tuat-marco joint international workshop on rice … joint international workshop on rice paddy...
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Program and Abstracts
TUAT-MARCO Joint International Workshop on Rice Paddy Module Development in SWAT 2014
– Development of a tool for sustainable rice production in Asia and world – Date： 18–21 November, 2014 Venue: Tokyo University of Agriculture and Technology (TUAT), Fuchu, Tokyo, Japan
Organized & Sponsored by: Tokyo University of Agriculture and Technology (TUAT) Leading Graduate School Program for Green and Clean Food Production, TUAT National Institute for Agro-Environmental Sciences (NIAES) Monsoon Asia Agro-Environmental Research Consortium (MARCO) Supported by: United States Department of Agriculture, Agricultural Research Service (USDA-ARS) World Association of Soil and Water Conservation (WASWAC)
Forest
River
Upland field
Paddy field
Rationale for the Workshop: Rice is a major staple food crop in Asia, and gaining increased popularity worldwide.
Because of the urgent regional and global issues related to rice production, water and food security, there is a strong need for modeling tools that have the capability to simulate water, nutrient, and other agrochemicals dynamics in watersheds containing irrigated or rain-fed rice paddy fields. However, at present, we do not have a reliable tool or model with a strong underlying scientific basis to quantitatively investigate such issues in order to protect water resources and to maintain sustainable rice production.
The Soil and Water Assessment Tool (SWAT) water quality model is one of the most popular and versatile watershed-scale models currently in use worldwide. SWAT has some useful functions that we can apply for modeling hydrology and chemical transport for rice paddy production systems, and some trial applications with the model have been conducted. However, actual source code (algorithms) for rice modeling has not been developed for SWAT.
This workshop will explore and exchange current information and knowledge on SWAT rice paddy module development and construct international network for developing SWAT rice paddy module. Abstract Submission:
Call for abstracts with 250 to 350 words in English for poster presentation. Field to watershed-scale monitoring & modeling studies of water and chemical dynamics are particularly welcome. For further information, please send E-mail to the contact address below. Registration Fee:
Free for attending the Workshop. Official Language:
The official language of the Workshop will be English. Contact at: Hirozumi Watanabe
Tokyo University of Agriculture and Technology (TUAT) E-mail: [email protected]
Sadao Eguchi
National Institute for Agro-Environmental Sciences (NIAES) E-mail: [email protected]
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TUAT-MARCO Joint International Workshop on Rice Paddy Module Development in SWAT 2014
– Development of a tool for sustainable rice production in Asia and world – 18–21 November 2014, Fuchu, Tokyo, Japan
PROGRAM
Registration at the Hotel Continental Address Fuchu 1-5-1, Fuchu, Tokyo Tel. +81-42-333-7111 Fax. +81-42-333-7117 H.P. http://www.hotel-continental.co.jp/english/
18:00 Icebreak in TUAT
09:00 Opening addresses Dr. Yasuhisa Kunimi
Vice-President, Tokyo University of Agriculture and Technology (TUAT), Japan
Dr. Kazuyuki Yagi Research Coordinator, National Institute for Agro-Environmental Sciences
(NIAES), Japan 09:15 Keynote lecture I: Simulation of rice paddy systems in SWAT: A global synthesis
of typical approaches, improved modified methods, and future development needs Dr. Philip Gassman
Center for Agricultural and Rural Development (CARD), Iowa State University, U.S.A.
Tuesday, November 18
Arrival of participants
Wednesday, November 19
Workshop 1st day
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10:00 SWAT rice paddy modeling in Japan: current progress and future needs Dr. Hirozumi Watanabe Tokyo University of Agriculture and Technology (TUAT), Japan 10:45 Coffee Break 11:15 A Monte Carlo approach to assess the impact of rice fields on water resources in
the coastal plain of Oristano, Sardinia (Italy) Dr. Pierluigi Cau
Center for Advance Research and Studies in Sardinia (CRS4), Italy 12:00 Lunch break and Poster Session 13:30 SWAT rice paddy module development in Japan Dr. Atsushi Sakaguchi
National Institute for Agro-Environmental Sciences (NIAES), Japan (Present affiliation: Yamaguchi University, Japan)
14:15 SWAT modeling in Vietnum: Towards the development of flood warning system
including rice paddy function Dr. Kim Loi Nguyen
Nong Lam University, Vietnum 15:00 Coffee Break and Poster Session 15:30 Development and testing of irrigation modules for rice Paddy using SWAT Dr. Balaji Narasimhan
Indian Institute of Technology Madras, India 16:15 Discussion on SWAT applications in different rice paddy watersheds Chair: Dr. Philip W Gassman 18:00 Welcome Dinner
(Participation is optional)
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09:15 Keynote lecture II: A framework for modeling paddy fields: linking agricultural
managements and biophysical responces in APEX Dr. Jaehak Jeong Texas Agricultural and Mechanical University, U.S.A.
