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1.
基于垂直带谱的南北过渡带1:5万植被类型图遥感制图研究——以太白山为例 总被引：1，自引：1，他引：1
The compilation of 1:250,000 vegetation type map in the North-South transitional zone and 1:50,000 vegetation type maps in typical mountainous areas is one of the main tasks of Integrated Scientific Investigation of the North-South Transitional Zone of China.In the past,vegetation type maps were compiled by a large number of ground field surveys.Although the field survey method is accurate,it is not only time-consuming,but also only covers a small area due to the limitations of physical environment conditions.Remote sensing data can make up for the limitation of field survey because of its full coverage.However,there are still some difficulties and bottlenecks in the extraction of remote sensing information of vegetation types,especially in the automatic extraction.As an example of the compilation of 1:50,000 vegetation type map,this paper explores and studies the remote sensing extraction and mapping methods of vegetation type with medium and large scales based on mountain altitudinal belts of Taibai Mountain,using multi-temporal high resolution remote sensing data,ground survey data,previous vegetation type map and forest survey data.The results show that:1)mountain altitudinal belts can effectively support remote sensing classification and mapping of 1:50,000 vegetation type map in mountain areas.Terrain constraint factors with mountain altitudinal belt information can be generated by mountain altitudinal belts and 1:10,000 Digital Surface Model(DSM)data of Taibai Mountain.Combining the terrain constraint factors with multi-temporal and high-resolution remote sensing data,ground survey data and previous small-scale vegetation type map data,the vegetation types at all levels can be extracted effectively.2)The basic remote sensing interpretation and mapping process for typical mountains is interpretation of vegetation type-groups→interpretation of vegetation formation groups,formations and subformations→interpretation and classification of vegetation types&subtypes,which is a combination method of top-down method and bottom-up method,not the top-down or the bottom-up classification according to the level of mapping units.The results of this study provide a demonstration and scientific basis for the compilation of large and medium scale vegetation type maps. 相似文献
2.
Demand for food plays an important role in the adjustment of prices for agricultural products and for adjusting agricultural structure.By using the extended linear expenditure system(ELES),we analyzed the food consumption structure of rural residents in the Ganzhou district of Zhangye city,and determined the basic food-consumption demand,the marginal propensity of consumption,the income elasticities of demand,and the own-price and cross-price elasticities of local rural residents,all of which illustrate the influencing factors on food consumption of rural residents and for forecasting the food-consumption structure.Those analyses show the following:the rural residents’ expenditure on household basic food consumption reaches about 7,050.35 Yuan;the marginal propensities of consumption of fruits and vegetables are relatively high(0.062 and 0.106,respectively),followed by meat(0.044);the demands for various foods are increasing as income increases,with the largest income elasticity of demand corresponding to fruits(1.354) and the lowest to cereal(0.310);fruits and vegetables have relatively high own-price elasticities(respectively-0.879 and-0.442),with the cereal having the lowest one(-0.184).An increase in cereal prices would greatly affect demand for other products;with the rising size of rural households,the consumption for meat is decreasing whereas it is increasing for cereal.The improvement of household education levels will lead to the increase of fruit consumption(E = 0.297),which indicates that people will pay more attention to diet and nutrition structure with the improvement of education.Further,although the amount of cereal expenditure is continually growing,the share will be declining with the increase of household income in 2006-2012.For all these reasons,therefore,the government should encourage the cultivation of economic crops and guide the development of stockbreeding to ensure the stability of cereal output.In order to attain the balance between supply and demand,it is important to rationally a 相似文献
3.
Urban resilience is an emerging research topic of urban studies, and its essence is described by the ability of cities to resist, recover, and adapt to uncertain disturbances. This paper constructs a "Size-Density-Morphology" urban ecological resilience evaluation system, uses a coupling coordination degree model to measure the degree of coupling coordination between urbanization and ecological resilience in the Pearl River Delta from 2000 to 2015, and conducts an in-depth discussion on its spatiotemporal characteristics. The results show the following.(1) From 2000 to 2015, the urbanization level of cities in the study area generally increased while the level of ecological resilience declined. The coupling coordination degree between the two systems decreased from basic coordination to basic imbalance.(2) In terms of spatial distribution, the coupling coordination degree between urbanization and ecological resilience of cities presented a circular pattern that centered on the cities at the estuary of the Pearl River and increased toward the periphery.(3) Ecological resilience sub-systems played variable roles in the coupling coordination between urbanization and ecological resilience. Specifically, size resilience mainly played a reverse blocking role;the influence of morphology resilience was generally positive and continued to increase over time;the effect of density resilience was positive and continued to decline and further became negative after falling below zero. The main pathways for achieving coordinated and sustainable development of future urbanization and ecological resilience in the Pearl River Delta include: leading the coordinated development of regions with new urbanization, improving ecological resilience by strictly observing the three areas and three lines, adapting to ecological carrying capacity, and rationally arranging urban green spaces. 相似文献
4.
