Co-evolution of soil and water conservation policy and human–environment linkages in the Yellow River Basin since 1949

Policy plays a very important role in natural resource management as it lays out a government framework for guiding long-term decisions, and evolves in light of the interactions between human and environment. This paper focuses on soil and water conservation (SWC) policy in the Yellow River Basin (YRB), China. The problems, rural poverty, severe soil erosion, great sediment loads and high flood risks, are analyzed over the period of 1949–present using the Driving force–Pressure–State–Impact–Response (DPSIR) framework as a way to organize analysis of the evolution of SWC policy. Three stages are identified in which SWC policy interacts differently with institutional, financial and technology support. In Stage 1 (1949–1979), SWC policy focused on rural development in eroded areas and on reducing sediment loads. Local farmers were mainly responsible for SWC. The aim of Stage 2 (1980–1990) was the overall development of rural industry and SWC. A more integrated management perspective was implemented taking a small watershed as a geographic interactional unit. This approach greatly improved the efficiency of SWC activities. In Stage 3 (1991 till now), SWC has been treated as the main measure for natural resource conservation, environmental protection, disaster mitigation and agriculture development. Prevention of new degradation became a priority. The government began to be responsible for SWC, using administrative, legal and financial approaches and various technologies that made large-scale SWC engineering possible. Over the historical period considered, with the implementation of the various SWC policies, the rural economic and ecological system improved continuously while the sediment load and flood risk decreased dramatically. The findings assist in providing a historical perspective that could inform more rational, scientific and effective natural resource management going forwar

Factors influencing improvements in air quality in Guanzhong cities of China, and variations therein for 2014-2020

It is interesting and important to know what factors cause improvements in regional air quality. This study analyzed the factors that improved the air quality in cities in the Guanzhong region of China-in terms of meteorology and controlling emissions-following the implementation of the "Action Plan for Air Pollution Prevention and Control" in 2013. The average air quality index (AQI) values, PM2.5, PM10, SO2, CO, and NO2 in these cities in 2020 decreased by 45.1%, 43.8%, 82.9%, 57.3%, and 31.6%, respectively, compared to the values in 2014, while the O3 concentration increased by 16.7%. During the COVID-19 pandemic of February to May 2020, lockdown measures in cities in Guanzhong resulted in reductions of approximately 18.4%, 24.2%, and 17.9% in the AQI, PM2.5, and PM10 concentrations compared to the same period in 2019. Principal component analysis showed that the yearly reduction in AQI in cities in Guanzhong was attributed mainly to reductions in industrial emissions, followed by reductions in emissions from homes and motor vehicle exhausts. We propose the strengthening of measures to control particulate matter, O3 and greenhouse gas to see the improvement of air quality among this region in the future