Analysing the impact of flood caused by improper land use activities in Muttur DS division

Abstract

Flood occurs due to both natural and man-made causes. Among these two most highlighted causes are conversions of natural landscapes for human usage. Muttur experiences severe flood hazards due to the North East Monson and exhaust of doubles with the Mahaweli River in rainy seasons. Flood damage increases as a result of inappropriate land use practices. The primary objective of the study is to analyze the relationship between the impact of the flood and improper land use activities. To achieve the objective the data is collected based on a questionnaire survey, furthermore, the land sat images are used to identify, how the land cover changes occurred in Muttur, with the help of the matrix method using ARC GIS 10.1 software. The study found that the Built-up land in Muttur is rapidly increasing annually is about 141, 50. The land area of water bodies is (-91, 82) and the non-built lands (-49, 68) continuously decreased. It is because water bodies and non-built-up lands are converted into urbanization and tourism development activities, therefore, rainy season water flowing directions are blocked, and it is caused a high impact of the flood. Furthermore, Chi-square analysis strongly proves improper land use activity is the reason for the high impact of the flood in Muttur. The total sample population is a hundred with a df value is 3 and a pvalue is about 0.001. The chi of the impact of the flood and the improper drainage system is 37.079, flood impact and urbanization chi respectively 23.775, Chi of the flood impacts and the deforestation/overgrazing of natural vegetation is 17.045, Flood impacts and the wetland converted into buildup/ development chi is 33.333, Flood and the Mining of sand and other resources chi is 12.676, and flood impacts and overpumping of groundwater chi is 28.671. To overcome this situation, the study recommends reducing the building construction in wetland areas, providing pipeline drinking water facilities to reduce the overpumping of groundwater, banning sand mining activity in hazardous areas, and implementing visible landuse management strategies in the research area.