Climate change resulting from CO_2 emissions has become an important global environmental issue in recent years.Improving carbon emission performance is one way to reduce carbon emissions.Although carbon emission performance has been discussed at the national and industrial levels,city-level studies are lacking due to the limited availability of statistics on energy consumption.In this study,based on city-level remote sensing data on carbon emissions in China from 1992–2013,we used the slacks-based measure of super-efficiency to evaluate urban carbon emission performance.The traditional Markov probability transfer matrix and spatial Markov probability transfer matrix were constructed to explore the spatiotemporal evolution of urban carbon emission performance in China for the first time and predict long-term trends in carbon emission performance.The results show that urban carbon emission performance in China steadily increased during the study period with some fluctuations.However,the overall level of carbon emission performance remains low,indicating great potential for improvements in energy conservation and emission reduction.The spatial pattern of urban carbon emission performance in China can be described as"high in the south and low in the north,"and significant differences in carbon emission performance were found between cities.The spatial Markov probabilistic transfer matrix results indicate that the transfer of carbon emission performance in Chinese cities is stable,resulting in a"club convergence"phenomenon.Furthermore,neighborhood backgrounds play an important role in the transfer between carbon emission performance types.Based on the prediction of long-term trends in carbon emission performance,carbon emission performance is expected to improve gradually over time.Therefore,China should continue to strengthen research and development aimed at improving urban carbon emission performance and achieving the national energy conservation and emission reduction goals.Meanwhile,neighboring cities with different neighborhood backgrounds should pursue cooperative economic strategies that balance economic growth,energy conservation,and emission reductions to realize low-carbon construction and sustainable development. 相似文献
5.
The Yangtze River Delta(YRD) is a region in China with a serious contradiction between economic growth and environmental pollution. Exploring the spatiotemporal effects and influencing factors of air pollution in the region is highly important for formulating policies to promote the high-quality development of urban industries. This study uses the spatial Durbin model(SDM) to analyze the local direct and spatial spillover effects of industrial transformation on air pollution and quantifies the contribution of each factor. From 2008 to 2018, there was a significant spatial agglomeration of industrial sulfur dioxide emissions(ISDE) in the YRD, and every 1% increase in ISDE led to a synchronous increase of 0.603% in the ISDE in adjacent cities. The industrial scale index(ISCI) and industrial structure index(ISTI), as the core factors of industrial transformation, significantly affect the emissions of sulfur dioxide in the YRD, and the elastic coefficients are 0.677 and-0.368, respectively. The order of the direct effect of the explanatory variables on local ISDE is ISCI>ISTI>foreign direct investment(FDI)>enterprise technological innovation(ETI)>environmental regulation(ER)> per capita GDP(PGDP). Similarly, the order of the spatial spillover effect of all variables on ISDE in adjacent cities is ISCI>PGDP>FDI>ETI>ISTI>ER, and the coefficients of the ISCI and ISTI are 1.531 and 0.113, respectively. This study contributes to the existing research that verifies the environmental Kuznets curve in the YRD, denies the pollution heaven hypothesis, indicates the Porter hypothesis, and provides empirical evidence for the formation mechanism of regional environmental pollution from a spatial spillover perspective. 相似文献
6.
