Screening Test of Small Seedless Watermelon Varieties in Beijing Area

[Objectives]This study was conducted to select small seedless watermelon varieties with excellent quality and high yield suitable for planting in Beijing.[Methods]Under the conditions of facility cultivation in Beijing,a screening test was conducted on seven small seedless watermelon varieties for growth process,field traits,yield traits,fruit quality,and disease resistance.[Results]Varieties Mitong,Motong and Tianbao Xiaowuzi had a short growth period and relatively stable growth,and bore fruit easily,and their female flowers were closely spaced.Their yields exceeded 60000 kg/hm~2,ranking in the top three among all varieties.The fruit had a thin skin,a bright red flesh color,and a high mass fraction of soluble solids in the center.The flesh was tight or crispy,and tasted good.They also showed good disease resistance.Overall,they showed excellent comprehensive agronomic traits,and are thus suitable for facility cultivation in Beijing and its surrounding areas.[Conclusions]This study provides a theoretical basis for the upgrading of varieties and the increase in production and farmers'income in the suburbs of Beijing.

Ecological Carrying Capacity in Beijing Mountainous Areas——Taking Fangshan District as an Example

[Objective] The aim was to investigate ecological carrying capacity of Fangshan District in Beijing. [Method] Ecological footprint and carrying capacity of Fangshan District in 2007 and 2008 were analyzed with ecological footprint model and the difference between ecological footprint and carrying capacity there was con- cluded. Furthermore, an assessment was made on relation between Fangshan de- velopment with local ecological carrying capacity to evaluate sustainable development of Fangshan District. [Result] Fangshan District is of lightly ecological deficit; ecologi- cal footprint per capita in 2007-2008 was deficit and tended to expand. Two meth- ods are available to reduce ecological ：deficit, including reduction of ecological foot- print and increase of carrying capacity. In general, supply and demand of carrying capacity in Fangshan are better, though with some problems. It is necessary to fur- ther develop related industries to final eliminate ecological deficit in order to achieve ecological conservation-orientation and sustainable development of Fangshan District. [Conclusion] The research provides theoretical references for overall evaluation on eco- logical carrying capacity of Fangshan District.

Diurnal Variations of Summer Precipitation in the Beijing Area and the Possible Effect of Topography and Urbanization

The present study examined the diurnal variations of summer precipitation in the Beijing area by usingsubdaily precipitation and wind observations. A combined effect of topography and urbanization on thecharacteristics of diurnal variations was suggested. It was shown that stations located in the plain areaexhibited typical night rain peaks, whereas those in the mountainous area exhibited clear afternoon peaks ofprecipitation diurnal variations. The precipitation peaks were associated with wind fields around the Beijingarea, which were found to be highly modulated by mountain-valley circulation and urban-country circulation.The lower-tropospheric wind exhibited a clear diurnal shift in its direction from north at 0800 LST to southat 2000 LST, which reflected mountain-valley circulation. The transitions from valley to mountain windand the opposite generally happened after sunset and sunrise, respectively, and both occurred earlier for thestations located closer to mountains. By comparing the diurnal variations of precipitation at stations in anortheast suburb, an urban area, and a southwest suburb, it was revealed that the northeast suburb grouphad the highest normalized rainfall frequency, but the southwest group had the lowest from late afternoon tolate evening. On the contrary, in the early morning from about 0200 to 1000 LST, the southwest group andurban group had the highest normalized rainfall frequency. This pattern might originate from the combinedeffects of mountain-valley topography and urbanization.

Evolution of Jobs-housing Spatial Relationship in Beijing Metropolitan Area:A Job Accessibility Perspective

With the urban expansion and economic restructuring, the jobs-housing relationship has become an important issue in studies on urban spatial structure. This paper employed a job accessibility model, which is an evaluation instrument to measure the jobs-housing relationship in Beijing Metropolitan Area from a job accessibility perspective. The results indicate that the population in the central city is declining, whereas the population in the suburbs is consistently growing and forming new population centers. However, the distribution pattern of employment is still highly centralized. Job accessibility varies in different locations, but the inner-city areas(within the Third Ring road) have seen improved job accessibility over time while job accessibility in the suburbs(especially outside the Fourth Ring road) has decreased, and this has led it to become a primary area of residential and employment mismatch. At the same time, the new towns in the outer suburbs have not yet demonstrated great potential to attract more jobs. In addition we find that, to some extent, urban planning changes the jobs-housing relationship, but a polycentric urban spatial structure is not yet evident. The floating population and related housing policy also affect the jobs-housing relationship. We propose some measures to resolve the spatial mismatch as well as some future research directions.

