Search

Unprecedented urbanization in China has directly resulted in residential vacancies, which has seriously stunted sustainable development, a part of China's new-type urbanization plan. Understanding the various types and mixes of residential vacancies is critical for the advancement of our knowledge of speculative urbanism and for devising vacancy-mitigation policies, but this issue remains insufficiently studied. Using municipal water consumption data, this study proposes a feasible and general-purpose framework for providing innovative insights into the variability in residential vacancies at the household level and the mixture of residential vacancies at the building level. This framework was applied to the city of Changshu, China, and four categories of vacant residences at the household level were identified: seasonally vacant residences, long-term vacant residences, newly built residences and occasionally vacant residences. The first category is closely related to tourism and seasonal industries, while the last three exhibit a Matthew effect. In addition to revealing significant and intensifying spatial clustering and three patterns of changes in vacancy mixtures (i.e., emergence, disappearance, and increases or decreases), the results identify particular types of vacant residences at the building level (e.g., extremely low-entropy long-term multihousehold buildings). The insights from this study can contribute to devising customized policies for alleviating residential vacancies. • The proposed framework reveals variability in and mixtures among residential vacancies using municipal water consumption. • The document representations of vacant residences are extracted based on the vacant residence corpus and Doc2Vec method. • Four categories of vacant residences at the household level are identified using the Doc2Vec and K-means++ methods. • Seasonally vacant residences are closely related to tourism and seasonal industries. • Long-term, newly built and occasionally vacant residences exhibit a Matthew effect. [ABSTRACT FROM AUTHOR]

Reducing water use and relieving negative environmental consequences contribute to regional water and ecological sustainability. This work examined water resource efficiency (WRE) and the effects of effective crop water use from the perspective of the water footprint. WRE was defined as the ratio of consumptive field water use (CWU) to the total crop water footprint (CWF), including the blue water footprint applied (BWFA), green water footprint (GWF), and grey water footprint (GYWF). WRE for the cultivation of the main crops (rice, wheat, maize, beans, and tubers) produced in China during the period of 1996–2015 was determined from estimates of provincial CWFs and CWUs. The results show that national CWF was estimated as 678.5 Gm³, of which GWF comprised 55.1%; the national crop CWU was approximately 455.6 Gm³ in the period considered, and this included 82.1% green and 17.9% blue water. The spatial patterns of CWF and CWU densities differed greatly but were stable over time, with increasing trends exhibited from 1996 to 2015. The national WRE for crops was 0.672, and that for beans was 0.869, an efficiency larger than that of any other crop. The indices for rice and wheat were approximately 0.630. WRE cannot be replaced by the global efficiency (GEF) or generalized efficiency (GE) indices, either for scientific evaluations or for considerations of spatial distributions. This study aids in the evaluation of effective water resource consumption by considering the process of agricultural water use, and also the impact of crop production on water quality and quantity. Hence, WRE is an advanced indicator linking measurements of water footprint with assessments of crop management and the sustainability of regional water resources. [Display omitted] • Water resources effectiveness (WRE) was assessed from the water footprint perspective. • WRE was 0.672 and varied among crops in grain production of China. • It's needs to reduce crop water footprint and improve WRE in rice production of China. • WRE is an improvement of agricultural water use efficiency evaluation index system. [ABSTRACT FROM AUTHOR]