耦合魔方——一个分析人地系统耦合机理的多维框架 总被引：1，自引：1，他引：1
Understanding the interactions between humans and nature in the Anthropocene is central to the quest for both human wellbeing and global sustainability.However,the time-space compression,long range interactions,and reconstruction of socio-economic structures at the global scale all pose great challenges to the traditional analytical frameworks of human-nature systems.In this paper,we extend the connotation of coupled human and natural systems(CHANS)and their four dimensions—space,time,appearance,and organization,and propose a novel framework:“Coupled Human and Natural Cube”(CHNC)to explain the coupling mechanism between humans and the natural environment.Our proposition is inspired by theories based on the human-earth areal system,telecoupling framework,planetary urbanization,and perspectives from complexity science.We systematically introduce the concept,connotation,evolution rules,and analytical dimensions of the CHNC.Notably there exist various“coupling lines”in the CHNC,connecting different systems and elements at multiple scales and forming a large,nested,interconnected,organic system.The rotation of the CHNC represents spatiotemporal nonlinear fluctuations in CHANS in different regions.As a system continually exchanges energy with the environment,a critical phase transition occurs when fluctuations reach a certain threshold,leading to emergent behavior of the system.The CHNC has four dimensions—pericoupling and telecoupling,syncoupling and lagcoupling,apparent coupling and hidden coupling,and intra-organization coupling and inter-organizational coupling.We mainly focus on the theoretical connotation,research methods,and typical cases of telecoupling,lagcoupling,hidden coupling,and inter-organizational coupling,and put forward a human-nature coupling matrix to integrate multiple dimensions.In summary,the CHNC provides a more comprehensive and systematic research paradigm for understanding the evolution and coupling mechanism of the human-nature system,which expands the analytical dimension of CHANS.The CHNC also provides a theoretical support for formulating regional,sustainable development policies for human wellbeing. 相似文献
7.
The Yangtze River Watershed in China is a climate change hotspot featuring strong spatial and temporal variability;hence, it poses a certain threat to social development. Identifying the characteristics of and regions vulnerable to climate change is significantly important for formulating adaptive countermeasures. However, with regard to the Yangtze River Watershed, there is currently a lack of research on these aspects from the perspective of natural and anthropogenic factors. To address this issue, in this study, based on the temperature and precipitation records from 717 meteorological stations, the RClim Dex and random forest models were used to assess the spatiotemporal characteristics of climate change and identify mainly the natural and anthropogenic factors influencing climate change hotspots in the Yangtze River Watershed for the period 1958-2017. The results indicated a significant increasing trend in temperature, a trend of wet and dry polarization in the annual precipitation, and that the number of temperature indices with significant variations was 2.8 times greater than that of precipitation indices. Significant differences were also noted in the responses of the climate change characteristics of the sub-basins to anthropogenic and natural factors;the delta plain of the Yangtze River estuary exhibited the most significant climate changes, where 88.89% of the extreme climate indices varied considerably. Furthermore, the characteristics that were similar among the identified hotpots, including human activities(higher Gross Domestic Product and construction land proportions) and natural factors(high altitudes and large proportions of grassland and water bodies), were positively correlated with the rapid climate warming. 相似文献
8.
《地理学报》1947,(Z1)
1. Location and Historical Development Chengtu, the capital city of western Szechwan, is located on the lower part of the Min and Tu alluvial fan (Fig.1) which has an area of about 6,000 sq.km., and is the most fertile irrigated fields of the western China. The autbor discusses the location and site of the city to compare with other cities on the alluvial fan, and finds that the selection and development of Chengtu as a capital city is due chiefly to the reason that it is situated at the terminus point o... 相似文献
9.
中国山地范围界定的初步意见 总被引：8，自引：1，他引：7
中国山地的范围一直缺乏可操作的、准确的量化方法,从而导致对山地及其内部资源、环境、人口和发展问题认识的不全面.同时,准确界定山地范围是实施数字山地战略的一项基础性工作.在前人研究的基础上,采用两种方案确定中国山地范围.方案一:将满足以下两种情况的国土界定为山地,1)海拔≥3 000 m;2)海拔≥1300～3 000 m,同时相对高差>200 m或坡度>25°.根据此标准计算,中国山地面积为4 000 265 km2,占中国陆地面积的41.67%.方案二:根据UNEP-WCMC的标准,将满足下述情况的国土定义为山地,1)海拔≥2 500 m;2)海拔≥1 500～2 500 m,坡度≥2°;3)海拔≥1 000～1 500 m,坡度≥5°或相对高差≥300 m;4)海拔≥300～1 000 m,相对高差≥300 m.根据此标准计算,中国山地面积为4 426 130 km2占中国陆地面积的46.11%.按两种方法计算所得的分省山地面积中,前5名都是西藏、青海、新疆、四川和云南.将两种方案计算的山地面积按高程划分为六级:①300～1 000 m(含300 m),②1 000～1 500 m(含1 000 m),③1 500～2 500 m(含1 500 m),④2 500～3 500 m(含2 500 m),⑤3 500～4 500 m(含3 500 m),⑥≥4 500 m.根据两种方案的定义,海拔3 500 m以上的山地面积相等;除了方案-在300～1 000 m间山地较方案二多324 508 km2外,其余几个级别山地的面积均为方案二大于方案-的山地面积,其中2 500～3 500 m间多133 432 km2,1 500～2 500 m间多336 186 km2,1 000～1 500 m间多282 273 km2. 相似文献
10.
