With increasing pressure on available water resources, irrigation systems in many countries are h... more With increasing pressure on available water resources, irrigation systems in many countries are having to find ways to improve performance. As often the main consumptive user, irrigation systems are having to release water for other uses and to produce ''more crop per drop''. Benchmarking is a valuable tool that has proven itself in the business and commercial sector, as well as in public sector enterprises. This paper describes and defines the benchmarking process, and goes on to outline its current application in the irrigation and drainage (I&D) sector. The paper highlights the difficulty of benchmarking in the I&D sector given the complexity and site-specific nature of irrigation and drainage systems, and emphasises the need for careful identification of which processes to benchmark. Preliminary benchmarking indicators are discussed, and attention drawn to efforts currently under way to apply and test this preliminary set. Emphasis is placed on the effort and resources required to bring about the required changes identified by the benchmarking exercise, and the role of change management as an integral part of the benchmarking process. The paper concludes that benchmarking provides a feasible mechanism for performance improvement in the I&D sector, but requires the active involvement of motivated individuals with support from the wider environment, encompassing an enabling socio-political environment and support from key stakeholders.
and I. Makin. 2001. Estimating the potential of rain-fed agriculture. Working Paper 20. Colombo, ... more and I. Makin. 2001. Estimating the potential of rain-fed agriculture. Working Paper 20. Colombo, Sri Lanka: International Water Management Institute.
IWMI's mission is to improve water and land resources management for food, livelihoods and nature... more IWMI's mission is to improve water and land resources management for food, livelihoods and nature. In serving this mission, IWMI concentrates on the integration of policies, technologies and management systems to achieve workable solutions to real problems¾ practical, relevant results in the field of irrigation and water and land resources.
This report draws on observations during a collaborative study between the Irrigation Department ... more This report draws on observations during a collaborative study between the Irrigation Department of Sri Lanka (SLID) and IWMI, which received financial support from France. The authors gratefully acknowledge the critical comments and suggestions received from colleagues in IWMI and SLID that have helped shape the ideas presented here. D. Renault, and I.W. Makin. 1999. Modernizing irrigation operations: Spatially differentiated resource allocations. Research Report 35. Colombo, Sri Lanka: International Water Management Institute. / modernization / irrigation systems / operating policies / water use / irrigation canals / sensitivity analysis / case studies / models / resource allocation / Sri Lanka / Kirindi Oya /
Soil salinity has often become a long-term problem associated with irrigated agriculture in the a... more Soil salinity has often become a long-term problem associated with irrigated agriculture in the arid and semi-arid regions. But the problem can be controlled by good management of surface and groundwater resources. Management of groundwater is achieved through drainage, although drainage may not be necessary for some time after the initial construction of a scheme. This paper introduces a regional model for predicting expected soil salinity conditions and groundwater depths over an irrigation scheme. The model considers all the main hydrological systems which influence soil salinity and makes optimal use of sparse point field data from grid surveys. The model can be used to identify priority areas for reclamation measures, ie areas where conditions combine to produce high salinity levels. Thus drainage development can be phased over a period of time and targeted where it will be most effective.
Improvements to normal operational procedures are investigated for the main types of irrigation s... more Improvements to normal operational procedures are investigated for the main types of irrigation system identified in Sri Lanka. Scheduled and unscheduled changes of flow regime the systems are likely to experience and the opportunities for improved operations related to the physical characteristics of each type are analyzed. Performance of several alternative manual operational procedures are evaluated and compared using a hydraulic model (Simulation of Irrigation Canal, SIC) for three different irrigation subsystem types (Single Bank canal; Double Bank canal; Canals with intermediate Storage). Results of these simulations show that current practice, based on a fixed frequency of operation of 12 hrs and a target water depth set to the spill level of the cross-regulator, is not far from the optimal for systems without on-line storage. A slight improvement can be expected if the frequency of operation is increased to 6 hrs. For systems with on-line storage it is recommended to split operational procedures into two parts, one related to the canal and one to the storage. Among different options investigated, discharge control at the downstream regulator of the storage appears to be the most reliable as it performs well whatever operation procedures are selected for the canal. Irrigation systems in Sri Lanka are subject to frequent positive flow changes (Supply fluctuations, Runoff, Return-flow changes). As far as water management is concerned, improvements to be expected from normal operation procedures appear to be somewhat limited because management of flow changes is not an objective. For instance little effort is made to harvest runoff under the current practices. One conclusion of the study is that new strategies for the harvest, storage and release of positive flow changes should be tested and, where appropriate, implemented to improve the overall efficiency of operation in irrigation systems in Sri Lanka.
