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Vliv hradních zřícenin na diverzitu vegetace v krajině / Effect of castle ruins on diversity of vegetation in the landscapeJavorský, Tomáš January 2013 (has links)
Medieval castle ruins undoubtedly create the face of the Czech landscape. Moreover, the few previous studies on this topic have shown that ruins are unique and extraordinary biotope. This work aims to characterize castle vegetation on thirty examined localities (thirty ruins). Phytosociological relevés and soil samples were collected, soil depth was measured and the cover of individual layers was observed - all of this on three spots on each locality. One of the places covered castle and the other ones the nearby forests (each one was chosen differently than the other). The castle walls were sampled separately. The results show that castles not only increase the diversity of forests by hosting a higher number of species but also by a different species composition - castles have a rather large set of species with high fidelity to ruins areas. Approximately half of the uniqueness of the ruins can be explained by the soil qualities, such as higher pH, higher quantity of calcium and magnesium, the other half remains unclear notwithstanding the usage of various explanatory variables. It is certain that castle ruins are from a biological point of view exceptional, unique and they surely deserve the attention which we owe them so far.
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L'influence du climat et des activités humaines sur l'histoire holocène de la végétation du nord-ouest de la Méditerranée / Influence of climate and human activities on the Holocene vegetation history of the north-western MediterraneanAzuara, Julien 18 December 2017 (has links)
Les influences respectives de l’anthropisation et de la variabilité climatique sur l’histoire de la végétation méditerranéenne sont difficiles à différencier et peuvent être variables d’une région à une autre. Ce travail de recherche a pour objectif de mieux caractériser l’influence des populations humaines et de la variabilité climatique sur la mise en place des environnements du nord-ouest de la Méditerranée (i) en apportant une contribution inédite à l’étude de l’histoire de la végétation de cette région et (ii) en développant de nouveaux outils de traitement des données paléo-environnementales. Pour cela, deux nouvelles séquences polliniques à haute résolution temporelle situées dans le Languedoc (France) et dans la région de Murcie (Espagne) ont été acquises. Elles couvrent respectivement les 7800 et 6500 dernières années. Dans le Languedoc, la végétation est dominée par des taxons plutôt mésophiles pendant la majeure partie de la séquence, notamment le hêtre qui forme des forêts à basse latitude en zone méditerranéenne. Ce dernier régresse sous l’effet d’une aridification croissante du climat, combinée à des crises d’aridités centennales. D’un autre côté, la végétation sclérophylle méditerranéenne s’installe progressivement depuis le Néolithique en lien avec une anthropisation croissante. Dans la région de Murcie, l’impact du climat sur la végétation est plus équivoque, c’est l’impact de l’Homme qui est le plus nettement visible. Les formations arbusitives et pionnières montrent clairement des phases de développement et de régression reliées aux variations de l’anthropisation du territoire. D’autre part, un travail de calibration du signal pollinique par rapport à la végétation a été initié. Le modèle de transport des grains de pollen, REVEALS, a été adapté aux environnements de dépôts côtiers tels que ceux étudiés dans cette thèse. De plus, des données en vue de la quantification de la production pollinique de douze des principaux taxons méditerranéens ont été collectées et traitées. Pour finir, l’analyse spectrale de séries temporelles paléoclimatiques a permis de caractériser l’influence de l’activité solaire, de la circulation thermohaline atlantique et de la variabilité climatique tropicale sur le climat du nord-ouest de la Méditerranée. La variabilité spatiale du signal climatique à l’Holocène en Méditerranée a également été discutée grâce à une remise en contexte des résultats de cette thèse à l’échelle de l’ensemble du bassin Méditerranéen. / Holocene climate fluctuations and human activities since the Neolithic have shaped present-day Mediterranean environments. Separating anthropogenic effects from climatic impacts to better understand Mediterranean paleoenvironmental changes over the last several millennia remains a challenging issue. This work aims to characterize the influence of human activities and past climate variability over the development of north western Mediterranean environments by (i) providing new data about the vegetation history of this region and (ii) developing new tools for paleoenvironmental data processing. Two high-resolution pollen sequences from Languedoc (France) and the Murcia region (Spain) are presented, covering the last 7800 and 6500 years, respectively. In Languedoc, the past vegetation is dominated by mesophilous forests during most of the sequence, in particular beech forests growing at low altitude within the Mediterranean area. However, recurrent abrupt climate changes, the late Holocene aridity trend, and human deforestation caused beech forests to decline. On the other hand, evergreen Mediterranean vegetation has developed gradually since the Neolithic due to the increasing human impact. In the Murcia region, the influence of past climate variability on the environment is less obvious. Changes in human activities are clearly driving most of the observed vegetation changes. Shrubs and pioneer plants show spread and decline phases alternatively in relation to archeological and historical records. Work to adapt pollen based land-cover reconstruction methods developed in northern Europe to the Mediterranean area was also initiated. REVEALS model of pollen dispersal and deposition was adapted to coastal sedimentary basins such as those studied in this PhD. However, to apply such pollen based land-cover reconstruction methods, pollen productivity estimates are needed. Thus, the data necessary to quantify the pollen productivity of 12 Mediterranean plant taxa were collected and processed. Finally, spectral analysis of paleoclimate time series using wavelets allowed us to characterize the influence of solar variability, the Atlantic thermohaline circulation, and tropical climate variability on the past climate of the north-western Mediterranean. The spatial variability of past climate changes in the Mediterranean is also highlighted by comparing our results obtained for the north western Mediterranean with paleoclimate data from the whole Mediterranean basin.