The concept of‘Beautiful China'is a new goal of ecological construction in the new era of socialism and aims to meet the needs of people as they strive for a better life.National land spatial planning is one major component of the Chinese state's overall planning for various spatial types.The concept of‘Beautiful China'is thus a leading goal of Chinese development in the second centenary.The background of this concept aims for‘ecological beauty'as well as the combined beauty of‘economy-politics-culture-society-ecology.'The construction of‘Beautiful China'therefore necessitates a differentiated evaluation index system that is built on the basis of local conditions.This concept is intimately related to land spatial planning and the idea of Beautiful China guides an important direction for this planning which itself provides an important mechanism and spatial guarantee for construction.The establishment of land spatial planning nevertheless needs to strengthen further discussion of the regional system of human-land relationship,point axis system,main functional division,sustainable development,resources and environmental carrying capacity as well as new urbanization,and the rural multi-system.The aim of this paper is to summarize current thinking in land spatial planning,scientifically analyze the natural geographical conditions,the socioeconomic development,the interrelationship of the land space,plan the goal,vision and path of land space,encourage the public to participate in and carry out dynamic evaluation,build an intelligent system platform for land and spatial planning to realize the goal of‘Beautiful China'from a geographical perspective.And they can also present key ideas relating to the compilation and implementation of land spatial planning. 相似文献
11.
本文研究热带亚热带土壤中重金属分布的垂直分异及其分层性特征.土壤剖面中,水溶态、可交换态和有机结合态的重金属浓度自上层向底层降低.水溶态和有机结合态重金属的分布与有机质一致,而与pH值相反.Fe-Mn氧化物结合态的重金属分布与粘粒一致.残渣态分布的差异极小. 相似文献
12.
以X射线衍射分析,研究了长江上游山地土壤的粘土矿物组成。根据土壤粘土矿物组成分类,划分了粘土矿物地带。采用土壤结构恢复试验,比较了不同粘土矿物组成土壤的结构形成特征。 相似文献
13.
南极洲万达盐湖水中悬浮物的流量 :水深 1 2m ,1 1 9 673mg/cm2 ·a;3 2m ,67 93mg/cm2 ·a;45m ,1 5 82mg/cm2 ·a;48m ,9 46mg/cm2 ·a ;60m ,1 3 5 5mg/cm2 ·a ;65m ,3 0 3 3mg/cm2 ·a。湖水悬浮物中粘土矿物主要为伊利石 ,含量 64～ 67% ,次为绿泥石 ,含量 2 5～ 3 0 % ,蒙脱石仅含 5 9～6 6% ,而高岭石含量极低。湖水悬浮物中痕量金属的含量 :水深 1 2m ,Cr 5 4 3 μg/g、Cu 1 1 9 3 μg/g、Ni 5 3 4μg/g、Co 2 3 9μg/g、Cd1 43 μg/g;3 2m ,Cr 44 9μg/g、Cu 1 1 8 7μg/g、Ni 5 0 2 μg/g、Co 1 9 4μg/g、Cd 1 5 1 μg/g;45m ,Cr 5 3 μg/g、Cu1 42 8μg/g、Ni 5 9 8μg/g、Co 1 9 8μg/g、Cd 1 83 μg/g ;60m ,Cr 1 3 2 μg/g、Cu 49 6μg/g、Ni 1 3 4μg/g;Co 4 3 μg/g、Cd 0 3 7μg/g ;65m ,Cr 7 4μg/g、Cu 1 7 6μg/g、Ni6 7μg/g、Co 2 4μg/g、Cd 0 3 6μg/g。悬浮物中痕量金属含量高低顺序 :Cu>Cr>Ni>Co >Cd。在水深 60m以上 ,悬浮物中痕量金属主要被束缚在硅酸盐、锰的氧化物及铁的氢氧化物悬浮物颗粒上 ,在水深 60m以下 ,则主要被束缚在硅酸盐矿物及有机质颗粒上。 相似文献
14.
