One of the following two methods is generally used for the estimation of irrigation requirement: 1. Method Based on 'Duty of Water': In this method, the designer has to first decide the duty of water for different crops in the command area of the system. Duty of water (or simply duty) for a given crop is defined as the area [...]
Flow of ground water through porous medium is governed by well-known Darcy's law which states that the rate of flow, Q through a saturated porous medium is: (i) Proportional to the difference in hydraulic head Ah between the two flow sections, (ii) Proportional to the area of flow cross-section A, and (iii) Inversely proportional to the length, L between the [...]
This article provides a paragraph on well irrigation. The amount of water stored in the earth's crust is estimated to be around 8 billion cubic kilometres, half of which is at depths less than 800 metres. This volume of water is about 35 times the combined storage of all the world's rivers, fresh water lakes, reservoirs and inland seas. Ground [...]