Estimation Of Pollutant Fluxes From River To Sea Under Spare Data

In order to prevent further deterioration of eco-environment of river basin and offshore area, protect ecological environment, utilize natural resources reasonably and sustainability, firstly the pollution status of the river basin and offshore area should be grasped clearly. It is the basis for accurate determination of pollutant fluxes from river to sea and distribution of total pollution load and environmental capacity to master deeply the pollutant fluxes of river basin and estuary area. Under the condition of water environmental monitoring at present and in a long period of time, the data of the pollutant fluxes of the river basin section and estuary area section from river to sea will be obtained insufficiently, meanwhile some kinds of problems in relative to spare data also exist, such as poor representation, mismatch of each other, big error and so on, which will doubtlessly bring tremendous difficulties for estimating pollutant fluxes from river to sea accurately. Based on this idea, in order to solve the practical problems in computing the pollutant fluxes of the river basin section and estuary area section from river to sea under spare data, made a research on the estimation method of fluxes from river to sea by synthetically using of probability theory, mathematical statistics, numerical analysis and other relative theories.Generally speaking, the Lagrange interpolation polynomial is used to count the pollutant fluxes under spare data, the fatal defect of this kind of analytic function is that the analytical continuation of the function is unstable, namely, when there are micro-error in original data, the calculated results will be infidelity due to the accumulation and propagation of errors, furthermore, this phenomenon will be more serious under spare data. Based on the basic principle of practicability, feasibility, conciseness and reality, after consulted to large amount of references, used the relative theory for data smooth processing, based on the condition that monitoring data are not usually enough to count the pollutant fluxes from river to sea, introduced more stable and reliable algorithm in allusion to the present estimation model’s defect and deficiency, that is, used Cubic Spline Function to interpolate spare data for the first time and used B Spline Function to correct the process of function fitting, established a new method by using of "double spline correction model" to calculate the pollutant fluxes from river to sea under spare data. Meanwhile, according to the present theory for estimating the pollutant fluxes, constructed a series of prediction models—weighted average prediction models and geometric mean prediction models. Through the comparison of the extant models, weighted average prediction models, geometric mean prediction models and double spline correction model, finally brought forward the theory and methods for estimating pollutant fluxes from river to sea under spare data optimally.Adopted the advanced mathematics treatment platform nowadays, such as Matlab、 MATHEMATICA and SPSS to construct the relative programs for calculating pollutant flux. Took liaodong bay basin for example, aiming at the pollutant fluxes of Daliaohe river, Shuangtaihe river, Dalinghe River and Xiaolinghe river in Liaodong bay basin, COD, kMN04, Total Phosphorus and Ammonia Nitrogen were selected as indices of pollutant fluxes, the new flux calculation model was used on them. Finally, after examined by Liaoning environmental statistics data and Liaohe basin’s relative investigation data gained by long-term environmental management practice the estimation result is in accordance with reality.