The function and future of the LOICS basins approach in promoting integrated coastal zone & watershed management with an emphasis on developing countries

Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2010

Evolution of the modern Nile delta promontories: development of accretional features during shoreline retreat

The active accretional features that have developed along the modern Nile Delta promontories during shoreline retreat are analysed using topographic maps, remote imagery, ground and hydrographic surveys, together providing 15 time-slice maps (1922-2000) at Rosetta and 14 time-slice maps (1909-2000) at Damietta. Small double sandy spits developed and persisted at Rosetta between 1986 and 1991. At Damietta, a much larger single spit, 9 km long, formed approximately east of the mouth of the Damietta Nile branch between 1955 and 1972, although its source has now been depleted. Both the Rosetta and Damietta inlets are associated with submerged mouth bars that accumulated prior to the damming of the Nile, but that continue to contribute to local sedimentation problems, particularly at Rosetta. The development of the active accretional features along the Nile promontories reflects a combination of factors including sediment availability, transport pathways from source areas, a decrease in the magnitude of Nile flood discharges, as well as the impact of protective structures at the river mouths.

Modelling phosphorus dynamics in multi-branch river systems: A study of the Black River, Lake Simcoe, Ontario, Canada

High rates of nutrient loading from agricultural and urban development have resulted in surface water eutrophication and groundwater contamination in regions of Ontario. In Lake Simcoe (Ontario, Canada), anthropogenic nutrient contributions have contributed to increased algal growth, low hypolimnetic oxygen concentrations, and impaired fish reproduction. An ambitious programme has been initiated to reduce phosphorus loads to the lake, aiming to achieve at least a 40% reduction in phosphorus loads by 2045. Achievement of this target necessitates effective remediation strategies, which will rely upon an improved understanding of controls on nutrient export from tributaries of Lake Simcoe as well as improved understanding of the importance of phosphorus cycling within the lake. In this paper, we describe a new model structure for the integrated dynamic and process-based model INCA-P, which allows fully-distributed applications, suited to branched river networks. We demonstrate application of this model to the Black River, a tributary of Lake Simcoe, and use INCA-P to simulate the fluxes of P entering the lake system, apportion phosphorus among different sources in the catchment, and explore future scenarios of land-use change and nutrient management to identify high priority sites for implementation of watershed best management practises.

The risk of river flooding

This section of the report outlines the effect of different levels of climate change on exposure to river flood risk, at national and watershed scales.

Haematological and gill responses in parasitized tilapia from valley of Tijucas River, SC, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phosphate distribution in the sediments along a cascade of reservoirs - (Paranapanema River, SE, Brazil)

Total phosphorus concentrations in the sediment of a cascade of 8 reservoirs located in the Paranapanema River (SE, Brazil) were analysed during two consecutive seasonal periods (2000 and 200 1). The reservoirs of Jurumirim, Chavantes, Salto Grande, Canoas 11, Canoas 1, Capivara, Taquarucu and Rosana were built during the last five decades with the purpose of hydroelectric generation. The sampling points were distributed along a 700 km of river stretch in 19 stations distributed in the river-reservoirs zones and main tributaries as well as in 5 stations representing the adjacent wetlands. The nutrient concentration was determined in samples from surface layers of sediment. Temporal and spatial changes were observed for both years. Three different areas could be identified along the river, considering not only Tot-P variations but also others physical and chemical characteristics such as organic matter concentration, nitrogen concentration of sediment and 02, pH, conductivity and Eh measured in the bottom layer of the water column. Higher values of Tot-P were found in the middle and lower region of the Paranapanema basin (maximum value of 1.96 mg g(-1) in Tibagi River in October/2001). Agricultural practices and cattle raising are the main external sources of nutrient in these regions. Superficial or sub-superficial watershed drainage and tributaries entrances are important nutrient contributors, leading to an increasing accumulation of nutrient in the sediment. This process seems to be especially important in the middle region of the Paranapanema Valley, were the values of Tot-P were higher comparing to the other areas.

