Le lac Alaotra est la plus grande étendue d’eau douce de Madagascar et les vastes plaines qui l’entourent ont tout naturellement attiré les convoitises des différents pouvoirs en place au cours de l’histoire, de sa colonisation. Essentiellement tournée vers la riziculture, cette région a bénéficié de nombreux aménagements qui ont transformé le paysage et le rapport des hommes à leur environnement. La combinaison au fil du temps des savoirs et savoir-faire paysans, techniciens, et l’intérêt des chercheurs en font aujourd’hui « le grenier à riz » de Madagascar. C’est autour de la maîtrise de l’eau, ressource essentielle dans ce pays d’économie rurale, que s’organise cette thèse de Géographie. À travers l’étude des vallées du sud-est de l’Alaotra, nous nous intéressons ici à montrer dans quelle mesure les aménagements hydro-agricoles permettent d’envisager un meilleur développement agricole et territorial et comment, dans un contexte de décentralisation, le contrôle et l’appropriation des ressources naturelles par les acteurs locaux peuvent engendrer des dynamiques et des modalités de gestion renouvelées de leur environnement. / Alaotra lake is the biggest body of fresh water in Madagascar and the vast plains surrounding it, have naturally become highly coveted by the various authorities over the course of it’s history and its colonization. Primarily based on rice cultivation, this region has benefited from numerous rural planning projects. As a result, the landscape as well as the relationship between the people and their land has been transformed. Over time, the combination of knowledges and know-how farmers, technicians and the research interest in this area, have made it Madagascar’s most significant rice granary. This geography thesis is structured around water management, an essential resource in a country based on rural economies. Through the study of the southeastern valleys, we will focus on showing the extent to which the hydro-agricultural planning allows us to consider better agricultural and territorial development and how, in a context of decentralization, the control and the appropriation of natural resources by local actors can lead to renewed management dynamics and procedures in their environment. / Ny farihy Alaotra no fihebanandranomandry lehibe indrindra ao Madagasikara , ary ny tany lemaka midadasika manodidina azy no nanitona ny fitsiriritan’ireo manampahefana nifandimby tao amin’ny tantaran’ny fiorenamponenana.Ny fambolem-bary no votoatim-piainana ao amin’io faritany io , ary fanajariana marobe no efa nanova tanteraka ny endrikin’ny tany sy ny fonenana eo . Ny fandrindrana ny fahalalàna sy fahaiza-miasan’ny tantsaha, ny mahay taozavatra , sy ny finiavan’ny mpikarodalana no nahatonga azy ho « lavabarin’i Madagasikara ». Manodidina ny fanafolahana ny rano , andry ijoroan’ny toekarenan’ny antsaha , no namolavolàna ity tandro-kevitra fandinihantany ity. Avy eo amin’ny fikatsahana natao tao amin’ireo lohasaha ao Atsimo-atsinanan’Alaotra no niaingan’ny sainay hampiseho fa ny fanajariana ny rano sy asatany no hahafahana mihevitra ny fivoaram-bokatra amin’ny voly sy ny faritany ; ary koa ao anatin’ny fitsinjarampitondrana , dia hahitàna fa ny fandinihana sy ny fandraisana an-tanana ireo loharanon-karena velona ataon’ny mpiasa eo antoerana no mety hiteraka fampandrosoana sy fivaozan’ny fitantanana ny toe-ponenana manotolo.

Between 1961 and 1976 Häi Hung province -- present day Häi Duong and Hung Yên -- lost the equivalent of two entire districts of agricultural land. How could so much land be abandoned under a collectivised agriculture system? And what role did poor water control infrastructure play in creating such a situation?¶ I answer these questions by examining the historical patterns of hydraulic development in northern Vietnam from the beginning of the 19th century until the introduction of the Production Contract system in 1981. Underlying both the French colonial and communist visions of modernity and economic development was a belief that improving agricultural productivity, of which large-scale hydraulic infrastructure was an important component, could catalyse growth in the rural economy, which could then finance industrialisation. I argue throughout this thesis that developing large-scale hydraulic infrastructure in the Red River delta has relied upon the creation of a hydraulic bargain between the state and water users. This is in contrast to Wittfogel's theory of the hydraulic state, insofar as developing hydraulic infrastructure has depended upon the active political and economic participation and support of water users, and not the absolute power of the state. The political economic history of the hydraulic bargain highlights the relative power of peasants to influence the direction of large-scale hydraulic development and, as such, the shape of the Red River delta's wet-rice economy.

