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1.
Uses of models of land use change are primary tools for analyzing the causes and consequences of land use changes, assessing the impacts of land use change on ecosystems and supporting land use planning and policy. However, no single model is able to capture all of key processes essential to explore land use change at different scales and make a full assessment of driving factors and impacts. Based on the multi-scale characteristics of land use change, combination and integration of currently existed models of land use change could be a feasible solution. Taken Sangong watershed as a case study, this paper describes an integrated methodology in which the conversion of land use and its effect model (CLUE), a spatially explicit land use change model, has been combined with a system dynamic model (SD) to analyze land use dynamics at different scales. A SD model is used to calculate area changes in demand for land types as a whole while a CLUE model is used to transfer these demands to land use patterns. Without the spatial consideration, the SD model ensures an appropriate treatment of macro-economic, demographic and technology developments, and changes in economic policies influencing the demand and supply for land use in a specific region. With CLUE model the land use change has been simulated at a high spatial resolution with the spatial consideration of land use suitability, spatial policies and restrictions to satisfy the balance between land use demand and supply. The application of the combination of SD and CLUE model in Sangong watershed suggests that this methodology have the ability to reflect the complex behaviors of land use system at different scales to some extent and be a useful tool for analysis of complex land use driving factors such as land use policies and assessment of its impacts on land use change. The established SD model was fitted or calibrated with the 1987–1998 data and validated with the 1998–2004 data; combining SD model with CLUE-S model, future land use scenarios were analyzed during 2004–2030. This work could be used for better understanding of the possible impacts of land use change on terrestrial ecosystem and provide scientific support for land use planning and managements of the watershed.  相似文献   

2.
Compared to the association between cigarette smoking and psychiatric disorders, relatively little is known about the relationship between smokeless tobacco use and psychiatric disorders. To identify the psychiatric correlates of smokeless tobacco use, the analysis used a national representative sample from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) wave 1. Smokeless tobacco use was classified as exclusive snuff use, exclusive chewing tobacco, and dual use of both snuff and chewing tobacco at some time in the smokeless tobacco user''s life. Lifetime psychiatric disorders were obtained via structured diagnostic interviews. The results show that the prevalence of lifetime exclusive snuff use, exclusive chewing tobacco, and dual use of both snuff and chewing tobacco was 2.16%, 2.52%, and 2.79%, respectively. After controlling for sociodemographic variables and cigarette smoking, the odds of exclusive chewing tobacco in persons with panic disorder and specific phobia were 1.53 and 1.41 times the odds in persons without those disorders, respectively. The odds of exclusive snuff use, exclusive chewing tobacco, and dual use of both products for individuals with alcohol use disorder were 1.97, 2.01, and 2.99 times the odds for those without alcohol use disorder, respectively. Respondents with cannabis use disorder were 1.44 times more likely to use snuff exclusively than those without cannabis use disorder. Respondents with inhalant/solvent use disorder were associated with 3.33 times the odds of exclusive chewing tobacco. In conclusion, this study highlights the specific links of anxiety disorder, alcohol, cannabis, and inhalant/solvent use disorders with different types of smokeless tobacco use.  相似文献   

3.
以黄河三角洲垦利县为例,对比分析了目视解译、机助分类等遥感土地利用信息提取方法,采用1981、1991和1995年3时相土地利用现状信息,研究确定了统一的监测分类系统,提出了土地利用面积及其空间分布动态监测方法.在此基础上,分析了垦利县地类面积增减变化,在GIS支持下分析了1981~1995年土地利用空间动态变化,同时进行了实地监测点土地利用变化分析,探明了该县土地利用动态变化规律.  相似文献   

