Urban River Health Analysis of the Jialu River in Zhengzhou City Using the Improved Fuzzy Matter-Element Extension Model

Adsorption-desorption characteristics of typical heavy metal pollutants in submerged zone sediments: a case study of the Jialu section in Zhengzhou, China

In recent years, the accumulation ability of heavy metals in sediment has become a key indicator for sediment pollution prevention and control. The adsorption-desorption processes of typical heavy metal pollutants in sediments under different conditions were explored and relied in this article. In addition, different binary competitive adsorption systems were designed to study the competitive adsorption properties of heavy metal contaminants, The quasi-secondary kinetic model simulated the adsorption kinetic process. The sediment adsorption rates for heavy metals were (in descending order) Cu, Pb, Cd, Zn. The Elovich equation simulated the desorption kinetics process better, and the sediment desorption rates for heavy metals were (in descending order) Cd, Cu, Zn, Pb. The average free adsorption energy E of heavy metals was within the range of 8-16 kJ∙mol-1. After the removal of organic matter, the ability of the sediment to sequester heavy metals decreases, The binary competitive adsorption results showed that the presence of interfering ions had the greatest effect on Cd and the least effect on Pb. The adsorption and desorption of the four heavy metals by the sediments in the submerged zone increased with the increase of temperature, and the ratio of desorption to adsorption also increased therewith: the adsorptions of heavy metals by the sediments were all spontaneous processes (under heat absorption reactions). The presence of organic matter can increase the ability of the sediment to sequester Cd, Pb, Cu, and Zn. Additionally, heavy metals exhibited significant selective adsorption properties.

A tale of two rivers: development, destruction, and despair in Ongata Rongai, Kenya

Introduction

Ongata Rongai is a rapidly growing peri-urban space in Nairobi Metropolitan, Kenya. The last 10 years have seen exponential population growth and building development leading to overcrowding and pressure on water and environmental resources. This original research sheds light on interactions among humans, animals, and this rapidly changing urban environment. It is therefore a quintessentially One Health study.

Methods

Qualitative and ethnographically informed methods are employed to better understand the impact of rapid growth on the riparian environment and the effect of this on those who depend on it. The reflexive use of archival material and a historical ethnographic approach enabled in-depth narratives to address these issues within a longitudinal context, and the use of deliberate walking alongside visual methodologies and more traditional anthropological methods make this study novel both in terms of methodological approach and findings.

Results

This study finds that people cite high levels of pollution from solid waste and sewage have made the rivers almost unusable and a hazardous place for both humans and animals. Yet, in the past, these rivers played key roles in daily life. There is frustration with structural-level actors' moribund attitude to the environment. The poor health of the rivers and riparian environment leads to human and animal health challenges, increased pressure on water resources, and economic pressure due to a loss of livelihoods.

Discussion

The study contributes to what is currently a fairly small literature on urban riparian spaces globally, but one which is of growing and vital importance given the rapidly increasing percentage of humans who now reside in urban spaces. It contributes to WASH and urban clean water knowledge as well as One Health, public health, and urban growth narratives, and directly addresses challenges faced by SDG 6.

Climate change and river health of the Marshyangdi Watershed, Nepal: An assessment using integrated approach

Climate change alters the river flow regimes causing significant changes in the structure and function of an aquatic ecosystem, ultimately affecting river health. This study applied a customized framework consisting of 1-index, 4-components, 6-indicators, and 43-metrics, to assess river health for two seasons and future periods, in the Marshyangdi Watershed, Nepal. Hydrological, water quality, biological and physical conditions were assessed using simulated results from a hydrological model, physiochemical analysis of water samples, macroinvertebrates assemblages analysis, and physical habitat condition assessment, respectively. Climate change impact on river health was assessed based on projected climate (precipitation and temperature) based on regional climate models under representative concentration pathways (RCP) 4.5 and 8.5 scenarios until the mid-century. Results showed moderate river health condition in both the seasons and it's deterioration for future scenarios and periods. It reveals the need to formulate appropriate measures for the conservation of the river health.