Micronucleus test and observation of nuclear alterations in erythrocytes of Nile tilapia exposed to waters affected by refinery effluent

Micronuclei and nuclear alterations tests were performed on erythrocytes of Oreochromis niloticus (Perciformes, Cichlidae) in order to evaluate the water quality from Paraiba do Sul river, in an area affected by effluents from an oil shale processing plant, located in the city of Sao Jose dos Campos, Brazil-SP. Water samples were collected on 2004 May and August (dry season) and on 2004 November and 2005 January (rain season), in three distinct sites, comprising 12 samples. It was possible to detect substances of clastogenic and/or aneugenic potential, as well as cytotoxic substances, chiefly at the point corresponding to the drainage of oil shale plant wastes along the river. The highest incidence of micronuclei and nuclear alterations was detected during May and August, whereas the results obtained in November and January were insignificant. This work shows that the effluent treatment provided by the oil shale plant was not fully efficient to minimize the effect of cytotoxic and mutagenic substances in the test organism surveyed. (c) 2006 Elsevier B.V. All rights reserved.

CONDITION of Hoplias aff. malabaricus (BLOCH, 1794) IN TWO COASTAL STREAMS of ITANHAEM RIVER BASIN, BRAZIL

The main purpose of this research was to measure the condition of the fish species Hoplias aff. malabaricus collected in Aguapeu River (black waters) and Branco River (white waters), which belong to Itanhaem River basin, a coastal watershed in São Paulo state, Brazil. Individuals of Hoplias aff. malabaricus were sampled by using gill nets, monthly from March 2001 to February 2002. The Condition Factor was obtained through the length-weight relationship, assuming that the higher the mass for a given length, the better the condition of the fish. The Condition Factor was compared among fishes from both rivers, resulting that Branco River individuals have significantly lower condition. Limnological aspects were studied from May 2001 to November 2002 and some show significant differences between Aguapeu River and Branco River. These were salinity, do and total organic N, which the higher values being observed in Branco River propably due to estuarine waters influence. However, the lower condition of the Branco River fishes should also be an effect of a disturbance due to the sand mining in this river, since this activity cause important alterations to the environment, affecting the whole biota, included aquatic macrophytes, invertebrates and fishes.

Major Aspects of the Mercury Cycle in the Negro River Basin, Amazon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Artisanal fisheries in a Brazilian hypereutrophic reservoir: Barra Bonita reservoir, middle Tietê river

Esse estudo avaliou aspectos quantitativos qualitativos do desembarque pesqueiro no reservatório hipertrófico de Barra Bonita. Os dados foram coletados mensalmente (julho/2004-junho/2006) em três localidades e informações sobre captura, esforço de pesca e técnicas de pesca foram registrados de 745 desembarques, totalizando 86.691,9 kg de pescado capturados. As espécies mais capturadas foram as exóticas tilápias, especialmente a tilápia-do-nilo (Oreochromis niloticus L.), que representaram 82,5% da biomassa total. A produtividade pesqueira do reservatório foi de 11,1 kg/ha-1/dia-1 com uma Captura Por Unidade de Esforço de 62,4 kg/pescador-1/dia-1 . Cinco técnicas de pesca foram identificadas: tarrafas, rede de espera, rede de arrasto, pesca da batida e pesca da batida + rede de espera. Análise de DCA relacionou as estratégias ativas com a captura de tilápia, as estratégias passivas com a captura de Pimelodus maculatus (Lacepède) e Triporthues angulatus (Spix & Agassiz) e a estratégia mista com a captura de tilápia, cascudos e Prochilodus lineatus (Valenciennes). Os resultados da ANCOVA foram significativos para todas as variáveis analisadas (época, local de pesca e técnicas de pesca). Os resultados mostram uma substituição da pesca da corvina, Plagioscion squamossisimus (Heckel) na década de 1990, pela tilápia-do-nilo. A substituição pode ter sido provocada pelo aumento da eutrofização do reservatório, aliado à mudança das estratégias de pesca. A pesca no reservatório de Barra Bonita seguiu padrões de outros reservatórios eutrofizados brasileiros, com a pesca sustentada pela exótica tilápia-do-nilo.

