| Phosphorus is a nutrient element which is necessary for crop growth and also mainly contribute to water eutrophication. Through surface runoff, river transport and the role of settlement and release, phosphorus migrating, spreading and accumulating among the soils, river and lake sediments. The form, content and distribution of phosphorus have a major impact on the ecological environment. However, there is lack of a systematic study on spatial distribution characteristics, relationships and influencing factors. In the studied area of Chaohu Basin, the soils, river and lake sediments samples are collected, and using the variogram method combined with GIS interpolation techniques, to compare the distribution of total phosphorus content of different types of samples, to reveal spatial distribution of phosphorus characteristics in the soils, river and lake sediments for the studied area, investigating the causes of enrichment and the regulations of migration and transformation. By the end, draw the following conclusions:1. The extent and scope of impact of human activities resulting in the total phosphorus content of different samples of the study area:river sediments and surface soil and lake sediments deep soil.2. Less variable range of the variogram in topsoil and instructions in a small range of variation strengthened; deep soil in a wide range between the sampling points and remain clear correlation. Variogram of the lake sediments beyond the step change domain, is the reason of their spatial distribution is the apparent distribution trends.3. The spatial distribution of soil phosphorus on the whole performance to a higher content developed for urban agglomerations and agricultural rivers. Urban land use due to the varying degrees affected by human activities, the significant difference. Due to human intervention is less, the TP content of woodland is generally lower than other types. 4. Regardless of surface or deep soil phosphorus distribution between different parent material types, the type of parent material is the dominant factor in determining their spatial distribution. Late Pleistocene loess parent material in soils of the phosphorus content is generally lower than in other types of parent material.5. The study area of prime agricultural land for the cinnamon soil and paddy soil samples exist more high-value discrete points in some areas by the strong influence of agricultural activities sake.6. Due to the mobility of phosphorus in the soil level is weak, the surface is generally higher than the deep.7. Around town, the interchange of tributaries and the estuary, river sediments, phosphorus content higher, while the birthplace of the upper reaches and sparsely populated areas, low levels. Flows through Hefei and other cities and counties Nanfei-shop port river sampling points of the phosphorus content is generally higher than other water system. River main stream of self-the birthplace of to into the Hukou, the sediments phosphorus content of basic the performance of to out of the the the trend of reduce the in the firstly increased and then, in urban upstream and downstream a certain distance Department to achieve the peak.8. Phosphorus content of river sediments and soil in areas less affected by human influence, the distribution trend is basically the same, the former town-intensive areas significantly higher than the latter, explain the only source of surface runoff is not a river phosphorus, agriculture and industrymunicipal sewage also contributed to its enrichment of the important reasons.9. Distribution of high-value area of Chaohu Lake sediment and from the town and the river estuary near and far. Sediment phosphorus content as a whole, the Chaohu Lake in northern than southern exposed area and the north shore of phosphorus rock to surface runoff.10. The Chaohu eastern half of the phosphorus in the lake sediments with high levels of phenomenon may have a close relationship with the calcium content in the sediment enrichment. |
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