Riziculture and the founding of monarchy in Imerina

1981 ◽  
Vol 22 (3) ◽  
pp. 289-308 ◽  
Author(s):  
Gerald M. Berg
Keyword(s):  
Water Management ◽  
Land Use ◽  
Direct Evidence ◽  
East Coast ◽  
Social Hierarchy ◽  
Paddy Rice ◽  
Rice Cultivation ◽  
Oral Traditions ◽  
Management Systems ◽  
Land Use Models

Many observers of Merina history have suggested that the organization of labour required to build and maintain irrigation works for paddy rice growing formed the basis of Merina monarchy. Though little direct evidence is available, inferences from land-use models and consideration of oral traditions and written accounts help to explain why irrigated riziculture became popular and how it spread through the central highlands to Imerina.Rice had been cultivated on the east coast of Madagascar for centuries and reached Imerina through the southern plateau but the hydraulic technology of Merina paddy rice growing arose from local needs from the late seventeenth to mid-eighteenth centuries. As swidden farmers exhausted the forests, paddy rice cultivation and water management systems attending it became increasingly important. Though irrigated riziculture enhanced the value of co-operative labour among hitherto isolated groups within Imerina, it cannot be seen as the direct cause of the monarchy's authority. It is suggested instead that the sacredness of land and the accumulation of rights in newly irrigated land by those who controlled water hastened the evolution of a rigid social hierarchy which exalted a few and subjugated the rest.

scholarly journals Towards risk-based flood management in highly productive paddy rice cultivation – concept development and application to the Mekong Delta

2018 ◽  
Vol 18 (11) ◽  
pp. 2859-2876 ◽  
Author(s):  
Nguyen Van Khanh Triet ◽  
Nguyen Viet Dung ◽  
Bruno Merz ◽  
Heiko Apel
Keyword(s):  
Land Use ◽  
Flood Risk ◽  
Large Scale ◽  
Flood Hazard ◽  
Mekong Delta ◽  
Flood Management ◽  
Paddy Rice ◽  
Rice Cultivation ◽  
Spatially Explicit ◽  
Risk Maps

Abstract. Flooding is an imminent natural hazard threatening most river deltas, e.g. the Mekong Delta. An appropriate flood management is thus required for a sustainable development of the often densely populated regions. Recently, the traditional event-based hazard control shifted towards a risk management approach in many regions, driven by intensive research leading to new legal regulation on flood management. However, a large-scale flood risk assessment does not exist for the Mekong Delta. Particularly, flood risk to paddy rice cultivation, the most important economic activity in the delta, has not been performed yet. Therefore, the present study was developed to provide the very first insight into delta-scale flood damages and risks to rice cultivation. The flood hazard was quantified by probabilistic flood hazard maps of the whole delta using a bivariate extreme value statistics, synthetic flood hydrographs, and a large-scale hydraulic model. The flood risk to paddy rice was then quantified considering cropping calendars, rice phenology, and harvest times based on a time series of enhanced vegetation index (EVI) derived from MODIS satellite data, and a published rice flood damage function. The proposed concept provided flood risk maps to paddy rice for the Mekong Delta in terms of expected annual damage. The presented concept can be used as a blueprint for regions facing similar problems due to its generic approach. Furthermore, the changes in flood risk to paddy rice caused by changes in land use currently under discussion in the Mekong Delta were estimated. Two land-use scenarios either intensifying or reducing rice cropping were considered, and the changes in risk were presented in spatially explicit flood risk maps. The basic risk maps could serve as guidance for the authorities to develop spatially explicit flood management and mitigation plans for the delta. The land-use change risk maps could further be used for adaptive risk management plans and as a basis for a cost–benefit of the discussed land-use change scenarios. Additionally, the damage and risks maps may support the recently initiated agricultural insurance programme in Vietnam.

