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.

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.

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.