Huairou District Research Articles

Rural Tourism in Globalizing Beijing: Reproduction of the Mountainous Suburbs into a New Space of Leisure Consumption

Rural tourism is increasingly becoming an important complementary service sector of major Chinese cities operating at their immediate adjacent suburban or rural zones. By promoting a green economy, such zones of rural–urban interface/interactions attract more and more public investments, business investors, and leisure seekers. Taking the Yanqi Nightless Valley of Huairou District, and the Ganyugou Village and Xibailianyu Village of Miyun District of Beijing as case studies, this paper investigates the private entrepreneurship, the local peasants’ business drive, and the role of the local governments in integrating the mountainous “backwater” into Beijing’s globalizing economy. Their joint efforts in reconstructing and branding rural tourism resorts, and the ways in which the rural socioeconomic setting was transformed into a post-productive, consumption-dominated, and creative-cum-quality service center is analyzed. The paper analyzes the success and failure of Beijing’s rural tourism business operations, and links their marketing with the capital city’s ambition to brand itself into a globalizing city. Results show that success is highly dependent on physical connectivity. Those seated at the “semi-periphery” with highways or other access corridors are capable of attracting large city clientele. Remote sites, on the contrary, can hardly benefit from the trickle-down process. Hence, a more integrative framework in favor of a more balanced development is finally addressed.

Ground-based MAX-DOAS observations of tropospheric formaldehyde VCDs and comparisons with the CAMS model at a rural site near Beijing during APEC 2014

Abstract. Formaldehyde (HCHO), a key aerosol precursor, plays a significant role in atmospheric photo-oxidation pathways. In this study, HCHO column densities were measured using a Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument at the University of Chinese Academy of Science (UCAS) in Huairou District, Beijing, which is about 50 km away from the city center. Measurements were taken during the period of 1 October 2014 to 31 December 2014, and the Asia-Pacific Economic Cooperation (APEC) summit was organized on 5–11 November. Peak values of HCHO vertical column densities (VCDs) around noon and a good correlation coefficient R2 of 0.73 between HCHO VCDs and surface O3 concentration during noontime indicated that the secondary sources of HCHO through photochemical reactions of volatile organic compounds (VOCs) dominated the HCHO values in the area around UCAS. Dependences of HCHO VCDs on wind fields and backward trajectories were identified and indicated that the HCHO values in the area around UCAS were considerably affected by the transport of pollutants (VOCs) from polluted areas in the south. The effects of control measures on HCHO VCDs during the APEC period were evaluated. During the period of the APEC conference, the average HCHO VCDs were ∼38%±20% and ∼30%±24% lower than that during the pre-APEC and post-APEC periods calculated at the 95 % confidence limit, respectively. This phenomenon could be attributed to both the effects of prevailing northwest wind fields during APEC and strict control measures. We also compared the MAX-DOAS results with the Copernicus Atmosphere Monitoring Service (CAMS) model. The HCHO VCDs of the CAMS model and MAX-DOAS were generally consistent with a correlation coefficient R2 greater than 0.68. The peak values were consistently captured by both data datasets, but the low values were systematically underestimated by the CAMS model. This finding may indicate that the CAMS model can adequately simulate the effects of the transport and the secondary sources of HCHO but underestimates the local primary sources.

Evaluation on the intervented effects of health promotion at an enterprise in Huairou district, Beijing

