The ecological status of the Welala and Shesher Wetlands, on the eastern side of Lake Tana, were studied during pre-rainy, main-rainy, post-rainy and dry seasons from May 2009 to January 2010. Species composition, div...The ecological status of the Welala and Shesher Wetlands, on the eastern side of Lake Tana, were studied during pre-rainy, main-rainy, post-rainy and dry seasons from May 2009 to January 2010. Species composition, diversity and abundance of macrophytes, benthic macro-invertebrates and birds were assessed and physico-chemical parameters were measured. Phosphate and silicate concentrations, conductivity, TDS and turbidity varied significantly (p 0.05) between the two wetlands. The values for dissolved oxygen and pH ranged between 4.8 - 7.8 mg/l and 6.7 - 7.6, respectively. The values for nitrate and phosphate ranged between 0.2 - 3.1 mg/l and 0.2 - 3.3 mg/l, respectively. A total of 274 benthic macro-invertebrate individuals belonging to 5 families were collected, 32, 699 individual birds belonging to 62 species were enumerated and 13 species of macrophytes were identified. The two wetlands are shrinking at an alarming rate, mainly because of unsustainable farming practices and a huge irrigation project on Ribb River which is at presently under construction. Farming practices include draining and pumping of water for irrigation and expansion of farmland at the cost of the wetlands. The construction of a dam in Ribb River prevents overflow from Ribb River into the wetlands and disrupts the connection with Lake Tana which is vital for the survival of these two wetlands. We conclude that the Welala and Shesher Wetlands are valuable wetlands which need urgently protection.展开更多
The traditional way of assessing water quality of water bodies is through measurement of biological, physical and chemical parameters. However, such assessments only reflect the concentration of pollutants at the time...The traditional way of assessing water quality of water bodies is through measurement of biological, physical and chemical parameters. However, such assessments only reflect the concentration of pollutants at the time of sampling not periodic pollution events. The goal of the study was to evaluate the river health using the macro-invertebrates that are found within the Mucheke and Shagashe rivers of Masvingo City as water quality monitors. The South African Scoring System (SASS 5) was used to score using the sensitivity of macro-invertebrates to levels of pollution in the two river systems. The data collection process was carried in April 2017 at four sampling sites using the kick sampling method and results validated by testing the physical, chemical and biological characteristics of the water and comparing them with the macro-invertebrates score. Results showed that the mean sensitivity score of macro-invertebrates showed variations depending on the selected site. Sample sites B2 and A2 downstream of the two river systems show high levels pollution tolerant macro-invertebrates as compared to sites A1 and B1 