10:00 SWAT modeling on nutrient dynamics in agricultural watersheds
Dr. Rui Jiang Northwest Agriculture and Forestry University, China
10:45 Coffee Break 11:15 SWAT coding for rice paddy module
Dr. Julien Boulange Tokyo University of Agriculture and Technology (TUAT), Japan
12:00 Lunch break and Poster session 13:30 Discussion on constructing base case rice paddy module scenarios Chair: Dr. Tasuku Kato 15:00 Coffee Break and Poster Session 15:30 General discussion and goal setting
Chair: Dr. Hirozumi Watanabe 16:45 Closing remarks
Thursday, November 20
Workshop 2nd day
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09:00 Leaving Tokyo University of Agriculture and Technology (TUAT)
Excursion to rice paddy fields in local agricultural areas/ Tama River watershed/ Japanese garden/ shrine/ temple…etc.
16:00 Return to Tokyo University of Agriculture and Technology (TUAT)
Friday, November 21
One-day scientific excursion
Saturday, November 22
Departure of participants
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Access to TUAT Fuchu Campus/ Hotel Continental from Airport
Railway Map To TUAT Fuchu Campus:
From Haneda Airport Take Tokyo Monorail to Hamamatsu-cho Station or Keikyu Line to Shinagawa Station. From there, take the JR Yamanote Line outbound and get off Shinjuku Station. From Shinjuku Station, take the Keio Line Special Express to Fuchu Station.
By Airport Limousine Bus
Board a bus bound for Fuchu Station. http://www.limousinebus.co.jp/en/platform_searches/index/4/140
From Narita Airport
From Narita Airport Station to Tokyo Station, take JR Narita Express. From Tokyo Station, take the JR Chuo Line Express and get off Shinjuku Station. From Shinjuku Station, take the Keio Line Special Express to Fuchu Station.
From Fuchu Station
Take the Keio Bus (for Kokubunji Station South Exit via Meisei Gakuen, with a mark ｢寺 91｣) from Bus Terminal No. 2 of boarding area of Fuchu Station North Exit and get off Harumicho Bus Stop close to TUAT. About 7 minute bus ride.
From Kita-Fuchu Station
Walk about 12 minutes to campus. To Hotel Continental:
Walk about 1 minute from Fuchu Station.
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Workshop location: Memorial Hall (Alumni 50th Anniversary Hall) Tokyo University of Agriculture and Technology (TUAT) Fuchu Campus
Address 3-8-1 Harumi-cho, Fuchu-shi, Tokyo, Japan URL http://www.tuat.ac.jp/en/basic_information/access/index.html
Hotel Continental
Address 1-5-1 Fuchu-cho, Fuchu-shi, Tokyo, Japan URL http://www.hotel-continental.co.jp/english/access/index.html
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Keynote-1
Simulation of rice paddy systems in SWAT: A global synthesis of typical approaches, improved modified methods, and future
development needs
Philip W. Gassman1
1Center for Agricultural and Rural Development, Iowa State University, Ames, Iowa, 50011-1070, United States
E-mail: [email protected]
ABSTRACT
The Soil and Water Assessment Tool (SWAT) ecohydrological watershed-scale model
was initially developed in the early 1990s to simulate the impacts of land use, management
systems and climate on hydrology and/or water quality. First adopted in the U.S., the use of
the model then spread to Europe and then later to Asia and other regions. The range of
applications that SWAT has been applied to have also expanded dramatically, which
influenced ongoing model development which has been virtually continuous over the past two
decades. A key component of many SWAT applications in Asia is accounting for rice paddy
production that is common in some subregions within the continent. However, most of these
studies do not provide explicit details of how rice production was simulated in SWAT. Other
research has revealed that significant problems occur when trying to represent rice paddy
systems in standard versions of SWAT, due to limitations in algorithms based on the runoff
curve number approach or the pothole option. In response, key modifications have been made
to SWAT in recent studies that have resulted in more accurate representation of rice paddy
systems. These developments point to the need for the incorporation of an enhanced rice
paddy module within SWAT to better capture rice paddy hydrological and pollutant dynamics,
which would support improved use of the model in Asia and other rice production regions. An
overview of global rice production will first be presented, followed by a history of SWAT
development, applications of the standard model for watersheds impacted by rice production,
code modifications to address deficiencies in replicating rice paddy systems, and
recommendations for developing a standard rice paddy module for future SWAT codes.
