There are many urgent problems in arid land hydrogeology and it is these issues which are tackled in this volume on desert environments. The UAE-Japan symposia provide a venue for the exchange of expertise, confronting such problems as purification, usage and management of groundwater, the assessment and protection of sustainable water resources, and soil enhancement techniques for moisture control in arid lands. The hope is that a better understanding of dryland environment, combined with innovative solutions and technologies, will contribute to the greening of desert lands.