Dissolved organic matter (DOM) is ubiquitously present in aquatic environments, playing an important role in the global carbon cycle and water quality. It is necessary to reveal the potential sources and explore spatiotemporal variation of DOM in rivers, especially in urban zones impacted by human activities.

Landscape composition and configuration determine the source of pollutants. They also determine the interception and pollution-holding potential of the surface landscape.

In China, the transfer of land management rights has always been a topic of much discussion, as it plays an important role in improving land use efficiency, achieving the optimal allocation of agricultural resources, and protecting farmers’ rights and interests.

It is common to see urban land expansion worldwide, and its characteristics, mechanisms, and effects are widely known. As socio-economic transition and the change of land use policies may reverse the trend of urban expansion, in-depth research on the process of urban land use change is required.

Soil erosion is a significant form of land degradation worldwide, leading to ecological degradation and a decline in agricultural productivity. The middle section of the northern slopes of Tianshan Mountain (MNSTM) in northwestern China is a high-priority area for soil water erosion prevention, and soil water erosion is a serious problem in the region.

Buckwheat is an important coarse grain often grown in China’s marginal and dry mountainous areas; however, few empirical studies have quantified the factors that increase land productivity and encourage buckwheat farmers’ market participation.

The Qilian Mountains (QMs), located in the northeast part of the Qinghai–Tibetan Plateau in China, have a fragile ecological environment, complex and sensitive climate, and diverse land-cover types. It plays an important role in the “Qinghai–Tibetan Plateau Ecological Barrier” and “Northern Sand Control Belt” in China’s “two screens and three belts” ecological security strategy.

Previous studies have demonstrated that grain loss in the harvest process accounts for a large loss in all aspects of the grain supply chain. This research extensively discusses the impact of farmland management scale on grain loss in the harvest process based on survey data on farmers’ productivity in the Shandong and Hebei provinces of China.

The withdrawal of rural residential land-use rights is a major initiative in China’s current rural land reform, and it is of great importance in promoting the rural revitalization and urbanization strategy. The Chinese government encourages farmers to withdraw from their residential bases in an orderly manner to effectively revitalize land resources.

As a proxy for human activity, per capita urban land has great significance for urban planning. We still lack a comprehensive understanding of per capita urban land from the perspective of urban–rural gradients.