During the 1980s, as part of a policy of liberalization, following budgetary cuts linked to the implementation of structural adjustment programs, management responsibilities for AHAs were transferred from ONAHA to coo...During the 1980s, as part of a policy of liberalization, following budgetary cuts linked to the implementation of structural adjustment programs, management responsibilities for AHAs were transferred from ONAHA to cooperatives concerned. Due to lack of financial resources, but also because of poor management, everywhere in Niger we are witnessing an accelerated deterioration of the irrigation infrastructure of hydro-agricultural developments. Institutional studies carried out on this situation led the State of Niger to initiate a reform of the governance of hydro-agricultural developments, by streng-thening the status of ONAHA, by creating an Association of Irrigation Water Users (AUEI) and by restructuring the old cooperatives. Indeed, this research aims to analyze the creation of functional and sustainable Irrigation Water User Associations (AUEI) in Niger in a context of reform of the irrigation sector, and based on the experience of the Konni AHA. It is based on a methodological approach which takes into account documentary research and the collection of data from 115 farmers, selected by reasoned choice and directly concerned by the management of the irrigated area. The data collected was analyzed and the results were analyzed using the systemic approach and the diagnostic process. The results show that the main mission of the AUEI is to ensure better management of water, hydraulic equipment and infrastructure on the hydro-agricultural developments of Konni. The creation of the Konni AUEI was possible thanks to massive support from the populations and authorities in the implementation process. After its establishment, the AUEI experienced a certain lethargy for some time due to the rehabilitation work of the AHA but currently it is functional and operational in terms of associative life and governance. Thus, the constraints linked to the legal system, the delay in the completion of the work, the uncertainties of access to irrigation water but also the problems linked to the change in mentality of certain ONAHA agents constitute the challenges that must be resolved in the short term for the operationalization of the Konni AUEI.展开更多
In this paper, we investigate a cooperation mechanism for satellite-terrestrial integrated networks. The terrestrial relays act as the supplement of traditional small cells and cooperatively provide seamless coverage ...In this paper, we investigate a cooperation mechanism for satellite-terrestrial integrated networks. The terrestrial relays act as the supplement of traditional small cells and cooperatively provide seamless coverage for users in the densely populated areas.To deal with the dynamic satellite backhaul links and backhaul capacity caused by the satellite mobility, severe co-channel interference in both satellite backhaul links and user links introduced by spectrum sharing,and the difference demands of users as well as heterogeneous characteristics of terrestrial backhaul and satellite backhaul, we propose a joint user association and satellite selection scheme to maximize the total sum rate. The optimization problem is formulated via jointly considering the influence of dynamic backhaul links, individual requirements and targeted interference management strategies, which is decomposed into two subproblems: user association and satellite selection. The user association is formulated as a nonconvex optimization problem, and solved through a low-complexity heuristic scheme to find the most suitable access point serving each user. Then, the satellite selection is resolved based on the cooperation among terrestrial relays to maximize the total backhaul capacity with the minimum date rate constraints. Finally,simulation results show the effectiveness of the proposed scheme in terms of total sum rate and power efficiency of TRs' backhaul.展开更多
This paper examines how farmers in central Lombok have organized themselves to manage agricultural water colle- ctively and to adapt to seasonally dry conditions. We interviewed eighteen village heads from October to ...This paper examines how farmers in central Lombok have organized themselves to manage agricultural water colle- ctively and to adapt to seasonally dry conditions. We interviewed eighteen village heads from October to December 2006. One of our questions we posed prior to field interviews was what might be the social and technical coping strategies that have allowed farmers to survive the lengthy dry seasons under the high population density of Lombok island. Some examples of organizational structure and practices in Central Lombok are presented. There were several common water management strategies that were revealed from these interviews including: methods of organization, flexible cropping systems, water allocation mechanisms, methods of compromise, alternative payments, and traditional water management practices. The statistical analysis comparing village characteristics and coping strategies suggests a relation between mosque number per village and farmers ability to cope. Farmers have shown their own unique coping strategies in times of water shortages and under decentralization occurring over the past decade. This decentralization involved turning over small scale irrigation systems (under 500 hectares), to the water user associations themselves in order to facilitate more efficient management and maintenance.展开更多
