The Construction of Evaluation System for the Initial Rainwater Reduction Facilities in Shanghai

2014 ◽  
Vol 1073-1076 ◽  
pp. 1017-1022
Author(s):  
Xiao Kang Wu ◽  
Chun Ming Ye ◽  
Yong Lin Li ◽  
Jia Wu

Initial rainwater pollution is an important non-point source pollution of urban drainage systems. The application of storage tanks and other reduction facilities has play a key role in reducing first flush pollution. Because of the lack of scientific evaluation system, the evaluation is disorderly and there are many operational problems. This case is based on the reduction facilities research of Suzhou Creek in Shanghai, through which a standard evaluation system and implementation procedure are built to perfect the incomprehensive and unscientific system, so that the efficiency can be improved.

2011 ◽  
Vol 356-360 ◽  
pp. 771-776
Author(s):  
Cheng Wu ◽  
Guo Chun Deng ◽  
Yan Li ◽  
Zhi Ying Li ◽  
Shu Hua Yang

A rapid quantitative risk evaluation system of non-point source pollution (NPSP), based on comprehensive consideration of various factors such as topographic features, land use construction, annual mean precipitation, soil erosion characteristics and pollutant removal cost, was constructed using an Spatial Analysis Module of GIS on watershed scale. We investigated the risk pattern of NPSP in the Dianchi Lake Watershed using the rapid risk assessment system. The results indicated that NPSP risk pattern showed the arc or normal distribution trend in the Dianchi Lake Basin, namely the medium risk area of NPSP is the largest (about 1311 km2). Moreover, the spatial difference of high risk NPSP pattern is remarkable: the high risk region for NPSP was primarily in the 10 km range of the southern and eastern parts and the 5 km range of western part around the Dianchi Lake.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 966 ◽  
Author(s):  
Minji Park ◽  
Young Soon Choi ◽  
Hyung Jin Shin ◽  
Inhong Song ◽  
Chun Gyeong Yoon ◽  
...  

Three watersheds in Korea (Dochoncheon, Gongjicheon, Seolseongcheon) with different land cover characteristics were selected for non-point source pollution monitoring. Event mean concentration (EMC) was calculated, and runoff characteristics were compared through first-flushing and statistical analyses. The mean of the water quality parameters was the highest in Seolseongcheon during dry days among the three watersheds. EMCs of biochemical oxygen demand (BOD) and total nitrogen (TN) were higher in Dochoncheon and Gongjicheon during rainy days, respectively. The upper Seolseongchun watershed showed overall greater values of chemical oxygen demand (COD), suspended solids (SS), total organic carbon (TOC), and total phosphorus (TP). First-flush analyses indicated that SS had the strongest and TN had the weakest effects on the first flush. BOD was the highest in Dochoncheon (urban watershed) and increased with increased number of antecedent dry days. Rainfall intensity appeared to affect SS runoff strongly in Gongjicheon and Seolseongcheon. COD showed strong correlation with SS and TOC in all watersheds, and organic matter (COD and TOC) demonstrated high factor loads during dry and rainy days. Thus, organic matter–related factors were classified as the major factors in pollutant loads. TP and TN were separately classified during dry days in Gongjicheon and Seolseongcheon, whereas these were the secondary factors during rainfall when the influence of non-point pollution was substantial. Cluster analyses showed that the monitoring sites in Dochoncheon and Gongjicheon watersheds were closer than Seolseongcheon. As a result of the comparison of non-point source pollution runoff in the three watersheds, it was difficult to explain the non-point source pollution runoff by specific characteristics such as land cover. For science-based management of non-point pollution, it is necessary to obtain additional survey data considering the climatic, geographical and major industries.


2012 ◽  
Vol 209-211 ◽  
pp. 2023-2026
Author(s):  
An Ning Suo ◽  
Hua Ru Wang ◽  
Yuan Bin Fu

Four indices which include surface runoff, soil erosion, agricultural nutrient loss, human and animal feces were selected and method to evaluate risk of non-point source pollution in watershed was constructed based on GIS. As a case, non-point source pollution in Dayanghe was evaluated. Results showed that very high risk area of non-point source pollution accounted for 3.41% area of the watershed, mainly located in farmland with steep slope along upper valley of the watershed. High risk area of non-point source pollution was located in farmland and human settlement placecs, accounted for 16.40% area of the watershed. Areas with low risk of non-point source pollution was riverbeds, shrub and grassland in eastern and western hilly with steep slope. Areas with lower risk of non-point source pollution located in middle of the watershed and accounted for 60.55% area. GIS-based risk evaluation system of non-point source pollution can reflect real map of pollution in the Dayanghe watershed and give implication for protection plan.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1955
Author(s):  
Mingxi Zhang ◽  
Guangzhi Rong ◽  
Aru Han ◽  
Dao Riao ◽  
Xingpeng Liu ◽  
...  

Land use change is an important driving force factor affecting the river water environment and directly affecting water quality. To analyze the impact of land use change on water quality change, this study first analyzed the land use change index of the study area. Then, the study area was divided into three subzones based on surface runoff. The relationship between the characteristics of land use change and the water quality grade was obtained by grey correlation analysis. The results showed that the land use types changed significantly in the study area since 2000, and water body and forest land were the two land types with the most significant changes. The transfer rate is cultivated field > forest land > construction land > grassland > unused land > water body. The entropy value of land use information is represented as Area I > Area III > Area II. The shift range of gravity center is forest land > grassland > water body > unused land > construction land > cultivated field. There is a strong correlation between land use change index and water quality, which can be improved and managed by changing the land use type. It is necessary to establish ecological protection areas or functional areas in Area I, artificial lawns or plantations shall be built in the river around the water body to intercept pollutants from non-point source pollution in Area II, and scientific and rational farming in the lower reaches of rivers can reduce non-point source pollution caused by farming.


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