Although numerous check dams have been constructed in many countries, and its effect on physical factors were well documented, only a few reports were available on its effect on biotic component in adjacent area. This...Although numerous check dams have been constructed in many countries, and its effect on physical factors were well documented, only a few reports were available on its effect on biotic component in adjacent area. This research aims to address effects of the check dam on reptile assemblage in an ephemeral stream based on an assumption that reptile live in the stream and adjacent area may be susceptible to prolonged hydroperiod after check dam construction. Ten stream transects and 40 terrestrial strip transects, including 5, 10, 25, and 50 m from the stream, were used to monitor reptile diversity and composition in a deciduous forest of northern Thailand during April 2009 to February 2011. Physical factors related to water pattern in the stream and the terrestrial habitats were also collected. Results on physical factors indicated that the water pattern and soil moisture in the stream, as well as leaf litter moisture in the terrestrial habitat were increased as a result of the check dam. However, rarefaction curve indicated that reptile diversity was not significantly different between pre- and post-check dam periods in every transect. Moreover, Morisita’s index of similarity indicated that reptile composition between pre- and post-check dam periods was approximately the same (86% - 100%). These results indicated that reptile assemblage was not affected by the check dam. It can be concluded based on data of one year after the check dam construction that check dam can effectively prolong water and moisture to the habitat with minimal effect on reptile assemblage in the area.展开更多
Japan ranks fifth in the world for the number of large dams. Environmental impacts of large dams are known, such as enormous losses of water or disruption of fish spawning, however, impacts of the dams on their up str...Japan ranks fifth in the world for the number of large dams. Environmental impacts of large dams are known, such as enormous losses of water or disruption of fish spawning, however, impacts of the dams on their up streams are functions of topography of the up stream. Haizuka Dam is located in Hiroshima Prefecture, Japan and its implementation will start in 2006. This large dam influences its up stream through dam making activities, which occurs in order and with different spatial presences that were categorized into chronological and spatial impacts. In this case study, spatial impacts were further divided into horizontal and vertical ones. The horizontal impacts were identified as new roads, diversion tunnel, dam lake, and submerged cultivated land, while vertical impacts were recognized as submerged historical monuments, slope protections, dam body, and deforested area in the reservoir. There were convergences of spatial and temporal impacts, however, the extent of the impacts was limited to the lake boundary.展开更多
The main purpose of this study was to determine the changes in the water quality of Melendiz and Karasu streams, which recharge the Mamasin dam, and to evaluate its environmental impacts on the dam site that provides ...The main purpose of this study was to determine the changes in the water quality of Melendiz and Karasu streams, which recharge the Mamasin dam, and to evaluate its environmental impacts on the dam site that provides drinking water and irrigation demand in Aksaray city in the Central Anatolia of Turkey. The field researches were focused on estimating the main sources of contamination, determining and evaluating the changes in the water quality due to the direct wastewater discharges into the Melendiz and Karasu rivers, which recharge the Mamasin dam sites. During the study, water samples were collected from Melendiz and Karasu stream and Mamasin dam, and then, the physical and chemical analyses of water samples were conducted. The relevant in-situ and laboratory analyses were carried out during the dry and wet seasons. The results of the analyses showed that in term of the surface water quality criteria in terms of NO3-N value of both rivers and dam waters, the water quality is always considered as the 1st class in Melendiz stream, the 2nd class in Karasu stream and the 3rd class in Mamasin dam lake. Whereas, in terms of NO4-N values of both rivers and dam waters, the water quality is always considered as the 1st class in Melendiz stream, the 2nd-3rd class in Karasu stream. The total organic carbon （TOC） range for Karasu river is usually from 20 mg/L to 40 mg/L. The high value of organic matter in the Karasu stream can be explained by the availability of intensive green wetlands around this water resource. Finally, the Ministry of Forest and Water Authority give some suggestions for estimating protection zones of Melendiz stream and Mamasin basin＇s area, such as using the results of environmental tracers to investigate the agricultural contamination, including more sophisticated applications of multiple-tracer analyses to evaluate the travel time of contaminants and estimate the boundary of protection zones.展开更多
Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the...Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the longitudinal gradient from headwater to downstream, fish species richness and abundance increased gradually, but then decreased significantly at the lower reaches. The highest species richness and abundance were observed in August and the lowest in February. Based on analysis of similarities （ANOSIM）, fish assemblages were significantly different in spatial variation but not in temporal variation. Although differences were observed both among sites and among stream orders, the lower R value in order-variation suggested stream order was not the optimal factor explaining the spatial variation of fish assemblages. In addition, dam construction did not significantly alter fish assemblages in the sites adjacent to and immediately downstream to dams. Using cluster analysis and non-metric Multi Dimensional Scaling analysis （NMS）, assemblages were separated into three groups at a Bray-Curtis similarity value of 42%： the upper, middle and lower groups. Following analysis of similarity percentages of species contributions （SIM- PER）, shifts in occurrence or abundance of S. curriculus, Z. platypus, R. bitterling and A. fasciatus contributed most to the differences amongst the three groups. Standard Deviation Redundancy Analysis （RDA） suggested that habitat structure （such as elevation, substrate, and flow velocity） contributed to the spatial and temporal pattem of fish assemblages in the Puxi Stream. In conclusion, the fish assemblages in Puxi Stream presented significant spatial but not temporal variation. Human disturbance has perhaps induced the decrease in species diversity in the lower reaches. However, no significant change was observed for fish assemblages in sites far from and immediately downstream from low-head dams [Current Zoology 56 （6）： 670-677, 2010].展开更多
文摘Although numerous check dams have been constructed in many countries, and its effect on physical factors were well documented, only a few reports were available on its effect on biotic component in adjacent area. This research aims to address effects of the check dam on reptile assemblage in an ephemeral stream based on an assumption that reptile live in the stream and adjacent area may be susceptible to prolonged hydroperiod after check dam construction. Ten stream transects and 40 terrestrial strip transects, including 5, 10, 25, and 50 m from the stream, were used to monitor reptile diversity and composition in a deciduous forest of northern Thailand during April 2009 to February 2011. Physical factors related to water pattern in the stream and the terrestrial habitats were also collected. Results on physical factors indicated that the water pattern and soil moisture in the stream, as well as leaf litter moisture in the terrestrial habitat were increased as a result of the check dam. However, rarefaction curve indicated that reptile diversity was not significantly different between pre- and post-check dam periods in every transect. Moreover, Morisita’s index of similarity indicated that reptile composition between pre- and post-check dam periods was approximately the same (86% - 100%). These results indicated that reptile assemblage was not affected by the check dam. It can be concluded based on data of one year after the check dam construction that check dam can effectively prolong water and moisture to the habitat with minimal effect on reptile assemblage in the area.