Key Word: SWAT, Rice Paddies, Potholes, Hydrology, Pollutants, Modified SWAT models
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Keynote-2
A framework for modeling paddy fields: linking agricultural managements and biophysical responses in APEX
Jaehak Jeong1 Minkyeong Kim2
1 Texas A&M AgriLife Research, Texas A&M University, USA 2 National Academy of Agricultural Science, Rural Development Administration, Republic
of Korea E-mail: [email protected]
ABSTRACT
There has been attempts to evaluate hydrologic and quality impacts of paddy fields at the
watershed scale, but only limited progress has been made especially with regard to water
quality assessment. Due to the lack of modeling procedures for simulating agricultural
managements of paddy fields common in Asian countries in watershed models, many
published paddy studies had to devise alternative techniques to mimic the biophysical
responses of paddy fields in response to agricultural managements such as puddling, flood
irrigation, transplanting, and irrigation management. The objectives of this study are 1) to
construct a modeling framework for simulating paddy processes by linking management
operations to biophysical responses in paddies within Agricultural Policy/Environmental
eXtender (APEX) model, 2) to test the paddy module against field monitoring data collected
at two experimental paddy fields in Korea, and 3) to evaluate and recommend agricultural
best management practices for controlling sediment and (or) nutrient loads from paddy fields
in various climate regions at the national scale in Korea. A preliminary calibration results on
the Icheon field in Korea indicates that APEX with the new process-based paddy modeling
framework accurately represents water quantity/quality responses of paddies to various
management operations during cropping seasons with improved prediction of water balance,
crop yield, and solute transport.
Key Word: Paddy Rice, Water Quality, APEX model, Irrigation
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Oral-1
SWAT rice paddy modeling in Japan: Current progress and future needs
Hirozumi Watanabe1, Boulange Julien1
1 Department of International Environmental & Agricultural Science, Tokyo University of
Agriculture and Technology, Japan
E-mail: [email protected]; [email protected]
ABSTRACT
In Japan, the environmental impacts associated with pollutant discharge from rice paddy fields is a major concern as rice paddies account for about 54% of the total agricultural land. SWAT model is the one of the strong candidates as a tool for the environmental assessments in watershed and river basin scale. Recently, STAT has been improved for its capability of modeling water and pollutants movements in watershed containing rice paddies. In this report, the current progress of modeling hydrology and pollutants transport in Japanese rice paddy environments and its future needs towards development of SWAT rice paddy module is discussed.
In the SWAT model, the key hydrological components of paddy fields were mainly simulated using water balance equations considering shapes and structures of rice paddies. The ponding depth, irrigation and drainage of rice paddies vary with the field operations and weather conditions in the field. Consequently, rice growing scenarios were created into the newly developed SWAT model. By simulating the hydrology of paddy, it is then possible to simulate sediments and dissolved substances in rice paddies and therefore their fate and transport in watersheds. Recent published study focused on water and sediment movement as well as pesticide transport in Japanese watershed containing rice paddies.
The current modification of SWAT that improving the prediction of rice paddy field hydrology mainly focused on the rice growing season. However during the off-crop season, SWAT model simulates the hydrology of the paddy fields using the classical curve number methods. Therefore the model ignore the presence of levees that prevent most runoff even when paddies are not ponding. Another concern may be the plot to plot irrigation system and wide variety of water recirculation systems. Such improvement will enhance the future applicability of SWAT rice module in different rice growing region in Asia and the world. Keywords: Paddy field in Japan, Hydrology, Pollutant, water balance, SWAT model, Rice module
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Oral-2
A Monte Carlo approach to assess the impact of rice fields on water resources in the coastal plain of Oristano, Sardinia (Italy)
P. Cau1, G. Lecca1, C. Soru1, D. Muroni1, E. Peneva2, P. A. Marras1
1 Center for Advanced Studies, Research and Development in Sardinia (CRS4 ), Italy.
2 University of Sofia, Bulgaria.
ABSTRACT
The Oristano plain, located in lower part of the Tirso basin, western part of the Mediterranean Sea, is one of the most fertile regions in Sardinia (Italy). Crop production (rice, corn, olive and grape) is progressively increasing, although water supply is limited. In this region, agriculture is the largest consumer of water, where its need is fulfilled exploiting mainly the Tirso river and the groundwater resources. Due to poor management strategies, available water supply, both ground and surface, and its quality are impoverishing. Because of wrong positioning and excessive pumping of production wells, seawater intrusion has been also documented.