目的： 为建立适合汽车制造企业工作场所健康促进（WHP）模式，对某汽车制造企业员工健康促进及干预效果进行评价研究。 方法： 于2016年3月，选择该企业接触有毒有害因素的500名在编员工作为研究对象，通过信息传播、技能培训、组织改变等进行干预；对研究对象进行干预前后的问卷调查，主要包括企业和员工的基本情况、职业卫生情况、职业卫生知识认知情况、一般健康知识认知情况、生活方式和健康知识需求等。 结果： 干预前后员工在每天工作时间、对现有劳动条件满意度和企业设置职业病危害因素警示标识或警示说明情况以及作业岗位佩戴个人防护用品的分布差异均有统计学意义（P<0.05）。干预前后员工对《中华人民共和国职业病防治法》了解程度分布差异有统计学意义（P<0.01），一般了解的员工由干预前的34.5%增加到66.6%；干预前后员工对职业病是可以预防的认知、对健康知识和高血压的认知以及希望企业提供个人职业病防护用品的认知分布差异均有统计学意义（P<0.05）。干预前后员工的每周锻炼次数分布差异有统计学意义（P<0.05），锻炼者的比例由干预前的70.2%上升到82.0%；干预前后员工每周早餐次数的分布差异有统计学意义（P<0.01），不吃早餐次数所占比例由9.5%下降到6.8%；饮食口味偏好分布差异有统计学意义（P<0.05），口味偏咸的员工由28.7%下降到22.0%。 结论： 该汽车制造企业工作场所健康促进模式在改善工作场所环境以及提高企业员工的健康意识、行为和认识方面起积极作用。.

Rural Greenway Recreation Post-evaluation (POE) Study - A Case Study of Shentangyu Greenway in Huairou District, Beijing

The post-use evaluation of rural greenways is of great value for improving rural greenway planning and design theory. Taking the Shentangyu Greenway in Huairou District of Beijing as an example, through on-site investigations, questionnaires and interviews, some problems in the planning, design, construction, and management of the greenway were obtained, and corresponding suggestions for improvement were proposed. It has certain reference value for the future construction of rural greenways.

Current status of rural grassroots health service provision in Beijing suburb

Objective To survey the current status of the rural primary medical service supply in Beijing suburb, and to discuss the relationship between policy environment and rural primary medical service. Methods A purposeful sampling method was adopted to select Beijing Huairou District as the study site. In July to August 2016 a questionnaire survey was conducted among 260 village doctors from 260 village clinics in 14 townships; 21 village clinics were site visited; 21 village leaders, 21 village doctors, and 42 villagers were invited for in-depth interview. The impact of policy environment on the provision of basic health service at the village level was analyzed. Results The facilities of the 260 village clinics basically met the needs, but the service quality was still insufficient. The basic situation of village clinics: 174 villages (66.9%) were funded by the1 486project, 164 (63.1%) village clinics were located in the center of the village. In 173 village clinics (66.5%) the legal representatives were village leaders, but 11 (52.4%) village officials thought that rural doctors should be the legal persons. The mean age of 260 village doctors were (62.7±8.9) years. Among 260 village doctors, 168 (64.6%) were working more than 40 years, 149 (57.3%) had secondary medical education, 72 (27.7%) had no medical professional qualification; 247 (95%) held practice certificates of rural doctors and only 3 (1.2%) held medical license; 244 (93.8%) village doctors took subsidy from the government. The continuing education was organized monthly by the township health centers. The source of training teachers was township health centers (247, 95.0%). The teaching form was mainly audio-visual education (191, 73.5%); the content was based on general medicine (245, 94.2%). The top 5 basic medical service items provided by village clinics were the diagnosis and differential diagnosis of common diseases, family visits, measurement of blood pressure, respiratory and pulse rates, body weight, height and vision, and intramuscular injection. Most village doctors (199, 76.5%) provided night-time medical service. For the medical care needs, 22 (52.4%) villagers said they were basically satisfied. The most satisfying aspect was the service attitude, and the most unsatisfactory aspect was the equipment and facilities. The management function of village committee was mainly in personnel recruitment (231, 89.5%), daily supervision (218, 84.5%) and performance assessment (113, 43.8%). The assessment of service quality was conducted by the township health service centers, particularly in public health service. Conclusions The current status of rural primary medical service still cannot fully meet the needs of rural residents. In order to upgrade the quality of rural primary medical service to meet the health needs of villagers, it is necessary to improve the internal policy environment, such as villager autonomy, socio-economic development and so on. Key words: Rural doctors; Policy environment; Basic medical services

THE LAND-USE AND LAND-COVER CHANGE ANALYSIS IN BEIJING HUAIROU IN LAST TEN YEARS

Abstract. With eCognition software, the sample-based object-oriented classification method is used. Remote sensing images in Huairou district of Beijing had been classified using remote sensing images of last ten years. According to the results of image processing, the land use types in Huairou district of Beijing were analyzed in the past ten years, and the changes of land use types in Huairou district were obtained, and the reasons for its occurrence were analyzed.

