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21.
In an attempt to anticipate possible futures of drylands of West Africa in the face of rapid socio-economic and environmental changes, we developed four scenarios based on recent survey data, the literature and our knowledge of the region. The four scenarios are inspired by those developed by the Millennium Ecosystem Assessment: (1) ‘downward spiral’ characterized by rapid climate change, expansion of agriculture and chaotic urban growth; (2) ‘integrated economy’ with integrated land management, food production for local markets and rural–urban exchanges; (3) ‘open doors’ characterized by large-scale out-migrations, land grabbing by foreign companies and development aid and (4) ‘climate change mitigation’ with an increase in biofuel crops, land management for carbon capture and development of off-farm activities. We conclude that the Sahel region is most likely moving away from being a highly climate-dependent region based on agriculture towards a more open and diversified economy. West African countries have to find a balance between the new opportunities and risks created by economic globalization.  相似文献   
22.
儿童是保护环境的积极行动者,激发其亲环境行为意愿是应对环境问题挑战的现实需求。然而,已有研究却很少关注儿童的亲环境行为意愿及其驱动机制。文章采用问卷调查和访谈相结合的混合研究方法,以南京市小学儿童为样本,旨在通过分析儿童自然经验图式的特点,探究日常和旅游两种情景的自然接触对儿童亲环境行为意愿的影响差异,并检验自然联结在其中扮演的中介角色。结果发现:① 与日常自然接触相比,旅游自然接触更能激发儿童的亲环境行为意愿;② 自然接触促进自然联结主要体现在情感维度,其次是认知维度,而自然联结促进亲环境行为意愿以认知路径为主,情感路径为辅;③ 情感型和认知型自然联结在自然接触与亲环境行为意愿间扮演双重中介角色,且认知型自然联结的中介效应高于情感型自然联结的中介效应。研究结果对科学制定面向儿童的自然空间规划和环境教育策略具有参考价值。  相似文献   
23.
阐述了GIS(地理信息系统)的概念、特点以及GIS技术应用的范围,分析了城市消防附属设施资源与GIS技术的紧密相关特性。以城市消防部门应用需求为基础,提出了基于GIS技术的城市消防应急指挥地理信息系统结构设计、数据库设计、专题空间地理信息数据设计、功能设计等。最后结合哈尔滨市城市消防应急指挥地理信息系统开发试验,展示了部分项目开发内容。  相似文献   
24.
Climate warming is having profound effects on the hydrological cycle by increasing atmospheric demand, changing water availability, and snow seasonality. Europe suffered three distinct heat waves in 2019, and 11 of the 12 hottest years ever recorded took place in the past two decades, which will potentially change seasonal streamflow patterns and long-term trends. Central Europe exhibited six dry years in a row since 2014. This study uses data from a well-documented headwater catchment in Central Europe (Lysina) to explore hydrological responses to a warming climate. We applied a lumped parameter hydrologic model Brook90 and a distributed model Penn State Integrated Hydrologic Model (PIHM) to simulate long-term hydrological change under future climate scenarios. Both models performed well on historic streamflow and in agreement with each other according to the catchment water budget. In addition, PIHM was able to simulate lateral groundwater redistribution within the catchment validated by the groundwater table dynamics. The long-term trends in runoff and low flow were captured by PIHM only. We applied different EURO-CORDEX models with two emission scenarios (Representative Concentration Pathways RCP 4.5, 8.5) and found significant impacts on runoff and evapotranspiration (ET) for the period of 2071–2100. Results from both models suggested reduced runoff and increased ET, while the monthly distribution of runoff was different. We used this catchment study to understand the importance of subsurface processes in projection of hydrologic response to a warming climate.  相似文献   
25.
生态地质环境从生态地质学和环境地质学发展而来,由地质环境、生态环境和社会经济环境三个子系统构成一个有机整体,它与环境类承载力结合形成生态地质环境承载力,表征环境能够承受的人类活动阈限。国内的生态地质环境承载力研究分为2000年以前的准备阶段、2000-2010年探索前进阶段、2011年至今的稳定发展阶段,国家重大方针政策实施和重大生态地质环境事件影响了承载力的研究方向。生态地质环境子系统和系统的承载力发展程度存在差异,生态环境承载力研究较多、地质环境承载力研究次之、社会经济环境承载力研究相对较少,系统承载力研究处于不断整合之中。已有研究在学科交叉融合、耦合机制、模拟预测模型集成和国家重大需求服务响应等方面存在不足。未来生态地质环境承载力研究应坚持系统观,统合子系统和系统两个尺度,从拓展学科纵深关联、深化多维耦合机制、发展集成模拟预测模型、面向国家与社会需求等方面将研究推向新高度。  相似文献   
26.