In this study, a modeling infrastructure, based on the semi-distributed SWAT hydrological model and the finite element CODESA 3D groundwater model, has been set up to study water dynamics in the area. SWAT is employed to model the hydrological cycle while the groundwater model, fed by SWAT, simulates groundwater dynamics. Uncertainties in the physical parameters of the groundwater system, due to the lack of direct access to the subsurface, strongly affect the design of water management policies, so that the risk of mismanagement becomes a critical factor. Stochastic modeling may provide uncertainty quantification and also add robustness to the analysis by means of probabilistic forecasts. A stochastic approach has been therefore employed to model hydraulic conductivity of the soil layers, under conditions of uncertainty. Such stochastic model is based on equiprobable realizations of the conductivity field that mimic the random occurrence of spatial discontinuities and heterogeneities (sand, silt or clay lenses). A Monte Carlo simulation, based on the hydrological and groundwater models has been carried out, where the hydraulic conductivity parameter is the sole source of uncertainty while the other physical parameters are assumed as deterministic and do not vary.
A critical variable for the system is the salt concentration on groundwater that is adversely impacting rice productivity, analysed under different water exploitation schemes.
Keywords: SWAT, CODESA 3D, Monte Carlo simulation, water management
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Oral-3
SWAT rice paddy module development in Japan
Atsushi Sakaguchi 1,2, Sadao Eguchi1
1 Carbon and Nutrient Cycles Division, National Institute for Agro-Environmental Sciences (NIAES), Japan
2 Present affiliation: Yamaguchi University, Japan E-mail: [email protected]
ABSTRACT
The water ponding and drainage management in paddy fields should significantly affect
the regional hydrology and water quality; however, the suitability of SWAT for simulating
paddy hydrology at a field scale has not been thoroughly examined. We applied both the
curve number procedure and pothole module to calculate the paddy field hydrology in a small
rice paddy watershed to which irrigation water is supplied from the outside (large scale
irrigation). The water balance components estimated using the pothole module resulted in
zero percolation on most days even under ponded conditions; zero water loss by percolation,
surface runoff, and evapotranspiration during drainage (non-ponding) period; and too small
evapotranspiration on a number of days during ponding period. On the contrary, the curve
number procedure apparently yielded a reasonable paddy field hydrology; however, this
procedure in principle cannot simulate the ponded water conditions, indicating inapplicability
for reflecting various paddy water management scenarios in the field. For this reason, we
developed a rice paddy module by modifying the pothole module; that is, the shape of
impoundment was changed from cone to cube; a new parameter ‘potential percolation rate of
the paddy field’ was introduced which determines the upper limit of the rate of percolation
into the subsoil and of which value was calibrated to fit the observed stream flow rate; the
excess irrigation water supplied from outside of the watershed was released directly to the
stream to avoid overflows from paddy fields; the rainfall-runoff and evapotranspiration
processes were activated during drainage periods; and the evaporation processes from the
ponded water and soil surface were modified in accordance with the observed evaporation
rate at a paddy field. The developed paddy module reasonably simulated the rice paddy
hydrology at the field and watershed scales.
Keywords: ponded and drained conditions, large scale irrigation, potential percolation rate
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Oral-4
SWAT modeling in Vietnam: Towards the development of flood warning system including rice paddy function
Nguyen Kim Loi1, Nguyen Duy Liem1, Pham Cong Thien1, Le Van Phan1, Le Hoang Tu1, Hoang Thi Thuy1, Nguyen Van Trai1, Tran Le Nhu Quynh1,
Le Tan Phuc1, Nguyen Thi Huyen1, Nguyen Thi Tinh Au2, Nguyen Thi Hong3, R. Srinivasan4 *
1Nong Lam University, Ho Chi Minh City 2University of Technical Education Ho Chi Minh City
3Hanoi University of Natural Sciences 4Texas A&M University, USA
ABSTRACT
Vu Gia watershed is located in the Central Vietnam where hurricanes represent a constant natural threat to human lives and physical infrastructure. Hydrological monitoring is considered as an effective tool to respond to high flood events by preventing and mitigating damages. The purpose of this study was to conduct and perform hydrological modeling to determine areas prone to be flooded during high rainfall events in the upstream Vu Gia watershed. The methodology involved: hydro-climatic data base building, a detailed Digital Elevation Model (DEM), a land use cover, and a soil map of the basin. With all this data, the SWAT model (Soil and Water Assessment Tool) was used to predict discharge values. These discharge values were used, along with the DEM, to predict flood hazard areas in the downstream of Vu Gia watershed floodplains. This procedure was made using the HEC-RAS model (Hydrological Engineering Center-River Analysis System). Finals results show the exact location of areas with high, moderate and low risk to be flooded at specific high flood events. The results also provided the location of critical areas, so that an early warning system can be located. Additionally, as a part of this study, valuable information was provided to at-risk residents about how to prevent and mitigate the effect of flood-related damages in low land areas of the Vu Gia watershed.