A survey on service status of rural doctors in Beijing suburb

Objective To survey the service status of rural doctors in Beijing suburb. Methods Twenty one village officials, 21 rural doctors and 42 local residents from 21 villages in Beijing Huairou district were selected with purposive sampling method as the objects of this qualitative study. The service status of rural doctors was assessed from four aspects: basic public health service, basic medical service, management ability, responsibility and communication ability. Results All the 21 village clinics provided basic public health services, including hypertension management (100.0%), diabetes management (100.0%); 11 clinics (52.4%) also provided vaccination services. Eighteen village doctors (85.7%) assisted township health center to provide signing health service, but were lack of knowledge about the types of service the general practitioners (GPs) should provide. The well performed basic medical services among 21 village clinics included diagnosis and differential diagnosis of common diseases in 19 (90.5%) clinics, home visits in 18 (85.7%) and physical examinations in 15 (71.4%), but the service like trauma management, changing dressing, subcutaneous injection, intravenous infusion were performed less well. The top three most satisfied aspects in the medical service were the service attitude (4.14 points), the quality of service (3.98 points) and service time (3.66 points), and the bottom three were equipment facilities, the types and varieties of drug, and the environment of clinics. In aspect of emergency service, 7 village doctors (33.3%) would choose self-referral by patients without preliminary on-site emergency treatment, 5(23.8%) would give on-site emergency treatment before self-referral by patients. In aspect of training needs, 18 (42.9%) local residents and 9 (42.9%) village officials considered that it was not necessary to provide training for village doctor because of relatively older age. In aspect of patient′s satisfaction, 21 village doctors (100.0%), 21 village officials (100.0%) and 34 villagers (81.0%) considered that the village doctor had a high professional sense of responsibility and medical ethics, and their doctor-patient communication skills were strong. Conclusion The survey reveals the current service status of village doctors in Beijing suburb, and it is necessary to take comprehensive measures to upgrade the competence of village doctors and to improve the quality of service in village clinics. Key words: Rural doctors; Professional competence; Qualitative research

Epidemiological characteristics of a cutaneous anthrax outbreak in Huairou District of Beijing

Epidemiological characteristics of a cutaneous anthrax outbreak in Huairou District of Beijing

The blue skies in Beijing during APEC 2014: A quantitative assessment of emission control efficiency and meteorological influence

Most previous studies attributed the alleviation of aerosol pollution to either emission control measures or favorable meteorological conditions. However, our understanding of their quantitative contribution is far from complete. In this study, based on model simulation using the CMA (China Meteorological Administration) Unified Atmospheric Chemistry Environment for aerosols (CUACE/Aero), in combination with simultaneous ground-based hourly PM2.5 observations, we aim to quantify the relative contributions of the emission control measures and meteorology to the blue-skies seen in Beijing during the Asia-Pacific Economic Cooperation (APEC) summit held in November of 2014. A series of model simulations have been performed over Beijing-Tianjin-Hebei (BTH) region by implementing nine different emission control schemes. To investigate the relative contributions of the emission control measures and meteorology, the study period has been divided into five episodes. Overall, the CUACE/Aero model can reasonably well reproduce the temporal and spatial evolution of PM2.5 during APEC 2014, although the model performance varies by different time periods and regions of interest. Model results show the emission control measures on average reduced the PM2.5 concentration by 41.3% in urban areas of Beijing and 39.7% in Huairou district, respectively, indicating emission control plays a significant role for the blue skies observed. Among all the emission control measures under investigation, local emission control in Beijing contributed the largest to the reduction of PM2.5 concentrations with a reduction of 35.5% in urban area of Beijing and 34.8% in Huairou, in contrast with the vehicle emission control in Hebei that contributed the least with a reduction of less than 1%. The emission control efficiency in five episodes has been assessed quantitatively, which falls in the range of 36.2%–41.2% in urban area of Beijing and 34.9%–40.7% in Huairou, indicative of no significant episode and geographic dependence in the emission control efficiency. The emission control measures and meteorology, however, alternated to dominate the absolute reduction of PM2.5 concentrations. When the weather conditions are unfavorable, emission control measures outperformed meteorology with a reduction of 55.3–59.4 μg/m3 in urban area of Beijing and 32.5–33 μg/m3 in Huairou. Conversely, when the northwesterly winds prevailed, meteorology tends to outweigh the role of emission control in accounting for the drop of PM2.5. The atmospheric dilution conditions are determined through the model calculation of the mass inflow of PM2.5 per unit volume near the surface. Our findings have significant implications for effective planning and implementation of emission control measures.

