Taking Guangzhou as a case, this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics
and influencing factors of private car travel in Chinese cities. As the research indicated, trip purposes of private car travel
are mainly commute and business affairs with a more flexible trip in the urban core area. And trip intensities are concentrated
in a certain extent, with trip frequency being lower in the urban core area than the peripheral area. In addition, the trip
time has two significant peaks occurring in the morning and afternoon, and one trough in the midday. And trip spatial distribution
is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area
while employment in urban area. Both kinds of commutes direct to the urban area. The study also shows that the characteristics
of private car travel are principally influenced by two aspects: travelers’ attributes and urban characteristics. The main
travelers’ social and economic attributes influenced it include the gender, education attainment, age, driving experience
and per capita monthly household income. The urban characteristics influenced it mainly cover the land use pattern, public
traffic facilities and spatial attributes of residential environment. 相似文献
A typical single-layer raw soil structure in villages and towns in China is taken as the research object. In the probabilistic seismic demand analysis, the seismic demand model is obtained by the incremental dynamic time history analysis method. The seismic vulnerability analysis is carried out for the raw soil structure of non-foundation, strip foundation, and spiral anchor composite foundation, respectively. The spiral anchor composite foundation can reduce the seismic response and failure state of raw soil structure, and the performance level of the structure is significantly improved. Structural requirements sample data with the same ground motion intensity are analyzed by linear regression statistics. Compared with the probabilistic seismic demand model under various working conditions, the seismic demand increases gradually with the increase of intensity. The seismic vulnerability curve is summarized for comparative analysis. With the gradual deepening of the limit state, the reduction effect of spiral anchor composite foundation on the exceedance probability becomes more and more obvious, which can reduce the probability of structural failure to a certain extent. 相似文献
This article analyses the trends in primary demand for fossil fuels and renewables, comparing regions with large and small domestic fossil fuel reserves. We focus on countries that hold 80% of global fossil fuel reserves and compare them with key countries that have meagre fossil fuel reserves. We show that those countries with large domestic fossil fuel reserves have experienced a large increase in primary energy demand from fossil fuels, but only a moderate or no increase in primary energy from renewables, and in particular from non-hydro renewable energy sources (NHRES), which are assumed to represent the cornerstone of the future transformation of the global energy system. This implies a tremendous threat to climate change mitigation, with only two principal mitigation options for fossil-fuel-rich economies if there is to be compliance with the temperature goals of the Paris Agreement: (1) leave the fossil fuels in the ground; and (2) apply carbon capture and storage (CCS) technologies. Combinations of these two options to exploit their respective possibilities synergistically will require strong initiatives and incentives to transform a certain amount of the domestic fossil fuel reserves (including the associated infrastructure) into stranded assets and to create an extensive CCS infrastructure. Our conclusion is that immediate and disruptive changes to the use of fossil fuels and investments in non-carbon-emitting technologies are required if global warming is to be limited to well below 2°C. Collective actions along value chains in business to divert from fossil fuels may be a feasible strategy.
Key policy insights
The main obstacle to compliance with any reasonable warming target is the abundance of fossil fuels, which has maintained and increased momentum towards new fossil-fuelled processes.
So far, there has been no increase in the share of NHRES in total global primary energy demand, with a clear decline in the NHRES share in India and China.
There is an immediate need for the global community to develop fossil fuel strategies and policies.
Policies must account for the global trade flow of products that typically occurs from the newly industrialized fossil fuel-rich countries to the developed countries.
The Government of Botswana has pledged a nationally determined contribution (NDC) as a commitment to the Paris Agreement. For the power sector, the NDC states that the government expects renewable energy (RE) to meet 25% of peak electricity demand by 2030. However, due to high initial cost of RE technologies, the government plans to maintain a coal-based power system in the future. Therefore, the purpose of this paper is to examine Botswana’s national plan from an economic perspective, using scenario and cost analysis, to explore the possibility of the power sector’s low carbon transition in the light of Botswana’s NDC. Five scenarios are designed to reflect a range of investment cost changes of RE technologies. While most scenarios only achieve 19% (P3, P4 and P5) and 54% (P6) of the NDC’s power sector target, the P7 scenario far exceeds the goal by achieving 188% of the NDC target. Furthermore, as the difference of levelized cost of electricity among the scenarios is minimal, the P7 scenario is the most attractive pathway for the government. Even for other scenarios, the government should still deploy the suggested capacity of solar photovoltaic (PV) as it is both economically and socially beneficial in the long term. However, in these cases, the government’s political will to meet the NDC’s power sector target and to promote the solar PV industry will be critical in designing future power sector policies.
Key policy insights
Model results show coal as the cheapest resource for electricity generation in Botswana up to 2030, but the cost competitiveness of solar photovoltaic (PV) against coal will continue to increase over time.
It is economically and socially beneficial to adjust the current national plan and substitute some share of coal with solar PV in the future energy mix.
Government support is critical in achieving the power sector’s NDC target, as cost reduction of solar PV alone does not guarantee success.
Encouraging independent power producers (IPP) with financial support mechanisms would be a suitable business model for developing the renewable energy industry.