Search

Copyright of South Architecture / Nanfang Jianzhu is the property of South Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Land normally serves as the carrier of urban and suburban districts in the spatial planning and development strategies. There is a great impact of land use structure on the habitat quality of urban suburbs in recent years. Taking the suburb of Wuqing District, Tianjin, China, as the research area, this study aims to evaluate the sustainable development of land use and habitat quality at the metropolis suburb. The data of land use was collected from 1980-2018. An InVEST model was used to determine the measure level of the habitat quality module. A numerical analysis was made in the habitat quality module to explore the change of land use transfer and land use dynamic degree in the key timeline. An attempt was made to clarify the integrated habitat degradation degree with land use and the evolution of habitat quality structure at the Beijing-Tianjin metropolitan suburb. A relationship model was established for the habitat quality and the spatiotemporal evolution of land use. The results showed that: (1) The type of land use in Wuqing District was dominated by the cultivated land during 1980-2018. Specifically, the area of farmland and unused land decreased significantly, whereas, the area of urban land and rural settlements increased rapidly. There was a relatively small proportion of woodland and grassland. (2) In land-use type transfer, there was the largest transfer area of cultivated land, followed by that of urban and rural residential land. The woodland and grassland shifted to the urban and rural residential land, whereas, the water area to the cultivated land. The unused land changed most. (3) In comprehensive land use dynamic degree (CLUDD), there was an increase in the change rate of land use for the urban land, rural residential land, and water areas, as well as a decrease in that of cultivated land. (4) There was a trend of "urban expansion and farmland contraction", and "human advancing and grass retreating", but in some years there was also a transition of "grass and water advancing". The habitat quality in Wuqing District was in the middle grade, but the area of the middle grade tended to decrease. There was an increase in the area of the low-grade habitat quality, whereas, a downward trend in that of lower grade, while that of the higher and the highest grade tended to expand. The finding can contribute to the precise implementation of the protection strategy of habitat quality and of "ecological civilization", especially for land planning in trans-regional metropolitan areas,further promoting new urbanization in China. [ABSTRACT FROM AUTHOR]

Northern China suffers from serious air pollution especially in winter, much of which derives from solid fuel used for domestic heating in rural areas. In order to reduce pollution emissions in the heating season, the Chinese government has introduced a "coal-to-gas conversion" policy, promoting a switch to natural gas which is much cleaner than the coal normally used for winter heating. The "coal-to-gas conversion" project will cover more than 1.8 billion m2 of heated built floor area and affect more than 12 million heat users in Beijing, Tianjin, Hebei, and the surrounding areas. Life cycle assessment and life cycle cost methods are applied to compare and analyze the environmental impact and economic cost of household energy usage for the whole year under 5 scenarios before and after "coal-to-gas conversion." In the three scenarios after "coal-to-gas conversion," the environmental impact decreases by around 50% while the total economic cost increases by around 80%. Particulate emissions responsible for air pollution are considerably reduced with accompanying benefits for human health, though significant, but reduced, impacts on freshwater and marine ecotoxicity remain. Improving thermal efficiency through natural gas utilization, implementing an energy-saving retrofit of rural housing, and promoting straw utilization yield benefits for people and the environment in rural areas of northern China. [ABSTRACT FROM AUTHOR]

The Chinese government has emphasized the consolidation of rural settlements because of their extensive use and hollowing-out in the hope that agricultural land losses can be mitigated nationally, the ecological environment can be protected, and improvements can be made to agricultural production and rural livelihoods. Rural settlement consolidation, however, necessitates a complex optimization approach that involves multiple aspects including rural development policies as well as the evaluation and classification of settlement layout, the land-use decision-making behaviors of villagers, and spatial layout optimization models. Current rural settlement consolidation methods lack these respective modules and have therefore led to unsatisfactory results. We therefore coupled a spatial layout evaluation module, system dynamics (SD) models, and the multi-agent system (MAS) to establish the rural settlement consolidation model (RSCM), an approach which can comprehensively consider all these aspects. This model was then applied in Jizhou District, Tianjin, using the three policy scenarios of ecology priority, coordinated ecology and economic development, and economy priority. The results of this analysis show that, in the first place, given an optimized rural settlement layout, the average suitability value and degree of average spatial compactness increased by 3.23% and 96.68% respectively. These outcomes indicate that the model can improve land-use suitability and solve the village hollowing-out issue. Data also show that landscape pattern indices including average plaque density, average patch shape index, and average fractal dimension all decreased by 54.17%, 26.20, and 4.60%, respectively, while average plaque area increased by 117.22%. These outcomes indicate that the use of this model can reduce rural settlement complexity and alleviate the pressure on the landscape matrix. Secondly, results show that the consolidation of rural settlements leads to clear socioeconomic and ecological benefits within the study area as well as improvements in agricultural production and rural livelihoods because of spatial layout adjustments. Third, ecological and economic policy priorities reduce the effectiveness of rural settlement consolidation, hinder economic development, and can even exacerbate the hollowing-out of villages. Rural development policies must therefore strike a balance between environmental protection and economic development. • A rural settlement consolidation model (RSCM) is presented. • A system dynamic model and a multi-agent system are coupled in a RSCM. • Land suitability, landscape pattern, and spatial compactness are considered in a RSCM. • The use of a RSCM can significantly optimize the consolidation of rural settlements. [ABSTRACT FROM AUTHOR]