Geographic Information System Design And Analysis of Sea Water wave Forecast for Early Detection of Seashore Erosion

Scientific process occurred in seashore is the erosion in a seashore area and then to be transported so other area from the mentioned seashore area will form sediment. Sea wave is one of seashore processes that give great contribution to sediment transport rate. Sea wave can be measured directly or to be generated by using wind data. Due to limitation of resources the direct measurement to sea wave in long term is very rarely conducted so it is often to be conducted by using forecast method. In this research it is conducted sea wave forecast at Lebih Beach in order to continuously monitor the seashore processes that occur in Lebih Beach. By using wind data from BMKG of area III Denpasar it is conducted analysis of wind frequency distribution to get dominant wind direction and speed that has effect in Lebih Beach. Based on the wind data it is formed wind data correction reference table whether the elevation factor, location factor, temperature difference factor, and wind stress factor. Then the fetch effective value is calculated. According to fetch value and wind stress value from the conversion reference table it is carried out plotting of wave forecast by using wave forecast graphic so it is obtained the wave forecast reference table. Based on wind data and wind speed that has effect it produced the forecast of wave period and height at Lebih Beach. In addition, it also produced an application that focused on the wave forecast process.