To reveal the steric sea level change in 20th century historical climate simulations and future climate change projections under the IPCC’s Representative Concentration Pathway 8.5 (RCP8.5) scenario, the results of two versions of LASG/IAP’s Flexible Global Ocean-Atmosphere-Land System model (FGOALS) are analyzed. Both models reasonably reproduce the mean dynamic sea level features, with a spatial pattern correlation coefficient of 0.97 with the observation. Characteristics of steric sea level changes in the 20th century historical climate simulations and RCP8.5 scenario projections are investigated. The results show that, in the 20th century, negative trends covered most parts of the global ocean. Under the RCP8.5 scenario, global-averaged steric sea level exhibits a pronounced rising trend throughout the 21st century and the general rising trend appears in most parts of the global ocean. The magnitude of the changes in the 21st century is much larger than that in the 20th century. By the year 2100, the global-averaged steric sea level anomaly is 18 cm and 10 cm relative to the year 1850 in the second spectral version of FGOALS (FGOALS-s2) and the second grid-point version of FGOALS (FGOALS-g2), respectively. The separate contribution of the thermosteric and halosteric components from various ocean layers is further evaluated. In the 20th century, the steric sea level changes in FGOALS-s2 (FGOALS-g2) are largely attributed to the thermosteric (halosteric) component relative to the pre-industrial control run. In contrast, in the 21st century, the thermosteric component, mainly from the upper 1000 m, dominates the steric sea level change in both models under the RCP8.5 scenario. In addition, the steric sea level change in the marginal sea of China is attributed to the thermosteric component.  相似文献   
27.
John Reilly 《Climate Policy》2013,13(2):155-158
Climate change is perhaps the central challenge that faces humanity. If the concept of green growth is to be anything more than a mere rebranding of the concept of sustainability, then it must elucidate the relationship between economic activity and pollution and provide a more detailed economic account of it. The articles in this Special Issue focus on ways in which GHG emissions may be reduced while satisfying the increasing demand for energy: from global, technological or economic solutions, to sub-national, financial or regulatory ones. Although the wide disparity in income between the least and most wealthy makes it difficult to reach a consensus on the best way to achieve a low-carbon society, the scale and potential effects of climate change make it imperative that one is reached.  相似文献   
28.
The Qinghai-Tibet Plateau(QTP)has the highestand largest permafrost coverage in the low-middlelatitudes all over the world.With the progress ofChina’s Western Development,human activities areincreasing significantly on the QTP.For instance,theQinghai-Tibet Railway project started in June2001iscurrently under construction,but permafrost problemwill be one of the critical factors for the engineeringconstruction.Frost heave and permafrost settlementmay destroy engineering construction[1,2]…  相似文献   
29.
Vulnerability assessment in karstic areas: validation by field experiments   总被引:2,自引:0,他引:2  
Several methods have been developed for vulnerability mapping in karstic areas. These methods need additional validation by field experiments. Several tests have been carried out in the Swiss Jura with natural and artificial tracers. The protective role of some intrinsic properties of the system, such as glacial deposits covering karst, epikarst storage and system dilution effect, have been clearly demonstrated. Use of three tracers in parallel showed the reactivity of the epikarst: all tracers arrived at the same time, but their relative concentration stayed clearly different. A classification of contamination scenarios into four classes is proposed. It is shown that the relevance of some intrinsic properties depends on the considered scenario class. The hydrodynamic state of the aquifer influences greatly flow velocities and can strongly modify contaminant concentrations at the output of the system. The spatial repartition (point vs diffuse) and the quantity of contaminant entering the system will also influence the output response. Hence, results from tracing experiments cannot be used straightforward for obtaining a representative value of flow velocity, dispersion or recovery rate.  相似文献   
30.
基于CLUE模型的2030年江西省土地利用变化情景分析   总被引:5,自引:0,他引:5  
引入“一切照常情景”、“规划情景"和”优化情景"三种生态系统变化情景,采用CLUE模型,对江西省2001~2030年的土地利用空间变化进行模型模拟,并用2005年的土地利用现状图对模拟结果进行了验证。研究表明:在“一切照常情景”中,耕地持续减少;建设用地急剧增加;林地面积基本保持稳定。在“规划情景”中,耕地持续增加;建设用地略有增加,并在2020年后基本保持不变;林地总面积变化不大,但是高密度森林面积比重增大;河流和湖泊面积略微减少,湿地面积大幅增加。在“优化情景”中,森林增加趋势较“规划情景”有所减缓,河流和湖泊,湿地均有显著增加。本研究对研究区今后的土地利用规划修编和土地可持续性管理具有重要的指导意义。  相似文献   
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