers’ perception of erosion features, and (ii) a ‘reduced productivity feedback’ whereby changes in soil depth result in a land use relocation. Quantities and spatial patterns of both land use change and soil redistribution are compared with the baseline scenario to assess the cumulative effect of including each of the interaction mechanisms in the modelling framework.Overall, total quantities of land use change (areas) and soil redistribution do not differ much for the different interaction scenarios. However, there are important differences in the spatial patterns of both land use and soil redistribution. In addition, by incorporating the perception and bio-physical feedback mechanisms, land use types with stable or increasing acreages are increasingly relocated from their original positions, suggesting a current location on landscape positions prone to soil erosion and sedimentation. Implementing the ‘reduced productivity feedback’ causes most of these effects. Another important outcome is that on-site land use changes trigger major off-site soil redistribution dynamics. These off-site effects are attributed to down slope or downstream changes in sediment transport rates and/or discharge caused by changes in land surface characteristics.The results of this study provide insight into the interactions between different processes occurring within landscapes and the influence of feedbacks on the development of the landscape. The interaction between processes goes across various spatial and temporal scales, leading to difficulties in linked model representation and calibration and validation of the coupled modelling system.  相似文献   

3.
传统的数学受体模式可概括地分为两大类,即化学质量平衡法(CMB)和多元技术(MVT),CMB由于要求已知所求源的成分谱。从而在应用中受到限制。MVT以因子模式为中心,由于因子模式的本征向量解法求解不唯一或称误差太大,使得MVT给人一种人造数据的印象。近年来,元素示踪体系将受体模式的应用范围从城市尺度扩展到区域尺度,由于该体系经验性太强,未能得到广泛的应用。本文针对现代受体模式中存在的一些关键性问题作了系统的评述。   相似文献   

4.
Domestic ducks are considered to be an important reservoir of highly pathogenic avian influenza (HPAI), as shown by a number of geospatial studies in which they have been identified as a significant risk factor associated with disease presence. Despite their importance in HPAI epidemiology, their large-scale distribution in monsoon Asia is poorly understood. In this study, we created a spatial database of domestic duck census data in Asia and used it to train statistical distribution models for domestic duck distributions at a spatial resolution of 1 km. The method was based on a modelling framework used by the Food and Agriculture Organisation to produce the Gridded Livestock of the World (GLW) database, and relies on stratified regression models between domestic duck densities and a set of agro-ecological explanatory variables. We evaluated different ways of stratifying the analysis and of combining the prediction to optimize the goodness of fit of the predictions. We found that domestic duck density could be predicted with reasonable accuracy (mean RMSE and correlation coefficient between log-transformed observed and predicted densities being 0.58 and 0.80, respectively), using a stratification based on livestock production systems. We tested the use of artificially degraded data on duck distributions in Thailand and Vietnam as training data, and compared the modelled outputs with the original high-resolution data. This showed, for these two countries at least, that these approaches could be used to accurately disaggregate provincial level (administrative level 1) statistical data to provide high resolution model distributions.  相似文献   

5.
地理信息系统具有对空间数据的存贮和管理能力,还提供强大的空间分析手段,满足了土壤景观生态研究往往要分析大量的庞杂的空间信息的要求。本文利用地理信息系统技术在黄土高原土壤景观生态学研究中开展了土壤景观生态信息系统方面的应用研究,并建立了《黄土高原土壤景观生态信息系统》,分析了黄土高原土壤景观生态信息系统的技术特征,并对建立黄土高原土壤景观生态信息系统的一些问题进行了探讨,为黄土高原土壤景观生态学研究提供科学依据。  相似文献   

