Use snail ecology to assess dam impact

Abstract This study documents major changes in streamflow hydrology over the Kolyma watershed due to climatic variations and human impacts. Streamflow seasonal cycles over the basin are characteristic of the northern region, with the lowest runoff in April and peak flow in June. Analyses of monthly flows and trends show that reservoir construction and operation have considerably affected streamflow regimes. Comparisons of mean monthly discharge records between pre- and post-1986 dam periods indicate that the mid–lower basin (downstream of the dam) experienced significant increase in low flows and decrease in peak flows after dam construction. For example, mean monthly flows during the post-dam period at the Ust’-Srednekan station (located 1423 km downstream of the dam) has strongly increased by about 205 m3 s−1 (or 522%–3157%) during December–April, and decreased by 133 m3 s−1 (41%) in June. Long-term monthly discharge data reveal an overall increase in streamflow during low flow seasons; the increase is greater for the stations located downstream of the dam. The Srednekolunsk station (1720 km from dam) shows low flow increase ranging from 130 (43%) to 268 m3 s−1 (454%) during November–April, and high discharge decrease by 2550 to 519 m3 s−1 during June–August in the post-dam era (1986–2000). These changes in flow patterns are mainly caused by reservoir regulation, as reservoirs release water in winter for power generation and store water in summer for flood control. Dam impact on flow regimes and changes are visible along the main river trunk; thus, the cold season discharge increase at the basin outlet is primarily the result of reservoir regulation. Annual discharge records show different changes within the Kolyma basin, with moderate increases in the upper basin and weak decreases in the mid–lower basin. Overall annual discharge near the basin outlet has decreased by 1.5% during 1978–2000. This study emphasizes the importance of human activities (particularly reservoirs) on seasonal and regional hydrology changes and points to the need to further examine natural causes and human impacts over other high-latitude watersheds.

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Macrofauna Communities In The Marine Section Of Ba Lai Estuary, Ben Tre Province

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v4i1.985 ◽

2020 ◽

Vol 4 (1) ◽

pp. first

Author(s):

Thai Thanh Tran ◽

Nguyen Thi My Yen ◽

Tran Thi Hoang Yen ◽

Pham Thanh Luu ◽

Ngo Xuan Quang

Keyword(s):

Distribution Pattern ◽

Environmental Changes ◽

Economic Value ◽

River Mouth ◽

Wiener Index ◽

Diversity Indices ◽

Left Bank ◽

Dam Impact ◽

The Right ◽

Macrofauna Communities

Macrofauna communities in Ba Lai estuary, Ben Tre province were investigated in three transects from the river mouth to the dam construction, in the order from the right, middle to the left bank. The community characteristics such as the composition, density, biodiversity, and the distribution pattern were recorded and analyzed. The results showed that the macrofauna communities in the marine section part of Ba Lai river consisted of 76 species belonging to 3 phyla: Mollusca, Arthropoda, and Annelida. In this study, it was notable that a high economic value of Ben Tre Clam (Meretrix lyrata) presented in the Ba Lai estuary with a density of 3160 ind /m2 on the right bank. The highest density was recorded in the mid transect of the river, followed by the right and the left (2907 +/- 4298, 1813 +/- 2056; 1730 +/- 1590 ind /m2, respectively). The biodiversity of macrofauna communities was measured by the species richness, Shannon – Wiener index, and Pielou's evenness. Diversity indices illustrated that the middle bank had the highest biodiversity. However, the statistical analysis results showed that the density and biodiversity indices in these transects were not significantly different. The main reason might be due to Ba Lai dam impact, which has been accreting alluvial, causing these locations gradually being similar in the environmental conditions. The distribution pattern of benthic macrofauna communities in this study should be considered as a typical distribution of benthos in rivers affected by dams. Macrofauna communities which gave rapid responses to environmental changes should be used as a bioindicator.

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Dworshak Dam Impact Assessment and Fishery Investigation and Trout, Bass and Forage Species: Combined Project Completion Report.

10.2172/919890 ◽

1992 ◽

Cited By ~ 1

Author(s):

Melo Maiolie ◽

David P. Statler ◽

Steve Elam

Keyword(s):

Impact Assessment ◽

Project Completion ◽

Dam Impact ◽

Forage Species

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Berbagai Dampak Hukuman (Punishment) dalam Pendidikan Terhadap Peserta Didik

Jurnal Inovatif Ilmu Pendidikan ◽

10.23960/jiip.v3i2.23232 ◽

2022 ◽

Vol 3 (2) ◽

pp. 161-174

Author(s):

Susmita Suharjo ◽

Farid Pribadi

Keyword(s):

Secondary Data ◽

Journal Articles ◽

Educational Tools ◽

Profound Impact ◽

Dam Impact ◽

The Subject ◽

The Impact

All humans are obliged to be educated. The objective of the subject of education is to improve the quality of oneself in order to become a complete person. In achieving that goal, education has tools to support its smooth running. One of the educational tools punishment which is punishment, has a profound impact on learners. The punishment in education is the punishment given to the learner aimed at edifying the offending learner. After the sentencing, the impact of the learner, the impact of each learner varied, to which in the study, researchers tried to dig up information on the impact of the punishment on the learner by using literature and secondary data, that is, data from previously existing sources such as journal articles, books, and scripts. Then the data was qualitatively analyzed using the miles and hubermans' methods. Analysis has resulted in some effect on learners. The effects are positive and dam impact.

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Temporal variability of fish larvae assemblages: influence of natural and anthropogenic disturbances

Neotropical Ichthyology ◽

10.1590/s1679-62252012000400017 ◽

2012 ◽

Vol 10 (4) ◽

pp. 837-846 ◽

Cited By ~ 12

Author(s):

David A. Reynalte-Tataje ◽

Evoy Zaniboni-Filho ◽

Andrea Bialetzki ◽

Angelo A. Agostinho

Keyword(s):

Water Flow ◽

Temporal Variability ◽

Fish Larvae ◽

River Mouth ◽

Temporal Distribution ◽

Dam Impact ◽

Environment Variables ◽

Lower Temperature ◽

River Mouths ◽

Second Period

Natural and induced disturbances greatly influence the temporal distribution of ichthyoplankton abundance. This study assesses and compares the temporal variability of fish larvae assemblages in controlled and free environments to determine the influence of environment variables on the main taxa in these systems. The study was conducted at the Chapecó (without dam impact) and Ligeiro (with dam impact) river mouths, which are located in the upper Uruguay River. Samples were made between October 2001 and March 2004 during three reproductive periods. The larvae assemblages were composed of small and medium-sized Characiformes and Siluriformes. The variation in the distribution of larvae was mainly temporal (>85%). When the three reproductive periods were compared, it was observed in the second period, characterized by a larger water flow and a lower temperature, that there was a reduction in abundance, a lower number of taxa, an absence of stages in post-flexion and a high dissimilarity in larvae assemblage structure. In general, the environmental variables of water flow and temperature most influenced the distribution of egg and larvae abundance. In the studied area, a smaller temporal variability was observed in the structure of larvae assemblages at the sampling sites in the Chapecó River mouth than in in the Ligeiro River mouth under the influence of dams.

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