China’s new light sources prove it’s serious about funding science

Government investment in basic scientific research leads to new products and stronger economic growth. Although this argument doesn’t work as well as it used to for scientists seeking public funding in Western countries and Japan, it still does wonders in China. There, funding for basic research is growing, largely on Beijing’s buy-in that it will be good for the economy. In Dalian, Chinese scientists unveiled earlier this month a new type of free-electron laser that generates extremely bright, short-wavelength light called vacuum ultraviolet. And in Beijing’s Huairou District, China is spending about $750 million on a state-of-the-art synchrotron that will help raise the country’s scientific capabilities and develop new products, Chinese scientists have told their government. Scheduled to start operating in 2023, the Huairou synchrotron will be a so-called fourth-generation low-emittance synchrotron with the ability to concentrate X-rays into the 10 nm range. The world’s first fourth-generation synchrotron started operating

The status and analysis of pulmonary function assessment of the elderly in communities of Beijing

Objectives To explore the status and characteristics of changes in lung function in the elderly in communities of Beijing, and to provide reference for improving the prevention and control of chronic lung disease in the elderly. Methods A stratified, segmented and cluster sampling method was used to investigate 1 144 subjects aged 60 years and over in communities of Beijing(Huairou District, Daxing District rural area and Xicheng District). Health status and pulmonary function were assessed, and characteristics of lung functions and their changes were analyzed in the elderly. Results The average vital capacity(VC)was 2.53L, and forced vital capacity(FVC)was 2.29 L, forced expiratory volume in one second(FEV1)was 1.81 L, 1 second rate(FEV1/FVC)was 83.42%.Static vital capacity was decreased in 1/3 of the elderly, and dynamic vital capacity, including FVC and FEV1, was reduced in about half of the elderly.Ratio of decline in lung function in the elderly was higher in male and in urban area than in women and in rural areas.Ratio of decline in each index of pulmonary ventilation function showed a significantly increased tendency along with the ageing.Lung dysfunction types in the elderly included a restricted(23.5%)and obstructive ventilation disorder(19.7%)and mixed ventilation disorder(12.8%). Conclusions The ratio of decline in lung function in the elderly is increased along with aging, and more significantly higher in female and in urban than in male and in countryside.Restrictive ventilation disorder in the elderly is more often in urban areas, while obstructive ventilation disorder occurs mostly in rural areas.Corresponding measures should be adopted for different groups of people. Key words: Respiratory function tests; Cross-sectional studies

Effect of different topographic data sources on soil loss estimation for a mountainous watershed in Northern China