The further study will add rice paddy field function to flood warning system, because the rice paddy field (ponded water) appear to have a function of controlling a large amount of water storage in the watershed. If rice paddy area particularly in lowland area can be considered as a buffer zone for mitigating disaster from flooding, more realistic hydrological processes in paddy fields should be incorporated into the flood warning system in Vietnam. Keywords: Flood warning, SWAT, HEC-RAS, Vu Gia watershed, Rice paddy, Vietnam.
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Oral-5
Development and testing of irrigation modules for rice Paddy using SWAT
V. M. Bindhu1, N. Nithila Devi2, K. Karpagam3, and B. Narasimhan4
1Associate Professor, Department of Civil Engineering, VIT Chennai Campus, INDIA 2Research Scholar, Department of Civil Engineering, IIT Madras, Chennai, INDIA
3Research Associate, Department of Civil Engineering, IIT Madras, Chennai, INDIA 4Associate Professor, Department of Civil Engineering, IIT Madras, Chennai, INDIA
ABSTRACT
Rice paddy is the largest staple food consumed by the people around the world next only
to maize. However, among the top three cereals, maize, wheat and rice, together which
account for 87% of total food grain production, rice consumes the maximum amount of water
to produce a unit weight of grain. SWAT is increasingly being used to simulate the
sustainability of rice production due to climate change. The irrigation routines in SWAT are
primarily developed to simulate agricultural crops that grow in non-flooded condition. As
paddy is a hydrophilic crop, it needs flooded condition for its optimal growth and vital
metobolic functions. In this study, the irrigation routines in SWAT have been modified to
simulate flooded irrigation. For realistically simulating the irrigation, the auto irrigation in
SWAT has been modified to simulate the irrigation demand based on the soil water deficit
using the depletion factor. Further, conveyance efficiency and application efficiency have
been explicitly incorporated to realistically simulate the amount of irrigation return flow to
the aquifer. The modified irrigation routine is applied for a field in Gadana basin in Tamil
Nadu, India where roughly 75% to 90% of the agricultural lands grow paddy in flooded
conditions during the monsoons. Daily values of irrigation, percolation and evapotranspiration
measurements were made, using tubes installed in fields, scattered across the basin. These
measurements coupled with ORYZA model is used for validation.
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Oral-6
SWAT modeling on nutrient dynamics in agricultural watersheds
Rui Jiang1 Chunying Wang2 Ryusuke Hatano2
1 College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China; E-mail: [email protected]
2 Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
ABSTRACT
The nutrients balance is required for agriculture management and the process-based model has the potential to access the dynamics of nutrients cycles. The aim of this study was to simulate the nitrogen (N) and potassium (K) using SWAT model in a dairy farming watershed (Shibetsu watershed) in eastern Hokkaido, Japan. Nitrogen simulation was applied in the watershed with external water source (EXT) by adding the N loading from EXT in point source discharge. Potassium was simulated by a SWAT-K module which is modified based on pesticide module in SWAT. The conceptual model for SWAT-K contains K cycle in soil and instream process. The soil pool plays an import role in the cycling of nutrients. Potassium may be added to the soil by fertilizer or residue application, weathering and deposition, and may be removed from the soil by plant uptake, leaching and erosion. The potassium in stream transports with streamflow and sediment, which includes adsorption, desorption, setting, resuspension, diffusion, and burial processes. The data used for N simulation (weather, soil, land use, stremflow, riverine NO3
--N concentration) were collected from 2003-2008 in Shibetsu watershed. The data used for SWAT-K (weather, soil, land use, stremflow, riverine soluble K concentration, biomass) were collected from 2003-2004. Potassium concentrations in vegetation, surface soil, and sediment were measured in 2013. The weathering rate was calculated by budget approach using the soil K concentration data measured in 1970 and 2013. The Fv (soil to plant transfer ratio) is the key parameter for plant uptake, which was calculated based on the K concentrations of plants and soils measured in 2013. The result yielded high Nash-Sutcliffe coefficient (Ens) values for daily streamflow (over 0.5) and monthly NO3
--N loading (over 0.7) and riverine K concentrations (over 0.6) during calibration and validation period. The work procedure for N and K simulation is similar with the nutrients simulation in rice paddy system. The main processes for rice paddy system in China are considered in the conceptual model for building a new module in SWAT. Key Word: nitrogen, potassium, conceptual model, rice paddy system
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Oral-7
SWAT coding for rice paddy module
Boulange Julien1, Watanabe Hirozumi1 1 Department of International Environmental & Agricultural Science, Tokyo University of
Agriculture and Technology, Japan E-mail: [email protected]; [email protected]
ABSTRACT
The Soil and Water Assessment Tool, SWAT model, is a physically-based basin scale
model developed to assist water resource managers in assessing the impact of management on
water supplies and nonpoint source pollution in watersheds. The source code of the model is
available online allowing researchers to modify the original SWAT code. Since the SWAT
model was reported to lack options and accuracy when dealing with areas where rice is
heavily cultivated, modifications of SWAT code applicable for use in watershed containing
paddy fields has been reported recently. In this report, key components useful in coding
SWAT program for rice paddy module will be presented using examples from a modified
SWAT code of PCPF-1@SWAT for the simulation of fate and transport of rice pesticide.
