Total pollution effect of urban surface runoff

For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD （chemical oxygen demand）, TSS （total suspend solid）, TP （total phosphorus）, TN （total nitrogen） and BOD （biochemical oxygen demand）. The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters： rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 （mass first flush ratio） and FF30 （first 30% of runoff volume） can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs （best management practices） facilities.

Analysis of the Relevance of Spatial Distribution Between Urban Parks and Transportation Infrastructure in Beijing Based on POI Data

In this paper,the relevance of spatial distribution between urban parks and transportation infrastructure in Beijing was studied grounded on POI data to guarantee the accuracy and scientificity.This paper focused on three aspects.Firstly,based on vector data of Beijing and POI data,the distribution of bus stations,subway stations,and parking lots as well as the road network density in the radiating region of each main entrance in urban parks were analyzed to assess traffic service ability in surrounding area of urban parks.Secondly,coupling relationship of spatial distribution between urban parks and transportation network in Beijing was analyzed using Kernel Density tools.Thirdly,Arc GIS was used to explore space pattern characteristics of large parks and association models between large parks and main transportation network,including two types of intersected and non-intersected and seven models.Finally,according to the comprehensive analysis of POI data,there was a contradictory relationship of interdependency and interaction between space pattern of urban parks and transportation infrastructure construction in Beijing,contributing to the scientific judgment of spatial characteristics of urban parks and transportation infrastructure as well as traffic accessibility and convenience.Quantified conclusions were thus obtained to explore coordinated development strategies for two systems of park green space and transportation network,thereby providing new ideas for the construction of harmonious and livable environment in Beijing.

Spatial econometric analysis on influencing factors of water consumption efficiency in urbanizing China

Due to the limitation of total amount of water resources, it is necessary to enhance water consumption efficiency to meet the increasing water demand of urbanizing China. Based on the panel data of 31 provinces in China in 1997-2013, we analyze the influencing factors of water consumption efficiency by spatial econometric models. Results show that, 1） Due to the notable spatial autocorrelation characteristics of water consumption efficiency among different provinces in China, general panel data regression model which previous studies often used may be improper to reveal its influencing factors. However, spatial Durbin model may best estimate their relationship. 2） Water consumption efficiency of a certain province may be influenced not only by its socio-economic and eco-environmental indicators, but also by water consumption efficiency in its neighboring provinces. Moreover, it may be influenced by the neighboring provinces＇ socio-economic and eco-environmental indicators. 3） For the macro average case of the 31 provinces in China, if water consumption efficiency in neighboring provinces increased 1%, water consumption efficiency of the local province would increase 0.34%. 4） Among the ten specific indicators we selected, per capita GDP and urbanization level of itself and its neighboring provinces have the most prominent positive effects on water consumption efficiency, and the indirect effects of neighboring provinces are much larger. Therefore, the spatial spillover effects of the economic development level and urbanization level are the primary influencing factors for improving China＇s water consump- tion efficiency. 5） Policy implications indicate that, to improve water consumption efficiency, each province should properly consider potential influences caused by its neighboring prov- inces, especially needs to enhance the economic cooperation and urbanization interaction with neighboring provinces.

Assessment of Climate Technology Demands in Chinese Sponge City

Sponge city is a development pattern used to realize natural accumulation, natural infiltration and natural purification of rainwater through urban planning and construction management. Sponge city technology is widely used as the critical approaches in natural rainwater management and it is one of the best techniques to adapt climate change events in modern cities. In the paper, we firstly reviewed background information of sponge city construction and the development, key technologies, and economic benefit analysis of stormwater management in foreign countries. Then, we analyzed the technology gap between China and developed countries in two aspects (planning design method and Low Impact Development (LID) project design). Then, we pointed out the main obstacles in sponge city technology transfer and proposed to improve the basic data sharing system and strengthen the economic return system. On the basis of sponge city planning theory and sponge city technologies, taking Shenzhen as an example, we analyzed the ideas and plans of sponge city construction in rainy areas and completed the assessment of current climate technology demands in Chinese sponge city. The study provides the basis for the improvements in sponge city construction and adaptation to climate change.

Impact of Untreated Sedimentation Tank Sludge Water Recycle on Water Quality During Treatment of Low Turbidity Water

The overall purpose of this research is to examine the impact of untreated sedimentation tank sludge water( USTSW) recycle on water quality during treatment of low turbidity water in coagulation—sedimentation processes. 950 m L of raw water and different concentrations of 50 m L USTSW are injected into six 1 000 m L beakers without coagulant.The results indicate that USTSW characterized as accumulated suspended solids and organic matter has active ingredients,which possess the equivalent function of coagulant. The optimal blended water turbidity is in the range of 10-20 NTU,within which USTSW recycle achieves the highest save coagulant rate. The mechanism of strengthening coagulation effect when USTSW recycle mainly depends on the chemical effect and physical effect. What is more,through scanning electron microscopy( SEM),it is found that the floc structures with USTSW recycle are more compact than those without USTSW recycle. Besides,the water quality parameters of color,NH3-N,CODMn,UV254,total aluminum,total manganese when USTSW recycle is better than the raw water without recycle,indicating that USTSW recycle can improve water quality with strengthening coagulation effect.

Actual Measurement of the Microclimate Environment of Green Spaces and Dynamic Simulation of Building Height in Xijing Community of Beijing

In this paper, three types of green spaces in Xijing Community in Shijingshan District of Beijing were selected for as the measuring points, the HOBO portable weather station was used to monitor the microclimate environmental changes in the same period and summarize the data of microclimate factors. The effectiveness of the simulation was verified by comparing the measured data with the simulated data obtained through ENVI-met. And strategies for microclimate adaptive design in residential areas were proposed according to the microclimate environmental characteristics of several green spaces.

Technology Demand Assessment of Adaption of Chinese Cities to Climate Change

Climate change adaptation is the process of preparing and actively adjusting to meet the climate change (negative effects and potential opportunities). Urban adaptation is aimed at the sensitivity level of risks and specific impacts of cities under the impact of climate change, and to develop policies and investment programs to reduce the vulnerability of cities to climate change risk. Urban adaptive action provides the basis and direction for the construction of urban resilience and sustainable development. Identifying the demand of adaption technologies, promoting the practical implementation of international technology transfer and reducing domestic emissions have important significance for the global response to climate change and improvement of the ability of urban adaptation. In this paper, through in-depth analysis on the concept and connotation of climate change, climate disasters and urban adaptation to climate change, the evaluation framework and steps of urban adaptation to climate change technology are determined, and six priority application technologies which can maximize the overall efficiency of sustainable development, improve the ability to adapt to climate change and at the same time reduce the cost at the greatest extent are identified.