The effect of topography on soil loss can be characterized by slope length and slope steepness factors. These factors are commonly evaluated using digital elevation models (DEM) which can be generated from a large variety of topographic data. The purpose of this study was to evaluate the effect of topographic data source on estimated soil loss for a mountainous watershed. The Dongtaigou watershed (90 ha) is located in Huairou District, Beijing, China. Data sources included topographic maps at 1:2000, 1:10,000, and 1:50,000 scales, and 30-m DEM from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Map (GDEM) dataset. The grid sizes considered were 2, 5, 10, 25, and 30 m. The results showed that the calculated average slope steepness and soil loss were reduced and the average slope length increased when the map scale was decreased. With results using 1:2000 map and 2-m grid as the reference, the land area with minimal soil loss (<2 t ha−1 year−1) was 5.7 ha, and the area with moderate soil loss (2–25 t ha−1 year−1) was 77.9 ha. Compared to these reference values, the 1:10,000 map would bring out a 42 % increase in the area with minimal soil loss, and a concurrent decrease of −8 % in the area with a moderate soil loss. For the 30-m ASTER GDEM V1, the calculated slope steepness is some 64 % lower than the reference value. The slope length, on the other hand, was increased by 265 % and soil loss decreased by 47 % in comparison with the reference values. For all map scales and grid sizes, the relative errors in the estimated soil loss were about 50 % of the relative errors in slope steepness.

Research and application of city ventilation assessments based on satellite data and GIS technology: a case study of the Yanqi Lake Eco‐city in Huairou District, Beijing

ABSTRACTA method of performing city‐scale ventilation assessments based on remote sensing (RS) and geographic information system (GIS) technology is proposed and applied effectively in an assessment of the local ventilation environment before and after the construction of the Yanqi Lake Eco‐city in Huairou District, Beijing. The ventilation environment of a city is dependent on its background wind environment and ventilation potential. The background wind environment can be assessed through meteorological statistical analyses or numerical simulations, whereas the ventilation potential can be estimated using the underlying surface dynamic roughness length (RL) and the surrounding sky view factor (SVF). Based on the principle of morphology, the RL of a vegetation area is determined mainly by the vegetation types, vegetation canopy area index and vegetation height, whereas the RL of an urban area is defined mainly by the building area coverage and building height. The SVF can be estimated according to high‐resolution digital raster elevation data. Based on the combination of the RL and SVF, the ventilation potential is graded, and the ventilation potential index (VPI) is defined and used to assess quantitatively the ventilation capacity of the city. The present study calculates the RL of the Yanqi Lake Eco‐city using Landsat‐TM5 satellite data from 26 July 2011, Geoscience Laser Altimeter System (GLAS) satellite data from 2005 and Beijing basic geographical data at 1:2000 from 2009. Subsequently, the RL and ventilation potential distribution of the Yanqi Lake Eco‐city is mapped at a 100 m spatial resolution. The ventilation conditions before and after the construction of the Yanqi Lake Eco‐city are evaluated using the VPI in combination with the background wind field. According to changes in the ventilation capacity, relevant policy suggestions for urban buildings and design factors for ventilated corridors are postulated.

Awareness and administration of antidiabetic drugs in patients with diabetes in Huairou district of Beijing

Objective To investigate the awareness and administration of antidiabetic drugs in patients with diabetes in Huairou district of Beijing. Methods A questionnaire survey on knowledge and administration of antidiabetic drugs were conducted in 900 diabetic patients from 16 communities in Huairou district of Beijing from November 2014 to February 2015. The related factors influencing antidiabetic drug use were analyzed with logistic regression method. Results A total of 899 questionnaires were recovered. Results showed that the rate of metformin single use was the highest (23.7%, 213/899), the rate of combination use of metformin and acarbose was 11.8%(106/899), and that of metformin and glipizide was 17.1% (154/899). Survey showed that 65.9% (592/899) patients were compliant immediately for antidiabetic agents, 32.2% (290/899) were not immediately compliant, 1.9% (17/899) did not use antidiabetic agents. Logistic regression analysis showed that the factors affecting the use of antidiabetic agents were the types of medication (t=-4.351, P=0.000) , adverse effects of drugs (t=6.999, P=0.000), awareness of diabetes to health hazard (t=-10.969, P=0.000) and the doctor's recommendation (t=-3.352, P=0.001). Conclusion The results showed that the administration of antidiabetic drugs in diabetic patients from Huairou district is basically followed the recommendation by 2013 edition of type 2 diabetes guidelines and the compliance rate of medication need to be further raised. Key words: Diabetes mellitus; Hypoglycemic agents; Cognition