The model has been continuously improved and expended resulting in a source code that
is currently divided in more than 300 files. These files can be sorted into 2 groups, (i)
variables initialization, and (ii) simulation. By reading the fig.fig input file, the SWAT model
triggers the appropriate algorithm to simulate the hydrologic cycle of the watershed.
Therefore the “simulation” group can be break down into 16 sub-groups which correspond to
the different options that are available in the fig.fig input file. The most used sub-groups are
the HRU and reach groups which can be further subdivided into files regarding hydrology,
pesticide, nutrient, and etc..
The rice paddy module belong to the HRU sub-group as potholes are declared into HRUs.
In addition, due to the specific managements that are involved in rice cultivation, the file
readmgt.f which checks the schedule of specific managements is also required. Then, the new
variables created need to be defined in allocate_parms.f and modparm.f and initialized in
zero.f, respectively.
Testing the modification is critical to ensure that all variables are correctly routed to the
appropriape compartment so that the mass balance of the HRU is not compromized.
Key words: SWAT code, rice Paddy, PCPF-1@SWAT, potholes, HRU
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Poster-1
Impact assessment of global warming on production of paddy rice in Central Taiwan by the DNDC model
Jennkuo Tsai1 Chiling Chen1 Minghuang Wu1 Hong-Shu Wu2 Rei-Chang Wang3 and
Win-Chang Sun3
1 Agricultural Chemistry Division, Taiwan Agricultural Research Institute 2.Chiayi Agricultural Experiment Branch, Taiwan Agricultural Research Institute, Taiwan
3.Tainan District Agricultural Research and Extension Station, Taiwan E-mail: [email protected]
ABSTRACT
The production of agricultural ecosystem might be affected by climate change. The aim
of this study is to assess the impact of global warming on the production of paddy rice
(Variety : Tainung 11) in central Taiwan by the DeNitrification and DeComposition (DNDC)
model. The related data were collected for model validation from two sites of long-term
ecological research, include Chiko and Yunlin located central Taiwan. The collected data
include the weather (daily minimum and maximum temperature, rainfall), management
(fertilization and irrigation) and yield from 2007 to 2011. The impact of 2℃ temperature
increasing on the production have also been simulated by the model in this study. The
simulation results of the DNDC model reveal that the correlation between simulated and
observed yields of two sites is 0.56 (p<0.01) using the same parameters. The results of impact
assessment under 2℃ temperature increasing reveal that the flowering might be 6 and 2 day
early, the period of grain filling might be shorted 9 and 6 days and yield might be reduced
1.3% and 5% for the first and second cropping season representatively. The result showed the
impact of global warming on the production of the second cropping season is greater than that
of the first one. The results are similar to the prediction by the CERES-Rice model.
