Out of the total volume of water applied at a given point on the soil surface, water in excess of soil intake rate will remain or flow over the land surface, depending on the topography or slope of land. More the slope, more rapid will be the movement of water towards the lower end of the field. Undulating topography also has its effect on the selection of irrigation methods. In an undulating field water will stagnate at low points and at the same time high spots will not receive adequate water. If this situation cannot be remedied by leveling / shaping because of shallow soils, it will not be possible to adopt gravity or surface irrigation methods in such fields.
Rainfall, temperature, humidity, wind velocity, radiation, etc., also have an effect on selection of irrigation methods, because of their effect on evapotranspiration. Wind velocity and direction as well as temperature greatly affect the performance of sprinkler irrigation method.
Water supply in terms of quantity and quality as well as the interval are important criteria for consideration while selecting appropriate method of irrigation. If available flow is top small to be used for gravity methods, pressure methods may be the only solution. Similarly, presence of salt in water is other factor of importance for selection of appropriate irrigation methods, since, the accumulation of salts in the root zone will adversely affect the production. In such a case a method, which will push the salt out of the root zone should be preferable.