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Application and Refinement of the Karst Disturbance Index in West Central, FloridaNorth, Leslie A. 26 April 2007 (has links)
A hierarchical and standardized environmental disturbance index, specifically designed for karst landscapes, was created by van Beynen and Townsend (2005). To assess the applicability of the index and provide recommendations for its refinement, the index was applied in four west-central Florida counties and interviews were conducted with local and state officials, community planners, and land resource managers. The karst disturbance index consists of 30 indicators contained within five broad categories: geomorphology, hydrology, atmosphere, biota, and culture. Data was readily available for most environmental indicators used to construct the index. Overall, levels of disturbance vary between the counties due to the level of urbanization, with the highly populated Hillsborough and Pinellas Counties having higher degrees of disturbance than less developed Pasco and Hernando Counties. While this result may seem obvious, the measure of disturbance using many indicators provides benchmarks of levels of disturbance that can be reassessed with time and highlights those aspects of the environment most in need of attention. Several minor issues arose during the testing: the need for broader indicator descriptions that encompass a variety of scenarios, a new water quality indicator, obsolete sinkhole data, and a lack of data for biota indicators. The lack of data for certain indicators suggests where future research efforts can be directed.
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Os mamíferos de médio porte e suas respostas à fatores ambientais, físicos e antrópicos, sobre diferentes perspectivas, no Parque Estadual da Ilha Grande RJIsadora Cristina Motta Lessa 08 February 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A variação espacial das características bióticas e abióticas de um
ambiente influencia na distribuição de médios mamíferos, sobre diferentes
escalas. O Parque Estadual da Ilha Grande (PEIG) possui ambiente bastante
heterogêneo e abriga uma mastofauna de médio porte ainda pouco estudada. O
objetivo deste estudo é avaliar o efeito das variáveis físicas, do micro-habitat, da
estrutura da vegetação e dos impactos antrópicos na comunidade e nas espécies de mamíferos de médio porte do PEIG. O registro das espécies foi por
armadilhas fotográficas e as variáveis do ambiente mensuradas por diferentes
métodos nas 49 estações de câmeras. Com os resultados desse estudo
inferimos que a riqueza de nove espécies de mamíferos de médio porte nativos,
corresponde a esperada para um ambiente insular. As espécies mais
abundantes foram Dasyprocta leporina, Agouti paca, Dasypus novemcinctus e
Didelphis aurita, a mais rara foi o Leopardus wiedii. A composição da
mastofauna difere entre as vertentes norte e sul da Ilha Grande (ANOVA,
p=0,01). O maior número de indivíduos foi registrado na vertente sul, onde há o
efeito da variação da altitude, menor variação do micro-habitat e menor
densidade da população humana. Contudo a estrutura da vegetação não difere
entre as vertentes e não afeta as espécies mais abundantes. Essas espécies
são sensíveis às variáveis físicas. Há impacto da densidade populacional nas
vilas sobre a composição e abundância das espécies de médios mamíferos,
apesar da caça não ter efeito nas áreas amostradas. Os mamíferos de médio
porte são sensíveis às variáveis de maior escala e podem ter sua comunidade
estruturada em função do impacto antrópico. A complexidade de habitat e o
controle de habitantes no PEIG são importante para manter a comunidade de
mamíferos de médio porte. / The spatial variation of the biotic and abiotic characteristics of environment affects the mammals distributions on different scales. The State Park of Ilha Grande
(PEIG) has heterogeneous habitats by diverse vegetation and is home to mediumsized