A water management study of Warabandi in northwest India in 1983 developed a methodology for asse... more A water management study of Warabandi in northwest India in 1983 developed a methodology for assessing the performance of large scale smallholder irrigation schemes by observing irrigated areas and carrying out random crop cutting. A study of Warabandi in 1988 took a shorter amount of time and concentrated on direct measurements of flow and seepage in order to assess the performance of the physical conveyance system. This paper contrasts these two approaches and gives practical guidance on how to go about carrying out a rapid assessment of the performance of the physical conveyance system of an irrigation scheme.
The introduction of computer assisted irrigation scheduling to a 20,000 ha smallholder rice and s... more The introduction of computer assisted irrigation scheduling to a 20,000 ha smallholder rice and sugarcane irrigation project in Thailand has provided an opportunity for continuous performance assessment. The provision of weekly information on performance is exerting an influence on the management of the system thus enabling timely response to operational problems. Kraseio Project has been operating with an improved water management system for two seasons, incorporating simple performance indicators, namely: actual versus targetted supply, along with equity, reliability and adequacy measures. Over these seasons the value of regular feedback of performance information has been demonstrated, in terms of increased awareness by project staff of operating constraints and their ability to quantify project performance.
Agricultural policy makers were helped to construct and use a decision support system (DSS) to id... more Agricultural policy makers were helped to construct and use a decision support system (DSS) to identify problems and assess potential solutions for a river basin in Sri Lanka. Through building the DSS themselves, policy makers should reach better decisions. The main aim of the study was to test whether this could be done using a tool called a Bayesian network (BN) which is accessible to non-specialists and able to provide a generic, flexible framework for the construction of DSS. Results from a workshop indicated that the approach showed promise, providing a common framework for discussion and allowing policy makers to structure complex systems from a multi-disciplinary perspective. The need for a multi-disciplinary perspective was clearly demonstrated. The study also suggested improvements to the ways in which BNs can be used in practice. Further workshops with farmers highlighted the importance of involving them in the planning process and suggested more effective ways of doing this while using BNs.
We describe the construction of a 10' latitude/longitude data set of mean monthly surface climate... more We describe the construction of a 10' latitude/longitude data set of mean monthly surface climate over global land areas, excluding Antarctica. The climatology includes 8 climate elements -precipitation, wet-day frequency, temperature, diurnal temperature range, relative humidity, sunshine duration, ground frost frequency and windspeed -and was interpolated from a data set of station means for the period centred on 1961 to 1990. Precipitation was first defined in terms of the parameters of the Gamma distribution, enabling the calculation of monthly precipitation at any given return period. The data are compared to an earlier data set at 0.5º latitude/longitude resolution and show added value over most regions. The data will have many applications in applied climatology, biogeochemical modelling,
Researchers in various international programs have studied the potential use of remotely sensed d... more Researchers in various international programs have studied the potential use of remotely sensed data to obtain accurate information on land surface processes and conditions. These studies have demonstrated that quantitative assessment of the soil-vegetation-atmosphere-transfer processes can lead to a better understanding of the relationships between crop growth and water management. Information on land surface can now be obtained at a wide range of spatial (5±5000 m) and temporal resolutions (0.5±24 days). However, even though considerable progress has been made over the past 20 years in research applications, remotely sensed data remain underutilized by practicing water resource managers.