Key Word: Paddy Rice, Global Warming, DNDC model
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Poster-2
Simulating potassium load from a dairy farming watershed with the modified Soil and Water Assessment Tool
Chunying Wang1, Rui Jiang2, Kanta Kuramochi1, Ryusuke Hatano1
1 Graduate School of Agriculture, Hokkaido University, Sapporo, Japan 2 College of Resources and Environment, Northwest A&F University, Yangling, China
E-mail: [email protected]
ABSTRACT
Potassium (K) is an essential nutrient for plant growth and it has been intensively used to
optimize agricultural crop yield. K ion can easily leach from soils during infiltration, thus, K
loss needs to be quantified for efficient nutrient management. Agriculture of Shibetsu river
watershed (main outlet SRW, eastern Hokkaido, Japan) mainly includes dairy farming. This
watershed receives intensive K input from fertilizer and manure applications (89.8 kg K ha-1
yr-1) and external groundwater (EXT, 8.0 kg K ha-1 yr-1). The Soil and Water Assessment
Tool (SWAT) was modified (SWAT-K) by including the main K dynamic processes
(application, solid-liquid distribution in soil, plant uptake, and transportation with water
movement and soil erosion). The exchangeable K release from structural and fixed K trapped
in the soil minerals was simplified as an input parameter in the model, which was estimated to
be 33 kg K ha-1 yr-1. The SWAT-K model was used to assess the riverine K load and K budget
in SRW. Measured daily soluble K load at the main outlet SRW was used to evaluate the
SWAT-K model from 2003 to 2004. SWAT-K well predicted the daily soluble K loads to
stream. Simulation results (2003-2008) showed that soluble and sediment absorbed K load
was 35.5 and 0.1 kg K ha-1 yr-1, respectively. K is weakly absorbed by sediment bounded with
organic matter and sediment absorbed K load only accounted for 0.3% of the total K load.
Simulation results also showed that plant uptake, leaching out of soil profile and soil storage
K was 17.8, 22.4, and 81.9 kg K ha-1 yr-1, respectively. The large amount of stream K load
and soil storage indicated that agricultural K input might be excessive and reducing the K
application is recommended.
Key word：Exchangeable potassium, Potassium load, Potassium budget, SWAT
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Poster-3
Applying SWAT model to evaluate soil runoff from the agricultural basin in sub-tropical island, Japan
Yoshiko Iizumi1 and Imelida Genson-Torrefranca2
1Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences, Japan
2Bohol Island State University, Republic of the Philippines E-mail: [email protected]
ABSTRACT
Extensive land managements in mountainous islands in tropical or sub-tropical regions
have caused serious soil discharge and massive damage to coral reef ecosystems in coastal
areas. The Todoroki River basin in Ishigaki Island, Japan, is faced with problems caused by
red soil runoff from agricultural lands. The aim of this study is to calculate the amount of soil
erosion on each sub-basin and to evaluate the effects of the countermeasures to reduce the soil
runoff. Area of the Todoroki River basin is about 11 km2. The land use consists of sugarcane
field (36%) and pasture land (30%) mainly, and a few residential areas. The length of river
channel is 3.1 km. The flux and concentrations of suspended solid (SS) were measured to
understand the current situation of the river basin from 2006 to 2009. The data of weather
elements (rain fall, wind velocity, air temperature, relative humidity and solar radiation)
measured at the Ishigaki Local Meteorological Observatory were used for input data. The data
of land use, soil type, fertilizer application for sugar cane, and river flux and SS
concentrations were collected from Okinawa Prefecture as input or validation data. The
simulation period is from 1 January 2007 to 31 December 2008. Time step of the simulation
was set to be 1 day. The results for the validation indicated a good correlation between the
river water flux estimated by H-Q curve and simulated by SWAT model. The amount of soil
erosion was relatively high in the sub-basins characterized by steep slopes, acidic cohesive
soil named Kunigami-maaji and sugar cane fields. Result obtained by the hypothetical
simulation suggested that if all sugar cane fields change into pasture lands, amount of soil
runoff from the catchment will be reduced by 46 %.
Key Word: Agricultural Basin, Soil Erosion, SWAT model
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Poster-4
Application of SWAT model on estimating water and solute movements in the Sakura River Basin, Ibaraki, Japan.
Seiko Yoshikawa, Saeko Yada, Kei Asada, Sunao Itahashi, Yasuhiro Nakajima, Kazunori
Kohyama, Sadao Eguchi
National Institute for Agro-Environmental Sciences
E-mail: [email protected]
ABSTRACT
The aim of this study is to test applicability of SWAT to model water quantity and quality
of the Sakura River basin in Ibaraki prefecture, Japan. The river is one of tributaries of Lake
Kasumigaura, which is the second largest lake in Japan and whose water is used for domestic,
agricultural and industrial purposes. The area of the basin is 335 km2 ,of which 29% is used as
paddy fields and 20% is as upland fields. The paddy fields are irrigated by Kasumigaura
irrigation channel.