文摘Japan ranks fifth in the world for the number of large dams. Environmental impacts of large dams are known, such as enormous losses of water or disruption of fish spawning, however, impacts of the dams on their up streams are functions of topography of the up stream. Haizuka Dam is located in Hiroshima Prefecture, Japan and its implementation will start in 2006. This large dam influences its up stream through dam making activities, which occurs in order and with different spatial presences that were categorized into chronological and spatial impacts. In this case study, spatial impacts were further divided into horizontal and vertical ones. The horizontal impacts were identified as new roads, diversion tunnel, dam lake, and submerged cultivated land, while vertical impacts were recognized as submerged historical monuments, slope protections, dam body, and deforested area in the reservoir. There were convergences of spatial and temporal impacts, however, the extent of the impacts was limited to the lake boundary.
文摘The main purpose of this study was to determine the changes in the water quality of Melendiz and Karasu streams, which recharge the Mamasin dam, and to evaluate its environmental impacts on the dam site that provides drinking water and irrigation demand in Aksaray city in the Central Anatolia of Turkey. The field researches were focused on estimating the main sources of contamination, determining and evaluating the changes in the water quality due to the direct wastewater discharges into the Melendiz and Karasu rivers, which recharge the Mamasin dam sites. During the study, water samples were collected from Melendiz and Karasu stream and Mamasin dam, and then, the physical and chemical analyses of water samples were conducted. The relevant in-situ and laboratory analyses were carried out during the dry and wet seasons. The results of the analyses showed that in term of the surface water quality criteria in terms of NO3-N value of both rivers and dam waters, the water quality is always considered as the 1st class in Melendiz stream, the 2nd class in Karasu stream and the 3rd class in Mamasin dam lake. Whereas, in terms of NO4-N values of both rivers and dam waters, the water quality is always considered as the 1st class in Melendiz stream, the 2nd-3rd class in Karasu stream. The total organic carbon （TOC） range for Karasu river is usually from 20 mg/L to 40 mg/L. The high value of organic matter in the Karasu stream can be explained by the availability of intensive green wetlands around this water resource. Finally, the Ministry of Forest and Water Authority give some suggestions for estimating protection zones of Melendiz stream and Mamasin basin＇s area, such as using the results of environmental tracers to investigate the agricultural contamination, including more sophisticated applications of multiple-tracer analyses to evaluate the travel time of contaminants and estimate the boundary of protection zones.
基金supported by the National Basic Research Program of China (2009CB119200)Anhui Provincial Natural Science Foundation (090413080)Natural Science Foundation of Anhui Education Bureau (KJ2008B211,KJ2009A110)
文摘Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the longitudinal gradient from headwater to downstream, fish species richness and abundance increased gradually, but then decreased significantly at the lower reaches. The highest species richness and abundance were observed in August and the lowest in February. Based on analysis of similarities （ANOSIM）, fish assemblages were significantly different in spatial variation but not in temporal variation. Although differences were observed both among sites and among stream orders, the lower R value in order-variation suggested stream order was not the optimal factor explaining the spatial variation of fish assemblages. In addition, dam construction did not significantly alter fish assemblages in the sites adjacent to and immediately downstream to dams. Using cluster analysis and non-metric Multi Dimensional Scaling analysis （NMS）, assemblages were separated into three groups at a Bray-Curtis similarity value of 42%： the upper, middle and lower groups. Following analysis of similarity percentages of species contributions （SIM- PER）, shifts in occurrence or abundance of S. curriculus, Z. platypus, R. bitterling and A. fasciatus contributed most to the differences amongst the three groups. Standard Deviation Redundancy Analysis （RDA） suggested that habitat structure （such as elevation, substrate, and flow velocity） contributed to the spatial and temporal pattem of fish assemblages in the Puxi Stream. In conclusion, the fish assemblages in Puxi Stream presented significant spatial but not temporal variation. Human disturbance has perhaps induced the decrease in species diversity in the lower reaches. However, no significant change was observed for fish assemblages in sites far from and immediately downstream from low-head dams [Current Zoology 56 （6）： 670-677, 2010].
基金supported by the National Basic Research Program of China(‘‘973’’Program,No.2013CB035906)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.51621092)Heilongjiang Provincial Major Scientific and Technological Project of Applied Technology Research and Development Plan(No.GA14A501)