Genesis of an unusual clastic dike in an uncommon braided river deposit

A clastic dike containing unusually large clasts occurs in the Quaternary deposits that unconformably cover the Mesoproterozoic sediments in the Fangshan District, Beijing area, China. The material into which the dike intruded is also uncommon because it consists mainly of loess-type silts that were deposited by braided rivers. The intrusion of the dike is explained as the result of the expulsion of pore water into the coarse, gravel-containing layers of a braided river system. The large size of the clasts in the dike is explained by an exceptionally strong upwards-directed flow which owed its high energy to a high hydrostatic pressure that had been built up because pore water could not gradually seep through the impermeable silt-sized material during ongoing burial. This uncommon dike is compared with a second example, in similar Quaternary sediments covering the Mesozoic rocks in the Huairou District.

Autotoxic effect of ginsenoside extrats on growth of American ginseng in different medium

Ginsenosides are the abundant secondary metabolites in American ginseng (Panax quinquefolium), it could be released into soil through root exudation and decomposition during plant growth. This study determined ginsenoside contents in American ginseng cultivated soil by HPLC. Three ginsenosides, Rb1, Rb2 and Rd, were detected in the rhizosphere soil of 3-4 years old American ginseng cultivated in Huairou District, Beijing, and their contents were 0.80-3.19 mg x kg(-1). Correspondingly, the contents of the three ginsenosides in soil solution were 4-16 mg x L(-1) at field water-holding capacity of 20%. According to the field soil test data, we designed the concentration of ginsenosides for bioassays (0.2-125 mg x L(-1) in solution or 0.2-125 mg x kg(-1) in soil). The results showed that radicle lengths of American ginseng were reduced by 6%-23% in solution containing 0.2-125 mg x L(-1) ginsenoside extract, and a significant difference was observed at concentration of 125 mg x L(-1) (P < 0.05). The shoot lengths of American ginseng were not significantly inhibited by 0.2-125 mg x L(-1) ginsenosides extractions. After 20 days of growth in nutrient solution amended with 25 mg x L(-1) ginsenosides extraction, plant height of 3-year-old American ginseng seedling was decreased by 28% compared to the control, and the biomass of aerial parts was also reduced by 50% (P < 0.05). However, the growth of newly-grown fibrous root was not significantly inhibited. Comparatively, when American ginseng embryos were cultivated into sterile or non-sterile soil, neither radicle lengths nor shoot lengths were significantly affected by 0.2-125 mg x kg(-1) ginsenoside extracts. In conclusion, ginsenosides showed autotoxic effect on growth of American ginseng radicle and adult seedling, however, this effect was weakened in field soil.

A climatic environmental performance assessment method for ecological city construction: Application to Beijing Yanqi Lake

In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches such as observation data analysis, meteorological model simulation, and remote sensing, a set of climatic environmental performance assessment methods is developed and established. These methods mainly focus on surface ventilation assessment and urban thermal environment assessment. With the Yanqi Lake ecological development demonstration area located in Huairou district, Beijing as an example, the assessment of the local climatic environment before and after the construction are conducted, and relevant policy suggestions for urban planning and construction are presented. The results show that after development, the ventilation capacity will decrease overall and the ventilation potential index will decrease from 0.53 to 0.44. While this is not a large reduction, and is still at a favorable level, the ventilation potential in some local areas will markedly decrease. Furthermore, the thermal environment will become poorer to some extent; the urban heat island (UHI) area and intensity will increase compared with the current situation; continuous heat islands may occur in local areas; the UHI potential index of the core area will rise from 0.0878 to 0.1217 (still a favorable level). Therefore, urban surfaces should be carefully developed and arranged during planning. It is suggested that the negative impacts of large areas of urban construction on the local climatic environment in the Yanqi Lake could be mitigated by 1) strengthening the airflow by introducing fresh, cold, northwesterly air via constructed ventilation corridors, 2) increasing the number of ecological cold sources, particularly for water bodies and green belts to prevent the UHI in the southern region of Yanqi Lake from becoming linked with each other, and 3) considering a pre-program before sub-domain and building planning to obtain optimum building locations. Different construction standards should be developed for different ventilation potential and UHI intensity levels. For strong heat island areas, land areas should be reserved to serve as cold sources.

