The spatiotemporal patterns of urban expansion have attracted worldwide attention and have been generalized into several prevalent hypotheses, such as the diffusion–coalescence hypothesis and the three-growth-type hypothesis. Although many studies have examined the applicability of these hypotheses, long-term research and evidence are still lacking. This study incorporated a compiled dataset of multisource remote sensing images and historical maps covering nine snapshots of the urban built-up area from 1914 to 2018 to monitor the urban expansion process in Hangzhou, China. A fractal analysis of the area–radius relationship was employed for areal demarcation to explore the heterogenous patterns across different intra-city spatial extents. The results show that (1) Hangzhou has experienced a turbulent period of primitive urbanization in the pre-reform era and a consecutive period of market-oriented urbanization after the economic reform; (2) the urban expansion pattern characterized by landscape metrics demonstrates the existence of multiple alternations between diffusion and coalescence phases with peculiarities across different intra-city spatial extents; (3) the analysis of urban growth types documents a consistent predominance of edge-expansion with wax and wane between infilling and leapfrogging; and (4) institutional reform, industrial development, and administrative division adjustment are the main drivers of urban expansion in Hangzhou. Our findings suggest that effective planning policies need to be raised to curb urban sprawl. Differentiated planning strategies should be proposed to accommodate unique conditions in different urban subregions. The integrated-analysis approach based on multisource remote sensing images and historical maps establishes a feasible pathway for long-term urban research.

Rural depression is a global issue in the process of worldwide urbanization. Compared with rural economic institution reform, rural land institution reform is more thorough in realizing rural revitalization. In this paper, polycentric governance theory is used to introduce marketization reform of collective profit-oriented land (MRCPL). MRCPL aims to allow rural collective profit-oriented construction land to be sold and leased with the same rights and at the same price as state-owned construction land. In the process of MRCPL, we suppose that the key subject is the central government, and the multiple auxiliary subjects include local governments, markets, villagers, and village collectives. Herein, Deqing County was selected as the research area and its achievements, conflicts, and potential risks in the process of MRCPL were studied. This study found that in Deqing County, a unified urban–rural construction land market has been preliminarily established, the rural revenue allocation mechanism has been updated, and the rural land finance mechanism has been developed. However, MRCPL may have conflicts with existing land requisition institutions and land banking institutions, and may also have conflicts within different subjects (farmers, village collective, local government, and central government). These conflicts may lead to potential risks, such as rent-seeking risk, land-financing risk, and real-estate-bubble risk. In general, the MRCPL aims to allow rural collective profit-oriented construction land to be sold and leased with the same rights and at the same prices as state-owned construction land. This reform can protect farmers’ land rights and promote the construction of urban and rural integration.

An important purpose of building VSC-HVDC is to eliminate the overload and optimize the power flow in electric power network. From the points of the transmission network, a VSC-HVDC in electric power network influences the two end nodes' injection power of DC transmission line virtually and the injection power will further influence the distribution of branch power. The elimination of overload in electric power network that caused by VSC-HVDC has been considered when making transmission network expansion planning. A fast optimization model for power of transmission network including VSC-HVDC is built to minimize the network power loss. A new genetic operation called shift operation which will change the order of chromosome's local coding is added to the algorithm to keep the diversity of population. Garver-6 system is taken as an example to verify the correctness of the fast optimization model and prove that the genetic algorithm with shift operation can avoid local convergence more effectively. The genetic algorithm with shift operation is a beneficial attempt to improve the global convergence of genetic algorithm. The fast optimization model for power of transmission network including VSC-HVDC is proved to be practical.