Second International Symposium on Large Rivers for Fisheries. Phnom Penh, Cambodia, Feb 1, 2003
In tropical floodplain systems local populations are generally highly dependent upon the system's... more In tropical floodplain systems local populations are generally highly dependent upon the system's natural aquatic resources. In such systems the annual fish production depends on a combination of biological and physical parameters, principally 1) hydrological factors; 2) environmental factors and 3) fish migrations. Developing management plans is complicated as assessing the role of each factor is usually made difficult by their diversity, their interactions or feed-back loops, and by the frequent absence of data on certain factors. We present here a tool developed to overcome these difficulties with the aim of facilitating the management of large tropical rivers. Despite the absence of adequate regional or national statistics and comprehensive time series data, a review of existing studies has allowed, the identification of ten factors driving the fish production in the Mekong River Basin. They are 1) hydrological factors: water level, flood duration; flood timing, flooding regularity; 2) floodplain factors: bank types, flooded zone land cover, dry season refuges, bank types, turbidity; 3) biological factors: longitudinal or lateral migrations. This assessment provided the framework for the production of a model integrating the driving environmental parameters and their interactions. Fishing, that also influences fish production, is not yet part of this model focussing on hydrological and ecological factors. The model is based on Bayesian networks. The above variables are interconnected in a logical fashion and related to fish production with the connections being expressed in terms of probabilities. The model calculates conditional probabilities at each level and the overall trend resulting from the sum of interactions within the system. When quantitative information is not available, probabilities are based on local knowledge drawn from experienced biologists and fishers. This model was developed for three groups of fishes (black fishes, white fishes and opportunists) and three geographic sectors (Upper Mekong, Tonle Sap system and Mekong Delta). The natural production that can be expected for each fish group in each sector is qualitatively expressed by a percentage between "Bad" and "Good". This result could have been converted into tonnes of fish had statistical time series been available. The model is transparent and user-friendly. Variables having the strongest influence on fish production are identified and each variable can be easily varied to assess the consequences of various management options on fish production.
With increasing pressure on available water resources, irrigation systems in many countries are h... more With increasing pressure on available water resources, irrigation systems in many countries are having to find ways to improve performance. As often the main consumptive user, irrigation systems are having to release water for other uses and to produce ''more crop per drop''. Benchmarking is a valuable tool that has proven itself in the business and commercial sector, as well as in public sector enterprises. This paper describes and defines the benchmarking process, and goes on to outline its current application in the irrigation and drainage (I&D) sector. The paper highlights the difficulty of benchmarking in the I&D sector given the complexity and site-specific nature of irrigation and drainage systems, and emphasises the need for careful identification of which processes to benchmark. Preliminary benchmarking indicators are discussed, and attention drawn to efforts currently under way to apply and test this preliminary set. Emphasis is placed on the effort and resources required to bring about the required changes identified by the benchmarking exercise, and the role of change management as an integral part of the benchmarking process. The paper concludes that benchmarking provides a feasible mechanism for performance improvement in the I&D sector, but requires the active involvement of motivated individuals with support from the wider environment, encompassing an enabling socio-political environment and support from key stakeholders.
and I. Makin. 2001. Estimating the potential of rain-fed agriculture. Working Paper 20. Colombo, ... more and I. Makin. 2001. Estimating the potential of rain-fed agriculture. Working Paper 20. Colombo, Sri Lanka: International Water Management Institute.
IWMI's mission is to improve water and land resources management for food, livelihoods and nature... more IWMI's mission is to improve water and land resources management for food, livelihoods and nature. In serving this mission, IWMI concentrates on the integration of policies, technologies and management systems to achieve workable solutions to real problems¾ practical, relevant results in the field of irrigation and water and land resources.
