962 resultados para Rivers and streams
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Part of the Department of Natural Resources' Water Fact Sheet Series. This one is about Nitrate in Iowa's rivers and streams.
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A report produced by the Department of Natural Resources on the historical pattern the rivers take.
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Fauna of Simuliidae (Diptera) from the state of Espírito Santo, Brazil: Distribution, new records and list of species. The fauna of Simuliidae in Brazil is composed of 87 species, 17 of which are recorded from the state of Espírito Santo. Entomological collections were carried out in 2010-2011 with the objective of increasing the knowledge of the species richness of this family in the state. Ninety three rivers and streams were sampled, each collection being carried out in a 50m transect. During the study period 30 species were collected, 13 of which represent new records for the state, 12 of the genus Simulium and one of the genus Lutzsimulium. Among these new state records one, Simulium lobatoi, also represents a new record from southeastern Brazil. The other newly recorded species are: Lutzsimulium hirticosta, Simulium distinctum, Simulium exiguum, Simulium oyapockense, Simulium botulibranchium, Simulium petropoliense, Simulium clavibranchium, Simulium rappae, Simulium minusculum, Simulium dinellii, Simulium ochraceum and Simulium scutistriatum.
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Proceedings of a workshop held in Omaha, Nebraska, 22-25 January, 1978. Edited by W.W. Sayre and J.F. Kennedy. Iowa Conservation Commission. IIHR Report No. 215. Iowa Institute of Hydraulic Research, the University of Iowa, Iowa City, Iowa.
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study of channel catfish in the Mississippi River to determine differences in year class abundance and causative factors
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The main objective of this study was to evaluate the hydraulic performance of riprap spurs and weirs in controlling bank erosion at the Southern part of the Raccoon River upstream U.S. Highway 169 Bridge utilizing the commercially available model FESWMS and field monitoring. It was found based on a 2 year monitoring and numerical modeling that the design of structures was overall successful, including their spacing and stability. The riprap material incorporated into the structures was directly and favorably correlated to the flow transmission through the structure, or in other words, dictated the permeable nature of the structure. It was found that the permeable dikes and weirs chosen in this study created less volume of scour in the vicinity of the structure toes and thus have less risk comparatively to other impermeable structures to collapse. The fact that the structures permitted the transmission of flow through them it allowed fine sand particles to fill in the gaps of the rock interstices and thus cement and better stabilize the structures. During bank-full flows the maximum scour hole was recorded away from the structures toe and the scourhole size was directly related to the protrusion angle of the structure to the flow. It was concluded that the proposed structure inclination with respect to the main flow direction was appropriate since it provides maximum bank protection while creating the largest volume of local scour away from the structure and towards the center of the channel. Furthermore, the lowest potential for bank erosion also occurs with the present set-up design chosen by the IDOT. About 2 ft of new material was deposited in the area located between the structures for the period extending from the construction day to May 2007. Surveys obtained by sonar and the presence of vegetation indicate that new material has been added at the bank toes. Finally, the structures provided higher variability in bed topography forming resting pools, creating flow shade on the leeward side of the structure, and separation of bed substrate due to different flow conditions. Another notable environmental benefit to rock riprap weirs and dikes is the creation of resting pools, especially in year 2007 (2nd year of the project). The magnitude of these benefits to aquatic habitat has been found in the literature that is directly related to the induced scour-hole volume.
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This study is a concise summary of a study of trail users on the Raccoon River Valley Trail commissioned by the Dallas County Conservation Board. It provides information associated with natural and cultural resources.
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This issue review provides an overview of funds dispersed for the soil and water conservation cost share program in the Department of Agriculture and Land Stewardship, DALS.
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The distribution and status of Iowa's fishes were last extensively described in Iowa Fish and Fishing (Harlan et al. 1987). Since then, numerous fish collections have been made in Iowa's interior and bordering rivers and streams. Excluding non-native species, there have been three documented accounts of new fish species distributional records in Iowa since 1987. In this paper, I describe new collections of Crystal Darter (Crystallaria asprella) and Bluntnose Darter (Etheostoma chlorosomum) from the Mississippi River. The first documented specimen of C. asprella in Iowa was collected in Pool 11 of the Upper Mississippi River (UMR) in 1995. One specimen of E. chlorosomum was collected in Pool 13 of the UMR in 1998, and another was collected in 1999. The bluntnose darter had not been collected since 1975 and was generally thought to be extirpated in Iowa.
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Water planning efforts typically identify problems and needs. But simply calling attention to issues is usually not enough to spur action; the end result of many well-intentioned planning efforts is a report that ends up gathering dust on a shelf. Vague recommendations like “Water conservation measures should be implemented” usually accomplish little by themselves as they don’t assign responsibility to anyone. Success is more likely when an implementation strategy — who can and should do what — is developed as part of the planning process. The more detailed and specific the implementation strategy, the greater the chance that something will actually be done.
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Summary of biological water quality data collected during the Floods of 2008.
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Physical habitat characteristics such as stream width, depth, instream cover, and substrate composition are important environmental factors that shape Iowa’s stream fish species assemblages. The Iowa Department of Natural Resources (IDNR) stream biological assessment program collects physical habitat data to help interpret fish assemblage sampling results in order to assess stream health condition and the attainment status of designated aquatic life uses. The quantitative habitat indicators and interpretative guidelines developed in this study are designed for specific applications within the stream bioassessment program. These tools might also be useful to natural resource managers for purposes such as stream habitat improvement prioritization, goal-setting, and performance assessment.
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The information presented in this summary document has been based on the comprehensive,"Task Force Report on Water-Oriented Outdoor Recreation, Fish and Wildlife." The overriding principle the main task force report conveyed is that Iowa should not forsake the remaining water-oriented fish and wildlife resource base in the name of economic development.The reader should refer to the task force document for more detailed information.
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Larval habitat for three highland Anopheles species: Anopheles albimanus Wiedemann, Anopheles pseudopunctipennis Theobald, and Anopheles punctimacula Dyar and Knab was related to human land uses, rivers, roads, and remotely sensed land cover classifications in the western Ecuadorian Andes. Of the five commonly observed human land uses, cattle pasture (n = 30) provided potentially suitable habitat for A. punctimacula and A. albimanus in less than 14% of sites, and was related in a principal components analysis (PCA) to the presence of macrophyte vegetation, greater surface area, clarity, and algae cover. Empty lots (n = 30) were related in the PCA to incident sunlight and provided potential habitat for A. pseudopunctipennis and A. albimanus in less than 14% of sites. The other land uses surveyed (banana, sugarcane, and mixed tree plantations; n = 28, 21, 25, respectively) provided very little standing water that could potentially be used for larval habitat. River edges and eddies (n = 41) were associated with greater clarity, depth, temperature, and algae cover, which provide potentially suitable habitat for A. albimanus in 58% of sites and A. pseudopunctipennis in 29% of sites. Road-associated water bodies (n = 38) provided potential habitat for A. punctimacula in 44% of sites and A. albimanus in 26% of sites surveyed. Species collection localities were compared to land cover classifications using Geographic Information Systems software. All three mosquito species were associated more often with the category “closed/open broadleaved evergreen and/or semi-deciduous forests” than expected (P ≤ 0.01 in all cases), given such a habitat’s abundance. This study provides evidence that specific human land uses create habitat for potential malaria vectors in highland regions of the Andes.
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Describe las distintos formas de encauzarse que puede tomar el agua dulce sobre la superficie de la Tierra. Las aguas tanto de los ríos como de los lagos están en constante movimiento, podemos conocer sus características, así como la vida animal que se encuentra en y cerca de ellas.