scholarly journals Urbanization effect on trends in sunshine duration in China

2017 ◽  
Vol 35 (4) ◽  
pp. 839-851 ◽  
Author(s):  
Yawen Wang ◽  
Martin Wild ◽  
Arturo Sanchez-Lorenzo ◽  
Veronica Manara

Abstract. There is an ongoing debate on whether the observed decadal variations in surface solar radiation, known as dimming and brightening periods, are a large-scale or solely local phenomenon. We investigated this issue using long-term sunshine duration records from China, which experienced a rapid increase in urbanization during the past decades. Over the period 1960–2013, 172 pairs of urban and nearby rural stations were analyzed. Urban and rural sunshine duration trends show similar spatial patterns during a dimming phase (1960–1989) and a subsequent period during which trends were leveling off (1990–2013). This indicates that rather than local effects, the trends in sunshine duration are on more of a national or regional scale in China. Nevertheless, in the dimming phase, the declining rate of sunshine duration in rural areas is around two-thirds of that in urban areas. The ratio of rural to urban dimming generally increases from a minimum of 0.39 to a maximum of 0.87 with increasing indices of urbanization calculated based on the year 2013. It reaches a maximum when the urbanization level exceeds 50 %, the urban population exceeds 20 million, or the population density becomes higher than 250 person km−2. After the transition into the leveling-off period, sunshine duration trends are no longer significantly affected by urbanization. Meanwhile, the number of laws and regulations related to air pollution and investment in pollution treatment have been increasing in China.

2016 ◽  
Author(s):  
Yawen Wang ◽  
Martin Wild ◽  
Arturo Sanchez-Lorenzo ◽  
Yonghui Yang ◽  
Veronica Manara ◽  
...  

Abstract. There is an ongoing debate on whether the observed decadal variations in surface solar radiation, known as "dimming and brightening", are a global or just local phenomenon. We investigated this issue using a comprehensive set of long-term sunshine duration records from China, which experienced a rapid growth in urbanization during past decades. 172 pairs of urban and nearby rural stations were analyzed over the period 1960–1989 ("dimming phase") and 1990–2013 ("brightening phase"). There is a large overlap in urban and rural sunshine duration trends for both dimming (≈ 86 %) and brightening (≈ 84 %) phases. This indicates that rather than urban dimming or rural brightening, the global dimming and brightening phenomena are more of national/regional scale in China. In the dimming phase, sunshine duration significantly declined in both urban and rural areas at an average rate of −0.20 h d−1 decade−1 and −0.14 h d−1 decade−1 respectively, i.e. rural dimming has been around two-thirds of urban dimming. This ratio generally increases from a minimum of 0.39 to a maximum of 0.87 with increasing indices of urbanization, reaching saturation when the urbanization level exceeds 50 %, or the urban population exceeds 20 million persons, or the population density becomes higher than 250 person km−2. Urbanization can be treated as a useful indicator for anthropogenic air pollution in studying pollution-driven changes in sunshine duration during the dimming phase when pollution control and monitoring were largely absent. After the transition into the brightening phase, the increasing number of environment-related laws and regulations as well as investments in the abatement of environmental pollution might have helped in counteracting air pollutants generated during the urbanization process. Therefore, in the brightening phase, urbanization no longer simply indicates an increase in air pollution and its effect on sunshine duration becomes insignificant. In conclusion, urbanization can give a general indication of pollution-driven sunshine dimming until pollution regulations become effective.


2016 ◽  
Author(s):  
Katsumasa Tanaka ◽  
Atsumu Ohmura ◽  
Doris Folini ◽  
Martin Wild ◽  
Nozomu Ohkawara

Abstract. Observations worldwide indicate secular trends of all-sky surface solar radiation on decadal time scale, termed global dimming and brightening. Accordingly, the observed surface radiation in Japan generally shows a strong decline till the end of the 1980s and then a recovery toward around 2000. Because a substantial number of measurement stations are located within or proximate to populated areas, one may speculate that the observed trends are strongly influenced by local air pollution and are thus not of large-scale significance. This hypothesis poses a serious question as to what regional extent the global dimming and brightening are significant: Are the global dimming and brightening truly global phenomena, or regional or even only local? Our study focused on 14 meteorological observatories that measured all-sky surface solar radiation, zenith transmittance, and maximum transmittance. On the basis of municipality population time series, historical land use maps, recent satellite images, and actual site visits, we concluded that eight stations had been significantly influenced by urbanization, with the remaining six stations being left pristine. Between the urban and rural areas, no marked differences were identified in the temporal trends of the aforementioned meteorological parameters. Our finding suggests that global dimming and brightening in Japan occurred on a large scale, independently of urbanization.


