Interpolating redundant spatial data from SHUMOO boat survey due to the current directions of Anyar river

Mapping bottom under water or bathymetry is important and more challenging for researchers. Using machine to collect data is the fastest and safeties method. SHUMOO is a boat which is constructed in order to collect the bathymetry data by sounding the shallow area. In this research, the data is taken from a part of the Anyar river which is located at Malang regency, East Java, Indonesia. The length and width of domain of observation are 100 and 35 meters respectively. Unfortunately, the original data which is obtain from SHUMOO consist of several redundant and staking points of water depth. This is due to the current or stream direction of Anyar river. Therefore, this paper is devoted to overcome this stacking data by interpolating the water depth which has redundant spatial coordinate. Here, the average interpolation will be used. The result shows at particular area UTM coordinate (681301, 9114722) by interpolating bathymetry height which has redundant spatial coordinate, the height class 0.65–0.72 meters of contour mapping is wider than by original data. Meanwhile, the contour map of interpolation data shows the opposite for the height class 0.85–0.92 meters which is smaller than the original data.