Provides syntheses of studies in three continents on the problem of achieving and understanding tropical rural development without compromising longer--term sustainability of the soil and water systems that underpin it. The studies were carried out in Central/South America, Africa and Asia during the 1990s, mostly through the support of the EU Science and Technology for Development Programme. The studies encompass examples of erosion measurement:; of erosion control and conservation techniques at soil and ecosystem levels; of the limits to uses of fragile tropical soils; of the effects of runoff combined with regulation on rivers and reservoirs; of the importance of indigenous people in the development processes and of the value and limitations of modelling at scales from soils to catchment. There is no single message from the book because there is no single solution to the problems of achieving sustainable tropical development. This book presents ideas, techniques and case studies, knowledge of which will help researchers in many scientific and social disciplines to understand the complexities better, and politicians and bureaucrats to understand the consequences of development decisions and learn from the failure of many earlier ones.