mammals, but they still few studied. Our goals in this study are to evaluate the
effect of variables physical, micro-habitat, vegetation structure and human impacts
on the mammals community and species. The record of the species was by camera-
traps and the environmental variables measured by different methods in 49 camera
stations. The results of this study inferred that the richness of nine species of native
medium size mammals corresponds to an island environment expected. The most
abundant species were Dasyprocta leporina, Agouti paca, Dasypus novemcinctus
and Didelphis aurita, the rarest was the Leopardus wiedii. The mammal fauna
composition differs between the northern and southern slopes of the Ilha Grande
(ANOVA, p = 0.01). The most of individuals was recorded on the southern slope, where there is the effect of variation in altitude, the lower variation of micro-habitat and lower human population density. However the vegetation structure does not
differ between the slopes and does not affect the most abundant species. These
species are sensitive to physical variables. There is an impact on the composition
and abundance of species of mammals by human population density in the villages on, despite the hunt wasnt effective in the sampled areas. The medium-sized
mammals are sensitive to larger-scale variables and may have structured their community due to the impact of human activity. The complexity of habitat and
population control in PEIG is important to keep the community of medium-sized
mammals.
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Human-rainforest interactions in Island Southeast Asia : Holocene vegetation history in Sarawak (Malaysian Borneo) and Palawan (western Philippines)O'Donnell, Shawn Alden January 2016 (has links)
This research employs a modern analogue approach to examine relationships between pollen, vegetation change, and land use in the tropical environments of Island Southeast Asia over the past ~5000 years. Interpretation of fossil pollen data relies upon uniformitarian principles. Few modern pollen- vegetation studies from the region exist, and those that do have focused on climatic or ecological aims. Main contributions of this study are: the collection and analysis of modern botanical data and pollen assemblages from various human-modified and ‘natural’ vegetation types; and the comparison of this modern dataset with fossil pollen sequences in order to test hypotheses relating to signatures of past land use. Some fossil assemblages showed statistical similarity with those from modern ‘cultured’ landscapes, whilst others aligned more closely with those from natural vegetation. Cores from the northern Kelabit Highlands of Sarawak, Malaysian Borneo, contain assemblages from 1700 cal BP onwards that are similar to those produced by modern arboriculture; a core from the southern Highlands contains fossil assemblages as old as 2000 cal BP that align with those from modern wet rice paddies. These ages coincide with the earliest archaeological dates from nearby sites. Earlier vegetation changes appear to relate to edaphic development and climatic fluctuations. In northern Palawan, western Philippines, the first fossil pollen sequence from the island records post-5000 cal BP marine regression, hydrological fluctuations that are likely related to ENSO cyclicities, and persistence of open landscapes with minor evidence of closed forest after 2750 cal BP. This contrasts with existing proxy data that imply increasingly closed forest through the Holocene. In a region where direct archaeobotanical evidence is sparse, and little modern pollen- vegetation work has been done, this research contributes to clarifying modes and timings of changes in subsistence-related disturbance, as well as bolstering recent interpretations from other palaeoclimatic proxies for ENSO intensification from ~4000 cal BP. These results, and those from similar future studies, can provide baseline data for long-term monitoring and conservation initiatives.