A micro case study of the legal and administrative arrangements for river health in the Kangaroo River (NSW)

2002 ◽  
Vol 45 (11) ◽  
pp. 161-168 ◽  
Author(s):  
C. Mooney ◽  
D. Farrier
Keyword(s):  
Water Management ◽  
Water Quality ◽  
Land Use ◽  
Drinking Water ◽  
Riparian Vegetation ◽  
Diffuse Pollution ◽  
Management Systems ◽  
River Health ◽  
New Development

Kangaroo Valley is a drinking water supply catchment for Kangaroo Valley village, parts of the Southern Highlands and Sydney. It is also a popular recreation area both for swimming and canoeing. Land use has traditionally been dominated by dairy farming but there has been significant and continuing development of land for hobby farms and rural residential subdivision. Dairy industry restructuring has affected the viability of some farms in the Valley and created additional pressure for subdivision. River health is a function of flows, water quality, riparian vegetation, geomorphology and aquatic habitat and riverine biota. River flows in the Kangaroo River are affected by water extraction and storage for urban water supply and extraction by commercial irrigators and riparian land holders which have a significant impact at low flows. Current water quality often does not meet ANZECC Guidelines for primary contact and recreation and the river is a poor source of raw drinking water. Key sources of contaminants are wastewater runoff from agriculture, and poorly performing on-site sewage management systems. Riparian vegetation, which is critical to the maintenance of in-stream ecosystems suffers from uncontrolled stock access and weed infestation. The management of land use and resulting diffuse pollution sources is critical to the long term health of the river. The Healthy Rivers Commission of New South Wales Independent Inquiry into the Shoalhaven River System Final Report July, 1999 found that the longer term protection of the health of the Kangaroo River is contingent upon achievement of patterns of land use that have regard to land capability and also to the capability of the river to withstand the impacts of inappropriate or poorly managed land uses. This micro case study of Kangaroo Valley examines the complex legal and administrative arrangements with particular reference to the management of diffuse pollution for river health. In the past, diffuse pollution has fallen through the gaps in legislation and its administration. Although water pollution legislation is broad enough to embrace diffuse pollution, in practice the Environment Protection Authority has focused on regulating point sources. Water legislation has traditionally been concerned with issues of water quantity rather than water quality. Legislation which allows agency intervention in relation to land degradation has grown from soil conservation roots, neglecting the flow-on effects upon water quality. Under the land use planning system existing land uses are protected from new regulatory requirements. A number of recent developments in NSW law and its administration have set the scene for addressing this past neglect. Water planning provisions in the Water Management Act 2000 have the potential to enable community based Water Management Committees to move away from a narrow focus on water quantity to the broader issues of river health, including water quality. Improved management of on-site sewage management systems is expected as a result of the Local Government (Approvals) Amendment (Sewage Management Regulation) 1998. A draft Regional Environmental Plan prepared for the Sydney Catchment Authority aims to improve the assessment of new development in terms of its impact on drinking water quality. It also moves away from an exclusive concern with controlling new development towards grappling with existing uses. Proposed amendments to the Environmental Planning and Assessment Act, 1979 as detailed in the White Paper, Plan First (2001) include the integration of imperatives derived from catchment strategies and water management plans into local land use plans.

Effect of land use change from paddy rice cultivation to upland crop cultivation on soil carbon budget of a cropland in Japan

2008 ◽  
Vol 125 (1-4) ◽  
pp. 9-20 ◽  
Author(s):  
Seiichi Nishimura ◽  
Seiichiro Yonemura ◽  
Takuji Sawamoto ◽  
Yasuhito Shirato ◽  
Hiroko Akiyama ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Soil Carbon ◽  
Carbon Budget ◽  
Paddy Rice ◽  
Rice Cultivation ◽  
Crop Cultivation ◽  
Upland Crop

scholarly journals Towards risk-based flood management in highly productive paddy rice cultivation – concept development and application to the Mekong Delta