4.
5.
Empirical studies have identified increasing rates of problematic Internet use worldwide and a host of related negative consequences. However, researchers disagree as to whether problematic Internet use is a subtype of behavioral addiction. Thus, there are not yet widely accepted and validated diagnostic criteria for problematic Internet use. To address this gap, we used mixed-methods to examine the extent to which signs and symptoms of problematic Internet use mirror DSM-5 diagnostic criteria for substance use disorder, gambling disorder, and Internet gaming disorder. A total of 27 university students, who self-identified as intensive Internet users and who reported Internet-use-associated health and/or psychosocial problems were recruited. Students completed two measures that assess problematic Internet use (Young’s Diagnostic Questionnaire and the Compulsive Internet Use Scale) and participated in focus groups exploring their experiences with problematic Internet use. Results of standardized measures and focus group discussions indicated substantial overlap between students’ experiences of problematic Internet use and the signs and symptoms reflected in the DSM-5 criteria for substance use disorder, gambling disorder, and Internet gaming disorder. These signs and symptoms included: a) use Internet longer than intended, b) preoccupation with the Internet, c) withdrawal symptoms when unable to access the Internet, d) unsuccessful attempts to stop or reduce Internet use, e) craving, f) loss of interest in hobbies or activities other than the Internet, g) excessive Internet use despite the knowledge of related problems, g) use of the Internet to escape or relieve a negative mood, and h) lying about Internet use. Tolerance, withdrawal symptoms, and recurrent Internet use in hazardous situations were uniquely manifested in the context of problematic Internet use. Implications for research and practice are discussed.  相似文献   

6.
Assessing and managing water use is crucial for supporting sustainable river basin management and regional development. The first consistent and comprehensive assessment of sectorial water use in the Pearl River Delta (PRD) is presented by analysing homogenized annual water use data from 2000 to 2010 in relation to socio economic statistics for the same period. An abstraction of water use, using the concept of water use intensity, and based on equations inspired by those used in global water resource models, is developed to explore the driving forces underlying water use changes in domestic, industrial and agricultural sectors. We do this at both the level of the region as a whole, as well as for the nine cities that constitute the PRD separately. We find that, despite strong population and economic growth, the PRD managed to stabilize its absolute water use by significant improvements in industrial water use intensities, and early stabilisation of domestic water use intensities. Results reveal large internal differentiation of sectorial water use among the cities in this region, with industrial water use intensity varying from -80 to +95% and domestic water use intensity by +/- 30% compared to the PRD average. In general, per capita water use is highest in the cities that industrialised first. Yet, all cities except Guangzhou are expected to approach a saturation value of per capita water use much below what is suggested in recent global studies. Therefore, existing global assessments probably have overestimated future domestic water use in developing countries. Although scarce and uncertain input data and model limitations lead to a high level of uncertainty, the presented conceptualization of water use is useful in exploring the underlying driving forces of water use trends.  相似文献   

7.
以黄河三角洲垦利县为例 ,对比分析了目视解译、机助分类等遥感土地利用信息提取方法 ,采用 1981、1991和 1995年 3时相土地利用现状信息 ,研究确定了统一的监测分类系统 ,提出了土地利用面积及其空间分布动态监测方法 .在此基础上 ,分析了垦利县地类面积增减变化 ,在GIS支持下分析了 1981~ 1995年土地利用空间动态变化 ,同时进行了实地监测点土地利用变化分析 ,探明了该县土地利用动态变化规律 .  相似文献   

8.
以黄河三角洲垦利县为例,对比分析了目视解译、机助分类等遥感土地利用信息提取方法,采用1981、1991和1995年3时相土地利用状信息,研究确定了统一的监测分类系统、提出了土地利用面积及其空间分布动态监测方法,在此基础上,分析了垦利县地类面积增减变化,在GIS支持下分析了1981-1995年土地利用空间动态变化,同时进行了实地监测点土地利用变分析,探明了该县土地利用动态变化规律。  相似文献   

9.
生物多样性的经济价值   总被引:21,自引:2,他引:19  
生物多样性的总经济价值包含了它的可利用价值(use value, UV)和非利用价值(non-use values, NUV)。可利用价值可以被进一步分成直接利用价值(direct use values, DUV),间接利用价值(indirect use values, IUV)和可选择价值(option values, OV),即可能的利用价值。非利用价值主要是存在价值(existence values, EV)。生物多样性所提供的使用价值常常不能就地实现,而可能会通过某种通道,在空间上的流动,到达一个具备适当外部条件的地区,实现其使用价值。我们称这种现象为生物多样性价值在空间上的流动。  相似文献   