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Os mamíferos de médio porte e suas respostas à fatores ambientais, físicos e antrópicos, sobre diferentes perspectivas, no Parque Estadual da Ilha Grande RJIsadora Cristina Motta Lessa 08 February 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A variação espacial das características bióticas e abióticas de um
ambiente influencia na distribuição de médios mamíferos, sobre diferentes
escalas. O Parque Estadual da Ilha Grande (PEIG) possui ambiente bastante
heterogêneo e abriga uma mastofauna de médio porte ainda pouco estudada. O
objetivo deste estudo é avaliar o efeito das variáveis físicas, do micro-habitat, da
estrutura da vegetação e dos impactos antrópicos na comunidade e nas espécies de mamíferos de médio porte do PEIG. O registro das espécies foi por
armadilhas fotográficas e as variáveis do ambiente mensuradas por diferentes
métodos nas 49 estações de câmeras. Com os resultados desse estudo
inferimos que a riqueza de nove espécies de mamíferos de médio porte nativos,
corresponde a esperada para um ambiente insular. As espécies mais
abundantes foram Dasyprocta leporina, Agouti paca, Dasypus novemcinctus e
Didelphis aurita, a mais rara foi o Leopardus wiedii. A composição da
mastofauna difere entre as vertentes norte e sul da Ilha Grande (ANOVA,
p=0,01). O maior número de indivíduos foi registrado na vertente sul, onde há o
efeito da variação da altitude, menor variação do micro-habitat e menor
densidade da população humana. Contudo a estrutura da vegetação não difere
entre as vertentes e não afeta as espécies mais abundantes. Essas espécies
são sensíveis às variáveis físicas. Há impacto da densidade populacional nas
vilas sobre a composição e abundância das espécies de médios mamíferos,
apesar da caça não ter efeito nas áreas amostradas. Os mamíferos de médio
porte são sensíveis às variáveis de maior escala e podem ter sua comunidade
estruturada em função do impacto antrópico. A complexidade de habitat e o
controle de habitantes no PEIG são importante para manter a comunidade de
mamíferos de médio porte. / The spatial variation of the biotic and abiotic characteristics of environment affects the mammals distributions on different scales. The State Park of Ilha Grande
(PEIG) has heterogeneous habitats by diverse vegetation and is home to mediumsized
mammals, but they still few studied. Our goals in this study are to evaluate the
effect of variables physical, micro-habitat, vegetation structure and human impacts
on the mammals community and species. The record of the species was by camera-
traps and the environmental variables measured by different methods in 49 camera
stations. The results of this study inferred that the richness of nine species of native
medium size mammals corresponds to an island environment expected. The most
abundant species were Dasyprocta leporina, Agouti paca, Dasypus novemcinctus
and Didelphis aurita, the rarest was the Leopardus wiedii. The mammal fauna
composition differs between the northern and southern slopes of the Ilha Grande
(ANOVA, p = 0.01). The most of individuals was recorded on the southern slope, where there is the effect of variation in altitude, the lower variation of micro-habitat and lower human population density. However the vegetation structure does not
differ between the slopes and does not affect the most abundant species. These
species are sensitive to physical variables. There is an impact on the composition
and abundance of species of mammals by human population density in the villages on, despite the hunt wasnt effective in the sampled areas. The medium-sized
mammals are sensitive to larger-scale variables and may have structured their community due to the impact of human activity. The complexity of habitat and
population control in PEIG is important to keep the community of medium-sized
mammals.
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The impact of climate change and human management on the water cycle of China : dealing with uncertainties / Impact du changement climatique et de la gestion humaine sur le cycle de l'eau en Chine : faire face aux incertitudesZhou, Xudong 04 December 2018 (has links)
La modélisation hydrologique est un moyen pratique de quantifier les réactions du débit des rivières au changement climatique et à la gestion humaine de l’environment et de l’eau. Cependant, il existe des incertitudes à la fois dans les entrées des modèle s(par exemple, les variables atmosphériques) et les modèles eux même(par exemple, les structures de modèle et les paramètres de modèle), qui peuvent affecter la précision du modèle et les conclusions. En se concentrant sur différentes sources d'incertitude, cette thèse passe en revue les études antérieures et propose de nouvelles approches pour estimer et comparer les incertitudes avec leurs applications concentrées sur la Chine. Cette thèse propose d’abord une approche tridimensionnelle de la partition de la variance qui estime l’incertitude des multiples produits de précipitation de types différents. La nouvelle estimation utilise des informations complètes dans les dimensions temporelle et spatiale et constitue donc un indicateur plus complet pour l'évaluation de l'incertitude, en particulier pour plusieurs jeux de données. Cette thèse propose ensuite un cadre ORCHIDEE-Budyko permettant d'attribuer le biais de décharge entre la simulation du modèle (fournie par le modèle de surface ORCHIDEE) et les observations aux sources d'incertitude des variables atmosphériques et de la structure du modèle. Le cadre qualifie la possibilité d'incertitudes différentes avec l'hypothèse de Budyko basée sur des facteurs physiques et le soutien de littératures existante. Cette thèse passe enfin en revue les activités humaines et leur impact sur le débit des rivières en Chine, ainsi que les approches associées utilisées pour la quantification. L’impact humain qui a été quantifié par la différence entre le débit fluvial observé et celui qui a été naturalisé est ensuite comparé à des