Development and preliminary application of a method to assess river ecological status in the Hai River Basin,north China

The river ecosystem in the Hai River Basin（HRB）, an important economic region in China, is seriously degraded. With the aim of river restoration in the HRB, we developed a method to assess the river＇s ecological status and conducted a preliminary application of the method.The established method was a predictive model, which used macroinvertebrates as indicator organisms. The river＇s ecological status was determined by calculating the ratio of observed to expected values（O/E）. The method included ecoregionalization according to natural factors, and the selection of reference sites based on combinations of habitat quality and macroinvertebrate community. Macroinvertebrate taxa included Insecta,Crustacea, Gastropoda, and Oligochaeta, with 39 families and 95 genera identified in the HRB. The HRB communities were dominated by pollution tolerant taxa, such as Lymnaeidae, Chironomus, Limnodrilus, Glyptotendipes, and Tubifex. The average Shannon–Wiener index was 1.40 ± 0.5, indicating a low biodiversity. In the river length of 3.31 × 10^4 km, 55% of the sites were designated poor, with a bad ecological status. Among nine secondary river systems, Luan and Zi-ya had the best and worst river conditions,respectively. Only 17 reference site groups were selected for river management in the 41 ecoregions examined. This study lays the foundation for river restoration and related research in the HRB, and we anticipate further developments of this novel method.

Research on Ecological Space Planning Oriented Urban River Landscape Planning

Based on the generalized landscape perspective, regional connotation of urban river landscape is expanded. The area connotation of urban river landscape is expanded based on the generalized landscape perspective. In addition to natural and functional attributes, river landscape should be regarded as a regional space element based on heterogeneous space scale. First, as for research method system, the space research models(including ecological footprint, space planning, and landscape pattern index, etc.) coupled with different angle scales and interdisciplinary theory, are utilized to study different correlations and results formed by urban river landscape elements and other regional space elements from the perspective of the regional ecological space, and the overall development goal of the urban river landscape pattern based on the goals of the regional ecological space planning is obtained. Second, the oriented urban river landscape planning and the "M" type close-tonature design strategy are evaluated through the city function zoning orientation and micro-scale urban river landscape pattern index. The research realizes the compatibility of overall goals in terms of the regional ecology, the development of urban functional areas, and the river landscape planning, without losing micro difference and maneuverability based on the urban river landscape planning and design oriented strategy, which innovates the new approach of urban river landscape planning and design with sustainable and balanced development of regional resources, multi-scale, and multiple objectives.

Rural Domestic Sewage Treatment Model: Case Study Based on Dongying Section of the Yellow River Basin

The 20th National Congress of the Communist Party of China proposed to promote the improvement of urban and rural living environment and build livable and workable villages and beautiful villages. The development and challenges of rural domestic sewage treatment coexist. Based on the field investigation of 15 administrative villages in 3 districts and counties of Dongying City, there is a big gap between the development status of rural domestic sewage treatment and expectations. Investigate rural domestic sewage treatment cases in-depth, and condense four modes of primitive, developmental, mature and advanced in a variety of different rural domestic sewage treatment models for discussion, among which, the village sewage treatment work under the mature mode has achieved remarkable results, and is at the forefront of the current rural domestic sewage treatment. Through the multi-case analysis method, the practical dilemma of sewage treatment in different models of villages is summarized, and the feasible improvement path is explored, which contributes to the ecological protection and high-quality development of Dongying and the Yellow River Basin.

Community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary during water and sediment discharge regulation

The community characteristics of macrobenthos in the Huanghe（Yellow River） Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes（1-month） in macrobenthic community structure in response to water and sediment discharge regulation（WSDR） in 2011.Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances（5, 10, 20, and 40 km）from the mouth of the Huanghe Estuary before（mid-June）, during（early-July）, and after（mid-July） WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively.Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods（Annelida, Mollusca, Arthropoda, and Echinodermata）. However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982,demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term（3 decadal）and short term（1-month） impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.

A Study on Water Quality Monitoring in Urban Watercourse of Xinli River in Binzhou City

This paper aims to explore the pH,COD,ammonia nitrogen,total nitrogen,total phosphorus and other indices regarding Xinli River water in Binzhou City.The results show that the pH of the water quality index is between 7.3 and 7.8,slightly alkaline;the COD content of Xinli River is about 140-163 mg/L,and the COD pollution is serious in some water sections;the ammonia nitrogen content of Xinli River is 0.2-2.17 mg/L,the total nitrogen content is about 0.799-1.3 mg/L,the total phosphorus content is about 0.54-0.92 mg/L,suggesting that the water eutrophication is very serious.Due to the large amount of domestic sewage discharged into Xinli River without treatment,slow circulation of river water and other factors,the eutrophication is serious in the urban watercourse.

Spatial–temporal distribution and potential ecological risk assessment of nonylphenol and octylphenol in riverine outlets of Pearl River Delta, China

The aquatic environments of the Pearl River Delta in Southern China are subjected to contamination with various industrial chemicals from local industries. In this paper, the occurrence, seasonal variation and spatial distribution of alkylphenol octylphenol （OP） and nonylphenol （NP） in fiver surface water and sediments in the runoff outlets of the Pearl River Delta were investigated. NP and OP were detected in all water and sediment samples and their mean concentrations in surface water during the dry season ranged from 810 to 3366 ng/L and 85.5 to 581 ng/L, respectively, and those in sediments ranged from 14.2 to 95.2 ng/g dw and 0.4 to 3.0 ng/g dw, respectively. In surface water, much higher concentrations were detected in the dry season than those in the wet season. In sediments, the concentrations in the dry season were also mostly higher. High concentrations of NP and OP were found in Humen outlet, likely due to high levels of domestic and industrial wastewater discharges. An ecological risk assessment with the use of hazard quotient （HQ） was also carried out and the HQvalues ranged from 3.6 × 10^-5 to 35 and 64% of samples gave a HQ 〉 1, indicating that the current levels of NP and OP pose a significant risk to the relevant aquatic organisms in the region.

Research strategy for constructing a green infrastructure network based on spatial prioritization

The destruction of the ecological system caused by urban expansion has led to the environmental deterioration,cities have become increasingly vulnerable.In this study,six districts and counties along the Yellow River in Zhengzhou were selected as the study area.First,green infrastructure elements were extracted by morphological spatial pattern analysis.Then,outside the urban areas,we used connectivity analysis to evaluate the importance of core areas,adopted minimum cumulative resistance model to extract potential corridors,and identified the important corridors by using the gravity model.Finally,in the urban areas,we set up an evaluation system to assess the demands for ecosystem services.The results showed that:(1)Seven landscape types of green infrastructure be identified in study area.(2)There are 17 vital cores,136 potential corridors,and 24 vital corridors outside the urban areas.(3)The blocks with high demand for ecosystem services are mostly concentrated in the old blocks with dense populations and poor infrastructure,and there are 5 blocks with comprehensive high-demand.Based on identified importance for green infrastructure land space,and high-demand level for ecosystem services areas in this study,a green infrastructure net plan was proposed based on spatial conservation prioritisation.