海南岛尖峰岭地区山地土壤发生特性 总被引：5，自引：0，他引：5
对地处热带的海南岛尖峰岭地区的山地土壤的发生和发育特性进行了研究。因母岩因素以及较弱的成土作用和较强的侵蚀作用 ,土壤质地普遍较粗 ,石砾含量高。由于山地气候的垂直分异 ,不同海拔高度土壤间的发生特性存在较大差异。高海拔地区土壤易风化矿物含量高 ,低海拔地区土壤中抗风化能力强的锆石含量高 ;高海拔区土壤中粘土矿物以三水铝石和埃洛石为主 ,含有一定量的铝蛭石 ,低海拔土壤以高岭石为主 ,有一定量的水云母。伴随海拔高度的增加 ,阳离子交换量 (CEC7)、盐基总量、盐基饱和度、pH下降 ,而代换性酸H 、Al3 却逐渐增多。高海拔区湿润的水分状况和酸性成土环境导致粘粒的硅铝率、硅铁铝率较低海拔土壤小。尖峰岭地区土壤类型以雏形土为主 ,山麓分布有淋溶土。 相似文献
15.
陈志清 《云南地理环境研究》1991,3(2):23-33
本文对采自中国、法国、比利时等国43块黄土样品进行实验室处理后,分析对比了它们在碳酸盐含量、粒度组成、重矿物组成及粘土矿物成分方面的共同特性及差异性。结果表明,中国黄土碳酸盐含量稳定,西欧不同类型的黄土碳酸盐含量差别很大。在粒度组成上,欧亚黄土并没有本质的差别,但西欧不同层位的黄土粒度组成呈有规律变化。对西欧重矿物的分析可以追溯黄土的物质来源,粘土矿物含量在欧亚不同黄土中也有差别。比较结果说明,欧洲的黄土堆积受第四纪冰期、间冰期的气候波动影响较大,中国黄土在堆积期间始终处在干旱、半干旱的气候条件下。 相似文献
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17.
本文运用模式计算方法对黄河水体中重金属的形态分配进行了研究。结果表明,pH是控制重金属形态分配的最重要因素,其次是重金属的初始浓度和悬浮物含量。并得出,在黄河水体中,cu、Pb主要以沉淀态存在,zn则以吸附态为主,水体中游离态重金属含量很低。上述结果将为拟建中的小浪底水库工程的重金属环境影响预测提供一定的科学依据。 相似文献
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19.
控制土壤硒化学行为因素的探讨 总被引：7，自引：0，他引：7
用Jackson系统分离土壤磷的程序,研究了我国土壤中结合态硒的含量及其控制因素。结果表明,在酸性环境中,Fe、Al、Mn的氧化物或矿物是控制土壤硒化学行为的主要因子,Ca、Mg、K的作用不大。在碱性环境中,Ca、Mg、K的化合物或矿物是制约土壤非闭蓄性硒均主要因子,而控制闭蓄性硒的则是Fe、Al、Ma的氧化物或矿物。P、Si不仅以络阴离子的形式参与土壤硒的固定和影响植物对硒的利用,而且以化台物或矿物的肜式影响硒在土壤中的循环。在所研究的土壤中,未发现Cr、V、Sr、Ba、Co、Cu、Ni.Ti,Cd、Pb等与结合态硒含量在统计学上相关。 相似文献
20.
对南极半岛西部海域的表层沉积物和岩芯S11样品中小于2微米粒级的分析表明,粘土矿物由蒙脱石、伊利石、绿泥石和高岭石组成。表层沉积物中以蒙脱石和伊利石两种矿物占优势。蒙脱石的变化趋势由北向南递减,在南设得兰群岛周围海区含量最高;伊利石的变化趋势与蒙脱石相反,主要分布在南极半岛西北侧。 岩芯S11中的粘土矿物仍由上述四种矿物组成。蒙脱石含量随深度增大而减少;伊利石和绿泥石含量随深度增大而增高。这种变化趋势表明蒙脱石在间冰期沉积物中最丰富,而伊利石和绿泥石在冰期沉积物中最丰富。 相似文献