2018 ◽  
Author(s):  
Nguyen Van Khanh Triet ◽  
Nguyen Viet Dung ◽  
Bruno Merz ◽  
Heiko Apel
Keyword(s):  
Land Use ◽  
Flood Risk ◽  
Large Scale ◽  
Flood Hazard ◽  
Mekong Delta ◽  
Flood Management ◽  
Paddy Rice ◽  
Rice Cultivation ◽  
Spatially Explicit ◽  
Risk Maps

Abstract. Flooding is an imminent natural hazard threatening most river deltas, as e.g. the Mekong Delta. An appropriate flood management is thus required for a sustainable development of the often densely populated regions. Recently, the traditional event based hazard control shifted towards a risk management approach in many regions, driven by intensive research leading to new legal regulation on flood management. However, a large-scale flood risk assessment does not exist for the Mekong Delta. Particularly, flood risk to paddy rice cultivation, the most important economic activity in the delta, has not been performed yet. Therefor the present study was developed to provide the very first in-sight on delta scale flood damages and risks to rice cultivation. The flood hazard was quantified by probabilistic flood hazard maps of the whole delta using a bivariate extreme value statistics, synthetic flood hydrographs, and a large scale hydraulic model. The flood risk to paddy rice was then quantified considering cropping calendars, rice phenology and harvest times based on a time-series of enhanced vegetation index (EVI) derived from MODIS satellite data, and a published rice flood damage functions. The proposed concept provided flood risk maps to paddy rice for the Mekong Delta in terms of expected annual damage. The presented concept can be used as a blueprint for regions facing similar problems due to its generic approach. Furthermore, the changes in flood risk to paddy rice caused by changes in land use currently under discussion in the Mekong Delta were estimated. Two land-use scenarios either intensifying or reducing rice cropping were considered, and the changes in risk were presented in spatially explicit flood risk maps. The basic risk maps could serve as guidance for the authorities to develop spatially explicit flood management and mitigation plans for the delta. The land-use change risk maps could further be used for adaptive risk management plans, and as basis for a cost-benefit of the discussed land use change scenarios. Additionally, the damage and risks maps may support the recently initiated agricultural insurance programme in Vietnam.

scholarly journals Temporal and Local Heterogeneities of Water Table Depth under Different Agricultural Water Management Conditions

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2148
Author(s):  
Jonathan A. Lafond ◽  
Silvio J. Gumiere ◽  
Virginie Vanlandeghem ◽  
Jacques Gallichand ◽  
Alain N. Rousseau ◽  
...  
Keyword(s):  
Water Management ◽  
Water Table ◽  
Cropping Systems ◽  
Irrigation Management ◽  
Sprinkler Irrigation ◽  
Water Table Depth ◽  
Management Systems ◽  
Integrated Water Management ◽  
Growing Seasons ◽  
Good Drainage

Integrated water management has become a priority for cropping systems where subirrigation is possible. Compared to conventional sprinkler irrigation, the controlling water table can lead to a substantial increase in yield and water use efficiency with less pumping energy requirements. Knowing the spatiotemporal distribution of water table depth (WTD) and soil properties should help perform intelligent, integrated water management. Observation wells were installed in cranberry fields with different water management systems: Bottom, with good drainage and controlled WTD management; Surface, with good drainage and sprinkler irrigation management; Natural, without drainage, or with imperfectly drained and conventional sprinkler irrigation. During the 2017–2020 growing seasons, WTD was monitored on an hourly basis, while precipitation was measured at each site. Multi-frequential periodogram analysis revealed a dominant periodic component of 40 days each year in WTD fluctuations for the Bottom and Surface systems; for the Natural system, periodicity was heterogeneous and ranged from 2 to 6 weeks. Temporal cross correlations with precipitation show that for almost all the sites, there is a 3 to 9 h lag before WTD rises; one exception is a subirrigation site. These results indicate that automatic water table management based on continuously updated knowledge could contribute to integrated water management systems, by using precipitation-based models to predict WTD.

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