simulations multi-modèles conduites par différents forçages. Les résultats montrent que l’incertitude dans les variables atmosphériques (par exemple, les précipitations) est grande, en particulier pour les modèles de circulation générale (GCMs). L'incertitude des précipitations est très probablement supérieure à celle de l'incertitude du modèle. L'incertitude associée au débit modélisé avec différents forçages est supérieure à l'ampleur de l'impact humain pour la plupart des régions, en particulier dans le sud de la Chine, ce qui rend la la quantification de l'impact humain pour ces régions difficile. Cette compréhension des incertitudes dans le cycle naturel de l'eau et de la gestion que lui imposent les hommes est une condition préalable à toute tentative de modélisation des pressions anthropiques. / Hydrological modeling is a practical means to quantify responses of river discharge to climate change and human management. However, there are uncertainties in both the model input (e.g., atmospheric variables) and the models (e.g., model structures and model parameters), that can affect the model accuracy and the conclusions. Focusing on different uncertainty sources, this thesis reviews the past studies and provides new approaches for estimating and comparing the uncertainties with their applications concentrated over China. This thesis first proposes a three-dimensional variance partitioning approach that estimates the uncertainty among multiple precipitation products with different types. The new estimation uses full information in temporal and spatial dimensions and thus is a more comprehensive metric for uncertainty assessment especially for multiple datasets. This thesis then proposes a ORCHIDEE-Budyko framework that helps attribute the discharge bias between model simulation (provided by land surface model ORCHIDEE) and observations to uncertainty sources of atmospheric variables and model structure. The framework qualifies the possibility of different uncertainties with physical-based Budyko hypothesis and support of related literatures. This thesis finally reviews the human activities and their impact on river discharge over China regions as well as the related approaches that used for the quantification. The human impact that quantified as the difference between observed river discharge and the naturalized ones is then compared with multi-model simulations driven by different forcing inputs. Results show that the uncertainty in atmospheric variables (e.g., precipitation) is large especially for General Circulation Models (GCMs). Precipitation uncertainty is very likely larger than that of the model uncertainty. The uncertainty in the modeled discharge with different forcing is larger than the magnitude of human impact for most of the regions especially in south China, which impedes the credibility of human impact quantification for those regions. This understanding of uncertainties in the natural water cycle and the management humans impose on it is a prerequisite before attempting to model the anthropogenic pressures.
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Metal mobility and transport from an oil-shale mine, Lake Nõmmejärv, EstoniaEkelund, Åsa January 2020 (has links)
Mining activities have a large impact on the environment, for example by the release of heavy metals from acid mine drainage and erosion of mine waste. North-eastern Estonia has the largest commercially exploited oil-shale deposit in the world. Waste from the mining processes have led to contamination of groundwater and streams polluted by phenols, oil products, sulphates and heavy metals. This thesis concerns the metal mobility from oil-shale mines in north-eastern Estonia, through water flow in the drainage system directed into Lake Nõmmejärv, which acts as a sedimentation basin for the mining water. A sediment core along with lake bottom surface samples were retrieved and analysed for heavy metals associated with mining. Water samples were collected and analysed for TOC. The sedimentary records show distinctively the change with the high inflow of water. The analysis of heavy metal content does not suggest a high impact on the environment, possibly because of a buffering effect by the limestone bedrock. The contents of heavy metals are somewhat elevated compared to background contents in Swedish lake sediments, but only cadmium and nickel levels are in the range that can be hazardous for the survival of organisms.
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Förekomst av rödlistade vedlevande svampar i skog med olika påverkansgrad: en pilotstudie / Occurrence of red-listed xylophagous fungi in forests with varying degrees of impact: a pilot studyManfredsson, Tommy January 2024 (has links)
This pilot study was conducted to test if there are differences in occurrence of red-listed xylophagous fungi in forests dependent on degrees of human impact on the forests. Three main degrees of human impact was investigated: little impact (natural forest); medium impact (semi-natural forest) and high impact (monoculture plantation). These forests were compared in three geographically distinct areas within the same municipality, Vindeln. Within each forest type, three experimental plots were randomly selected, resulting in a total of 27 research plots. The study was conducted in northern Sweden, Västerbotten county in the following locations: Svartberget, Skatan and Kulbäcksliden. The pilot study found significant differences between natural forests and monoculture plantations. The natural forests harboured the most red-listed species, followed by the semi-natural forests, while the monoculture plantations had the fewest. The semi-natural was closer to the natural forest but did not yield significant differences when comparing the various areas. Despite the small dataset, the results are clear that the natural forests harbour the highest abundance of red-listed xylophagous fungi when comparing the degree of human impact in three different forest ecosystems.