Anthropogenic influences on Cd, Cr,Cu, Ni, Pb and Zn concentrations in soils and sediments in a watershed with sugar cane crops at São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mountain watershed management in the development and conservation of natural resources

Includes bibliography

Hydrosedimentological disequilibrium in a small, urbanized watershed

AIM: In this paper we estimate the sediment yield and other related information for a small urbanized watershed, located in Sorocaba, São Paulo State. The driving forces that produce the observed scenario are presented and discussed; METHODS: Over a year, water samples and hydrologic information concerning the river channel were collected monthly at one sampling site. In the laboratory, water samples were oven dried (80 ºC) and the total suspended solid weighed for each sample. To estimate sediment yield we used Colby's simplified method. The sediment delivery ratio (SDR) was estimated using two methods: the relief - length ratio and the bifurcation ratio; RESULTS: The annual sediment yield estimated for the period was 1,636.1 t. The total specific sediment yield was 541.7 t.km -2.y-1. Bedload was the predominant fraction. The SDR changed between 60 and 66% according to the method employed. CONCLUSIONS: The main driving forces of hydrosedimentological disequilibrium are the lack of riparian vegetation, the dumping of construction wastes at inadequate sites, and the launching of untreated sewage. Hence, if these three factors were controlled, a significant improvement in the environmental quality, particularly water quality, might be achieved.

River Size and Fish Assemblages in Southwestern South Dakota

We studied relations between river size, fish species diversity, and fish species composition along four major rivers in the Great Plains of southwestern South Dakota to assess patterns of species diversity and composition. We expected diversity to increase with river size and fish composition to change via species addition downstream. Previous surveys of 52 sampling stations provided fish assemblage data, and we used the Geographic Information System (GIS) to determine watershed area by station. Watershed area did not predict species richness or species diversity (Fisher's a), so species richness of 12 ± 3.5 SD species and Fisher's a of 2.3 ± 0.87 SD characterized species diversity in the study area. Cluster analysis of faunal similarity (Sorensen's Index) among the 52 sampling stations identified two geographically distinct faunal divisions, so species composition was variable within the study area, but changed via species replacements among faunas rather than species additions downstream. Nonnative species were a minor component of all faunas. Uniform species diversity may be a recent phenomenon caused by impacts of Missouri River dams on native large-river fishes and the unsuitability of rivers in the Great Plains for nonnative species. Variation in faunal composition may also be recent because it was affected by dams.

Herbicides in the upper Poxim River, Sergipe, and the risk of contamination of water resources

Increased agricultural activity in watershed areas has been causing concern over contamination by herbicides in agricultural areas. The problem becomes more important when contamination can affect water for human consumption, as happens with water from the Poxim river, which supplies the city of Aracaju, capital of the State of Sergipe. The aim of this study was to evaluate the risk of contamination by herbicides to both surface and groundwater in the upper sub-basin of the Poxim River, and to detect the presence of the active ingredients Diuron and Ametrine up-river from the sugar-cane plantations. Risk analysis was carried out using criteria from the Environmental Protection Agency (EPA), the GUS index, and the GOSS method. It was observed that several active ingredients are at risk of leaching, demonstrating the importance of monitoring the river to control both the quality of water and the frequency and volume of herbicides used in the region. Based on the results, monitoring was carried out bi-monthly from July 2009 to July 2010 at two sampling points. Water samples were analyzed in the laboratory, where the presence of Diuron and Ametrine was noted. Water quality in the Sub-basin of the Rio Poxim is being influenced by the use of herbicides in the region. There was an increase in herbicide concentration in the surface water during the rainy season, possibly caused by soil runoff.