6.
Diffuse nutrient loss from agriculture into the soil, groundwater and surface water affects their quality. Different policies are in force throughout the European Union aiming for their limitation. They were implemented through action plans on a regional scale.Hydrological modelling can be a powerful method for efficiently evaluating their effectiveness. In order to be useful whatever the action and for every reporting unit (whole Region, water bodies, nitrate vulnerable zones, fields...) the model must be physically based, it must simulate water and nutrient fluxes in the root zone and the vadose zone as well as being geographically flexible. This paper presents such a model and its application in the context of Wallonia (Southern part of Belgium). It also presents a calculation of what water and nutrient flows could be under a given climatic scenario until 2015.In Belgium, water quality depends upon Regions. Wallonia implemented the European Nitrate Directive through two action plans the first in 2002 and the second in 2007. These actions plans were modelled and compared to a scenario without any modification in the farmers’ practices.The modelling showed the need for two indicators: nitrate concentration under the root zone as fast indicator of the actions’ efficiency and transfer time from surface to groundwater table. The first action plan hardly modified farmers’ field practices and consequently it did not impact water quality. The second action plan had more impact (reduction up to 10 mg/l NO3 under the root zone). It was mainly due to catch crop introduction in the nitrate vulnerable zone, if they are followed by a reduction of the mineral fertilisation (not mandatory). Our results show that new actions are necessary. We show where and to what extent they have to be implemented.Nevertheless, the greatest variation in nitrate leaching from the root zone seems to be dependent on the weather, more than the action plans. Particularly the rainy period between 1998 and 2002 had a huge impact on nitrogen flows. Our hydrological modelling is showed to be a powerful tool of nitrogen management in a still uncertain climatic evolution context.Finally, we showed that patience and perseverance will be necessary to reach the targets of the WFD in the Walloon context. The map of transfer time shows that 8% of the groundwater bodies need over 15 years to be impacted by mitigation measures.  相似文献   

7.
探讨微观主体——农户土地利用行为与宏观农业景观格局之间的互动机理,对于了解农户行为的变迁,认识和理解农业景观格局的演变特征和过程,进而调控农户土地利用行为和优化农业景观格局,显然具有重要的理论与现实意义。论文利用构建的农户土地利用决策模型、个体对群体与群体对整体权重影响模型,利用实际收集的陕西省米脂县孟岔村2007年与2008年数据(地籍、地块面积与农户收入等数据),探讨占优势的土地利用决策与占优势的农业景观格局关系。得出如下结论:①占优势的土地利用决策并不一定形成该土地利用方式占优势的土地利用格局;②当年占优势的农户整体土地利用决策并不一定形成次年该土地利用方式占优势的土地利用格局。并提出今后需要进一步研究与探讨的问题:①完善农户土地利用决策模型,在模型中增加风险规避、土地轮作、特殊地类转化等因素;②进一步探索整合地块面积及其空间布局与土地利用决策的方法。  相似文献   

8.
景观生态学是研究景观尺度上的生态学问题;3S技术为景观生态学研究提供了极为有效的一系列工具,成为资料收集、存储、处理和分析所不可缺少的手段,利用3S技术在景观数据的获取、景观空间格局分析、景观生态监测、评价与管理、景观空间模拟、景观生态规划等方面的应用研究,对3S技术在景观生态学中的广泛应用起推动作用。  相似文献   

9.
While several empirical and theoretical studies have clearly shown the negative effects of climate or landscape changes on population and species survival only few of them addressed combined and correlated consequences of these key environmental drivers. This also includes positive landscape changes such as active habitat management and restoration to buffer the negative effects of deteriorating climatic conditions. In this study, we apply a conceptual spatial modelling approach based on functional types to explore the effects of both positive and negative correlations between changes in habitat and climate conditions on the survival of spatially structured populations. We test the effect of different climate and landscape change scenarios on four different functional types that represent a broad spectrum of species characterised by their landscape level carrying capacity, the local population turnover rates at the patch level (K-strategies vs. r-strategies) and dispersal characterstics. As expected, simulation results show that correlated landscape and climatic changes can accelerate (in case of habitat loss or degradation) or slow down (in case of habitat gain or improvement) regional species extinction. However, the strength of the combined changes depends on local turnover at the patch level, the overall landscape capacity of the species, and its specific dispersal characteristics. Under all scenarios of correlated changes in habitat and climate conditions we found the highest sensitivity for functional types representing species with a low landscape capacity but a high population growth rate and a strong density regulation causing a high turnover at the local patch level.The relative importance of habitat loss or habitat degradation, in combination with climate deterioration, differed among the functional types. However, an increase in regional capacity revealed a similar response pattern: For all types, habitat improvement led to higher survival times than habitat gain, i.e. the establishment of new habitat patches. This suggests that improving local habitat quality at a regional scale is a more promising conservation strategy under climate change than implementing new habitat patches. This conceptual modelling study provides a general framework to better understand and support the management of populations prone to complex environmental changes.  相似文献   

