Mapping the impact of a large municipal waste disposal area on surface water: 1993-2017, case of Laogang, Shanghai.

In China, the impact of waste disposal facilities is always a cause of concern for the government and the public. Laogang Municipal Waste Disposal Area (LMDA), Shanghai, one of the largest municipal waste disposal areas in the world was selected as case in this study, and it was attempted to analyze the changes in the surface water quality, and map the impacted area by LMDA on surrounding streams from its operation period of 1993-2017. The results showed that, during the whole period, only biochemical oxygen demand (BOD5) showed a continuous improvement with a percentage of 85.92%, however, chemical oxygen demand (CODcr), ammonia (NH4+-N) and total phosphorus (TP) significantly improved but BOD5 slightly deteriorated began from 2013. Using spatial analysis tools and Kendall's concordance test, CODcr and phenol at LMDA showed a significant impact on surrounding surface water; especially, the impacted area for CODcr decreased from 106.30 km2 to 22.86 km2 from 1993 to 2017, which dropped from 4.3 to 0.9 times the area of LMDA. Surprisingly, NH4+-N and TP at LMDA were affected by the surrounding streams, instead of having an impact on them. Interestingly, heavy metals and non-metals such as Hg, As, Zn, and Se in the surrounding streams were unlikely affected by LMDA. The driving forces for surface water quality improvement included the eco-remediation of closed unsanitary landfills, upgrade in waste shipping and terminals, operation of sanitary landfills and incineration plants for landfill diversion. Capsule: Impacted area of municipal waste disposal area is not so large.

Assessing the health of an urban stream: a case study of Suzhou Creek in Shanghai, China.

Restoration of urban streams and rivers has increased rapidly in developing countries in recent years. Estimating river health provides a new perspective on evaluating the ecological conditions of streams and rivers. The Suzhou Creek restoration project in Shanghai, China is a milestone for environmental protection. Based on the environmental and ecological data, including 17 indicators in five categories, collected from March 11 to April 20, 2007, the river health index (RHI) for Suzhou Creek was constructed and analysed to quantify the ecosystem of this urban river after a restoration project. The RHI scores of 34 sites ranged from 19.24 to 33.36, i.e. from poor to good. There were no significant RHI differences among stream orders, while differences in land use resulted in significant differences in channel flow status (B12), channel alteration (B21), channel sinuosity (B22), bank stability (B23), bank profile type (B25) and riparian vegetative zone width (B31). River restoration led to improved hydrological condition and channel physical form, while ammonia nitrogen (B44) and indicator scores of the presence of macro-invertebrate families (B51) were the lowest of any indicator. This case study supports the use of river health assessment as a supplement to water quality analysis in China.

[Willingness to pay for ecosystem services of urban river in Shanghai].

The contingent valuation method (CVM) is one of the most dominating and standard techniques for eliciting the willingness to pay (WTP) for the ecosystem services provided by environment and resources. Taking Zhangjiabang Creek, a model project in the comprehensive management of urban river in China, as a case study, 800 payment card CVM questionnaires were surveyed and 646 as useful questionnaires were feed back in August 2003, then, the mean WTP, 195.07 - 253.04 Yen per person every year in the future 3 years, to the ecosystem services of the urban river was got in the payment card CVM study, and the figure was compared to some other river CVM studies. Distribution shape and range of WTP were probed, and the regression relationship between respondents WTP and their socioeconomic information such as income, education level, donation experience, and environmental attitude was discussed, what's important, an environmental economics explanation was given to the regression results. Some biases which influence the mean WTP of payment card CVM are inspected and corresponding countermeasures were seriously noticed and implemented in the survey. Finally the critiques and controversies that CVM is faced with were advanced, but the reliability of CVM is also given based upon environmental decision-making theory.