that are on the upper course and have more of pollution sensitive macro-invertebrates. On validation, to a large extent the levels of pollution indicated by macro-invertebrates were found to be congruent to the levels of pollution indicated by the physical, chemical and biological parameters. The research concludes that the presence of specific types of macro-invertebrates can be used to assess the levels of pollution in Mucheke and Shagashe rivers of Masvingo City.展开更多
Reference conditions having no or only minor anthropogenic disturbances, are a basic requirement for ecological studies in rivers. To study ecological impact of a dam, two sites were pre-classiifed as reference or lea...Reference conditions having no or only minor anthropogenic disturbances, are a basic requirement for ecological studies in rivers. To study ecological impact of a dam, two sites were pre-classiifed as reference or least disturbed in the Andhi Khola River, Nepal, using Rapid Field Bioscreening （RFB） protocol. Biological （macroinvertebrates） and physico-chemical samples were collected in the month of January and February 2013. Multi-habitat sampling （MHS） was employed in sample collection of macro-invertebrates fauna. Validation of the pre-classiifed sites was done using several indices viz. Nepalese biotic score （NEPBIOS）, Biological monitoring working party （BMWP）, Hindu-Kush Himalayan biotic score （HKHBIOS）, Hilsenhoff （HILSENHOFF） ＆ National Sanitation Foundation Water Quality Index （NSFWQI）. The NEPBIOS, HKHBIOS, HILSENHOFF, RFB ＆ NSFWQI indices predicted the river quality at al two sites as good with quality class Ⅱ. Only BMWP/ASPT water quality index predicted the river quality at al two sites as Excelent with quality class Ⅰ. Hence preselected sites with quality of rank Ⅱ i.e. good qualities were validated as reference sites. The study demonstrated that the multi-metric approach is suitable for application in the monitoring and assessment of rivers where dams are built to produce hydropower.展开更多
永定河是京津冀区域重要水源涵养区和生态屏障,为了解永定河水系的水生态健康状况,2016年对永定河水系大型底栖动物进行调查,共布设样点30个,采集到底栖动物38种,其中水生昆虫33种(摇蚊科16种),环节动物门3种,软体动物2种。从耐污值(Tol...永定河是京津冀区域重要水源涵养区和生态屏障,为了解永定河水系的水生态健康状况,2016年对永定河水系大型底栖动物进行调查,共布设样点30个,采集到底栖动物38种,其中水生昆虫33种(摇蚊科16种),环节动物门3种,软体动物2种。从耐污值(Tolerance Value,TV)看,TV≤3的敏感类群所占百分比为13.2%,TV≥7的耐污类群所占百分比为44.7%。从类群出现频率看,出现频率最高的3个种分别为霍甫水丝蚓(Limnodrilus hoffmeisteri)、德永雕翅摇蚊(Glyptotendipes tokunagai)和云集多足摇蚊(Polypedilum nubifer),分别为46.7%、40.0%和36.7%,3个物种均为耐污值较高的种类。采用底栖动物完整性指数(Benthic Index of Biotic Integrity,B-IBI)方法评价永定河水系生态健康状况。通过分布范围分析、判别能力检验及相关性分析等,确定永定河水系生态状况评价B-IBI的核心指标体系,包括总分类单元数、摇蚊分类单元数和BI指数(Botic Index)3个指标。根据比值法,以参照点25%分位数确定永定河水系底栖动物完整性评价标准。根据参照点25%分位数确定永定河水系底栖动物完整性评价标准,即B-IBI>2.13为健康,1.60~2.13为亚健康,1.06~1.60为一般,0.53~1.06为较差,0~0.53为极差。B-IBI评价结果显示,永定河水系6.7%河段处于健康状态,23.3%河段处于亚健康状态,36.7%河段处于一般状态,20.0%河段处于较差和13.3%处于极差状态。除官厅水库坝上和宁车沽闸下外,其余样点的底栖动物完整性均受到不同程度的损害,表明永定河水系水体的健康状况整体不容乐观。展开更多