10.
E Shulman 《CMAJ》1986,134(10):1113-1121
Data from a cross-sectional survey of the health of Ontario children carried out in 1983 were used to provide estimates of the prevalence, patterns and sociodemographic correlates of the use of tobacco, alcohol and illicit drugs (substance use) among adolescents aged 12 to 16 years. Ninety-one percent of selected households participated. The prevalence rates of all categories of substance use, except use of inhalants, increased with increasing age. Among children aged 14 to 16 years the rates for girls were higher than those for boys for all categories of substance use except use of other, nondefined drugs. The prevalence rates of substance use tended to be higher in small urban areas except for use of marijuana (more prevalent in large urban areas) and use of inhalants (more prevalent in rural areas). The strongest evidence of clustering of substance use within families was found for smoking. Children who used less prevalent drugs (e.g., "hard" drugs) also tended to use the more prevalent ones (e.g., marijuana, tobacco and alcohol). Associations between substance use and low socioeconomic status suggested a positive relation with smoking and a negative relation with use of alcohol. The findings highlight the need for preventive programs aimed at specific subgroups in the adolescent population.  相似文献   

11.
Eutrophication resulting from nutrient enrichment decreases water quality and harms ecosystem structure and function, and its degree is significantly affected by land use in the catchment. Quantifying the relationship between eutrophication and land use can help effectively manage land use to improve water quality. Previous studies principally utilized land use quantity as an indicator to link water quality parameters, but these studies lacked insight into the impact of land use intensity. Taking the upper catchment of Miyun Reservoir as a case study, we developed a method of aggregating land use quantity and intensity to build a new land use indicator and tested its explanatory power on water quality. Six nutrient concentrations from 52 sub-watersheds covering the whole catchment were used to characterize the spatial distribution of eutrophication. Based on spatial techniques, empirical conversion coefficients, remote sensing data, and socio-economic statistical data, land use intensity was measured and mapped visually. The new land use indicator was calculated and linked to nutrient concentrations by Pearson correlation coefficients. Results demonstrated that our new indicator incorporating intensity information can quantify the different nutrient-exporting abilities of different land use areas. Compared to traditional indicators that only incorporate land use quantity, most Pearson correlation coefficients between the new indicator and water nutrient concentrations increased. This new information enhanced the explanatory power of land use on water nutrient concentrations, and so will be able to help us understand the impact of land use on water quality and guide decision making for better land use management.  相似文献   

12.
使用工具曾被认为是人类独有的能力,然而,在过去的50年中,学界逐渐认识到工具的使用普遍存在于整个动物界。其中,使用工具最多的类群是哺乳类、鸟类和昆虫。动物使用工具有一定目标性,然而大多数动物仅考虑当前的目标,而非长远目标。动物使用工具的行为受到环境因素和动物自身认知能力、生理特点与进化历史的影响,并可能表现出一定的个体差异。有些动物使用工具的行为是与生俱来的,然而大部分高等动物通过试错学习获得使用工具的能力。通过模仿学习,一些使用工具的行为可以传播和演化,从而在种群中广泛分布。工具的使用是动物认知领域的核心概念之一,开展动物使用工具的研究,能够加深对动物认知能力和行为进化的理解。  相似文献   

13.
土地利用冲突是区域土地开发利用过程中存在的客观问题,对区域经济社会发展和生态安全具有重要影响。识别、测度区域土地利用冲突,明晰其时空演化格局,有助于优化区域土地利用结构,促进土地资源的可持续利用。以重庆市为例,基于景观格局构建了土地利用冲突测度模型,从县域、镇域以及格网3个尺度全面和系统地分析了1995-2020年重庆市土地利用冲突的时空演化特征,并耦合多目标规划(Multi-Objective Programming,MOP)-斑块生成土地利用变化模拟模型(Ptach-generating Land Use Simulation,PLUS)模拟了重庆市2030年不同发展情景下土地利用冲突格局。结果表明:(1)1995-2020年重庆市县域、镇域与格网不同尺度下的土地利用冲突格局具有较大相似性,不同尺度的土地利用重度冲突区主要分布在重庆中心城区及周边地区,区县建成区。土地利用一般冲突区主要分布于渝东南和渝东北地区。研究期内土地利用冲突有所加剧,其中土地利用重度冲突区占比增加了3.09%。(2) 1995-2005年重庆市土地利用冲突区主体位于乡村地域,但冲突程度较低,随着工业化、城市化进程及人口的集聚,2005年后土地利用冲突热点区域的城市地域集聚效应显著,城市及周边地区土地利用冲突区面积和土地利用冲突度均显著提升。(3) 区域土地利用冲突空间格局不仅受到了人为经济社会活动的驱动影响,在空间格局上受自然生态环境基底影响显著,其中地形地貌的限制加剧了土地利用重度冲突区。(4)不同发展情景模拟中经济优先发展情景下土地利用冲突最为严重,生态优先发展情景下土地利用冲突最小,可持续发展情景兼顾了经济和生态发展的用地需求,土地利用冲突强度处于中间范围,但区域发展总福利最大,是未来区域发展路径最优选择。  相似文献   