2016 ◽  
Vol 16 (21) ◽  
pp. 13969-14001 ◽  
Author(s):  
Katsumasa Tanaka ◽  
Atsumu Ohmura ◽  
Doris Folini ◽  
Martin Wild ◽  
Nozomu Ohkawara

Abstract. Worldwide observations indicate secular trends of all-sky surface solar radiation on a decadal time scale, termed global dimming and brightening. Accordingly, the observed surface radiation in Japan generally shows a strong decline until the end of the 1980s and then a recovery until around 2000. Because a substantial number of measurement stations are located within or close to populated areas, one may speculate that the observed trends are strongly influenced by local air pollution and are thus not of large-scale significance. This hypothesis poses a serious question as to what regional extent the global dimming and brightening are significant: are the global dimming and brightening truly global phenomena, or regional, or even only local? Our study focused on 14 meteorological observatories that measured all-sky surface solar radiation, zenith transmittance, and maximum transmittance. On the basis of municipality population time series, historical land use maps, recent satellite images, and actual site visits, we concluded that eight stations have been significantly influenced by urbanization, with the remaining six stations being left pristine. Between the urban and rural areas, no marked differences were identified in the temporal trends of the aforementioned meteorological parameters. Our findings suggest that global dimming and brightening in Japan occurred on a large scale, independently of urbanization.


2021 ◽  
pp. 001946622110132
Author(s):  
Astha Agarwalla ◽  
Errol D’Souza

The policy responses to Covid-19 have triggered large-scale reverse migration from cities to rural areas in developing countries, exposing the vulnerability of migrants living precarious lives in cities, giving rise to debates asserting to migration as undesirable and favouring policy options to discourage the process. However, the very basis of spatial concentration and formation of cities is presence of agglomeration economies, benefits accruing to economic agents operating in cities. Presence of these agglomeration benefits in local labour markets manifests themselves in the form of an upward sloping wage curve in urban areas. We estimate the upward sloping wage curve for various size classes of cities in Indian economy and establish the presence of positive returns to occupation and industry concentration at urban locations. Controlling for worker-specific characteristics influencing wages, we establish that higher the share of an industry or an occupation in local employment as compared to national economy, the desirability of firms to pay higher wages increases. For casual labourers, occupational concentration results in higher wages. However, impact of industry concentration varies across sectors. Results supporting presence of upward sloping urban wage curve, therefore, endorse policies to correct the market failure in cities and promote migration as a desirable process. JEL Classification Codes: J2, R2


2007 ◽  
Vol 35 (69_suppl) ◽  
pp. 35-44 ◽  
Author(s):  
Samuel J. Clark ◽  
Mark A. Collinson ◽  
Kathleen Kahn ◽  
Kyle Drullinger ◽  
Stephen M. Tollman

Aim: To examine the hypothesis that circular labour migrants who become seriously ill while living away from home return to their rural homes to convalesce and possibly to die. Methods: Drawing on longitudinal data collected by the Agincourt health and demographic surveillance system in rural northeastern South Africa between 1995 and 2004, discrete time event history analysis is used to estimate the likelihood of dying for residents, short-term returning migrants, and long-term returning migrants controlling for sex, age, and historical period. Results: The annual odds of dying for short-term returning migrants are generally 1.1 to 1.9 times (depending on period, sex, and age) higher than those of residents and long-term returning migrants, and these differences are generally highly statistically significant. Further supporting the hypothesis is the fact that the proportion of HIV/TB deaths among short-term returning migrants increases dramatically as time progresses, and short-term returning migrants account for an increasing proportion of all HIV/TB deaths. Conclusions: This evidence strongly suggests that increasing numbers of circular labour migrants of prime working age are becoming ill in the urban areas where they work and coming home to be cared for and eventually to die in the rural areas where their families live. This shifts the burden of caring for them in their terminal illness to their families and the rural healthcare system with significant consequences for the distribution and allocation of health care resources.


2019 ◽  
Vol 1 (1) ◽  
pp. 66-71
Author(s):  
Bogdan Stanescu ◽  
Adriana Cuciureanu

The present article presents the expertise realized by the Department of Environmental Monitoring Pollution Evaluation within the INCD ECOIND, in the evaluation of the quality of urban soils in the municipality of Bucharest and the main big cities in Romania. The current data available at the level of the 27 member states of the European Union show that annually over 100,000 hectares of land are introduced into the urban environment, a direct consequence of the development of cities. There are a number of legislative obstacles to strategic soil protection measures. Moreover, at the level of the local authorities there is a conflict regarding the measures of soil protection in the long term, on the one hand, and, the accelerated economic development in the short term, on the other. European environmental experts consider that the urban development, absolutely necessary for the economic growth, requires an adequate management of the natural resources in order for the development to be done on a sustainable basis, respectively to follow a series of strategic objectives. In our country, at least in the last decade, we find on a large scale the conversion of industrial areas into commercial or residential areas. The footprint of industrial activities can be found even after long periods of time present by identifying the remnant of soil pollution or in those areas known as historically polluted (for example the town of Copsa Mica). The conclusions stemming from the assessment of pollution in urban areas over large areas, in correlation with the potential sources of pollution, underline the need to monitor the quality of soils in the urban environment, but also to apply a performance management in order to protect this natural resource in the long term.