应用大型底栖动物生物完整性指数(Benthic Index of Biological Integrity,B-IBI)评价河流健康已成为河流生态系统管理的重要方法。根据2010年5月对浑河流域62个采样点的底栖动物调查数据,基于采样点的水质等级、栖息地质量综合评估指...应用大型底栖动物生物完整性指数(Benthic Index of Biological Integrity,B-IBI)评价河流健康已成为河流生态系统管理的重要方法。根据2010年5月对浑河流域62个采样点的底栖动物调查数据,基于采样点的水质等级、栖息地质量综合评估指数、人类干扰强度和河岸土地利用评估等标准,选择同属于辽河水系的太子河流域的8个采样点作为参照点,构建浑河流域B-IBI生物完整性指数。通过对34个生物参数的分布范围检验、判别能力分析以及相关性检验,最终确定浑河流域B-IBI生物完整性指数由总分类单元数、EPT(蜉蝣目Ephemeroptera、襀翅目Plecoptera、毛翅目Trichoptera)相对丰度、耐污类群相对丰度、最优势类群分类单元数、直接收集者相对丰度以及香农威纳多样性指数6个参数构成。根据各参数值随干扰增强的变化趋势,采用比值法计算各指标的分值和评价标准。结果表明:浑河流域B-IBI平均得分为2.56,河流健康状态处于一般状态;62个采样点中,9个处于健康状态,13个处于亚健康状态、22个处于一般状态、10个处于差状态,8个处于极差状态;从流域空间尺度上来看,河流健康状态从上游区到下游区逐渐变差。相关性分析表明,B-IBI与水温、电导、溶解性固体总量、硝酸盐、总氮、五日生化需氧量等水环境指标呈现显著负相关,表明B-IBI指数对于水质污染具有较好的指示性作用。综上所述,浑河流域由于受城市工业区的分布影响,大型底栖动物生物完整性呈现出明显的空间分布差异,上游区河流生物完整性较好、中下游底栖动物群落呈现出明显的退化趋势。展开更多
为了了解大清河水系生态健康状况,在该水系的河流、湖泊和水库布设了20个采样点,分别于2018年5月和9月,在各采样点,对大型底栖动物进行了采样调查;采用大型底栖动物完整性指数(benthic index of biotic integrity,B-IBI)方法,对大清河...为了了解大清河水系生态健康状况,在该水系的河流、湖泊和水库布设了20个采样点,分别于2018年5月和9月,在各采样点,对大型底栖动物进行了采样调查;采用大型底栖动物完整性指数(benthic index of biotic integrity,B-IBI)方法,对大清河水系水体健康状况进行了评价;通过分布范围分析、箱线图和相关分析等方法,确定大清河水系大型底栖动物完整性指数评价体系的主要指标,包括总分类单元数、优势类群数量所占百分比、摇蚊科(Chironomidae)数量所占百分比和敏感类群生物量;根据比值法,以参考点的25%分位数值,确定大清河水系大型底栖动物完整性评价体系的评价标准。研究结果表明,在20个采样点,共采集到大型底栖动物46种,包括扁形动物门1种,环节动物门3种,软体动物门6种和节肢动物门36种(其中有水生昆虫30种);耐污值≤3的敏感类群数量占全部类群数量的16.8%,耐污值≥7的耐污类群数量占42.9%;出现频率最高的3种物种为霍甫水丝蚓(Limnodrilus hoffmeisteri)、中华摇蚊(Chironomus sinicus)和德永雕翅摇蚊(Glyptotendipes tokunagai),其出现频率分别为45%、35%和30%,3种物种的耐污值都较高;大型底栖动物完整性系数评价体系结果显示,在大清河水系的河流、湖泊和水库的20个采样点中,唐河上游和西大洋水库入库处的采样点水体的健康状况为健康,拒马河西上游、白沟河、漕河、沙河和团泊洼的采样点水体的健康状况为亚健康,大石河、拒马河下游、中易水、南拒马河、界河、白洋淀和大清河的采样点水体的健康状况为一般,瀑河、潴龙河、府河和独流减河的采样点水体的健康状况为差,孝义河和北大港水库的采样点水体的健康状况为很差。展开更多
文摘The ecological status of the Welala and Shesher Wetlands, on the eastern side of Lake Tana, were studied during pre-rainy, main-rainy, post-rainy and dry seasons from May 2009 to January 2010. Species composition, diversity and abundance of macrophytes, benthic macro-invertebrates and birds were assessed and physico-chemical parameters were measured. Phosphate and silicate concentrations, conductivity, TDS and turbidity varied significantly (p 0.05) between the two wetlands. The values for dissolved oxygen and pH ranged between 4.8 - 7.8 mg/l and 6.7 - 7.6, respectively. The values for nitrate and phosphate ranged between 0.2 - 3.1 mg/l and 0.2 - 3.3 mg/l, respectively. A total of 274 benthic macro-invertebrate individuals belonging to 5 families were collected, 32, 699 individual birds belonging to 62 species were enumerated and 13 species of macrophytes were identified. The two wetlands are shrinking at an alarming rate, mainly because of unsustainable farming practices and a huge irrigation project on Ribb River which is at presently under construction. Farming practices include draining and pumping of water for irrigation and expansion of farmland at the cost of the wetlands. The construction of a dam in Ribb River prevents overflow from Ribb River into the wetlands and disrupts the connection with Lake Tana which is vital for the survival of these two wetlands. We conclude that the Welala and Shesher Wetlands are valuable wetlands which need urgently protection.