10.
1IntroductionAsaveryhighandcoldregion,theQingzangPlateau(TibetQinghaiPlateau)isverypeculiarinecologicallandscapefeature.Alth...  相似文献   

11.
Numerical modelling of fire-related smoke haze episodes in Southeast Asia is important for both prediction and assessment of atmospheric impacts, especially when observational data are fragmentary, as is the case in Indonesia. This work describes the atmospheric fate of smoke particles emitted during the 1997 Indonesian fires modelled with a regional atmospheric chemistry model. We established a new fire emission inventory and calculate that 55 teragram (Tg) of particulate matter and 1098 Tg of carbon were released during this fire episode. Our emission estimate is an intermediate value compared with other studies. Utilising different scenarios, we demonstrate the variable atmospheric impacts of surface vegetation fires and peat soil fires separately and also investigate the sensitivity of smoke dispersion to the differing meteorological conditions of an El Niño and a normal year. When peat fires are included in the emission inventory, modelled ambient particle concentrations exceed the ambient air quality standard across transboundary scales. In a scenario including only surface vegetation fires, ambient air quality standards are exceeded only in areas close to the main fires. This scenario demonstrates the prominent role of fires in peat areas in causing regional air pollution episodes. In years with normal meteorological conditions, intermittent precipitation and associated wet deposition during the dry season are predicted to remove most of the particulate emissions close to the sources. Strongly reduced rainfall and generally stronger southeasterly winds during El Niño years provide favourable conditions for larger scale smoke haze pollution.  相似文献   

12.
We consider a large-eddy simulation of a buoyant line source in a convective boundary layer. The motion of the line source as a function of time is influenced by two contributions: internal buoyancy (plume rise) and ambient turbulence. The advantage of large-eddy modelling with respect to laboratory and atmospheric experiments is that the simulations allow us to distinguish between these two contributions. For the part due to internal buoyancy we formulate an integral model for plume rise. A new feature in this model is the fact that plume looping, which is characteristic for plume dispersion in a convective boundary layer, promotes entrainment and therefore reduces plume rise. The contribution by ambient turbulence to plume motion is modelled in terms of the standard deviation of vertical velocity fluctuations. The results of these models are consistent with our large-eddy simulations.  相似文献   

13.
This work is concerned with the dynamic modelling of the papermaking section of an integrated newsprint mill, and the subsequent application of two direct search methods in a proof-of-concept optimization study of broke recirculation strategies. The effect of the current broke recirculation policy on the mixed pulp properties at the paper machine headboxes was quantified using a dynamic simulation generating data for an objective function which reflected the rate of change in measurable (flow, consistency and temperature) and immeasurable (total dissolved solids and fibre length distribution) parameters. Genetic Algorithm and the Nelder–Mead simplex methods were then linked dynamically to the simulation and used to find improved ways of recirculating broke pulp. Specifically, the profile of the changes to the broke ratio was modelled using a quadratic function and a second-order transfer function, and the coefficients of these functions were optimized. The optimized broke recirculation resulted in a significant reduction in the value of the objective function, thus, suggesting that the fluctuations in the properties of the mixed pulp stream could be dampened and paper machine headbox stability improved. It is expected that this process enhancement strategy would contribute to an increase in production yield (via a reduction in the occurrence of paper machine breaks), and thus an overall reduction in the waste of materials and energy.  相似文献   

14.
15.
自然保护区功能区划的指导思想和基本原则   总被引:9,自引:0,他引:9       下载免费PDF全文
自然保护区划分核心区、缓冲区和实验区是其实施科学管理的一项基础性工作.通过理论分析,指出自然保护区功能区划应以充分发挥保护区多种功能和解决保护区自身的可持续发展问题为目的.系统阐述了核心区、缓冲区、实验区的科学涵义,认为分区管理不能视为分级保护管理,与核心区相比,实验区的管理要求更高.提出功能区划应遵循保护第一,缓冲区与核心区景观同质,核心区与缓冲区生态完整,实验区与当地社会经济条件相适应,利于管护等原则.最后在佛坪国家级自然保护区进行了实例研究.  相似文献   

