共查询到20条相似文献，搜索用时 140 毫秒
1.
The Beautiful China Initiative(BCI)is a plan for the sustainable development of the Chinese nation as well as for China to fulfill the United Nations’2030 Agenda for Sustainable Development.The Chinese government’s“five-in-one”approach provides strategic arrangements for developing the BCI,and President Xi Jinping proposed a timetable and“road map”for the BCI at the National Conference on Ecological and Environmental Protection.Nevertheless,the theoretical basis,evaluation index system,evaluation criteria and effectiveness of the BCI are currently unclear.This paper begins by exploring the basic content of the BCI from narrow and broad perspectives.It regards the theory of human-nature harmonious coexistence and the five-in-one beauty theory as the core theoretical bases of the BCI and constructs a five-element BCI evaluation index system(ecological environment,green development,social harmony,system perfection and cultural heritage)and utilizes the assessment method of the United Nations’Human Development Index to assess scientifically the effectiveness of the BCI in 341 prefecture-level cities.The results show the average BCI index(the Chinese Academy of Sciences Beauty Index)score to be 0.28,which is quite low,while the average scores for the individual element indexes of the ecological environment index,green development index,social harmony index,system perfection index and cultural heritage index are 0.6,0.22,0.29,0.22 and 0.07,respectively.All of these are relatively low values,with relatively large discrepancies in regional development,indicating that progress in the BCI is generally slow and unbalanced.To realize the BCI’s timetable and roadmap to a high quality and high standard,it is suggested that a common system for evaluating the progress of the BCI is developed and promulgated so that dynamic monitoring and phased evaluations can take place;BCI technical assessment standards are compiled and published;BCI comprehensive zoning is undertaken;pilot projects adapted to local conditions are launched in BCI sample areas;and BCI results are incorporated into performance indicators at all levels of government. 相似文献
2.
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
3.
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
4.
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
5.
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
6.
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
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.
Protected areas have a double mandate of both "protection" and "use." Naturebased tourism is considered an effective tool in terms of environmental conservation. Understanding the causes and consequences of a spatiotemporal succession of tourism construction is an important channel to explore the changes of tourism-environment interaction in the protected area. To analyze the spatio-temporal variations in tourism construction lands, we adopted Mt. Bogda as an example. We systematically quantified the interaction between these changes and environmental variables and explored the evolution process of tourism-environment interaction of the mountainous protected area in the northwest arid region. Our results revealed the following:(1) In the Bogda protected area, the proportion of tourism construction lands first appeared to be increasing, then decreasing dramatically, and finally growing slowly. The spatial expansion of tourism construction lands followed the "core-periphery" pattern, respectively showing shapely infilling, reasonable agglomeration, barycenter shift, and outlying growth from 1990 to 2018 as the stages of concentrating on the core.(2) The higher land-use intensity of tourism construction drove the changes of landscape fragmentation, diversity, stability, primitive, and nature degree in the protected area. The coupling coordination between tourism and the environment in the Bogda area decreased at first, and then slowly increased. Meanwhile, tourism did not cause irreversible damage to the natural environment, and the coupling coordination degree between tourism and the environment was still in the state of balanced development. It expressed the states of original balanced, development exceeds environment and barely balanced, and superiorly balanced. The historical evolution of tourism-environment interaction in Bogda reflects the pattern of periodic changes in China’s protected areas to a certain extent. 相似文献
9.
《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
10.
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
11.
敦煌莫高窟古代生土建筑物风蚀机理与防护对策的研究* 总被引：1，自引：1，他引：1
利用低温冻融实验和风洞模拟实验研究古代生土建筑的风蚀机理,结果表明:挟沙风风蚀速率明显大于净风的风蚀速率,其风蚀率是净风的130倍,冻融是风蚀速率增大的一个重要因素,偏西风的降水和风蚀是造成莫高窟古代生土建筑风蚀毁坏的方要原因.实验表明,采取5%LS和10%PS防护材料是防止风蚀的一条重要途径. 相似文献
12.