A Comprehensive Assessment Approach for Water-Soil Environmental Risk during Railway Construction in Ecological Fragile Region Based on AHP and MEA

With China’s government facilitating railway projects, more railway lines inevitably pass through ecological fragile regions (EFRs). Railway construction activities in EFRs might cause detrimental impacts on the local water-soil environment (WSE), which is the basis of the local ecological system that if destroyed can induce secondary disasters. Studies on the WSE risk (WSER) during railway construction in EFRs are limited. As such, this study aims to offer preliminary insight into the WSER assessment of railway construction in EFRs. WSERs were identified firstly based on the literature review and field surveys, and thus a risk index framework for WSER assessment including 5 categories of WSERs and 16 second-order risks was established. Then a comprehensive quantitative assessment method was developed by integrating analytic hierarchy process (AHP) and matter-element analysis (MEA) to assess the overall WSERs of railway construction in EFRs. A case (i.e., the Mingan subproject of Hefei-Fuzhou railway) was selected to demonstrate and validate the developed approach. Results show that the proposed assessment approach can be applied to evaluate the WSERs during railway construction. In addition, the case study demonstrates that the risk of construction methods should be the key focus. Findings from this study enrich the knowledge body of sustainable railways and guide the project managers to conduct practical WSER assessment of railway construction.

Initial allocation of flood drainage rights based on a PSR model and entropy-based matter-element theory in the Sunan Canal, China

The pursuit of flood prevention safety and the mitigation of drainage contradiction against an unnecessary influx of floodwater require a modern and efficient model to optimize the management of the initial allocation of flood drainage rights. We attempted to formulate a framework for initial flood drainage rights allocation to promote the sustainable drainage of the Sunan Canal, China. The Pressure-State-Response (PSR) model was constructed using a literature review and interviews with experts and directors using 18 key indicators being determined from field surveys and library studies. We then assessed the flood status of Zhenjiang City, Changzhou City, Wuxi City and Suzhou City in the Sunan Canal zone using an entropy-based matter-element model. The flood drainage rights for a total of 400m3/s was allocated to the four cities in accordance with their flood status. Our research demonstrated that, overall, the four cities may gain the flood drainage rights of 106.67m3/s,120.40m3/s, 118.22m3/s and 54.71m3/s, respectively. Specifically, the calculation of the flood drainage for Wuxi was very close to the actual allocation in 2016, whereas there were differences in the other cities that should not be neglected.

Spatial-Temporal Coupling Analysis of the Coordination between Urbanization and Water Ecosystem in the Yangtze River Economic Belt

As a primary pioneering region in China's ongoing urbanization process, the Yangtze River Economic Belt's (YREB's) urbanization process is itself continually accelerating, causing increasing pressure on the area's water ecosystem. It is necessary to examine the coordination relationship between the urbanization system and the water ecosystem in the YREB for realizing sustainable urban development. To this purpose, we use two comprehensive index systems, along with an improved coupling coordination degree (CCD) model. This method is used to analyze the coordination between urbanization and the water ecosystem across spatial gradients and temporal scales in the YREB, from 2008 to 2017. The factors acting as obstacles were diagnosed by utilizing the obstacle degree model. The results show that: (1) the coordination state of each region gradually improved during the 2008-2017 period. In terms of spatial distribution, the coordination state between two systems gradually increased from east to west. Moreover, the spatial differences across the 11 analyzed regions gradually narrowed with the passage of time. (2) The coordination between the two systems, from 2008 to 2017, evolved from a state of serious imbalance to a state of good coordination. The two systems passed from an initial period of imbalance or antagonism, coupled with rapid growth (2008-2011), through a period of basic coordination with steady growth (2011-2014), and finally toward a period of good coordination with slow growth (2014-2017). (3) Spatial urbanization and pressures on subsystems are the key factors acting as obstacles in the urbanization system and water ecosystem, respectively. Facing the process of rapid urbanization in China, the coupling analysis of the coordination between urbanization and the water ecosystem can help the government to formulate a reasonable new-type urban development strategy. This strategy will play an important role in China's sustainable urban development and water environmental protection. The findings of this study provide important support for urban planning in the future.