16.
北京市景观水体嗅味污染特征   总被引:3,自引:1,他引:2  
以北京市9处典型景观湖泊水体为研究对象,对其嗅味污染特征进行深入分析,并结合相关水质指标对水体嗅味污染特征进行初步解析. 研究发现,北京市景观水体中主要的嗅味污染物为土臭素(geosmin),2-甲基异莰醇(2-methylisoborneol,2-MIB)以及β-紫罗兰酮(β-ionone),其质量浓度平均值分别达613.84,1 319.57和143.00 ng/L. 通过对水质参数进行深入分析发现,北京市主要景观水体富营养化问题严重,TP是北京市景观水体的限制性水质因素,且有机物污染程度较高〔ρ(DOC)≥5.17 mg/L〕. 在研究的景观水体中,玉渊潭、福海和北海嗅味污染较为突出,前海和西海嗅味污染较轻. 北京市主要景观水体中嗅味污染与水中ρ(TP),ρ(DOP)和ρ(DOC)表现出显著相关,说明水体中存在的大量DOP和有机污染物是水体富营养化和嗅味污染的主要原因.   相似文献   

17.
气候变化对湿地景观格局的影响研究综述   总被引:4,自引:1,他引:3  
气候变化是影响湿地景观格局变化的主要自然因素。文章从气候变化对湿地水资源面积、湿地土地利用格局、湿地植被空间格局及湿地生物多样性格局的影响研究等方面进行了综述,并对完善气候变化下湿地景观格局变化的研究方法和技术手段进行了探讨。指出:应用气候模型进行未来气候预测时,应合理选择气候变化情景,并确保不同模型的时空尺度匹配;应用"3S"技术提取湿地类型信息、观测湿地土地覆盖变化时要确保信息的精度,不同来源的数据必须采取制图综合等手段;实现气候变化下湿地景观结构与生态过程相结合的动态格局分析。  相似文献   

18.
解决城市生态环境问题的生态基础设施途径   总被引:10,自引:1,他引:9  
对待城市生态环境问题,该研究放弃了就事论事的单一分析和工程途径,而是提出解决生态环境问题必须依靠综合、系统的途径,即:通过建立生态基础设施来整合相关的生态过程与景观结构。以山东东营市为例,论文提出从3个步骤来实现综合问题的综合解决:①通过德尔菲法实现问题的综合与多目标的确定;②通过建立生态基础设施,综合地解决以水为核心的多个生态环境问题,实现多个目标;③评价生态基础设施对解决多目标问题的作用和效益,并为修正方案提供依据。文章在区域、城市和场地3个尺度上,提出解决东营市生态环境问题的生态基础设施实施战略。  相似文献   

19.
--A region surrounding Qinghai Lake was chosen as thestudy area and nine ecological landscape types that were recognizedbased on Landsat TM image classification of land cover/use typesalong with the ancillary data, and their ecological features andthe measures dealing with the eco-environmental problems arepresented in this paper. The study has shown that using thisapproach the ecological landscape types in a region like the studyarea can be readily recognized and their ecological features can berather accurately derived. Moreover, the deterioration in near alllandscape ecological types in the area is quite serious. Therefore,effective and proper measures have to be taken in order to realizea sustainable development of the region.  相似文献   

20.
基于生态服务的城乡景观生态安全格局的构建   总被引:6,自引:0,他引:6  
以安徽淮北市为例,针对城市发展所造成的城乡生态环境品质降低等问题,期望通过景观生态安全格局的构建,维护区域生态系统健康与稳定。文章基于生态系统服务和景观生态安全格局理论,利用生态服务功能价值评价以及耗费距离模型等分析方法,通过模拟重要生态廊道,与现有廊道进行对比,发现问题并提出优化策略,优化城市景观结构与功能,改善城乡生态系统服务。研究结果表明,淮北城市森林在空间上的衔接性不高;研究区域内众多湿地没有足够的廊道相连,尚未形成良好的湿地生态网络;主城区交通廊道密度较高,但连接度不够,乡村地区交通廊道分布较少且稀疏。因而进行城乡景观生态安全格局的构建十分重要和必要。研究结果可为淮北生态城市建设提供一定的参考,为其他相关研究提供思路和方法上的借鉴。  相似文献   

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