Mehari A.,UNSECO IHE |
Van Steenbergen F.,MetaMeta |
Irrigation and Drainage | Year: 2011
Spate irrigation, a floodwater harvesting and management system, has for the past 70 centuries provided a livelihood for about 13 million resource-poor people in some 20 countries. Despite being the oldest, the system still remains the least studied and the least understood. It is only in the past two decades that the system has been subject to some modernization interventions, much of which focused on improving floodwater diversion efficiency. Effective floodwater diversion measures are necessary, but they must be supplemented with equally effective field water management and soil moisture conservation measures if sustainable improvement of land and water productivity is to be achieved. This paper draws on studies conducted in the past 5 years, particularly in the Republic of Yemen, Pakistan and Eritrea. The studies employed both qualitative and quantitative methods and assessed the modernization package that could result in lasting enhancement of crop productivity in spate irrigated agriculture. The suggested modernization measures include: avoid overstretching the command area; limit the number of irrigation turns to two or an irrigation gift of 1000mm; avoid field bund heights of more than 1m; adopt a field-to-field water distribution system instead of an individual field water distribution system; opt for water rights and rules that entitle downstream fields to the more frequent small and medium floods thereby ensuring equity in both water quality and quantity; optimize soil water-holding capacity and infiltration rate through pre-and-post irrigation tillage, combined tillage as well as soil mulching. © 2010 John Wiley & Sons, Ltd.
Hijdra A.,Rijkswaterstaat |
Arts J.,University of Groningen |
Woltjer J.,University of Groningen
Water Resources Management | Year: 2014
In the past canals were developed, and some rivers were heavily altered, driven by the need for good transportation infrastructure. Major investments were made in navigation locks, weirs and artificial embankments, and many of these assets are now reaching the end of their technical lifetime. Since then the concept of integrated water resource management (IWRM) emerged as a concept to manage and develop water-bodies in general. Two pressing problems arise from these developments: (1) major reinvestment is needed in order to maintain the transportation function of these waterways, and (2), it is not clear how the implementation of the concept of IWRM can be brought into harmony with such reinvestment. This paper aims to illustrate the problems in capital-intensive parts of waterway systems, and argues for exploring value-driven solutions that rely on the inclusion of multiple values, thus solving both funding problems and stakeholder conflicts. The focus on value in cooperative strategies is key to defining viable implementation strategies for waterway projects. © 2014 Springer Science+Business Media Dordrecht.
Proceedings WODCON XX - Congress and Exhibition: The Art of Dredging | Year: 2013
Human interference has drastically changed fluviatile, deltaic and coastal hydro-morphological regimes. Normalisation of rivers and construction of embankments have reduced the supply of sediments to floodplains and deltas leading to erosion. Drainage, extraction of groundwater and changes in land-use for urbanisation, agriculture and industrialisation for growing populations have caused land subsidence in many coastal and deltaic zones. These increasing pressures make these areas more vulnerable for the consequences of climate change such as sea level rise, increased frequency of storms, and damage to ecosystems. Changes in seasonal precipitation may cause changes in sedimentation and erosion patterns leading to floods and droughts in river basins. Adaptation measures are absolutely necessary to overcome these challenges for which dredging is an important tool. This creates opportunities for the dredging sector. This paper focuses on the relations between flood protection measures and dredging for navigation in river systems. An example of flood management by making space for water is the Dutch programme Room for the River. River discharges are enlarged by a number of measures such as deepening, or widening of river beds, lowering of floodplains, construction of side channels and relocation of dikes. In general increase of flood conveyance capacity will lead to a decrease in flow velocity and increase in sedimentation. Other measures such as for the Water Framework Directive also have effects on the morphology of the river. More frequent dredging will be required to remove restrictions for navigation, which may lead to hindrance for navigation. The Dutch Rhine, an important transport axis from main port Rotterdam to Germany, will be presented as a case study. This case is further complicated by erosion of the river bed in the upstream part caused by measures for regulation and navigation. Erosion of the river bed results in bottlenecks for water management and navigation. In order to maintain the sediment balance it is required that sediments from dredging have to be relocated within the river system, but this does not solve the problem. Understanding of the hydro-morphological system is crucial to solve these dilemmas and find sustainable solutions. Also smart dredging methods are required to reduce hindrance for shipping. © 2013 WODA.
Hydro International | Year: 2013
All measures are planned around the users, nature and the landscape and are carried out in close cooperation with water boards, other public authorities, NGOs and private organizations. Hydrography plays a major role in the work of Rijkswaterstaat. New demands from policymakers and the public as well as pressure on the budgets pose new challenges for the hydrographic department of Rijkswaterstaat. The Netherlands has a love and hate relationship with water. First of all water is of major economic importance to the Netherlands for the transportation of goods from all over the world through the Port of Rotterdam to the European hinterland. Rijkswaterstaat has made an inventory of all the uses of hydrographic information within the organization, the most important being safety. The information is used to guarantee safe shipping to the major harbors of the North Sea as well as on the main inland waterways.
20th ITS World Congress Tokyo 2013 | Year: 2013
This paper reports on the recent developments in the Netherlands concerning Open Data in relation to Traffic Information. Open Data is one of the emerging developments which influence the availability of traffic information. Dilemmas will be sketched and solutions will be given to bring traffic information to the next level.