http://www.mdpi.com/journal/water/special_issues/urban_land_use/ Dear Colleagues, Humanity has crossed the line from being a rural to urban species since 2007. For the first time in history, more people live in cities and urban areas than in the countryside. Starting in the developed nations, where the urbanization process has been significantly decelerated in the meantime, urbanization has especially increased in Asia and South America as well as in Africa to a substantial extent in the second half of the last century. Especially in developing and emerging countries, the hydrological and hydrogeological setting of each region has deteriorated through growing urbanization processes. Urban areas show, in contrast to the rural areas, a rapid interaction between surface water and groundwater as well as between drinking water and sewage system. Urbanization and the attended changes in the settlement and land use structure will eventually lead to negative consequences for the environment as well as for the water resources. In this context, one of the key tasks of sustainable and long-term land and natural resources management is to optimize water resource utilization referring to the spatial distribution of people and their activities. Klaus Baier, Ph.D. Guest Editor {snippet name="submission_info"} http://www.mdpi.com/2073-4441/2/4/711/ Within the German-Vietnamese joint research project “Integrated Water Resources Management Vietnam”, Planning and Decision Support Tools on a regional scale are being developed. A Water Balance Tool is utilized to calculate and assess water demands and compares these with the quantity of water resources to identify surpluses or deficits. The sensitivity of water resources and the contamination potential are combined to display water quality aspects within a Contamination Risk Tool. A resulting evaluation is carried out with a Ranking Tool. It identifies areas with high priority need for action. The Planning and Decision Support Tools are being discussed with Vietnamese institutions and authorities. http://www.mdpi.com/2073-4441/2/4/711/ Tue, 28 Sep 2010 00:00:00 CEST Water 2010-09-28 2 4 Article 711 725 2073-4441 Planning and Decision Support Tools for the Integrated Water Resources Management in Vietnam 2010-09-28 doi: 10.3390/w2040711 Christian Jolk Sandra Greassidis Sylvia Jaschinski Harro Stolpe Björn Zindler http://www.mdpi.com/2073-4441/2/3/649/ Similar to other Asian nations, suburban areas in Japan are characterized by dense intermixtures of residential areas and farmlands. These hybrid rural/urban areas are evaluated negatively in modern planning frameworks. However, mixed rural/urban landscapes may prove advantageous when attempting to reconstruct sustainable wastewater treatment systems. This research examines the potential for abandoned paddy fields to reduce nitrogen (T-N) and phosphorous (T-P) loads, an increasingly problematic source of eutrophication in many closed water areas, from households in suburban areas. Our results indicate that abandoned paddy fields remaining in mixed urban/rural areas have significant potential to reduce both nitrogen and phosphorous loads. Accordingly, we suggest that abandoned paddy fields can play an important role in reducing pollution loads in mixed urban/rural areas. http://www.mdpi.com/2073-4441/2/3/649/ Sun, 19 Sep 2010 00:00:00 CEST Water 2010-09-19 2 3 Article 649 667 2073-4441 The Potential for Abandoned Paddy Fields to Reduce Pollution Loads from Households in Suburban Tokyo 2010-09-19 doi: 10.3390/w2030649 Jiro Kogi Mariko Miyamoto Jay Bolthouse Makoto Yokohari