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Land use and land cover change (LUCC) modeling is crucial to urban planning and policy making. A well-used and effective paradigm for LUCC is the ANN-CA model which employs an artificial neural network (ANN) to calculate a transition probability over each land cell from various driving factors, and then uses a cellular automaton (CA) to evolve all cells consecutively to update their land usage and coverage according to the estimated probability distribution. This paper focuses on the effect of delays or perturbations possibly taking place between land cells on the LUCC modeling. To this end, a new ANN-CA model is proposed which adopts an asynchronous communicating cellular automaton (ACCA), rather than the conventional synchronous CA. Especially, the ACCA allows every cell to communicate with its neighbors independently at random times via a specific protocol, which offers a natural way to include stochastic delays in exchanging the current land usages between cells. As a result, every change of a cell's land use in the ACCA may not affect its neighbors immediately, but is subject to delays that might play an important role in modeling the practical LUCC. Numerical analysis of the new model are carried out over three regions of Chongqing city, China with different scales: Yongchuan District, Sanjiao Town, and Huangguashan Village, and experimental results demonstrate that the proposed ANN-ACCA model can achieve a higher accuracy for LUCC simulation as compared to conventional ANN-CA models. [ABSTRACT FROM AUTHOR]

• Using population and economic dynamic rate data in the FLUS model is more accurate. • The improved model enhances the simulation accuracy significantly in the long-term. • Multi-scenario simulation of land use change can provide a basis for future planning. The conflicts between various types of land use in rural areas of China are becoming more and more obvious, therefore, how to more accurately simulate and predict the future land cover changes in rural areas has become an important topic of current academic research. In this research, the dynamic multi-year data was used to replace the static one-year data and brought into the future land use simulation (FLUS) model for the simulation of land use in Huangguashan village, Chongqing, China. The accuracy results of the two sets of simulations are compared in terms of accuracy kappa coefficient and Overall Accuracy (OA). Next, using the improved FLUS model, four different future development scenarios of priority ecological conservation, priority economic development, priority farmland conservation and priority integrated development were set up to simulate the land use data of Huangguashan village in 2030. The results of the research found that (1) the kappa coefficient and OA values were higher for the simulation of FLUS model using dynamic multi-year data. The simulation results are closer to the actual situation, especially the simulation enhancement effect is more obvious for the long-term; (2) by comparing the land use types of four different future development scenarios, it is suggested that Huangguashan village should adopt the integrated development priority scenario as the direction of future policy formulation and planning development in the future. This research can provide more effective scientific decision support and significance for governments to formulate multi-scheme rural land use development policies. [ABSTRACT FROM AUTHOR]

Aiming at the plugging of natural gas hydrate in the development of Sichuan and Chongqing gas field in winter, PetroChina Southwest Oil and Gasfield Company has carried on a lot of researches on the prevention and management technology of natural gas hydrate and gained some important research results and better prevention effects. Based on the present situation of the plugging of natural gas hydrate in Sichuan and Chongqing sour gas field in winter recently, this paper analyzed and summarized the main reasons of hydrate plugging, introduced there search and application development on the prevention of natural gas hydrate and management technology such as the prediction of natural gas hydrate formation in Sichuan and Chongqing oil and gas field, the development and field application of the kinetic hydrate inhibitors, and put forward the development direction. [ABSTRACT FROM AUTHOR]