Analytical approximation to the solutions of Richards' equation with applications to infiltration, ponding, and time compression approximation

A recent approach to solve Richards' equation is further improved. This approach brings understanding into the physical processes of infiltrat- ion and ponding. In particular we apply it to analyze the standard hydrologic tool of Time Compression Approximation (TCA). We also suggest that the new approach provides a more reliable alternative to TCA, e.g. for predicting ponding time.