In Vietnam as well as many countries which apply the irrigated agriculture over the world, the process of promoting thesocialization trend in irrigation for the basic irrigation organizations, of which the main factor...In Vietnam as well as many countries which apply the irrigated agriculture over the world, the process of promoting thesocialization trend in irrigation for the basic irrigation organizations, of which the main factor is water users, is very important. Thispaper aimed to optimize the decentralization of management and exploitation of irrigation works for water users, organizations inQuan Lo-Phung Hiep irrigation system of Mekong River Delta. The research has implemented a survey on 384 water users alongfour canals of level 2 of Quan Lo-Phung Hiep irrigation system under two sets of index： （1） water users＇ perception assessment of theirrigation works （14 indicators） and （2） assessment of the management efficiency in the irrigation works （six indicators）. Theresearch proposes the decentralization process from building, After determining the correlation coefficients, the multi-objective linearregression equation will be shown on six single objective functions. With the aim at achieving the highest efficiency in themanagement and exploitation of the irrigation works, there should be a shift in terms of the water users＇ perception of the irrigationworks. These study results also demonstrate that about 65%-68% of the change in the indicators of the exploitation efficiency in theirrigation works is explained by some water users＇ perception indexes of irrigation works, including the quality of irrigation service andthe output efficiency in agricultural production. By using the algorithm for multi-objective optimization problem, the optimal results inperception are determined. The input data is generated for the matrix supporting the decision making, and the decentralization ofmanagement and exploitation of irrigation works meets the three criteria, i.e., effectiveness, sustainability and flexibility.展开更多
The paper analyzes the practical use of management mode of small-scale farmland irrigation works in China,and studies various problems existing in the present management mode.It puts forward a mode named Water-consume...The paper analyzes the practical use of management mode of small-scale farmland irrigation works in China,and studies various problems existing in the present management mode.It puts forward a mode named Water-consumer Association which is the most practical one at present.It points out some rules which must be mastered in solving problems appearing in using this mode.展开更多
文摘During the 1980s, as part of a policy of liberalization, following budgetary cuts linked to the implementation of structural adjustment programs, management responsibilities for AHAs were transferred from ONAHA to cooperatives concerned. Due to lack of financial resources, but also because of poor management, everywhere in Niger we are witnessing an accelerated deterioration of the irrigation infrastructure of hydro-agricultural developments. Institutional studies carried out on this situation led the State of Niger to initiate a reform of the governance of hydro-agricultural developments, by streng-thening the status of ONAHA, by creating an Association of Irrigation Water Users (AUEI) and by restructuring the old cooperatives. Indeed, this research aims to analyze the creation of functional and sustainable Irrigation Water User Associations (AUEI) in Niger in a context of reform of the irrigation sector, and based on the experience of the Konni AHA. It is based on a methodological approach which takes into account documentary research and the collection of data from 115 farmers, selected by reasoned choice and directly concerned by the management of the irrigated area. The data collected was analyzed and the results were analyzed using the systemic approach and the diagnostic process. The results show that the main mission of the AUEI is to ensure better management of water, hydraulic equipment and infrastructure on the hydro-agricultural developments of Konni. The creation of the Konni AUEI was possible thanks to massive support from the populations and authorities in the implementation process. After its establishment, the AUEI experienced a certain lethargy for some time due to the rehabilitation work of the AHA but currently it is functional and operational in terms of associative life and governance. Thus, the constraints linked to the legal system, the delay in the completion of the work, the uncertainties of access to irrigation water but also the problems linked to the change in mentality of certain ONAHA agents constitute the challenges that must be resolved in the short term for the operationalization of the Konni AUEI.