文摘The traditional way of assessing water quality of water bodies is through measurement of biological, physical and chemical parameters. However, such assessments only reflect the concentration of pollutants at the time of sampling not periodic pollution events. The goal of the study was to evaluate the river health using the macro-invertebrates that are found within the Mucheke and Shagashe rivers of Masvingo City as water quality monitors. The South African Scoring System (SASS 5) was used to score using the sensitivity of macro-invertebrates to levels of pollution in the two river systems. The data collection process was carried in April 2017 at four sampling sites using the kick sampling method and results validated by testing the physical, chemical and biological characteristics of the water and comparing them with the macro-invertebrates score. Results showed that the mean sensitivity score of macro-invertebrates showed variations depending on the selected site. Sample sites B2 and A2 downstream of the two river systems show high levels pollution tolerant macro-invertebrates as compared to sites A1 and B1 that are on the upper course and have more of pollution sensitive macro-invertebrates. On validation, to a large extent the levels of pollution indicated by macro-invertebrates were found to be congruent to the levels of pollution indicated by the physical, chemical and biological parameters. The research concludes that the presence of specific types of macro-invertebrates can be used to assess the levels of pollution in Mucheke and Shagashe rivers of Masvingo City.
基金funded by the Kathmandu University,Nepal and the Royal Norwegian Government(FFDN-NPL 100062)
文摘Reference conditions having no or only minor anthropogenic disturbances, are a basic requirement for ecological studies in rivers. To study ecological impact of a dam, two sites were pre-classiifed as reference or least disturbed in the Andhi Khola River, Nepal, using Rapid Field Bioscreening （RFB） protocol. Biological （macroinvertebrates） and physico-chemical samples were collected in the month of January and February 2013. Multi-habitat sampling （MHS） was employed in sample collection of macro-invertebrates fauna. Validation of the pre-classiifed sites was done using several indices viz. Nepalese biotic score （NEPBIOS）, Biological monitoring working party （BMWP）, Hindu-Kush Himalayan biotic score （HKHBIOS）, Hilsenhoff （HILSENHOFF） ＆ National Sanitation Foundation Water Quality Index （NSFWQI）. The NEPBIOS, HKHBIOS, HILSENHOFF, RFB ＆ NSFWQI indices predicted the river quality at al two sites as good with