On Effects of Weights in Spatial Interpolation

Chaokui Li, Liang Chen, Yong Wang and Shuanning Zheng 
Institute of Geospatial Information Science, Hunan University of Science and Technology, Xiangtan,  Hunan 411201, China

Abstract.  Nowadays, GIS software systems provide some generic interpolation methods. Errors may occure due to inappropriate setting of parameters. For example, in IDW, the default value of exponent is 2. But experiments prove that 2 may not be the best. This article discusses the inverse distance weighted method
and the spline Functions. It was found that: (1) The choice of weights of IDW has great impact on interpolation results, we must choose the exponent according to the specific circumstances in the problem domain; (2) In some areas, data points are scarce or missing, increasing the exponential value of IDW appropriately can improve the  results; (3) In comparison to  IDW, splines are more suitable for situations where surface changes gradually, such as temperature, elevation, groundwater temperature, concentration of pollution, and so on.

Keywords: IDW, regularized spline, rension spline, exponential, weight

In: Wan, Y. et al. (eds) Proceeding of the 8th international symposium on spatial accuracy assessment in natural resources and environmental sciences, World Academic Union (Press).

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