14.
基于CLUE-S模型的不同情景下区域土地利用布局优化   总被引:7,自引:0,他引:7  
许小亮  李鑫  肖长江  欧名豪 《生态学报》2016,36(17):5401-5410
土地利用规划要求把土地资源最终配置在空间上,而现有文献更多是对土地利用结构的优化,很少对全局土地利用布局优化,鉴于此,为减轻土地利用规划的多目标冲突,同时为提高资源配置效率,释放空间效应,对不同情景下的土地利用布局优化进行研究。用非线性优化模型中的理想点法求取了不同情景下最优土地利用结构,用Logistic回归提取了不同用地的优化布局规则,以不同情景下的土地优化结构为数量约束,借助CLUE-S模型的全局配置能力对各情景下的用地布局作优化,并以扬州市为实例进行阐述。结果表明:(1)优先发展经济情景下,2025年扬州土地利用经济产值是10.4×10~7万元,优先保护生态情景下,目标年生态服务价值是9.7×10~5万元,保障公众福利情景下,公众福利大小是351271 hm~2;(2)经济增长目标对土地利用结构的情景变化最为敏感,而公众福利目标的敏感性最小;(3)与基期年比,发展经济与保育生态情景下的土地优化布局变化最大,前者主要是市区城镇工矿用地向东部及西北扩张,后者则是在西南丘陵及南部长江岸边配置了大量园地、林地。提出的不同情景下土地利用布局的优化方法可为土地利用规划及生态规划提供有力技术支持。  相似文献   

15.
Abstract. In a rural landscape, scale vegetation patterns of woody species are controlled by both abiotic and land use factors. The woody species composition in 126 sample plots was analysed and land use factors and some abiotic parameters were quantified using land register data. The relative importance of land use and abiotic factors was differentiated using a partial Canonical Correspondence Analysis (CCA); the influence of land use in neighbouring areas was explored by changing the scale of land use sampling. The woody species composition appears to be controlled equally by land use and abiotic factors. The fraction of floristic variation in tree species composition explained by land use variables was 33.2 % in 1980 and 30.8 % in 1992, while abiotic variables accounted for 31.2 %. Part of the 17 % of the floristic variance explained is related to the surrounding land use. Thus, when the land use of the sampled plots and the surrounding land use are considered simultaneously, up to 36.9 % of the species variation may be explained. Partial CCA enabled us to quantify the respective proportion of floristic variance which could be explained by land use (36.9 %), abiotic variables alone (20.2 %), shared variance (12.0 %) and unexplained variance (31.2 %). Our results indicated that a delayed effect of variation in land use on plant populations may exist. This delay may result either from population characteristics or from inadequate land use assessment. This study indicates the need for simultaneously examining land use and abiotic patterns in ecological studies, as many Mediterranean-type ecosystems have been shaped by these patterns.  相似文献   

16.
The use of stones as hammers to break open nuts was studied in a captive group of 7 Cebus apella. Only the single adult female and an infant showed no tool use. Tool use significantly reduced the time required to break open the nuts and obtain the kernel and led to fewer nuts being abandoned. Individual differences and social processes surrounding tool use are described. The development of tool use in a juvenile female is documented, along with the same female's novel use of a previously neglected object as a tool and the subsequent use of this object by the other members of the group.  相似文献   