quality class Ⅱ. Only BMWP/ASPT water quality index predicted the river quality at al two sites as Excelent with quality class Ⅰ. Hence preselected sites with quality of rank Ⅱ i.e. good qualities were validated as reference sites. The study demonstrated that the multi-metric approach is suitable for application in the monitoring and assessment of rivers where dams are built to produce hydropower.
文摘永定河是京津冀区域重要水源涵养区和生态屏障,为了解永定河水系的水生态健康状况,2016年对永定河水系大型底栖动物进行调查,共布设样点30个,采集到底栖动物38种,其中水生昆虫33种(摇蚊科16种),环节动物门3种,软体动物2种。从耐污值(Tolerance Value,TV)看,TV≤3的敏感类群所占百分比为13.2%,TV≥7的耐污类群所占百分比为44.7%。从类群出现频率看,出现频率最高的3个种分别为霍甫水丝蚓(Limnodrilus hoffmeisteri)、德永雕翅摇蚊(Glyptotendipes tokunagai)和云集多足摇蚊(Polypedilum nubifer),分别为46.7%、40.0%和36.7%,3个物种均为耐污值较高的种类。采用底栖动物完整性指数(Benthic Index of Biotic Integrity,B-IBI)方法评价永定河水系生态健康状况。通过分布范围分析、判别能力检验及相关性分析等,确定永定河水系生态状况评价B-IBI的核心指标体系,包括总分类单元数、摇蚊分类单元数和BI指数(Botic Index)3个指标。根据比值法,以参照点25%分位数确定永定河水系底栖动物完整性评价标准。根据参照点25%分位数确定永定河水系底栖动物完整性评价标准,即B-IBI>2.13为健康,1.60~2.13为亚健康,1.06~1.60为一般,0.53~1.06为较差,0~0.53为极差。B-IBI评价结果显示,永定河水系6.7%河段处于健康状态,23.3%河段处于亚健康状态,36.7%河段处于一般状态,20.0%河段处于较差和13.3%处于极差状态。除官厅水库坝上和宁车沽闸下外,其余样点的底栖动物完整性均受到不同程度的损害,表明永定河水系水体的健康状况整体不容乐观。
文摘应用大型底栖动物生物完整性指数(Benthic Index of Biological Integrity,B-IBI)评价河流健康已成为河流生态系统管理的重要方法。根据2010年5月对浑河流域62个采样点的底栖动物调查数据,基于采样点的水质等级、栖息地质量综合评估指数、人类干扰强度和河岸土地利用评估等标准,选择同属于辽河水系的太子河流域的8个采样点作为参照点,构建浑河流域B-IBI生物完整性指数。通过对34个生物参数的分布范围检验、判别能力分析以及相关性检验,最终确定浑河流域B-IBI生物完整性指数由总分类单元数、EPT(蜉蝣目Ephemeroptera、襀翅目Plecoptera、毛翅目Trichoptera)相对丰度、耐污类群相对丰度、最优势类群分类单元数、直接收集者相对丰度以及香农威纳多样性指数6个参数构成。根据各参数值随干扰增强的变化趋势,采用比值法计算各指标的分值和评价标准。结果表明:浑河流域B-IBI平均得分为2.56,河流健康状态处于一般状态;62个采样点中,9个处于健康状态,13个处于亚健康状态、22个处于一般状态、10个处于差状态,8个处于极差状态;从流域空间尺度上来看,河流健康状态从上游区到下游区逐渐变差。相关性分析表明,B-IBI与水温、电导、溶解性固体总量、硝酸盐、总氮、五日生化需氧量等水环境指标呈现显著负相关,表明B-IBI指数对于水质污染具有较好的指示性作用。综上所述,浑河流域由于受城市工业区的分布影响,大型底栖动物生物完整性呈现出明显的空间分布差异,上游区河流生物完整性较好、中下游底栖动物群落呈现出明显的退化趋势。
文摘为了了解大清河水系生态健康状况,在该水系的河流、湖泊和水库布设了20个采样点,分别于2018年5月和9月,在各采样点,对大型底栖动物进行了采样调查;采用大型底栖动物完整性指数(benthic index of biotic integrity,B-IBI)方法,对大清河水系水体健康状况进行了评价;通过分布范围分析、箱线图和相关分析等方法,确定大清河水系大型底栖动物完整性指数评价体系的主要指标,包括总分类单元数、优势类群数量所占百分比、摇蚊科(Chironomidae)数量所占百分比和敏感类群生物量;根据比值法,以参考点的25%分位数值,确定大清河水系大型底栖动物完整性评价体系的评价标准。研究结果表明,在20个采样点,共采集到大型底栖动物46种,包括扁形动物门1种,环节动物门3种,软体动物门6种和节肢动物门36种(其中有水生昆虫30种);耐污值≤3的敏感类群数量占全部类群数量的16.8%,耐污值≥7的耐污类群数量占42.9%;出现频率最高的3种物种为霍甫水丝蚓(Limnodrilus hoffmeisteri)、中华摇蚊(Chironomus sinicus)和德永雕翅摇蚊(Glyptotendipes tokunagai),其出现频率分别为45%、35%和30%,3种物种的耐污值都较高;大型底栖动物完整性系数评价体系结果显示,在大清河水系的河流、湖泊和水库的20个采样点中,唐河上游和西大洋水库入库处的采样点水体的健康状况为健康,拒马河西上游、白沟河、漕河、沙河和团泊洼的采样点水体的健康状况为亚健康,大石河、拒马河下游、中易水、南拒马河、界河、白洋淀和大清河的采样点水体的健康状况为一般,瀑河、潴龙河、府河和独流减河的采样点水体的健康状况为差,孝义河和北大港水库的采样点水体的健康状况为很差。
