Abstract:
Over consumption of water resources due to unplanned and inappropriate irrigation methods would be a threat to the ecosystem health and to the sustainable agriculture in Vavuniya District. The objective of this study was to identify the most appropriate irrigation method using remotely sensed or derived hydro geological and meteorological information. The impact of different types of irrigation methods on water use efficiency, water consumption, socio economic aspects of irrigation and soil condition were considered to fulfil the objective of this study. Evaporative fraction, soil moisture content, hydrological parameters and the meteorological parameters were derived using satellite imageries namely the products of Moderate Resolution Imaging Spectro-radiameter (MODIS), MOD 09 A1 (Solar Zenith Angle), MOD 11 A1 (Land Surface Temperature), MOD 13 A1 (Normalized Different Vegetation Index) and MOD 43 B3 (Surface Albedo) and the Shuttle Radar Topography Mission (SRTM) DEM (90m resolution) associated with field reference data during January 2014 to June 2014. Estimation of evaporative fraction and soil moisture content were collectively done with the aid of Surface Energy Balance Algorithm (SEBAL) methodin Ilwis 3.7 environment. Appropriate geometric corrections and image processing operations were applied. Parameterization of hydrological and meteorological parameters was done using automated operations associated with auxiliary information of respective imageries. Information on socio economic aspects of irrigation methods were gathered from semi structured interviews and secondary data sources. This study revealed that integral of hydrological, topographical, meteorological and socio economic factors signifying the importance of micro irrigation methods as viable and effective irrigation method in agriculture. Encouraging the farmers to use micro irrigation methods by providing the credit facilities and the subsidy to install micro irrigation systems is vital for the water resource conservation and thereby the sustainable agriculture.
