China’s urbanization has undergone decades of extensive development, resulting in significant imbalances between urban land conversion and population growth, with a variety of environmental consequences. This study examines the temporal and spatial characteristics of land conversion and population growth in 286 Chinese cities from 1986 to 2010, as well as the possible threats to food security associated with land urbanization at this time. We found that, in China, the rate of urban land conversion far outpaces that of urban population growth, with this imbalance being more prominent in the Yangtze River Basin and cities in the eastern coastal provinces than that in other areas. Although the rate of land urbanization has been higher than that of population urbanization for many years, many cities still have a relatively low construction land area per capita (<50 m²/person), and they are mainly concentrated in the Yangtze River Basin. Although large areas of high-quality farmland have been converted to “new cities” without enough immigrants to utilize the developed infrastructure, the impact of this loss of arable land on food production has been insignificant. However, the waste of land caused by blind land expansion without considering population growth is still a cause for concern.

To study the vibration characteristics of viscoelastic slurry pipe structures under fluid–structure interaction (FSI), we constructed a three-dimensional FSI pipe model based on the finite element method to systematically investigate the effects of fluid effects, pipe length, and wall thickness on the vibrational characteristics of viscoelastic slurry pipes. A modal analysis demonstrated that fluid effects not only significantly reduced the natural frequency of the pipe but also disrupted the symmetry of the vibration modes and eliminated the phenomenon of frequency degeneracy. The frequency reduction caused by FSI reached 54%, which was dominant compared with the water-attached effects, and its impact intensified with the increasing vibration order. The water-attached effect exhibited differences between odd and even orders, attributed to the influence of vibration modes on the distribution of fluid inertial forces, with a contribution of 45.07% to 55.24% in the odd orders and of only 37.69% to 38.93% in the even orders. When the FSI and water-attached effects acted together, the frequency reduction was further aggravated, but the reduction ratio did not follow a simple linear superposition. The parametric analysis of the pipe showed that when the pipe length increased from 1 m to 3 m, the growth rate of its natural frequency was only 26.52% that of the shorter pipe, indicating that the longer the pipes, the slower the growth rate of frequency. When the wall thickness increased from 5 mm to 11 mm, the growth rate of the first-order natural frequency decreased from 15.43% to 7.44%, suggesting that the frequency improvement effect caused by the stiffness augmentation diminished with the increase in wall thickness. The research results hold significant guiding significance for the structural design of slurry pipe systems in practical engineering and the safe operation of pipe systems.