基金supported by National Natural Science Foundation of China (No. 62201593, 62471480, and 62171466)。
文摘In this paper, we investigate a cooperation mechanism for satellite-terrestrial integrated networks. The terrestrial relays act as the supplement of traditional small cells and cooperatively provide seamless coverage for users in the densely populated areas.To deal with the dynamic satellite backhaul links and backhaul capacity caused by the satellite mobility, severe co-channel interference in both satellite backhaul links and user links introduced by spectrum sharing,and the difference demands of users as well as heterogeneous characteristics of terrestrial backhaul and satellite backhaul, we propose a joint user association and satellite selection scheme to maximize the total sum rate. The optimization problem is formulated via jointly considering the influence of dynamic backhaul links, individual requirements and targeted interference management strategies, which is decomposed into two subproblems: user association and satellite selection. The user association is formulated as a nonconvex optimization problem, and solved through a low-complexity heuristic scheme to find the most suitable access point serving each user. Then, the satellite selection is resolved based on the cooperation among terrestrial relays to maximize the total backhaul capacity with the minimum date rate constraints. Finally,simulation results show the effectiveness of the proposed scheme in terms of total sum rate and power efficiency of TRs' backhaul.
文摘This paper examines how farmers in central Lombok have organized themselves to manage agricultural water colle- ctively and to adapt to seasonally dry conditions. We interviewed eighteen village heads from October to December 2006. One of our questions we posed prior to field interviews was what might be the social and technical coping strategies that have allowed farmers to survive the lengthy dry seasons under the high population density of Lombok island. Some examples of organizational structure and practices in Central Lombok are presented. There were several common water management strategies that were revealed from these interviews including: methods of organization, flexible cropping systems, water allocation mechanisms, methods of compromise, alternative payments, and traditional water management practices. The statistical analysis comparing village characteristics and coping strategies suggests a relation between mosque number per village and farmers ability to cope. Farmers have shown their own unique coping strategies in times of water shortages and under decentralization occurring over the past decade. This decentralization involved turning over small scale irrigation systems (under 500 hectares), to the water user associations themselves in order to facilitate more efficient management and maintenance.
文摘In Vietnam as well as many countries which apply the irrigated agriculture over the world, the process of promoting thesocialization trend in irrigation for the basic irrigation organizations, of which the main factor is water users, is very important. Thispaper aimed to optimize the decentralization of management and exploitation of irrigation works for water users, organizations inQuan Lo-Phung Hiep irrigation system of Mekong River Delta. The research has implemented a survey on 384 water users alongfour canals of level 2 of Quan Lo-Phung Hiep irrigation system under two sets of index： （1） water users＇ perception assessment of theirrigation works （14 indicators） and （2） assessment of the management efficiency in the irrigation works （six indicators）. Theresearch proposes the decentralization process from building, After determining the correlation coefficients, the multi-objective linearregression equation will be shown on six single objective functions. With the aim at achieving the highest efficiency in themanagement and exploitation of the irrigation works, there should be a shift in terms of the water users＇ perception of the irrigationworks. These study results also demonstrate that about 65%-68% of the change in the indicators of the exploitation efficiency in theirrigation works is explained by some water users＇ perception indexes of irrigation works, including the quality of irrigation service andthe output efficiency in agricultural production. By using the algorithm for multi-objective optimization problem, the optimal results inperception are determined. The input data is generated for the matrix supporting the decision making, and the decentralization ofmanagement and exploitation of irrigation works meets the three criteria, i.e., effectiveness, sustainability and flexibility.
基金Supported by Provincial Water Conservancy Research and Technology Promotion Project:Research on Key Technical Problems of Farmland Water Conservancy Projects in Shandong Province(SDSLKY201401)
文摘The paper analyzes the practical use of management mode of small-scale farmland irrigation works in China,and studies various problems existing in the present management mode.It puts forward a mode named Water-consumer Association which is the most practical one at present.It points out some rules which must be mastered in solving problems appearing in using this mode.