Global in the Local: Ecocriticism in China

As I revise this introductory essay, I have been experiencing the exceptionally good weather in Beijing, with the APEC summit being held in Beijing's suburban Huairou District, and the hazy and smoggy weather having quietly disappeared. People might well raise the question: will blue sky come back to Beijing after the APEC summit, as many of the factories have now stopped working simply for the APEC conference? Obviously no one can answer this challenging question satisfactorily. Perhaps this is one of the very reasons why ecocriticism, environmental studies, and eco-aesthetics are now largely talked about in China not only by literary scholars and humanities intellectuals but also by ordinary people. The Chinese government has already recognized this tough social problem but it is a bit too late, for China, having achieved huge successes in its economic reform, has now been suffering from environmental pollution, especially in big cities. In the capital city Beijing and its surrounding areas, people often endure hazy, smoggy air, seldom seeing blue sky and white clouds. They realize that our living environment is in danger. They could not help but call for saving our environment, for saving the Earth, for they realize people will suffer more in the near future with the worsening of our living conditions. Actually the coming of ecocriticism into Chinese academic arena has both a theoretical background as well as the environmental necessity. As we all know, since the 1990s, along with the increasing decline

Effects of DEM grid size on predicting soil loss from small watersheds in China

The topography (slope gradient and slope length) has an important effect on soil erosion by water. Slope gradient and slope length factor are the parameters of the universal soil loss equation that is commonly used to predict soil erosion. These factors are usually extracted from the digital elevation model (DEM). Thus the DEM grid size will influence topographic factors and therefore soil loss calculation. The purpose of this study was to investigate the effect of DEM grid size on the topographic factors and therefore soil loss prediction on a typical watershed in northeast of China. The site for the case study was Dontaigou watershed which is located at Huairou district, Beijing, China. Contour lines of 2 m interval digitized from 1:2,000 scale of topographic maps were used to generate DEM with grid size of 2 m. The DEMs with grid sizes of 3–30 m, at 1 m intervals, were created using the nearest neighbor resampling method. In total, 29 DEMs with different grid sizes were obtained. Four different scenarios of the channel initiation threshold were used to extract the drainage channel and let the slope length cutoff. Chinese soil loss equation was used to predict the soil loss. The results show that DEM grid size had different effects on the topographic factor. The average calculated slope steepness factor decreased with the increase of the DEM grid size in a linear decay function. The average slope length factor increased with DEM grid size when the drainage channel was not considered. It slightly decreased with DEM grid size and then increased when the drainage channel suitable for DEM grid size was used. However, comparing different grid sizes, the LS factor and the soil loss prediction of DEM grid size less than or equal to 10 m were close to those of 2 m DEM. The channel initiation threshold had effects on the extraction of slope length and then slope length factor. We found that the effect of DEM grid size on predicting soil loss depends on selection of suitable channel initiation threshold.

Research on Sitting Transformer Substations in Rural Areas Based on Improved Genetic Algorithm

The process of urbanization, Beijing faces a number of environmental problems. Especially in the last few years, there has been constantly sustained fog and haze, which makes the implementation of electric heating in rural areas gradually on the agenda. After the implementation of electric heating, the irrationality of the regional power grid layout will be further amplified. With the rapid growth of electricity load in the planning area, the requirement of the power supply grid reliability and power quality is also increasing. Therefore, on the basis of power load forecasting in consideration of the the electric heating, and based on the particularity of rural power network, we achieve the Huairou District substation site with the use of improved genetic algorithm. The results can provide reference for the selection of substation of the whole Beijing rural area.