Fisheries ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 81-86
Author(s):  
Magomed Gimbatov

The article considers the potential of Dagestan aquaculture (with trout as case study) to increase the level of social and economic development of rural areas of the republic. An economic analysis of the prospects for the development of forestry was carried out taking into account the territorial features of the Republic of Dagestan. The study shows that the socio-economic effect of the trout farming development in Dagestan can be considered as particularly significant. Its successful implementation will accelerate the solution of the following problems of the republic: - Increase of self-sufficiency of the population, fish products of own production, with fresh and high quality; - Increased consumption of fish products per capita, especially in rural areas; - Expansion of the tax base and increase of cash receipts, in the form of taxes and other payments to the budget and extrabudgetary funds at all levels; - Creation of a significant number of new jobs in rural areas and, as a result, the reduction of rural migration to urban areas; - The revival of fish processing plants; - Increased production of environmentally friendly food products in the region. The results of the study can be used in the development of the Rural Development Strategy of the region. Sustainable and large-scale development of aquaculture (fish farming) will bring the economy of the area to a higher level and make a significant contribution to improving the well-being of the rural population of the Republic of Dagestan.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 298 ◽  
Author(s):  
Sayed Mohammad Nazim Uddin ◽  
Jean Lapegue ◽  
Jutta Gutberlet ◽  
Jan Franklin Adamowski ◽  
Caetano C. Dorea ◽  
...  

The use of closed-loop sanitation systems (CLSS), or reuse-oriented sanitation systems, has increased in recent years, and such systems have been successfully implemented in many parts of the world. However, no research has explored Traditional CLSS (T-CLSS) for a long-term humanitarian situation. This study explores the strengths, weaknesses, opportunities and threats (SWOT) of T-CLSS in peri-urban and rural contexts in three different provinces in Afghanistan (the first study of its kind in Afghanistan). Participatory research tools, such as transect walks, focus group discussions, smart community gatherings and interactive workshops, were applied to assess the SWOT associated with T-CLSS. The results indicate that T-CLSS has been practiced historically in both peri-urban and rural areas using local and traditional knowledge, skills and technologies. The socio-cultural acceptance of the system in both rural and peri-urban areas is an important strength of this established system. However, due to chronic development challenges in the study regions, T-CLSS may possibly lead to exposure to microbial contaminants. It is recommended that the feasibility of an improved CLSS be assessed and implemented in light of the issues that are inherent in the use of T-CLSS in Afghanistan.


1999 ◽  
Vol 3 (3) ◽  
pp. 363-374 ◽  
Author(s):  
M. Lobmeyr ◽  
D. Lohmann ◽  
C. Ruhe

Abstract. This paper investigates the ability of the VIC-2L model coupled to a routing model to reproduce streamflow in the catchment of the lower Elbe River, Germany. The VIC-2L model, a hydrologically-based land surface scheme (LSS) which has been tested extensively in the Project for Intercomparison of Land-surface Parameterization Schemes (PILPS), is put up on the rotated grid of 1/6 degree of the atmospheric regional scale model (REMO) used in the Baltic Sea Experiment (BALTEX). For a 10 year period, the VIC-2L model is forced in daily time steps with measured daily means of precipitation, air temperature, pressure, wind speed, air humidity and daily sunshine duration. VIC-2L model output of surface runoff and baseflow is used as input for the routing model, which transforms modelled runoff into streamflow, which is compared to measured streamflow at selected gauge stations. The water balance of the basin is investigated and the model results on daily, monthly and annual time scales are discussed. Discrepancies appear in time periods where snow and ice processes are important. Extreme flood events are analyzed in more dital. The influence of calibration with respect to runoff is examined.


Author(s):  
Herbert Weinblatt ◽  
Erik Minge ◽  
Scott Petersen

Vehicle classification data are an important component of traffic-monitoring programs. Although most vehicle classification conducted in the United States is axle based, some applications could be supplemented or replaced by length-based data. The typically higher deployment cost and reliability issues associated with collecting axle-based data as compared with length-based data present a challenge. This paper reports on analyses of alternative length-based vehicle classification schemes and appropriate length bin boundaries. The primary analyses use data from a set of 13 Long-Term Pavement Performance weigh-in-motion sites, all in rural areas; additional analyses are conducted with data from 11 Michigan Department of Transportation weigh-in-motion sites located in rural and small urban areas and one site located in an urbanized area. For most states, the recommended length-based vehicle classification scheme is a four-bin scheme (motorcycles, short, medium, and long) with an optional very long bin recommended for use by states in which significant numbers of longer combination vehicles operate.


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