For modeling the basin characteristics, digital data including DEM (10m mesh by MLIT),
land use data (100m mesh), and soil map data (100m) were used. Besides, Solpy-J
(Soil-Profile Physical Properties Dataset, Japan) were used for soil physical property and
irrigation water supplying data were also used. For calibration and validation of the model,
stream water flow data and SS (solid suspension) data measured by MLIT at the lower reach
of the river were used. For model run, a period of three years was assigned to the warm-up,
one year to the calibration, and another one year to the validation. By adjusting several
parameters manually, stream water flow was simulated relatively good (Ens =0.55), while SS
was poor and needed further adjustment of parameters.
Water and solute movements in a tributary basin; Sakasa River Basin (10 km2) were also
simulated by SWAT. Channel network was input by burn in, and agricultural managements
were input in the model. Simulated stream flow and NO3-N were in poor performance when
compared with measured data. For improving model reliability, further adjustment of
parameters and continuous monitoring were needed.
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Poster-5
Calibration and validation of a SWAT model for water quantity and sediment simulation in the Thac Ba
reservoir basin, Vietnam and China
Nguyen Ngoc Tue1 and Thomas Ballatore2
1 Hanoi University of Science and Technology, Vietnam 2 Lake Basin Action Network, Japan
ABSTRACT
The Thac Ba reservoir (230.4 km2), constructed in Vietnam in 1970, is a vital source of
drinking water for millions of inhabitants of the downstream Hanoi region. In recent years,
changes in land use in the watershed have led to an increased influx of sediment and nutrients,
challenging the long-term sustainable use of the waterbody. The reservoir lies in an
international drainage basin (34% in PR China; 66% in Vietnam) and until recently (Nguyen
2013) modeling work had not been carried out due to the difficulty in acquiring consistent
data from both countries. Here, we describe data collection efforts and present the results of
calibrated and validated SWAT model on streamflow and sediment. For monthly values on
data collected during 1992–2003, the model performance in terms of both the coefficient of
determination (R2) and Nash-Sutcliffe coefficient (NSE) were very good with R2 = 0.885 and
NSE = 0.914 for streamflow and R2 = 0.826 and NSE = 0.849 for sediment. The NSE for
daily streamflow calibration was lower (NSE = 0.628) yet still acceptable. With
approximately 36% of the watershed’s land use as agriculture (mainly paddy fields), we
expect further refinement of paddy field modeling will help improve the daily results and
allow for more effective prediction of the effect of changing land use and climate on
streamflow discharge as well as sediment runoff within the watershed.
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Poster-6
Effects of flow regime shift on nutrient discharge from a suburban watershed into the Seto inland sea
Yuta Shimizu1 and Shin-ichi Onodera2
1JSPS Research Fellow, National Agriculture and Food Research Organization (NARO),
Western Region Agricultural Research Center (WARC) 2Hiroshima University
ABSTRACT
The Seto inland sea, which is the largest enclosed sea in western Japan, has the greatest
fisheries production because inflowing rivers bring a large amount of nutrients into the sea.
Recently, frequent discoloration of aquacultured Nori (Porphyra thalli) has been a serious
problem due to mainly decrease of nitrogen flux from rivers. However, changes in amount of
nutrient flux from inflowing rivers are still little known. This study aims to confirm the effect
of flow regime shift on nutrient discharge from a watershed into the Seto Inland Sea using
SWAT. The Takaya River watershed (133km2), a tributary of the Ashida River in western
Japan, is suburban watershed in western Japan that eventually drains into the north part of the
Seto Inland Sea. The area is characterized by a temperate climate with annual mean
precipitation and temperature of 1,117mm and 15.4°C, respectively. In this study, SWAT was
applied to the Takaya River watershed for the period from 1979 to 2010.
The result shows that the frequency of small-scale flood events has decreased and
extreme flood events have increased in the watershed. Furthermore, flood events may have
increased in magnitude while base flow periods have been extended. In addition, mean flow
rate during base flow condition decreased from the 1980s to the 2000s. The results imply that
the runoff trend may have caused a flow regime shifts. Fluxes of T-N and T-P per flood event
in the 2000s was higher than in the 1980s owing to land-use change and increased quantities
of domestic wastewater. Capability for nutrient transportation during base flow conditions has
decreased while large amounts of nutrients can be transported in the flood event. Once flood
events occur, substantial amount of nutrients may be transported towards the ocean.
Accordingly, it is suggested that a flow regime shift owing to climate change may be an
important driver. Although change of human activities may be one of the reasons, it is
suggested that flow regime shift owing to climate change may be an important driver.
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