This report draws on observations during a collaborative study between the Irrigation Department ... more This report draws on observations during a collaborative study between the Irrigation Department of Sri Lanka (SLID) and IWMI, which received financial support from France. The authors gratefully acknowledge the critical comments and suggestions received from colleagues in IWMI and SLID that have helped shape the ideas presented here. D. Renault, and I.W. Makin. 1999. Modernizing irrigation operations: Spatially differentiated resource allocations. Research Report 35. Colombo, Sri Lanka: International Water Management Institute. / modernization / irrigation systems / operating policies / water use / irrigation canals / sensitivity analysis / case studies / models / resource allocation / Sri Lanka / Kirindi Oya /
Soil salinity has often become a long-term problem associated with irrigated agriculture in the a... more Soil salinity has often become a long-term problem associated with irrigated agriculture in the arid and semi-arid regions. But the problem can be controlled by good management of surface and groundwater resources. Management of groundwater is achieved through drainage, although drainage may not be necessary for some time after the initial construction of a scheme. This paper introduces a regional model for predicting expected soil salinity conditions and groundwater depths over an irrigation scheme. The model considers all the main hydrological systems which influence soil salinity and makes optimal use of sparse point field data from grid surveys. The model can be used to identify priority areas for reclamation measures, ie areas where conditions combine to produce high salinity levels. Thus drainage development can be phased over a period of time and targeted where it will be most effective.
Improvements to normal operational procedures are investigated for the main types of irrigation s... more Improvements to normal operational procedures are investigated for the main types of irrigation system identified in Sri Lanka. Scheduled and unscheduled changes of flow regime the systems are likely to experience and the opportunities for improved operations related to the physical characteristics of each type are analyzed. Performance of several alternative manual operational procedures are evaluated and compared using a hydraulic model (Simulation of Irrigation Canal, SIC) for three different irrigation subsystem types (Single Bank canal; Double Bank canal; Canals with intermediate Storage). Results of these simulations show that current practice, based on a fixed frequency of operation of 12 hrs and a target water depth set to the spill level of the cross-regulator, is not far from the optimal for systems without on-line storage. A slight improvement can be expected if the frequency of operation is increased to 6 hrs. For systems with on-line storage it is recommended to split operational procedures into two parts, one related to the canal and one to the storage. Among different options investigated, discharge control at the downstream regulator of the storage appears to be the most reliable as it performs well whatever operation procedures are selected for the canal. Irrigation systems in Sri Lanka are subject to frequent positive flow changes (Supply fluctuations, Runoff, Return-flow changes). As far as water management is concerned, improvements to be expected from normal operation procedures appear to be somewhat limited because management of flow changes is not an objective. For instance little effort is made to harvest runoff under the current practices. One conclusion of the study is that new strategies for the harvest, storage and release of positive flow changes should be tested and, where appropriate, implemented to improve the overall efficiency of operation in irrigation systems in Sri Lanka.
A water management study of Warabandi in northwest India in 1983 developed a methodology for asse... more A water management study of Warabandi in northwest India in 1983 developed a methodology for assessing the performance of large scale smallholder irrigation schemes by observing irrigated areas and carrying out random crop cutting. A study of Warabandi in 1988 took a shorter amount of time and concentrated on direct measurements of flow and seepage in order to assess the performance of the physical conveyance system. This paper contrasts these two approaches and gives practical guidance on how to go about carrying out a rapid assessment of the performance of the physical conveyance system of an irrigation scheme.
The introduction of computer assisted irrigation scheduling to a 20,000 ha smallholder rice and s... more The introduction of computer assisted irrigation scheduling to a 20,000 ha smallholder rice and sugarcane irrigation project in Thailand has provided an opportunity for continuous performance assessment. The provision of weekly information on performance is exerting an influence on the management of the system thus enabling timely response to operational problems. Kraseio Project has been operating with an improved water management system for two seasons, incorporating simple performance indicators, namely: actual versus targetted supply, along with equity, reliability and adequacy measures. Over these seasons the value of regular feedback of performance information has been demonstrated, in terms of increased awareness by project staff of operating constraints and their ability to quantify project performance.