Ambient noise as the new source for urban engineering seismology and earthquake engineering: a case study from Beijing metropolitan area

In highly populated urban centers, traditional seismic survey sources can no longer be properly applied due to restrictions in modern civilian life styles. The ambient vibration noise, including both microseisms and microtremor, though are generally weak but available anywhere and anytime, can be an ideal supplementary source for conducting seismic surveys for engineering seismology and earthquake engineering. This is funda- mentally supported by advanced digital signal processing techniques for effectively extracting the useful information out from the noise. Thus, it can be essentially regarded as a passive seismic method. In this paper we first make a brief survey of the ambient vibration noise, followed by a quick summary of digital signal processing for passive seismic surveys. Then the applications of ambient noise in engi- neering seismology and earthquake engineering for urban settings are illustrated with examples from Beijing metro- politan area. For engineering seismology the example is the assessment of site effect in a large area via microtremor observations. For earthquake engineering the example is for structural characterization of a typical reinforced con- crete high-rise building using background vibration noise.By showing these examples we argue that the ambient noise can be treated as a new source that is economical, practical, and particularly valuable to engineering seis- mology and earthquake engineering projects for seismic hazard mitigation in urban areas.

Suburbanization and Subcentering of Population in Beijing Metropolitan Area:A Nonparametric Analysis

This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic density function approach,we employ the nonparametric analysis to characterize the spatial pattern of population densities in the Beijing metropolitan area and identify the suburban subcenters.Our findings suggest that the population has spread with rapid urban growth in the Beijing metropolitan area,and the compact urban form has been replaced by a more dispersed polycentric spatial distribution.However,compared with the decentralization of western cities,the spatial extent of the decentralization of population in the Beijing metropolitan area is quite limited.The rapid growth of population in the near suburbs has expedited the sprawl of the central city,with a larger central agglomeration of population dominating the metropolitan area.In this sense,the spatial pattern of the Beijing metropolitan area is still characterized by the continuous compactness.However,our findings do provide the evidence that the city has been turning to a polycentric structure.We find significant population subcenters have emerged in the suburbs of Beijing since the 1980s.But the polycentricity emerged in the Beijing metropolitan area is very different by nature from that observed in Western cities.The subcenters emerged are adherent to the development scheme planned for the city,so it can be referred to as the so called 'planned polycentricity'.

Correlation Between Economic Development Level and Landscape Pattern in Beijing Peri-urban Areas

With the rapid changes of demographic and socio-economic structure, various ecological and environmental problems have emerged in peri-urban areas. Studies on the correlation between socio-economic development and eco-environmental preservation are inadequate. This paper analyzes the landscape pattern of peri-urban areas to address this issue. First, it studies the differentiation of economic development levels in Beijing peri-urban areas. Then, it explores the correlation between economic development level of each town and its landscape pattern using Pearson Correlation and grade difference indices. Furthermore, it summarizes the problems within current landscape pattern. Three conclusions are drawn from the analysis: (1) on the whole, the economic de- velopment level in Beijing peri-urban areas basically matches with landscape pattern; (2) landscape contagion degree decreases with the growth of economic development level in as much as 30% of Beijing peri-urban areas. This is an irrational phenomenon accord- ing to our judgment; (3) landscape fragmentation grades in more than half of the towns are higher than their economic development grades, suggesting that attention should be paid to excessive fragmentation of land use.

Assessment of Industrial Land Use Intensity: A Case Study of Beijing Economic-technological Development Area

In recent years, great economic output of land has been achieved in economic-technological development areas in China, but the intensity of land use in some of these areas is very low. The degree of the low intensity of land use needs to be evaluated. The current method of comprehensive evaluation and grading by one index system has the limitations due to the existence of differences between regions and industries. This paper evaluates industrial land use intensity by Total Factor Productivity (TFP) analysis, which not only measures the intensity but also illustrates the ef-ficiency of input factors. This method is applied to the Beijing Economic-technological Development Area (BDA). A comparison analysis on factor use efficiency and input structure of capital and labor between industries is also carried out in the absence of a labor-income ratio.

Evaluation of the forest ecosystem health in Beijing area

The evaluation of ecosystem health has become one of the main research topics of ecosystem science, thus more and more assessment methods and frameworks have been put forward in recent years. However, the attention people pay to ecosystem health is actually more about what the social functions the ecosystem affords, which depend on the integrity and maintenance of the ecosystem structure and function, and the intensity of disturbance from outside. Accordingly, this research commenced from three main aspects, selected the evaluation indices, and then established the Evaluation Index System of Beijing Forest Ecosystem Health （EIS-BFEH）. In the EIS-BFEH, each of the three foundations contained an easily-operated and standard sub-index system, which compounded the specific natural and social conditions of Beijing and was concrete enough to measure and evaluate. Then with the method of the Analytical Hierarchy Process （AHP）, the comprehensive index （CI） could be obtained, which represented the health of the forest ecosystem. As a case study, the forest ecosystems in the Badaling area were sampled, evaluated, compared and ranked by use of the EIS-BFEH. The result show that the health of natural forests is much better than that of plantations in the Badaling forest center： the average comprehensive index of the former is 7.9, while the latter is only 6.6. From the results, it could also be found that there are nine units in the healthy state, two units in the subhealthy state, and only one unit of Robiniapseudoacacia in the morbid state.

