Previous studies that quantified variations in runoff have mainly focused on the combined impacts of climate and human activities or climate and land cover change. Few have separated land cover change from human activities, which is critical for effective management of water resources. This study aims to investigate the impact of changing environmental conditions on runoff using the Soil and Water Assessment Tool (SWAT) model; we examined three categories: climate, land cover change and direct human activities. The study area was the Wei River Basin, a typical arid to semi-arid basin that was divided into five sub-zones (UZ, MZ, DZ, JZ and BZ). Our results showed the following: (1) the calibrated SWAT model produced satisfactory monthly flow processes over the baseline period from 1978 to 1986; (2) compared to the baseline period, the impact of climatic variations decreased and the impact of direct human activities increased from the 1990s to the 2000s, while the impact of land cover change was generally stable; and (3) climatic variations were the main cause of runoff declines over the entire basin during the 1990s and in the UZ, MZ and JZ areas during the 2000s, while direct human activities were most important in the DZ and BZ areas during the 2000s.

Under economic fluctuations, the sustainable development of enterprises is crucial. Currently, there are few studies on the interaction between economic policy uncertainty (EPU) and the sustainable development behavior of enterprises. Based on a panel vector autoregressive (PVAR) model, this paper explores the static and dynamic interactions among EPU, enterprise investment, and enterprise profitability and then analyzes regional heterogeneity in these factors. It finds that EPU has an inhibitory effect on the investment and profitability of enterprises, while the investment and profitability of enterprises also have an inhibitory effect on EPU. In addition, there are contribution differences and regional differences in the degrees of influence of the three factors. In the long run, EPU and the inhibition of enterprise investment and profitability are strongest in China’s central region. The results show that the stronger the certainty of economic policy, the more conducive this policy is to promoting enterprise investment behavior and improving enterprise profitability. Therefore, to ensure normal economic development, the government should limit changes in economic policy as much as possible; doing so is critical for promoting investment behavior and improving the profitability of enterprises.

A precise multi-scenario prediction of future population, based on micro-scale census data and localized interpretation of global scenarios, is significant for understanding long-term demographic changes. However, the data used in previous research need to be further refined. Few studies have focused on predicting the sex ratio at birth, which is vitally important for estimating the future size and structure of the population. It is also important to interpret and set parameters for China’s future population development in line with the framework for global shared socioeconomic pathways. This paper, therefore, used the structural population data for provinces, prefectures, and counties from the Sixth National Population Census of China. It comprehensively considered the impact of China’s economic development level, specific population policies, and loss of an only child on key parameters, and localized the population change parameters for different scenarios. A population–development–environment model was used to explain the population change parameters. The population of 340 districts was refined, forecast, and aggregated to the national scale. The results show that the Chinese population is expected to first increase then decrease under the five paths from 2010 to 2050. The aging demographic structure is not reversed under any paths, and the increase or decrease in the urban and rural populations between adjacent node years is closely related to the fertility rate and urbanization speed. We suggest that measures should be taken to encourage childbearing, manage the aging population problem, and reduce the pressure on young and middle-aged people.

Water-saving irrigation behavior (WSIB) is important for sustainable economic and social development in river basins and is promoted by improving water-saving awareness. Understanding the factors of WSIB could facilitate water demand management and information campaigns. Using the theory of planned behavior, this paper analyzes the influence of subjective attitude, perceived behavioral control and subjective norms on behavioral intention and final behavior with a structural equation model (SEM). Moreover, comparative study of the upper, middle and lower reaches of a river basin is also carried out to examine the regional differences. A survey of 546 rural residents in Heihe River Basin (HRB), which is located in northwest China, shows that (1) water-saving expectations and subjective norms have a significant impact on WSIB in upstream areas, and perceived behavioral control and subjective norms have positive effects in the middle and lower reaches; (2) the transformation of awareness into WSIB is slow and non-significant in all areas, mainly hindered by expected economic benefits; and (3) family water-saving experiences and social networks promote WSIB in the midstream and downstream areas. Compared with the midstream and downstream reaches, historical water-saving experience has no obvious effect on WSIB in the upper reaches. These findings highlight policies that (1) strengthen economic interests and increase the transformation of water-saving awareness into WSIB; (2) strengthen public awareness and neighborhood interaction, setting good examples to promote WSIB; and (3) increase farmer participation in relevant decision-making.

By integrating multiple remote sensing data sources this study accurately assesses the spatiotemporal characteristics of changes in ecosystem service values (ESVs) in the Yellow River Basin from 2000 to 2015 through Theil-Sen median trend analysis and the Mann-Kendall test. The stability and continuity of the ESVs were comprehensively characterized using coefficients of variation and the Hurst exponent. The degree of coherence between ESVs and economic growth (represented by gross domestic product GDP) on the same temporal and spatial scales was analyzed using ecological-economic coordination (EEC) models. The results show that (1) from 2001 to 2015 the total ESV and the ESV per unit area in the Yellow River Basin generally showed a U-shaped pattern (decreasing slightly then increasing rapidly). (2) The areas with increasing ESVs made up approximately 55.6% of the total area of the river basin. The areas with a decreasing pattern were mainly in the west and north of the Yellow River Basin. (3) The stability and continuity of the ESVs showed a clustered, compact distribution. (4) The most common level of EEC was slightly uncoordinated followed by slightly coordinated and highly coordinated. The proportion of coordinated areas was relatively higher in cultivated land and the lowest in built-up land.