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Precise measurements of discharges at the outlet of a small catchment, using high resolution sensing equipment, can currently be done without difficulty. In particular, measurements can take place even during dry periods, when high temperatures increase actual evapotranspiration on the catchment and diurnal streamflow fluctuation changes occur in a harmonic wave at any time of the day. Some 10-15 years ago, a current runoff measurement record based on a high resolution equipment clearly recognizing a diurnal wave-shape fluctuation could hardly be available. The measurement of discharge ordinates from the catchment, and from free water pan evaporation, showed an undulating fluctuation tendency. However, the discharge minima appeared at day time and their maxima at night. The measured discharge data are represented not only by a fluctuating form, but also by a mild form, an even straight line, or by a flat depletion curve. For the purpose of analyzing the wave shape of discharge we implemented the Fourier series model, simulating the measured data through the Fourier input, output, and transformation coefficients. The purpose of this analysis was to use the Fourier equations in order to substitute the missing data (when the discharge or evaporation measurements collapsed). Due to very sensitive data, when the measured discharge series are jagged, the equation can be smoothed by the harmonic approximation or by the polynomial approximation. Our study was carried out on the small experimental catchment of the Starosuchdolsky Brook, in the vicinity of the campus of the Czech University of Life Sciences Prague. The harmonic analysis provided an interesting outcome, as well as innovative methodology.

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catchment depletion curve harmonic coefficients high resolution sensing fourier series rainless periods

Directory of Open Access Journals - Sweden

Climate-Determined Suitability of the Water Saving Technology "Alternate Wetting and Drying" in Rice Systems: A Scalable Methodology demonstrated for a Province in the Philippines Texte intégral

2015

Nelson, Andrew | Wassmann, Reiner | Sander, Björn Ole | Palao, Leo K.

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Climate-Determined Suitability of the Water Saving Technology "Alternate Wetting and Drying" in Rice Systems: A Scalable Methodology demonstrated for a Province in the Philippines Texte intégral

2015

Nelson, Andrew | Wassmann, Reiner | Sander, Björn Ole | Palao, Leo K.

70% of the world’s freshwater is used for irrigated agriculture and demand is expected to increase to meet future food security requirements. In Asia, rice accounts for the largest proportion of irrigated water use and reducing or conserving water in rice systems has been a long standing goal in agricultural research. The Alternate Wetting and Drying (AWD) technique has been developed to reduce water use by up to 30% compared to the continuously flooded conditions typically found in rice systems, while not impacting yield. AWD also reduces methane emissions produced by anaerobic archae and hence has applications for reducing water use and greenhouse gas emissions. Although AWD is being promoted across Asia, there have been no attempts to estimate the suitable area for this promising technology on a large scale. We present and demonstrate a spatial and temporal climate suitability assessment method for AWD that can be widely applied across rice systems in Asia. We use a simple water balance model and easily available spatial and temporal information on rice area, rice seasonality, rainfall, potential evapotranspiration and soil percolation rates to assess the suitable area per season. We apply the model to Cagayan province in the Philippines and conduct a sensitivity analysis to account for uncertainties in soil percolation and suitability classification. As expected, the entire dry season is climatically suitable for AWD for all scenarios. A further 60% of the wet season area is found suitable contradicting general perceptions that AWD would not be feasible in the wet season and showing that spatial and temporal assessments are necessary to explore the full potential of AWD.

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philippines agriculture food security rice climate change

International Livestock Research Institute - Kenya

Climate-Determined Suitability of the Water Saving Technology "Alternate Wetting and Drying" in Rice Systems: A Scalable Methodology demonstrated for a Province in the Philippines Texte intégral

2015

and leo kris palao. | andrew | nelson | reiner wassmann | bjoern ole sander

70% of the world�??s freshwater is used for irrigated agriculture and demand is expected to increase to meet future food security requirements. In Asia, rice accounts for the largest proportion of irrigated water use and reducing or conserving water in rice systems has been a long standing goal in agricultural research. The Alternate Wetting and Drying (AWD) technique has been developed to reduce water use by up to 30% compared to the continuously flooded conditions typically found in rice systems, while not impacting yield. AWD also reduces methane emissions produced by anaerobic archae and hence has applications for reducing water use and greenhouse gas emissions. Although AWD is being promoted across Asia, there have been no attempts to estimate the suitable area for this promising technology on a large scale. We present and demonstrate a spatial and temporal climate suitability assessment method for AWD that can be widely applied across rice systems in Asia. We use a simple water balance model and easily available spatial and temporal information on rice area, rice seasonality, rainfall, potential evapotranspiration and soil percolation rates to assess the suitable area per season. We apply the model to Cagayan province in the Philippines and conduct a sensitivity analysis to account for uncertainties in soil percolation and suitability classification. As expected, the entire dry season is climatically suitable for AWD for all scenarios. A further 60% of the wet season area is found suitable contradicting general perceptions that AWD would not be feasible in the wet season and showing that spatial and temporal assessments are necessary to explore the full potential of AWD | Nelson et al., 'Climate-determined suitability of the water saving technology "alternate wetting and drying" in rice systems: a scalable methodology demonstrated for a province in the Philippines', PLoS One 10, no. 12 (2015): e0145268(19 p.).

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information rice methane soil requirements classification ...

GARDIAN - United States of America

Update on the role of market mechanisms in intended nationally determined contributions Texte intégral

2015

Obergassel, Wolfgang | Gornik, Markus

Market mechanisms - the Clean Development Mechanism (CDM), Joint Implementation (JI) and Art. 17 emission trading - have been a central feature of the Kyoto Protocol. The Parties to the United Nations Framework Convention on Climate Change (UNFCCC) intend to adopt a new comprehensive climate agreement at this year's Conference of the Parties (COP) in Paris. The shape of the new agreement is emerging only slowly, including the role market mechanisms will play. To gauge the potential scope of market mechanisms in the forthcoming Paris agreement, this paper surveys the submitted INDCs on the question to what extent they envisage the use of market mechanisms. In detail, the paper looks at five questions for each INDC: - Does the INDC make any mention of market mechanisms? - Does the Party plan to use market mechanisms to achieve its contribution to the Paris agreement? - If a Party intends to use market mechanisms, does the INDC specify which mechanisms or types of units the country intends to use? - Does the Party quantify the extent to which it intends to use market mechanisms? Under the Kyoto Protocol, use of mechanisms has been supposed to be supplemental to domestic action, though this principle has never been quantified. - Does the Party specify how the use of mechanisms will ensure environmental integrity and avoid double counting?

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ddc:320

Wuppertal Institut - Germany