Estimation of river ecosystem biodiversity based on the Chao estimator

2017 ◽  
Vol 27 (1) ◽  
pp. 205-216 ◽  
Author(s):  
Anna Budka ◽  
Agnieszka Łacka ◽  
Krzysztof Szoszkiewicz
Ecoscience ◽  
2021 ◽  
pp. 1-20
Author(s):  
Christian Nozais ◽  
Warwick F. Vincent ◽  
Claude Belzile ◽  
Michel Gosselin ◽  
Marie-Amélie Blais ◽  
...  

2021 ◽  
Vol 13 (11) ◽  
pp. 6287
Author(s):  
Suyeon Kim ◽  
Sang-Woo Lee ◽  
Se-Rin Park ◽  
Yeeun Shin ◽  
Kyungjin An

It is imperative to develop a methodology to identify river impairment sources, particularly the relative impact of socioeconomic sources, to enhance the efficiency of various river restoration schemes and policies and to have an internal diagnosis system in place. This study, therefore, aims to identify and analyze the relative importance of the socioeconomic factors affecting river ecosystem impairment in South Korea. To achieve this goal, we applied the Analytical Hierarchy Process (AHP) to evaluate expert judgement of the relative importance of different socioeconomic factors influencing river ecosystem impairment. Based on a list of socioeconomic factors influencing stream health, an AHP questionnaire was prepared and administered to experts in aquatic ecology. Our analysis reveals that secondary industries form the most significant source of stream ecosystem impairment. Moreover, the most critical socioeconomic factors affecting stream impairment are direct inflow pollution, policy implementation, and industrial wastewater. The results also suggest that the AHP is a rapid and robust approach to assessing the relative importance of different socioeconomic factors that affect river ecosystem health. The results can be used to assist decision makers in focusing on actions to improve river ecosystem health.


2021 ◽  
pp. 117538
Author(s):  
Jiahui Shang ◽  
Wenlong Zhang ◽  
Xinqi Chen ◽  
Yi Li ◽  
Lihua Niu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabella Schalko ◽  
Ellen Wohl ◽  
Heidi M. Nepf

AbstractWood is an integral part of a river ecosystem and the number of restoration projects using log placements is increasing. Physical model tests were used to explore how the wood position and submergence level (discharge) affect wake structure, and hence the resulting habitat. We observed a von-Kármán vortex street (VS) for emergent logs placed at the channel center, while no VS formed for submerged logs, because the flow entering the wake from above the log (sweeping flow) inhibited VS formation. As a result, emergent logs placed at the channel center resulted in ten times higher turbulent kinetic energy compared to submerged logs. In addition, both spatial variation in time-mean velocity and turbulence level increased with increasing log length and decreasing submergence level. Submerged logs and logs placed at the channel side created a greater velocity deficit and a longer recirculation zone, both of which can increase the residence time in the wake and deposition of organic matter and nutrients. The results demonstrate that variation in log size and degree of submergence can be used as a tool to vary habitat suitability for different fish preferences. To maximize habitat diversity in rivers, we suggest a diverse large wood placement.


Sign in / Sign up

Export Citation Format

Share Document