Your search found 6 records
1 Li, Y. H.; Cui, Y. L.. 1996. Real-time forecasting of irrigation water requirements of paddy fields. Agricultural Water Management, 31(3):185-193.
Irrigation requirements ; Water requirements ; Irrigation water ; Forecasting ; Rice ; Paddy fields ; Irrigation scheduling ; Evapotranspiration ; Computer models ; Mathematical models
(Location: IWMI-HQ Call no: PER Record No: H019336)
This paper presents the principle and methods of computerizing irrigation scheduling of paddy fields under intermittent submerged conditions. Models for forecasting daily evapotranspiration of rice are discussed. Under intermittent submerged conditions, there is no ponded water layer for most days after the rice turns green, so slight water stress occurs occasionally. The physiological mechanism and ecological characteristics of rice under limited water supply are quite different from those under submerged conditions; therefore, in estimating the evapotranspiration of rice, both lag and overshoot are considered in the model. Another feature of the model concerns the accounting for the contribution from the slow drainage of mobile water after the disappearance of the water layer in the paddy field. The model is compiled in Lotus 123 worksheets and is available as a menu-driven package.
2 Cabangon, R. J.; Castillo, E. G.; Lu, G.; Cui, Y. L.; Tuong, T. P.; Bouman, B. A. M.; Li, Y.; Chen, C.; Wang, J.; Liu, X. 2001. Impact of alternate wetting and drying irrigation on rice growth and resource-use efficiency. Barker, R.; Loeve, R.; Li, Y. H.; Tuong, T. P. (Eds.). Water-saving irrigation for rice: proceedings of an international workshop held in Wuhan, China, 23-25 March 2001. Colombo, Sri Lanka: International Water Management Institute (IWMI) pp.55-79.
Crop-based irrigation ; Rice ; Fertilizers ; Nitrogen ; Rain ; Crop yield ; Percolation ; Seepage ; Paddy fields ; Experiments / China / Hubei / Tuanlin
(Location: IWMI-HQ Call no: IWMI 631.7.2 G592 BAR Record No: H027863)
3 Xie, C. B.; Cui, Y. L.; Lance, J. M. 2003. Water Supply systems: Resource allocation, seepage and performance assessment. In Pereira, L. S.; Cai, L. G.; Musy, A.; Minhas, P. S. (Eds.), Water savings in the Yellow River Basin: Issues and decision support tools in irrigation. Beijing, China: China Agriculture Press. pp.46-64.
Water allocation ; Canals ; Seepage ; Water conveyance ; Irrigation systems / China / Yellow River Basin
(Location: IWMI-HQ Call no: 631.7 G592 PER Record No: H040060)
4 Roost, Nicolas; Cui, Y. L.; Xie, C. B.; Huang, B. 2003. Water supply simulation for improved allocation and management. In Pereira, L. S.; Cai, L. G.; Musy, A.; Minhas, P. S. (Eds.), Water savings in the Yellow River Basin: Issues and decision support tools in irrigation. Beijing, China: China Agriculture Press. pp.275-290.
Simulation models ; Computer models ; Water supply ; Irrigation systems ; Water delivery ; Water conveyance ; Water allocation ; Policy ; Conjunctive use ; Groundwater ; Reservoirs / China / Yellow River Basin
(Location: IWMI-HQ Call no: 631.7 G592 PER Record No: H040073)
5 Roost Nicolas; Cai, Xueliang; Molden, David; Cui, Y. L.. 2008. Adapting to intersectoral transfers in the Zhanghe Irrigation System, China: Part I - In-system storage characteristics. Agricultural Water Management, 95(6): 698-706.
Farm ponds ; Recharge ; Hydrology ; Water storage ; Water reuse ; Remote sensing ; Irrigation canals ; Irrigation systems ; Reservoirs ; Water allocation / China / Zhanghe Irrigation System / Yangtze River Basin
(Location: IWMI HQ Call no: 631.7.1 G592 ROO Record No: H040568)
The Zhanghe Irrigation System (ZIS), in Central China, has drawn attention internationally because it managed to sustain its rice production in the face of a dramatic reallocation of water to cities, industries and hydropower uses. Ponds, the small reservoirs ubiquitous in the area, are hypothesized to have been instrumental in this. Ponds are recharged by a combination of return flows from irrigation and runoff from catchment areas within the irrigated perimeter. They provide a flexible, local source of irrigation water to farmers. This paper assesses the storage capacity and some key hydrological properties of ponds in a major canal command within ZIS. Using remote sensing data (Landsat and IKONOS) and an area–volume relationship based on a field survey, we obtained an overall pond storage capacity of 96 mm (per unit irrigated area). A comparative analysis between 1978 and 2001reveals that part of this capacity results from a very significant development of ponds (particularly in the smaller range of sizes) in the time interval, probably as a response to rapidly declining canal supplies. We developed a high-resolution digital elevation model from 1:10,000 topographic maps to support a GIS-based hydrological analysis. Pond catchments were delineated and found to extensively overlap, forming hydrological cascades of up to 15 units. In a 76-km2 area within the irrigation system, we found an average of close to five ‘connected’ ponds downstream of each irrigated pixel. This high level of connectivity provides opportunities for multiple reuses of water as it flows along toposequences. A fundamental implication is that field ‘losses’ such as seepage and percolation do not necessarily represent losses at a larger scale. Such scale effects need to be adequately taken into account to avoid making wrong assumptions about water-saving interventions in irrigation.
6 Roost Nicolas; Cai, Xueliang; Turral, Hugh; Molden, David; Cui, Y. L.. 2008. Adapting to intersectoral transfers in the Zhanghe Irrigation System, China: Part II – Impacts of in-system storage on water balance and productivity. Agricultural Water Management, 95(6): 685-697.
Farm ponds ; Irrigation systems ; Reservoirs ; Water balance ; Simulation models ; Rice ; Crop production ; Irrigation canals ; Groundwater ; Drainage ; Evapotranspiration ; Water distribution / China / Zhanghe Irrigation System / Yangtze River Basin
(Location: IWMI HQ Call no: 631.7.1 G592 ROO Record No: H040569)
This paper investigates the impacts of farm ponds in a context of declining supplies in a major canal command within the Zhanghe Irrigation System (ZIS), in Central China. As dam supplies have been diverted to higher-valued uses (hydropower, cities and industry), farmers have responded by constructing small storages within their fields. These farm ponds have given them sufficient flexibility in water supply to practice varying forms of alternate wetting and drying irrigation for rice without compromising yields and incomes. Ponds are recharged by a combination of return flows from irrigation and runoff from catchment areas within the irrigated perimeter. Various scenarios of water supply incorporating the main reservoir, in-system reservoirs, farm ponds and irrigation practices were simulated using the OASIS model. OASIS integrates surface and groundwater flows, and contains a crop growth module to aggregate the impacts of different water management regimes. The modelling and sensitivity analysis show that further reductions in main reservoir supplies will have a negative effect on rice production in dry and average years, and that ponds have played a crucial role in adapting agriculture to reduced canal supplies. The flexibility allowed by the ponds has resulted in increased water productivity, except in high rainfall years, but net depletion has not decreased, as local supplies have substituted for water from the main reservoir. The study demonstrates the importance of properly accounting for return flows and the necessity to understand crop production in relation to the actual depletion of water (as evapotranspiration) within an irrigation system.
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