Spatial Assessment of Cancer Incidences and the Risks of Industrial Wastewater Emission in China

Human Activity Intensity Assessment by Remote Sensing in the Water Source Area of the Middle Route of the South-to-North Water Diversion Project in China

Human activities have significantly affected the natural eco-environment, which could lead to land cover changes. The human activity intensity of land surface (HAILS) represent human activity at the regional scale and can be monitored efficiently over a long term based on land cover data collected by remote sensing techniques. In this study, we quantify the HAILS index for 2000, 2010, and 2015 based on land cover, and analyze its temporal and spatial variation to illustrate the potential influence of human activities on the water quality in the water source area of the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP). The results show that from 2000 to 2015, the HAILS decreased in general but increased with the highest increment of 78.4% around water resources. The area showing high values of HAILS increased at a rate of 30.8% from 2000 to 2015. In the riparian zone around the water body, the HAILS rose at an increment of 0.68% in 2010 to 0.05% in 2015. On the basis of the variation of the HAILS, it has been revealed that human activities, increased mainly around water bodies, may increase the risk of water pollution.

Spatiotemporal Variations in Gastric Cancer Mortality and Their Relations to Influencing Factors in S County, China

Increasingly stricter and wider official efforts have been made by multilevel Chinese governments for seeking the improvements of the environment and public health status. However, the contributions of these efforts to environmental changes and spatiotemporal variations in some environmental diseases have been seldom explored and evaluated. Gastric cancer mortality (GCM) data in two periods (I: 2004⁻2006 and II: 2012⁻2015) was collected for the analysis of its spatiotemporal variations on the grid scale across S County in Central China. Some environmental and socioeconomic factors, including river, farmlands, topographic condition, population density, and gross domestic products (GDP) were obtained for the exploration of their changes and their relationships with GCM's spatiotemporal variations through a powerful tool (GeoDetector, GD). During 2004⁻2015, S County achieved environmental improvement and socioeconomic development, as well as a clear decline of the age-standardized mortality rate of gastric cancer from 35.66/10⁵ to 23.44/10⁵. Moreover, the GCM spatial patterns changed on the grid scale, which was spatially associated with the selected influencing factors. Due to the improvement of rivers' water quality, the distance from rivers posed relatively larger but reversed impacts on the gridded GCM. In addition, higher population density and higher economic level (GDP) acted as important protective factors, whereas the percentage of farmlands tended to have adverse effects on the gridded GCM in period II. It can be concluded that the decline of GCM in S County was spatiotemporally associated with increasingly strengthened environmental managements and socioeconomic developments over the past decade. Additionally, we suggest that more attentions should be paid to the potential pollution caused by excessive pesticides and fertilizers on the farmlands in S County. This study provided a useful clue for local authorities adopting more targeted measures to improve environment and public health in the regions similar to S County.

Monitoring 40-Year Lake Area Changes of the Qaidam Basin, Tibetan Plateau, Using Landsat Time Series

Areal changes of high-altitude inland lakes on the Qaidam Basin (QB) of the Tibetan Plateau are reliable indicators of climate change and anthropogenic disturbance. Due to the physical difficulties to access, our knowledge of the spatial patterns and processes of climatic and human impacts on the Basin has been limited. Focusing on lake area changes, this study used long-term Landsat images to map the patterns of lakes and glaciers in 1977, 1990, 2000, and 2015, and to monitor the spatially explicit changes of lakes between 1977 and 2015. Results revealed that the total number of lakes (area > 0.5 km2) increased by 18, while their total area expanded by 29.8%, from 1761.5 ± 88.1 km2 to 2285.9 ± 91.4 km2. Meanwhile, glaciers have decreased in area by 259.16 km2 in the past four decades. The structural equation model (SEM) was applied to examine the integrative effects of natural and anthropogenic factors on lake area. Precipitation change exhibited the most significant influence on lake area in the QB from 1977 to 2000, while human activities also played an important role in the expansion of lakes in the QB in the period 2000–2015. In particular, extensive exploitation of salt lakes as mining resources resulted in severe changes in lake area and landscape. The continuously expanding salt lakes inundated the road infrastructure nearby, posing great threats to road safety. This study shed new light on the impacts of recent environmental changes and human interventions on lakes in the Qaidam Basin, which could assist policy-making for protecting the lakes and for strengthening the ecological improvement of this vast, arid basin.