Harmonizing multi-sectorial water management with minimum flow requirements in an anthropogenically impacted river basin. The case of Vu Gia – Thu Bon, Central Viet Nam

The low flow phenomenon is significantly concerned since it severely impacts socio economic activities. During low flow periods, diminished freshwater resources are often unable to provide adequate water for crop production, hydropower generation and urban water supply, as well as to maintain water quality of freshwater bodies due to high concentration of pollutants and saltwater intrusion. Accordingly, determining the required minimum flows in rivers during low flow periods is important to reduce the impact of saltwater intrusion and maintain a sustainable water supply for different water users such as agriculture, domestic use and industries. Located in the central coastal zone of Viet Nam, the Vu Gia – Thu Bon river basin experiences drought during the dry season along with salt intrusion due to low flow. The region was chosen as an in-depth case study since it provides crucial information regarding the low flow phenomenon and drought situation during the period 1976 - 2014. This research aims to develop a generally applicable methodology to assess minimum flow requirements in the rivers. The goal of this thesis is (1) to analyze the low flow phenomenon and minimum flow requirements; (2) to quantify the potential water demand from the different user categories; (3) to assess the performance of the existing irrigation system in regards to water supply availability and water demand; (4) to determine the required minimum flow to prevent salt intrusion and satisfy the water demand from different activities during low flow periods; and (5) to derive a generally applicable methodology to assess minimum flow requirements in multi-sectorial water management scenarios. Firstly, statistical analysis was conducted to examine trends in precipitation and flow during the study period. Thereafter, a flow duration curve and SPEI index were calculated to understand the flow pattern and drought events in the region. The potential water demand was quantified for the agricultural sector, as well as domestic and industrial uses to map the water utilization pattern. The Penman – Monteith equation was applied to calculate the potential evapotranspiration using the data from the dry year 2005. Furthermore, the performance of the irrigation system was accessed by analyzing the two indicators of Relative Water Supply and Relative Irrigation Supply. Finally, a calculation of the minimum flow requirement was carried out by applying the hydrodynamic model MIKE 11. The model was run for different upstream discharge datasets to test the response of the salt concentration, and then define where the salt concentration remains under threshold values at chosen measurement points. Six different scenarios were developed to predict the minimum flow requirements toward the changes in potential water use, sea level rise and water use efficiency. In general, the analysis of precipitation and flow revealed strong increasing trends, however these were mostly seen in rainy season. On the other hand, the SPEI index showed a decrease of drought events in the years post 2000. The yearly potential demand of the Vu Gia -Thu Bon Delta was calculated as 309 million m3, of which 203 million m3 is for agriculture, 89 million m3 is for domestic use, and only 17 million m3 is for industry. Furthermore, the analysis of Relative Water Supply and Relative Irrigation Supply revealed the constraints of the irrigation system to supply sufficient water for the crops, especially from February to June. Finally, the results of the six scenarios were mapped presenting the spatial and temporal extents of the minimum flow requirements in the Vu Gia – Thu Bon river basin. The described methodology includes transferable state-of-the-art techniques, making it an applicable approach to determine the minimum flow requirement in an anthropogenically influenced river basin. This methodology has been successfully tested in the Vu Gia - Thu Bon river basin and can be extrapolated to similar river basins

Opportunities for improving irrigation efficiency with quantitative models, soil water sensors and wireless technology

Increasingly serious shortages of water make it imperative to improve the efficiency of irrigation in agriculture, horticulture and in the maintenance of urban landscapes. The main aim of the current review is to identify ways of meeting this objective. After reviewing current irrigation practices, discussion is centred on the sensitivity of crops to water deficit, the finding that growth of many crops is unaffected by considerable lowering of soil water content and, on this basis, the creation of improved means of irrigation scheduling. Subsequently, attention is focused on irrigation problems associated with spatial variability in soil water and the often slow infiltration of water into soil, especially the subsoil. As monitoring of soil water is important for estimating irrigation requirements, the attributes of the two main types of soil water sensors and their most appropriate uses are described. Attention is also drawn to the contribution of wireless technology to the transmission of sensor outputs. Rapid progress is being made in transmitting sensor data, obtained from different depths down the soil profile across irrigated areas, to a PC that processes the data and on this basis automatically commands irrigation equipment to deliver amounts of water, according to need, across the field. To help interpret sensor outputs, and for many other reasons, principles of water processes in the soil–plant system are incorporated into simulation models that are calibrated and tested in field experiments. Finally, it is emphasized that the relative importance of the factors discussed in this review to any particular situation varies enormously

