Analysis of the Impact of Land Use Change on Tidal Flood in Kendari City
Sitti Marwah, La Ode Alwi

Abstract
This study used a survey method and plot trial method. The biophysical data of land consisted of land use, climate, topography, and land quality. The hydrological data of land comprised erosion, sedimentation, run-off, and run-off coefficient. The hydrological data of watershed (DAS) included the ratio of the maximum and minimum discharge. The objectives of the study were: 1) to analyze the impact of land use changes in the Wanggu watershed on the decrease in the forested area, land quality and the hydrological condition of the watershed; 2) to find out agro-technology applied by farmers in the upstream part of the Wanggu watershed and drainage system in the city of Kendari; and 3) to formulate land use to prevent floods in the city of Kendari. The research was conducted from January 2014 to July 2014. The results of this study showed that: 1) there was a decrease in the forested area by 10,908.7 ha (24.0%) of the watershed, so that the remaining forested area was 19.1 <30% of the Wanggu watershed; 2)there was a decline in land quality such as the weight of soil volume, porosity and soil organic matter, land cover and potential interception; 3) there was a decrease in infiltration capacity, soil permeability; 4) there was an increase in run-off by 499.5 mm / yr, run-off coefficient 25.6%, erosion 23.1 tonnes / ha / year, and the ratio of the maximum and minimum discharge from 49.1 to 75.9> 30, indicating that the Wanggu watershed was in a critical condition; 5) the implementation of agro-technology by farmers was not in accordance with the ability and suitability of the land; 6) the technology of soil and water conservation was not implemented by farmers as shown by the farm erosion by 48.3 tons / ha / yr > TSL 16.7 tons / ha / yr and residential area by 26.0 tons / ha / yr > TSL 9.1 tonnes / ha / yr, leading to land degradation; 7) the rob flood in the city of Kendari was as high as 2-5 m for 3-6 days due to 24.4% decrease in the forest area of the Wanggu watershed and land degradation affecting the hydrological condition of the Wanggu watershed, residential wastes, drainage systems and poor environmental sanitation, the loss of marshes in Kendari bay area, high rainfall of 2.7391 mm / yr and high tide levels exceeding highway; 8) the study tried to formulate flood prevention in the city of Kendari with land use of a minimum forest size of 30% (13,613.3 ha) and agroforesty 37.3% (16,938.3 ha); 9) there was an efforts to apply the technology of agronomic and vegetative soil conservation; 10) there was an increase in the quantity and quality of the drainage system in the city of Kendari of the Wanggu watershed.

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