Precision agriculture, have a determinant role in the management of agriculture, has a direct effect in the reduction of production costs as the environmental impacts from the management of localized farming. The conservation of water and soil is of great importance to the management of water resources. Thus, this study aimed to analyze the system John Deere Surface Water Pro, as the best way to make the altimeter work, taking into account the routine of the property, as sowing and harvesting the rice paddy. Was also tested using the tool JD - APEX created in Software CAMPEIRO CR 7 for processing the data obtained in the field, together with John Deere APEX Software for managing soil water. JD Tool - APEX provides the functionality of converting the generated map in APEX shapefile of lines, which is subsequently used for the monitor John Deere 2630 GS3. The maps generated from the research were tested in the field and evaluated its power to identify whether the data collected in different studies may be used for water management in irrigated rice management. It was concluded that the tools created with few adjustments are appropriate and effective for the demarcation and establishment of contour lines for the management of water in irrigated rice. / A agricultura de precisão, tem hoje papel decisivo na gestão da agricultura, tem ação direta tanto na diminuição dos custos de produção quanto nos impactos ambientais a partir da gerenciamento localizada da lavoura. A conservação da água e do solo é de grande importância para a gestão dos recursos hídricos. Neste sentido, este trabalho teve como objetivo analisar o Sistema John Deere Surface Water PRO, quanto a melhor maneira de fazer o trabalho altimetrico, levando em consideração a rotina da propriedade, como semeadura e colheita em lavoura de arroz irrigado. Também foi testado a utilização da ferramenta JD - APEX criada no Software CR CAMPEIRO 7 para o processamento dos dados obtidos no campo, em conjunto com Software John Deere APEX para o gerenciamento da água no solo. A ferramenta JD APEX oferece a funcionalidade de conversão do mapa gerado no APEX em arquivo shapefile de linhas, que posteriormente é utilizado no monitor John Deere GS3 2630. Os mapas gerados a partir das pesquisas, foram testados a campo e avaliado seu potêncial visando identificar se os dados coletados em diferentes trabalhos, podem ser utilizadas para gerenciamento de água no manejo do arroz irrigado. Concluiu-se que as ferramentas criadas, com poucos ajustes, serão adequadas e eficientes para a demarcação e implantação de curvas de nível para o manejo da água na cultura do arroz irrigado.

From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / It is argued that Arizona has traditionally and persistently pursued a style of politics in which state government is a reactor rather than an initiator, and that its role has been subordinate to the federal government and local and private water users. The lack of adequate water policies has led to an inability to respond to new conditions and demands, such as conflicts among traditional water users, Indian claims, rising water costs, energy developments and environmental concerns. Past themes of administrative fragmentation and lack of concern over water and water planning have been responsible for these deficiencies. There is some evidence that the customary decision-making process is changing and the state is establishing its own water planning capability.

From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / A dual purpose reservoir control problem can logically be modelled as a game against nature. The first purpose of the reservoir is flood control under uncertain inflow, which corresponds to short -range operation (SRO); the second purpose, which the present model imbeds into the first one, is water supply after the flood has receded, and corresponds to long-range operation (LRO). The reservoir manager makes release decisions based on his SRO risk. The trade-offs involved in his decision are described by a utility function, which is constructed within the framework of Keeney's multiattribute utility theory. The underlying assumptions appear to be quite natural for the reservoir control problem. To test the model, an experiment assessing the utility criterion of individuals has been performed; the results tend to confirm the plausibility of the approach. In particular, most individuals appear to have a risk-averse attitude for small floods and a risk-taking attitude for large ones.