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This book is focused in the formulation of a framework for the sustainable management of the irrigation systems transferred to the users organizations by the government. It describes the experience of the irrigation management transfer in Colombia, the impacts from a technical, social, environment and economic point of view, the current status of some transferred systems and proposes management alternatives in view of sustainability based on an integrated and participatory approach.

The damages caused by floods remain an issue in the Chi River Basin, Thailand. Therefore, an integrated flood management framework needs to be developed to minimize the negative effects of floods of different magnitude. In response, a hydrological model (SWAT) and a hydraulic (1D/2D SOBEK) model were integrated to simulate floods in detailed way and to analyse the current system. The developed modelling framework enabled to analyse the impacts of different structural and non-structural measures based on economic and technical efficiency criteria. An optimum combination of aforesaid measures was then chosen since it could considerably reduce flood extent and its damage. Additionally, the study illustrates the effects of land use changes on floods, which indicated little or no significant potential impact on flood regime at river basin level, but rather at sub-basin scale. This finding is important for a better understanding of the scale and direction of impacts of future developments.

In this book strategies for using very soft organic clay as a fill material for road embankment constructions are compared, and an optimisation scheme is presented. Computer programs for simulation of evaporative drying, for simulation of consolidation, and for slope stability calculation were used to analyse clay behaviour. Field and laboratory testing programs for a trial embankment were set up in order to study the relations of parameters, to examine suitability and workability of the clay, and to verify the improvement methods. An optimisation technique was applied as a rational method for using very soft organic clay for road embankments leading to an economic construction. Also recommendations are presented based on a rational method for conditioning and emplacing very soft organic clay in a safe and economic way.

The demand of land for producing food, for urban development such as housing, industry, shopping areas, infrastructure and also for recreation has increased during the history of mankind. This has, among others, resulted in the reclamation of swamps, flood plains, tidal areas and even lakes by impoldering. To get insight in the system behavior for different land use and soil composition under temperate humid and humid tropic conditions, model simulations can be used. The existing package OPOL, based on a non steady model, was further developed to the version OPOL5 for the simulation of hydrological conditions and optimization of the main components of water management systems in polder areas in the temperate humid and humid tropical zone. The model can show system's behavior and also the effects of variation in the main components of the systems to the overall costs. In this way, the designs of pumped drainage systems in polder areas can be optimized by varying the main components until the annual equivalent costs are minimum. A GIS tooi has been used to complement OPOL5 for the simulation of the real situation in an area with respect to land use, damage, topography, and soil type. The model package has been applied for case studies in the temperate humid zone - the Netherlands - and the humid tropical zone - Thailand.

Lowland is defined as an area which is relatively low in relation to surface or groundwater levels. Tidal lowlands are lowland areas which are influenced by the vertical tides and their characteristics are in accordance with thier hydro-topographical conditions. Tidal lowlands become more and more important in Indonesia and will be the future for agricultural development because, there is a continuous loss of fertile agricultural lands for urban and industrial development mainly in Java. It is estimated that the rate of the loss of agricultural land is about 30,000 ha/year. So far, over 5.5 million ha out of more than 39.4 million ha of tidal lowlands have been identified as potential for agricultural development. Out of the 5.5 million ha, about 3.3 million have already been reclaimed. This study is dealing with soil and water management strategies for tidal lowlands. The term 'soil and water management' in this study is defined as the management of the integrated processes of soil and water quality (acidity or salinity) and water quantity for the purpose of improved agriculturtal practices. The research consists of three levels of interest, namely field, system, and delta level, which are inter-related.

During the past decades huge investments have been made in flood protection, drainage and irrigation schemes to reclaim and develop many polder areas in Bangladesh. In these areas a careful water management is required to get optimal results from the investments in the physical infrastructure and enable the farmers to have a better living. However, In many instances the actual water management in the Flood Control and Drainage (FCD) schemes has been below expectation, resulting in lower yields than were envisaged during the feasibility, design and construction stages. In order to formulate suitable water management strategies for this type of areas research has been conducted in a pilot polder 43/2A. In the framework of this research water management strategies and practices have been developed in consultation with the farmers considering the needs of agriculture, fisheries, navigation and environment. As per requirement in the field and considering the results of the hydrodynamic simulations, a new water management strategy has been developed.This strategy is designed to achieve the maintaining of preferred water levels during the year which will give optimal benefits that were not thought of earlier. The strategy has been prepared to match the normal practice of the farmers.This has also resulted in recommendations for land use zoning, linked to topography, soil and water management conditions. Based on the developed criteria and water management strategy a land suitability analysis has been performed for the present and potential conditions in polder 43/2A.

Egypt is a country of tremendous land resources but limited water resources. The area of cultivated land is only 3.2% of the gross area. The river Nile is the main source of water. In the recent years the Government established large-scale agricultural projects in light of food security related to the population growth. Expansion of irrigated agriculture has to be predominantly realized by increasing the water use efficiency. In Egypt, the dominant irrigation method is surface irrigation, which covers approximately 83% of the irrigated areas. Surface irrigation or gravity methods are generally characterized by a low efficiency. One opportunity to increase the efficiency is to convert surface irrigation to modern irrigation systems, which are generally highly expensive for a country like Egypt. Another option to increase the efficiency of surface irrigation systems is to convert the traditional irrigation method based on continuous flow to surge flow irrigation. Surge flow irrigation is the intermittent application of water to furrows in a series of relatively short on and off time periods. This study has been carried out to demonstrate the applicability of surge flow irrigation for water saving under the short field conditions that prevail in Egypt. The results indicate that surge flow irrigation is an effective irrigation method to save water and to increase crop production.