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Water quality of the Red River system in the period 2012 - 2013 / Chất lượng nước hệ thống sông Hồng giai đoạn 2012 - 2013Le, Thi Phuong Quynh, Ho, Tu Cuong, Duong, Thi Thuy, Nguyen, Thi Bich Ngoc, Vu, Duy An, Pham, Quoc Long, Seidler, Christina 07 December 2015 (has links) (PDF)
Few data are available on the quality of Red river water that is used for multi-purposes, including for domestic water demand in some rural areas. This paper presents the observation results of the Red River water quality in two years 2012 and 2013. The monitoring results showed that the average concentrations of nutrients (N, P) were still far lower than the allowed value of the Vietnamese standard limits for surface water quality (QCVN 08:2008/BTNMT, column A2). Due to the impoundment of two big dams in the Da tributary, the suspended solids contents in river water decreased remarkably. The dissolved heavy metal (DHM) concentrations varied in a high range: Cu: 10 – 80 μg.l-1; Zn: 2 – 88 μg.l-1; Cr: 0.2 – 5.1 μg.l-1; Pb: 2 - 107 μg.l-1; Cd: 2 – 12 μg.l-1; Mn: 2 - 35 μg.l-1; and Fe: 160 – 2370 μg.l-1. Most of the mean values of DHM were lower than the allowed values of the QCVN 08:2008/BTNMT, but at several points of time, several DHM (e.g. Fe, Cd, Pb) contents exceeded the allowed values. The Total Coliform (TC) and Fecal Coliform (FC) densities varied in a high range: TC: 23 to 13,000MPN.100ml-1 and FC: 0 to 1,600MPN.100ml-1 and they exceeded the allowed values QCVN 08:2008/BTNMT at several points observed. The dissolved organic carbon (DOC) contents were in low level and the particulate organic carbon (POC) content mainly derived from soil organic leaching and erosion in the basin. The results underlined the need for regularly monitoring the river water quality, and there should be some effective solutions to manage and treat the waste sources in order to provide safe water for different actual purposes use in the Red River basin. / Rất ít số liệu sẵn có về chất lượng nước sông Hồng, dòng sông được sử dụng cho nhiều mục đích, bao gồm cả cung cấp nước sinh hoạt ở một số vùng nông thôn. Bài báo trình bày các kết quả quan trắc chất lượng nước sông Hồng trong hai năm 2012 và 2013. Kết quả quan trắc cho thấy chất dinh dưỡng (N, P) thấp xa so với giới hạn cho phép của tiêu chuẩn Việt Nam về chất lượng nước mặt (QCVN 08: 2008/BTNMT cột A2). Do có hai hồ chứa trên sông Đà, hàm lượng chất rắn lơ lửng trong nước sông giảm đáng kể. Các kim loại nặng hòa tan (DHM) có hàm lượng dao động trong khoảng rộng: Cu: 10-80 μg.l-1; Zn: 2-88 μg.l-1; Cr: 0,2-5,1 μg.l-1; Pb: 2-107 μg.l-1; Cd: 2-12 μg.l-1; Mn: 2-35 μg.l-1; và Fe: 160 - 2370 μg.l-1. Hầu hết các giá trị trung bình của DHM thấp hơn giá trị cho phép của quy chuẩn QCVN 08: 2008/BTNMT, tuy nhiên, tại một số thời điểm, một số DHM (ví dụ Fe, Cd, Pb) có hàm lượng vượt quá giới hạn cho phép. Mật độ tổng coliform (TC) và coliform phân (FC) dao động trong khoảng rộng: TC: 23 đến 13,000MPN.100ml-1 và FC: 0 đến 1,600MPN.100ml-1 và tại một số thời điểm mật độ TC và FC vượt giá trị cho phép của Quy chuẩn QCVN 08:2008/BTNMT. Hàm lượng cabon hữu cơ hòa tan (DOC) ở mức thấp, và hàm lượng cacbon hữu cơ dạng không tan (POC) chủ yếu có nguồn gốc từ đất rửa trôi và xói mòn trong lưu vực. Kết quả quan trắc nhấn mạnh nhu cầu giám sát thường xuyên chất lượng nước sông, và nên có các giải pháp hiệu quả để quản lý và xử lý các nguồn gây ô nhiễm trong lưu vực nhằm cung cấp nước sạch cho các mục đích sử dụng nước sông Hồng như hiện nay.
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