Land Use Pattern Analysis of Hilly Areas in Beijing Based on Case Study

In view of the population explosion in urban districts of Beijing City, limited land resources fail to meet needs of citizens, thus it is imperative to plan land uses of its hilly areas reasonably, avoid urban sprawl and figure out the way of sustainable development. Through analyzing land use patterns of hilly areas in Hong Kong and Los Angeles, it is to explore valuable experience for the development of hilly areas in Beijing.

The “Valley Economy” Model of Regional Development: A Case Study of Mountain Areas in Beijing, Northern China

A case study is presented of a regional development model for valley economies in the mountain areas of Beijing, China. The nature and framework of the valley economy model are described and the development of the model, which is specific to the mountain areas of Beijing, is analyzed. Five different valley economy models applied in the Beijing mountain areas are compared. The major purpose of the valley economy model is to develop the regional economy, including the selection of appropriate industries, the allocation of industrial space, the establishment of supply chains and the integration of various industries. Pilot experiments using the valley economy model have been conducted in seven counties(districts) in Beijing: Pinggu, Huairou, Changping, Mentougou, and Fangshan districts, and Yanqing and Miyun counties. Five models for developing the Beijing mountain areas have been explored, including: creative cultural industries, characteristic industry clusters, the promotion of large tourist areas, natural scenic tourism and folk cultural tourism. Each model has its own unique features and potential to help in the regional development of mountain areas.

Multi-scale wavelet separation of aeromag-netic anomaly and study of faults in Beijing area

In this paper, through a multi-scale separation of the aeromagnetic anomaly by wavelet transform technique, we reprocessed the aeromagnetic data collected 20 years ago in Beijing area and analyzed the aeromagnetic anomaly qualitatively, integrating geological structure features in the area. In particular, we studied the spatial distributions of the two main faults called Shunyi-Liangxiang fault and Banqiao-Babaoshan-Tongxian fault, which have cut and gone through the central Beijing area striking in NE and EW directions, respectively. The influences of these two faults on the earthquakes have also been discussed briefly.

Valley Density Evaluation and Typical Development Pattern in Mountainous Areas of Beijing

Based on geographical differences and space differentiation, valley economy is a new pattern and new perspective for the development of mountainous areas, integrating ecological protection, industrial nurture, and village integration. On the basis of natural and geographical differentiation of valley, we give an overview of the spatial distribution of valley in mountainous areas of Beijing and spatial difference in valley density, and sum up the typical development pattern of valley economy, using DEM data. The results show that the spatial distribution of valley presents an asymmetric shape of inverted V or branch; Miyun, Yanqing, and Changping have high valley density, while Pinggu, Fangshan and Mentougou have low valley density; there is a significant positive relationship between valley density and the spatial distribution of river and reservoir. The development pattern of valley economy is divided into five types: leisure and high-end upgrade-based pattern, ecological development and transition demonstration-based pattern, folk culture and creation-driven pattern, scenic spots-driven and valley-linked pattern and leisure agriculture and specialty-led pattern.

Application of WRF 3DVar to a high-resolution model over Beijing area

To improve the weather forecasting over the Beijing area for the 2008 Olympic Games,a triple-nested(27/9/3km) WRFVar/WRF system with 3-h update cycle was established.Experiments have been done for a convective event that occurred on August 1,2006.The results showed that the high-resolution rapid update cycle gave a good precipitation forecast;the tunings of background error statistics(BES) and observation-error statistics in WRFVar improved the skill of the precipitation forecast;the BES for the fine domain(3 km) obtained by interpolation from its parent domain(9 km) can be used in 3 km WRFVar as a reasonable approximation.The user can now save a great deal of work related to the derivation of the fine mesh BES from the forecast over a period of time;the rapid update cycle with 3-h frequency has satisfied the forecast,and the update cycle with 1-h frequency was not necessary.

Study on the Circular Agriculture Development in Beijing's Mountain Areas

Circular agriculture is an essential way to realize the positive recycling of ecology and harmonious development of the country construction.The sustainable development of Beijing's mountain areas depends on the background and orientation of ecological economy.Beijing's mountain areas bear the responsibility of protecting the ecological safety of the whole Beijing district and also the exploration of circular agriculture in mountain areas is very important to promote the sustainable use of agriculture resources.Beijing's mountain areas have possessed some practical experience in recycling agriculture development.Through summarizing the development mode and analyzing the development practice,the article puts forward three key segments of promoting Beijing circular agriculture development:strengthen propagate,develop superiority and built management mechanism.