17.
Perceptions of family alcohol use have been linked to adolescent alcohol use behaviors, yet there have been no studies that have assessed this relationship in young adults. This study examined perceptions of family alcohol use and their association with participants’ self-reported alcohol use. Participants included 171 undergraduate students (mean age = 21.67, 71.9 percent female, 75.4 percent Caucasian). Participants completed measures assessing quantity and frequency of alcohol use, negative consequences of use, and sibling relationship quality. They also reported their perceptions of alcohol use for siblings and parents during a typical week. Perceptions of siblings’ quantity of weekly alcohol use were significantly associated with participants’ quantity of alcohol use (r = .21, p = .006) and frequency of alcohol use (r = .23, p = .002). Perceptions of parental alcohol use were not related to the participants’ alcohol use patterns.  相似文献   

18.
北京市土地利用生态分类方法   总被引:9,自引:0,他引:9  
唐秀美  陈百明  路庆斌  杨克  宋伟 《生态学报》2011,31(14):3902-3909
本文从国内外土地利用分类体系的现状分析入手,分析了当前土地利用分类体系与生态保护存在的矛盾,提出进行土地利用生态分类。首先,将北京市的土地利用现状类型分析归并为9个一级类15个二级类,确定各土地利用类型基准生态服务价值,然后提出各土地利用类型生态系统服务价值的区位修正方法,在对各种土地利用类型生态系统服务价值进行区位修正的基础上,划分出6个一级生态用地类型。其次,对北京市进行生态适宜性评价,生成生态适宜性分布图,将已生成的土地利用生态一级分类图与生态适宜性分布图进行叠加,对一级生态用地类型进行了二级划分,得到6个大类、18个亚类的北京市土地利用生态用地类型。最后,以北京市2007年的土地利用现状图为例,对北京市的土地利用生态分类方法进行应用,得到了2007年北京市土地利用生态分类图并分析了各土地利用生态用地类型的分布状况。  相似文献   

19.
Inhalant use is especially prevalent among antisocial youth and can have serious health consequences. However, the extant literature has not investigated how use of various inhalants may co-occur among incarcerated youth. This study begins to address this gap in the literature by using latent class analyses to form distinct typologies of inhalant use. Study participants were residents (N = 723) of 27 Missouri Division of Youth Services facilities. Interviews assessed psychiatric symptoms, antisocial traits, delinquency, trauma, suicidality, and substance use behaviors. The mean age of the mostly male, ethnically diverse sample was 15.5 (S.D. = 1.2) years old. The study revealed the following classes of inhalant use: (1) severe polyinhalant use; (2) moderate polyinhalant use; (3) gas and permanent marker use; and (4) low-use. Compared to the low-use class, members of the severe polyinhalant use class had experienced more than double the rate of head injuries, the highest rates of traumatic experiences, and the highest rates of mental illness diagnoses. The gas and markers class had the highest rate of reporting hearing voices, followed by the severe polyinhalant use class, and the moderate polyinhalant use class. Results of this study underscore the need to address the high rate of head injuries and mental health diagnoses that contribute to severe polyinhalant use.  相似文献   

20.
基于地形梯度的岩溶槽谷区土地利用空间格局分析   总被引:5,自引:0,他引:5  
王权  李阳兵  刘亚香  胡先培 《生态学报》2019,39(21):7866-7880
揭示当前多因素驱动机制下岩溶槽谷区典型地貌单元在地形梯度上土地利用分布的一般规律与差异性特征具有重要意义。以2017年landsat TM高清影像和30 m×30 m DEM(Digital Elevation Model)为数据源,并结合实地调查,通过地形位分布指数、土地利用多样性指数、土地利用程度指数及土地利用相对合理性指数指标计算,探讨岩溶槽谷区地形梯度的土地利用类型空间分布共同特征与差异。结果表明:(1)岩溶槽谷区土地利用类型呈现山坡(高地形位)-槽坝(低地形位)两种分布格局特色存在,且土地利用类型在地形梯度上主要以低、中、高3种地形位组合模式;(2)土地利用类型在地形梯度上呈现梯度效应,表现出各自分布特征与差异;(3)岩溶槽谷区土地利用多样性、土地利用程度和土地利用合理性在地形梯度上分布格局既存在一些共同性特征,又存在各自差异性;(4)地形梯度土地利用特征差异性是受自然因素、社会经济因素、政策因素共同作用的结果。  相似文献   

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