TWINLATIN: Twinning European and Latin-American river basins for research enabling sustainable water resources management. Combined Report D3.1 Hydrological modelling report and D3.2 Evaluation report

Water use has almost tripled over the past 50 years and in some regions the water demand already exceeds supply (Vorosmarty et al., 2000). The world is facing a “global water crisis”; in many countries, current levels of water use are unsustainable, with systems vulnerable to collapse from even small changes in water availability. The need for a scientifically-based assessment of the potential impacts on water resources of future changes, as a basis for society to adapt to such changes, is strong for most parts of the world. Although the focus of such assessments has tended to be climate change, socio-economic changes can have as significant an impact on water availability across the four main use sectors i.e. domestic, agricultural, industrial (including energy) and environmental. Withdrawal and consumption of water is expected to continue to grow substantially over the next 20-50 years (Cosgrove & Rijsberman, 2002), and consequent changes in availability may drastically affect society and economies. One of the most needed improvements in Latin American river basin management is a higher level of detail in hydrological modelling and erosion risk assessment, as a basis for identification and analysis of mitigation actions, as well as for analysis of global change scenarios. Flow measurements are too costly to be realised at more than a few locations, which means that modelled data are required for the rest of the basin. Hence, TWINLATIN Work Package 3 “Hydrological modelling and extremes” was formulated to provide methods and tools to be used by other WPs, in particular WP6 on “Pollution pressure and impact analysis” and WP8 on “Change effects and vulnerability assessment”. With an emphasis on high and low flows and their impacts, WP3 was originally called “Hydrological modelling, flooding, erosion, water scarcity and water abstraction”. However, at the TWINLATIN kick-off meeting it was agreed that some of these issues resided more appropriately in WP6 and WP8, and so WP3 was renamed to focus on hydrological modelling and hydrological extremes. The specific objectives of WP3 as set out in the Description of Work are

IoT-based smart irrigation management system using real-time data

An adequate water supply is essential for the growth and development of crops. When rainfall is insufficient, irrigation is necessary to meet crop water needs. It is a crucial and strategic aspect of economic and social development. To combat climate change, there is a need to adopt irrigation management techniques that increase and stabilize agricultural production while saving water, using intelligent agricultural water technologies. Internet of things (IoT) based technologies can achieve optimal use of water resources. This article introduces a smart realtime irrigation management system based on the internet of things. It provides optimal management of irrigation decisions using real-time weather and soil moisture data, as well as data from precipitation forecasts. The proposed algorithm is developed in real-time based on the IoT, enabling us to guide irrigation and control the amount of water in agricultural applications. The system uses real-time data analysis of climate, soil, and crop data to provide flexible planning of the irrigation system’s use. A case study from the Fez-Meknes region in Morocco is presented to demonstrate the proposed system’s effectivenes

