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This paper describes the results of a study of hydrologic factors affecting floods from humid region in northeastern Ohio. Statistical multiple correlation analysis was used to relate floods to hydrologic and basin characteristics. Results of the study emphasize that the characteristics of floods from small and large watersheds are so significantly different that the two problems cannot be combined into one solution. The studies show that the most important hydrologic characteristics in large watersheds were: drainage area size and main channel slope. For small watersheds the most important hydrologic characteristics were: drainage area size, rainfall intensity and soil index. For watershed effect by reservoir storage it was found that: (1) small drainage areas are relatively more affected by storage than large drainage areas; (2) storage of less than 25 acre feet per square mile will not have significant effect on the mean annual flood (for drainage area above 70 square miles).  相似文献   
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Citizen science has been gaining momentum in the United States and Europe, where citizens are literate and often interested in science. However, in developing countries, which have a dire need for environmental data, such programs are slow to emerge, despite the large and untapped human resources in close proximity to areas of high biodiversity and poorly known floras and faunas. Thus, we propose that the parataxonomist and paraecologist approach, which originates from citizen‐based science, is well suited to rural areas in developing countries. Being a paraecologist or a parataxonomist is a vocation and entails full‐time employment underpinned by extensive training, whereas citizen science involves the temporary engagement of volunteers. Both approaches have their merits depending on the context and objectives of the research. We examined 4 ongoing paraecologist or parataxonomist programs in Costa Rica, India, Papua New Guinea, and southern Africa and compared their origins, long‐term objectives, implementation strategies, activities, key challenges, achievements, and implications for resident communities. The programs supported ongoing research on biodiversity assessment, monitoring, and management, and participants engaged in non‐academic capacity development in these fields. The programs in Southern Africa related to specific projects, whereas the programs in Costa Rica, India, and Papua New Guinea were designed for the long term, provided sufficient funding was available. The main focus of the paraecologists’ and parataxonomists’ activities ranged from collection and processing of specimens (Costa Rica and Papua New Guinea) or of socioeconomic and natural science data (India and Southern Africa) to communication between scientists and residents (India and Southern Africa). As members of both the local land user and research communities, paraecologists and parataxonomists can greatly improve the flow of biodiversity information to all users, from local stakeholders to international academia.  相似文献   
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Deep black clayey sediments of the Dead Sea, previously covered with water at times of higher sea level, are being mined for therapeutic purposes and for the preparation of cosmetic products under the name Black Mud. It was claimed that the beneficial properties are due to the presence of bitumen (asphalt) as attested by the colour. Less commonly, the curative properties have been ascribed to humic acids or to organic matter derived from algae in the lake. Asphalt from the Dead Sea has been of major economic importance to the region and was used as a medication for 2000 years until the mid-20th century. Geochemical analysis of the Black Mud showed that it contains relatively little organic matter (ca. 0.6–0.8% organic carbon) and that the organic matter is mostly derived from the land masses surrounding the lake. Asphalt was totally absent and the concentration of humic acids very low. The black colour of the mud is rather due to the poorly crystallised iron sulphides. Based on this, the therapeutic properties of the mud are ascribed to its content of reduced sulphur species, its physical and chemical properties and possibly its brine content, but not to the presence of organic matter.  相似文献   
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