Distributed simulation method of non-point source nitrogen and phosphorus loss form constitution in hilly regions

Abstract

The present invention discloses a distributed simulation method of non-point source nitrogen and phosphorus loss form constitution in hilly regions. The method comprises the following steps of according to related data and materials collected about meteorology, runoff, sediment, digital elevation model, soil, land use, vegetation cover, administrative divisions and social economy, processing various spatial data and attribute data via GIS (Geographic Information System) technology and making a thematic layer; then constituting an integrated simulation method which has physical mechanisms and takes dissolved and absorbed non-point source pollution loads into consideration; and quantitatively simulating temporal and spatial distribution characteristics of non-point source nitrogen and phosphorus loss form. In comparison with the existing simulation method, according to the distributed simulation method of the non-point source nitrogen and phosphorus loss form constitution in hilly regions disclosed by the present invention, a new technical approach for non-point source nitrogen and phosphorus loss form simulation in loss hilly regions is provided, and a difficult problem that the dissolved and absorbed non-point source loads cannot be accurately quantified because of extensive ranges of occurrence is overcome. The method is simple and easy to apply, the estimation accuracy of the constitution ratio of non-point source loss load form is improved, and technical support can be provided for a non-point source pollution control decision.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering, and relates to a distributed simulation method for the form composition of non-point source nitrogen and phosphorus loss in hilly areas, in particular to a distributed simulation method for form composition of non-point source nitrogen and phosphorus loss in hilly areas based on GIS . Background technique [0002] The proportion of form composition is an important means to evaluate the formation process of non-point source pollution, and it is also the theoretical basis for formulating non-point source pollution control countermeasures. The typicality of the water and sediment process in my country's loess hilly areas makes it necessary to study the composition ratio of nitrogen and phosphorus loads from non-point sources, and the distributed simulation research on the composition ratio of nitrogen and phosphorus forms has an important reference role for the formulation of pollu...

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Problems solved by technology

At present, the combination of SCS-CN, USLE / RULSE and non-point source pollution monitoring is the most widely used. There are few research reports on the coupling of rainfall runoff, soil erosion and non-point source pollutant transport.

The runoff simulation part of many comprehensive non-point source pollution models for river basins abroad, such as AGNPS and SWAT, basically uses the runoff curve number method (SCS-CN). Whether the SCS method is completely suitable for the actual situation in my country still needs to be corrected locally; in addition , the SCS method does not include a separate simulation of soil inflow, and soil inflow also has an important contribution to erosion and sediment transport and the formation of agricultural non-point source pollution. Considering the above reasons, it is difficult to estimate the amount of nitrogen and phosphorus loss in the watershed based on the existing integrated model

[0004] From the above analysis, we can see that a lot of research has been done on the sub-processes of non-point source pollution at home and abroad in the past, and remarkable results have been achieved. The source pollution model is carried out separately, or the hydrological model is combined with the soil erosion model, or the soil erosion model is combined with the non-point source pollution model, or the comprehensive model with local characteristics developed abroad does not organically combine the three The study of the form and composition of non-point source pollution has not been combined with the typicality of water and sediment processes in my country's loess hilly areas and the particularity of nitrogen and phosphorus loss

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