The Research of Impact of Returning Cultivated Land to Forests in Poverty Areas around Beijing-Tianjin on Local Economy——A Case of Shunping County in Hebei Province, China

Taking Shunping County of Hebei Province as an example,according to the relevant survey data in the year 2008 after returning cultivated land and data in the year 2001 before returning cultivated land, the thesis analyzes the impact of implementation of project of returning cultivated land to forests on local land use structure, three industrial added value and famers' per capita income. The results show that returning cultivated land has played a certain positive role on the local economic development and the improvement of people's life level.However, there are also some shortcomings: although famers' income is increasing with low growth rate, a large portion of famers still have not shaken off poverty; the farmers depends on subsidies greatly and the compensation mechanism of returning cultivated land is not considered well. China should further perfect the ecological compensation plan, and build rational ecological compensation mechanism in order to make the areas of returning cultivated land have self-blood-producing function; Shunping County should make full use of the location advantage in areas around Beijing-Tianjin, develop deep processing based on fruit trees industry, strengthen farmers' skill training, and increase input in the agricultural infrastructure construction to propel the sustainable development of agriculture.

A Study of the Radiation-Climate Effect of Aerosol over Beijing Area

In this paper, the monthly-averaged planetary albedo and equivalent blackbody temperature are calculated by using Gauss-Seidle numerical model to solve the equation of radiative transfer, based on measured aerosol data over Beijing aera. With the increase of atmospheric turbidity, the planetary albedo has different characteristics in different seasons, and there is an evident decrease in the winter season. It means that the local aerosol has an heating effect to the atmosphere in winter. The correlation feature between the surface temperature and the horizontal visibility from 1963 to 1986 is analyzed, and anticorrelation is discovered in winter. It is found that surface temperature increases with the increase of aeresol.

A study on the innovation of regional environmental management mechanism in Beijing,Tianjin and Hebei area within the background of ecological civilization

Within the background of the need to promote the construction of ecological civilization and the current confl ict between the economic growth and the constraints of environment and resources, after a review of the theoretical study and practical exploration of ecological civilization, the article makes an analysis of the status quo of ecological civilization development in Beijing, Tianjin, and Hebei area, sums up the main problems there, and explores the development strategic framework to improve the regional ecological environment. It comes to the following conclusions: as the ecological and environmental problems in the BTH area are mainly the air pollution and so on, we should seek to build a mechanism of environmental management for sustainable development from the different aspects of industrial distribution, energy utilization, institution construction and market participation. We should capitalize on the chance to construct the ecological civilization, promote to change the regional economic growth pattern, improve the quality and effi ciency of development, and fi nally promote the synergetic development of ecological environment in the BTH area.

Numerical study of aerosol effect on three types of clouds and precipitation in Beijing area

Three types of rainfall （storm, moderate and slight rainfall） in the Beijing area were simulated by the Weather Research and Fore- cast （WRF3.2） model coupled with Milbrandt-two-moment cloud microphysics scheme, to explore the effect of aerosols on clouds and precipitation under continental and maritime aerosol scenarios. Results indicate that an increase of aerosols has various effects on clouds and precipitation. （1） The amount of surface precipitation is obviously affected. With an increase of aerosol con- centration, the 48-hr total precipitation of storm and moderate rainfall decreased by 23% and 16.6%, respectively, and the 24-hr total precipitation of slight rainfall decreased by 14.0%. （2） The distribution of surface precipitation is also clearly affected. The average precipitation for a rain storm increases in most parts of western Beijing and decreases by more than 20 mm in most parts of eastern Beijing with increasing aerosol concentration. The average precipitation of moderate rainfall decreases by 0.1-5 mm in most parts of the Beijing area. The effect of increased aerosol concentration is weak for slight rainfall distribution in the study area. （3） With an increase of aerosol concentration, a narrower width and lower precipitation peak value are found in the storm rainfall, and its duration is prolonged for the high aerosol concentration. An earlier precipitation termination of moderate rainfall is found with increasing aerosol concentration. （4） The upper-air hydrometeors vary with aerosol concentration, For storm and moderate rainfall, significantly higher cloud water concentration and lower rain water were found under the continental aerosol scenario.

Walkability Assessment of Microclimatic Environments of Six Typical Communities in Central Urban Area of Beijing from the Perspective of the Elderly

Community walking space is the most used space in residents’daily life,such as commuting and walking,and is also the most basic type of space for outdoor activities.The microclimatic environment of walking space not only affects the health status of residents,but also determines the service effi ciency of outdoor public space.Based on actual measurement and simulation of microclimatic environment,the status quo of walkability of microclimatic environments in six typical communities is evaluated by quantitative methods,and general problems and optimization suggestions are put forward,in order to provide new ideas for future community environment transformation.