Agricultural policy makers were helped to construct and use a decision support system (DSS) to id... more Agricultural policy makers were helped to construct and use a decision support system (DSS) to identify problems and assess potential solutions for a river basin in Sri Lanka. Through building the DSS themselves, policy makers should reach better decisions. The main aim of the study was to test whether this could be done using a tool called a Bayesian network (BN) which is accessible to non-specialists and able to provide a generic, flexible framework for the construction of DSS. Results from a workshop indicated that the approach showed promise, providing a common framework for discussion and allowing policy makers to structure complex systems from a multi-disciplinary perspective. The need for a multi-disciplinary perspective was clearly demonstrated. The study also suggested improvements to the ways in which BNs can be used in practice. Further workshops with farmers highlighted the importance of involving them in the planning process and suggested more effective ways of doing this while using BNs.
We describe the construction of a 10' latitude/longitude data set of mean monthly surface climate... more We describe the construction of a 10' latitude/longitude data set of mean monthly surface climate over global land areas, excluding Antarctica. The climatology includes 8 climate elements -precipitation, wet-day frequency, temperature, diurnal temperature range, relative humidity, sunshine duration, ground frost frequency and windspeed -and was interpolated from a data set of station means for the period centred on 1961 to 1990. Precipitation was first defined in terms of the parameters of the Gamma distribution, enabling the calculation of monthly precipitation at any given return period. The data are compared to an earlier data set at 0.5º latitude/longitude resolution and show added value over most regions. The data will have many applications in applied climatology, biogeochemical modelling,
Researchers in various international programs have studied the potential use of remotely sensed d... more Researchers in various international programs have studied the potential use of remotely sensed data to obtain accurate information on land surface processes and conditions. These studies have demonstrated that quantitative assessment of the soil-vegetation-atmosphere-transfer processes can lead to a better understanding of the relationships between crop growth and water management. Information on land surface can now be obtained at a wide range of spatial (5±5000 m) and temporal resolutions (0.5±24 days). However, even though considerable progress has been made over the past 20 years in research applications, remotely sensed data remain underutilized by practicing water resource managers.
Second International Symposium on Large Rivers for Fisheries. Phnom Penh, Cambodia, Feb 1, 2003
In tropical floodplain systems local populations are generally highly dependent upon the system's... more In tropical floodplain systems local populations are generally highly dependent upon the system's natural aquatic resources. In such systems the annual fish production depends on a combination of biological and physical parameters, principally 1) hydrological factors; 2) environmental factors and 3) fish migrations. Developing management plans is complicated as assessing the role of each factor is usually made difficult by their diversity, their interactions or feed-back loops, and by the frequent absence of data on certain factors. We present here a tool developed to overcome these difficulties with the aim of facilitating the management of large tropical rivers. Despite the absence of adequate regional or national statistics and comprehensive time series data, a review of existing studies has allowed, the identification of ten factors driving the fish production in the Mekong River Basin. They are 1) hydrological factors: water level, flood duration; flood timing, flooding regularity; 2) floodplain factors: bank types, flooded zone land cover, dry season refuges, bank types, turbidity; 3) biological factors: longitudinal or lateral migrations. This assessment provided the framework for the production of a model integrating the driving environmental parameters and their interactions. Fishing, that also influences fish production, is not yet part of this model focussing on hydrological and ecological factors. The model is based on Bayesian networks. The above variables are interconnected in a logical fashion and related to fish production with the connections being expressed in terms of probabilities. The model calculates conditional probabilities at each level and the overall trend resulting from the sum of interactions within the system. When quantitative information is not available, probabilities are based on local knowledge drawn from experienced biologists and fishers. This model was developed for three groups of fishes (black fishes, white fishes and opportunists) and three geographic sectors (Upper Mekong, Tonle Sap system and Mekong Delta). The natural production that can be expected for each fish group in each sector is qualitatively expressed by a percentage between "Bad" and "Good". This result could have been converted into tonnes of fish had statistical time series been available. The model is transparent and user-friendly. Variables having the strongest influence on fish production are identified and each variable can be easily varied to assess the consequences of various management options on fish production.
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Papers by Ian Makin