Drainage, waterlogging, and salinity

Nowadays, various areas in the world have faced waterlogging and salinity problems, which are intensified by a myriad of factors including use of wastewaters for irrigation, unsuitable cropping pattern, torrential rains and floods, lack of sufficient drainage, uncontrolled drainage, lack of adequate knowledge, wrong management decisions, very poor construction and rehabilitation rates of drainage systems, increase of irrigation systems without paying any attention to their adverse impacts on soil and quality of water resources, etc. One effective way to reduce waterlogging and salinity problems is drainage. It is necessary to do a comprehensive study on previous works to arouse awareness of drainage, waterlogging, and salinity and to avoid trial and error policies in these fields. The present paper aims to study drainage, waterlogging, and salinity in the different regions of the world and to present challenges and prospects for further research and making a better decision in this field. The results indicate that the frequency distribution of studies carried out in India, Australia, the USA, Pakistan, and other countries is 23%, 20%, 15%, 12%, and 30%, respectively. While frequency distribution is 45%, 30%, and 25% for focus on salinity, comprehensive studies, and focus on waterlogging, respectively, based on the previous investigations.