Technologies for climate change adaptation: agricultural sector

This Guidebook presents a selection of technologies for climate change adaptation in the agricultural sector. A set of twenty two adaptation technologies are showcased that are primarily based on the principals of agroecology, but also include scientific technologies of climate and biological sciences complemented with important sociological and institutional capacity building processes that are required to make adaptation function. The technologies cover monitoring and forecasting the climate, sustainable water use and management, soil management, sustainable crop management, seed conservation, sustainable forest management and sustainable livestock management. Technologies that tend to homogenize the natural environment and agricultural production have low possibilities of success in conditions of environmental stress that are likely to result from climate change. On the other hand, technologies that allow for, and indeed promote, diversity are more likely to provide a strategy which strengthens agricultural production in the face of uncertain future climate change scenarios. In this sense, the twenty two technologies showcased in this Guidebook have been selected because they facilitate the conservation and restoration of diversity while at the same time providing opportunities for increasing agricultural productivity. Many of these technologies are not new to agricultural production practices, but they are implemented based on assessment of current and possible future impacts of climate change in a particular location. Agro-ecology is an approach that encompasses concepts of sustainable production and biodiversity promotion and therefore provides a useful framework for identifying and selecting appropriate adaptation technologies for the agricultural sector. The Guidebook provides a systematic analysis of the most relevant information available on climate change adaptation technologies in the agriculture sector. It has been compiled based on a literature review of key publications, journal articles, and e-platforms, and by drawing on documented experiences sourced from a range of organizations working on projects and programmes concerned with climate change adaptation technologies in the agricultural sector. Its geographic scope is focused on developing countries where high levels of poverty, agricultural production, climate variability and biological diversity currently intersect. Key concepts around climate change adaptation are not universally agreed. It is therefore important to understand local contexts – especially social and cultural norms - when working with national and sub-national stakeholders to make informed decisions about appropriate technology options. Thus, decision-making processes should be participative, facilitated, and consensus-building oriented and should be based on the following key guiding principles: increasing awareness and knowledge, strengthening institutions, protecting natural resources, providing financial assistance and developing context-specific strategies. For decision-making the Community–Based Adaptation framework is proposed for creating inclusive governance that engages a range of stakeholders directly with local or district government and national coordinating bodies, and facilitates participatory planning, monitoring and implementation of adaptation activities. Seven criteria are suggested for the prioritization of adaptation technologies: (i) The extent to which the technology maintains or strengthens biological diversity and is environmentally sustainable; (ii) The extent to which the technology facilitates access to information systems and awareness of climate change information; (iii) Whether the technology support water, carbon and nutrient cycles and enables stable and/or increased productivity; (iv) Income-generating potential, cost-benefit analysis and contribution to improved equity; (v) Respect for cultural diversity and facilitation of inter-cultural exchange; (vi) Potential for integration into regional and national policies and can be scaled-up; (vii) The extent to which the technology builds formal and information institutions and social networks. Finally, recommendations are set out for practitioners and policy makers: • There is an urgent need for improved climate modelling and forecasting which can provide a basis for informed decision-making and the implementation of adaptation strategies. This should include traditional knowledge. • Information is also required to better understand the behaviour of plants, animals, pests and diseases as they react to climate change. • Potential changes in economic and social systems in the future under different climate scenarios should also be investigated so that the implications of adaptation strategy and planning choices are better understood. • It is important to secure effective flows of information through appropriate dissemination channels. This is vital for building adaptive capacity and decision-making processes. • Improved analysis of adaptation technologies is required to show how they can contribute to building adaptive capacity and resilience in the agricultural sector. This information needs to be compiled and disseminated for a range of stakeholders from local to national level. • Relationships between policy makers, researchers and communities should be built so that technologies and planning processes are developed in partnership, responding to producers’ needs and integrating their knowledge

Comparing estimates of actual evapotranspiration from satellites, hydrological models, and field data: a case study from Western Turkey

Evapotranspiration / Estimation / Remote sensing / Satellite surveys / Field tests / Measurement / Productivity / Crops / Water requirements / Water balance / Irrigation management / River basins / Hydrology / Models / Turkey / Gediz River

Web GIS to support irrigation management: a prototype for SAGRA network, Alentejo Portugal

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial TechnologiesAn efficient water management, not only allows significant savings in costs of irrigation, but also an effective control on the quality of products, which can have obvious consequences on income operation and reducing the environmental impact of irrigation. As the Internet is becoming the easiest way of information distribution, irrigation management system can also be benefitted with it. Integrating GIS functionality with internet capacity will redefine the way of decision making, sharing and processing of information. In irrigation systems weather plays an imperative role in decision making, implementing and forecasting. Temperature, humidity, precipitation, and solar radiation are the most important parameters to calculate evapotranspiration by which crop water requirement can be determined. SAGRA (Sistema Agrometeorológico para a Gestão da Rega no Alentejo) network is providing information to the farmers through web but still lacks the use of GIS in their information to decision support system. Irrigation management support system can be benefitted with the use of Web GIS. In this thesis, web based GIS is designed using popular open source tools and software. Using data from automatic weather station maps are produced using Geo-statistical interpolation techniques and published in web map. These maps can be viewed with popular online maps like Google maps, Microsoft Bing and Openstreet maps. Animated weather maps are also created which are useful for visualizing changing pattern of weather parameters and water requirement over time

Water Demand Analysis within the Pursat River Catchment

MK16 Fostering Evidence-based IWRM in Stung Pursat Catchment (Tonle Sap Great Lake)In order to address water resources issues and develop capacities for implementing IWRM, there is a need for better collaboration between sectors and use of scientific data in decision making. Collaborative and informed decision-making rely on better understanding of, and access to quantitative and qualitative research results. Multi-stakeholder Platforms (MSPs) are forums to share and discuss such research outputs with various government sectors and water users. This report contributes to the Stung Pursat MSP process by providing information about changes in water balance in Pursat. The objectives of the Water Demand Analysis within the Pursat River Catchment report are to: Present and compare the water balance in the Pursat catchment under two scenarios; a) natural scenario (absence of Dam No. 1, No. 3, and No. 5) and b) dam scenario (presence of Dam 1, 3, and 5); and Apply and critique th