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Investigation of environmental and land use impacts in forested permafrost headwaters of the Selenga-Baikal river system,Mongolia-Effects on discharge,water quality and macroinvertebrate diversity

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International Soil and Water Conservation Research 2021年第4期9卷 605-619页

作者： Martin Pfeiffer Georg Küstner Erdenetsetseg Erdenesukh Wolf von Tümpling Jürgen Hofmann Department of Biogeography University of BayreuthUniversitätsstraße 3095447 BayreuthGermany Department of Aquatic Ecosystem Analysis and Management(ASAM) Helmholtz Centre for Environmental Research-UFZBrückstraße 3a39114 MagdeburgGermany Department of Ecology National University of MongoliaBaga toiruu 47Ulaanbaatar 210646Mongolia Department of Animal Ecology and Tropical Biology BiocenterJulius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany National Dong Hwa University No.1Sec.2Da Hsueh Rd.ShoufengHualien 97401Taiwan Central Laboratory for Water Analytics&Chemometrics Helmholtz Centre for Environmental Research-UFZBrückstrasse 3a39114 MagdeburgGermany Büro für Integrierten Gewässerschutz-BiG Werner-Voß-Damm 54 b12101 BerlinGermany

Headwater streams play a major role for provision of ecosystem services,*** *** investigated a high-altitude headwater catchment of the Kharaa River(including 411st-order rivers)to understand the impact of land cover(especially forest cover),environment and human usage on runoff,chemical water quality and macroinvertebrate fauna in a river basin under discontinuous permafrost conditions in an arid,sparsely populated region of *** verify our hypotheses that different landuses and environmental impacts in permafrost headwaters influence water quality,we investigated 105 sampling sites,37 of them at intermittent stream sections without water *** was positively impacted by land cover types steppe,grassland and forest and negatively by shrubland,forest burnt by wild fires(indicating a reduction of permafrost)and *** quality was affected by altitude,longitude and latitude,shrub growth and water *** diversity of macroinvertebrates was driven by water temperature,iron content of the water,flow velocity,and subbasin size(adjusted R^(2)=0.54).Sample plots clustered in three groups that differed in water chemistry,macroinvertebrate diversity,species composition and *** study confirms that steppes and grasslands have a higher contribution to runoff than forests,forest cover has a positive impact on water quality,and diversity of macroinvertebrates is higher in sites with less nutrients and *** excellent ecological status of the upper reaches of the Kharaa is severely threatened by forest fires and human-induced climate change and urgently needs to be conserved.

关键词： Ecosystem services Ephemeroptera-Plecoptera-Trichoptera (EPT)complex GIS-based analysis IWRM-MoMo project Land use land cover(LULC) Natural reference state Runoff self-purification capacity Stream water chemistry

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Study of water renewal and sedimentation of a square harbor encapsulated in a coastal front with seawalls due to wind-induced hydrodynamic circulation

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International Journal of Sediment Research 2021年第3期36卷 373-383页

作者： Yiannis Savvidis Evangelos Keramaris InternationalHellenicUniversity DepartmentofEnvironmentalEngineering UniversityofThessaly DepartmentofCivilEngineering

In the current study in the middle of a coastal zone, a harbor basin in the form of a square area recessed to the front is considered. A breakwater of variable length and position offers protection from waves. The water renewal time and the self-purification capacity of the harbor under the influence of alongshore currents due to wind-induced water circulation of varying intensities were examined. Furthermore, the transport of particulate matter released from the upstream side of the coastal zone and the possible influence(via sedimentation) on the lateral basin was investigated. The current study was based on the use of a two-dimensional depth-averaged hydrodynamic model and a quasi-three-, dimensional transport model while the effect of partial closing of the harbor’s entrance was examined. The(1) adjustment and(2) validation of the reliability of the numerical model at a laboratory level were done using a recent research based on the use of a particle image velocimetry(PIV) measurements ensuring very good agreement between numerical and experimental results. The current study showed that the partial closing of the opening between the harbor basin and the extended coastal zone, with a breakwater of length equal to 1/3 of the opening, seems to be the most acceptable technical solution.

关键词： Coastal zone Numerical model PIV measurements Renewal time self-purification capacity Matter transport

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Impact of hydroelectric projects on river environment: Analysis of water quality changes in Ningxia Reach of Yellow River

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Water Science and Engineering 2008年第2期1卷 66-75页

作者： Sun Dongpo Lu Ruili Song Yongjun Yan Jun Faculty of Water Conservancy Engineering North China University of Water Conservancy and Electric Power Zhengzhou 450011 P. R. China School of Civil Engineering and Water Conservancy Ningxia University l~nchuan 750021 P. R. China

In this paper, the relationship between hydroelectric projects and the river environment is analyzed. Recently, the large-scale regulation of runoff by large hydroelectric projects in the Ningxia Reach of the Yellow River has altered natural runoff processes, causing an increase in the probability of low discharge and an overall adjustment of riverbed evolution and river characteristics. During low-flow years, the combined effects of these two changes can weaken the self-purification capacity and reduce the water environmental capacity of the river. This is one of the main reasons for the recent decrease of water quality in the Ningxia Reach. This research shows that it is necessary to implement river training projects to maintain stable flow paths, not only for adjusting river regimes and for flood control, but also for increasing the self-purification capacity and the water environmental capacity of the river. Methods and proposals for coordinating the operation of hydroelectric projects with the protection of the river environment are presented in the interest of promoting sustainable development.

关键词： runoff adjustment hydroelectric project self-purification capacity fluvial process water environmental capacity

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