滹沱河上游水系变迁问题的讨论 总被引：1，自引：0，他引：1
本文着重讨论了滹沱河上游水系变迁的三个争议较大的问题。研究表明：（１）阳武河袭夺问题是不存在的，其干、支流分别沿ＮＷ和ＮＥ两组性质不同的构造发育而成；（２）奇村宽谷在更新世期间曾长期作为滹沱河汊道与界河铺峡谷并存，后因西部山地河流的超补偿堆积而最终断流。（３）滹沱河是一条先成河，自上新世末形成以来，其总的流路并未改变。石岭关风口早于盆地而形成，可能是一条更古老的河流所造成。 相似文献
13.
若干特殊地表风蚀的风洞实验研究 总被引：10，自引：1，他引：10
经风洞模拟实验,本文对四种特殊地表在净风和挟沙风情况下的风蚀特性,进行了定量的研究。揭示了原始地表结构受人为破坏后,其抗风蚀能力急剧降低的特点。探讨了风成沙粒配、戈壁风蚀平衡与风蚀有关的几个问题。 相似文献
14.
黄河下游清水冲刷阶段河床的调整及其对基准面变化的反应 总被引：1，自引：1，他引：0
本文采用黄河下游的实测资料,分析了三门峡水库下洩清水阶段,河床的调整及其对基准面的反应。认为在来水来沙条件变化的情况下,河床纵剖面以近于平行的方式调整;横断面形态向窄深式发展;河型的转化主要取决于地貌临界值和粉沙—粘土含量。从长时间看,下游的淤积特性不会发生根本性的变化。 相似文献
15.
广州山水格局及其保护 总被引：2，自引：2，他引：2
广州“山水”的概念，不应仅仅理解为“云山珠水”。从越秀山、白云山起，向东北绵延200km的山脉，以及相辅的山丘台地，构成广州山的格局；广州的水，除了珠江以外，还应包括众多的河涌、湖泊、沼泽、滩涂等湿地。这些山地和湿地，对于广州的生态环境有十分重要的作用。保护和合理利用广州优越的山水条件，是建设现代化山水城市的必然要求。 相似文献
16.
风洞实验方法在沙漠学研究中的应用 总被引：7，自引：0，他引：7
风沙运动和防治风沙、风雪流工程等的模拟实验研究表明,风洞实验技术应用于沙漠学研究中,进行半定量、定量的测量,可以提高研究水平,更好地解决生产实践任务。 相似文献
17.
黄河口近期环境演变与河口治理 总被引：4，自引：0，他引：4
本文分析了近几年来尾闾河道及河口滨海区实测资料，认为尾闾河道河相关系趋向于转好，河口变化造成的溯源冲淤作用影响范围仅有２０几ｋｍ，并且只有在汛期水流强度较大时，才发生溯源调整作用，非汛期淤积严重。由于河口砂咀向海凸出，三角洲前缘形成强流带，加上波浪作用及异重流发育，河口砂咀延伸速度明显减缓。最后，作者对目前河口治理中存在问题的解决提出了建议，尤其指出不应轻易放弃目前良好的河口行水环境。 相似文献
18.
塔里木河现代河道冲淤变化的探讨 总被引：3，自引：3，他引：3
通过对现代塔里木河干流河道大断面的泥沙堆积情况、河道的基本特征和上游来水来沙条件的研究，认为塔里木河河道冲淤较大，主槽摆动频繁；涨水时低滩地淤积，落水时冲刷；每经一个汛期，滩面有所抬高；长时期内滩槽相对高差变化不大；河道淤积量大小主要取决于上游来沙、来水量，尤其是汛期水沙量对河道变迁的意义重大 相似文献
19.
北洛河下游河槽形成与输沙特性 总被引：8，自引：0，他引：8
北洛河发湖泊于黄河粗沙来源区，年均含沙量达１２８ｋｇ／ｍ＾３年均流量仅２５ｍ＾３．ｓ，是典型的多沙河流，但由于泥沙主要由高含沙洪水输送，平水流量小，含沙量低，经常保持窄深稳定河槽，使高含沙洪水挟带的泥沙能顺利输送而不淤，并形成弯曲性河流。 相似文献
20.
西江河口(磨刀门)沉积环境分析 总被引：5，自引：1，他引：4
本文采用粒度概率曲线、频率曲线与粒度基本参数相结合的方法,分析西江河口(磨刀门)沉积环境,重点探讨河口拦门沙及其沉积结构的形成。认为波浪作用是西江河口拦门沙形成的主要动力;对粒度概率曲线的过渡式和双跃式加以区别,并探讨其成因。 相似文献