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1
Sagehashi, Masaki, Hiroko Mori, Yuta Hareyama, Kazuyuki Sakuma, Michihiro Akiba, and Masaaki Hosomi. "Integration of the rice paddy water management into a coupled surface-subsurface water flow model in the Sakuragawa River watershed (Japan)." Hydrology Research 47, no. 1 (June 6, 2015): 137–56. http://dx.doi.org/10.2166/nh.2015.162.
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Rice paddy water management was integrated into a distributed three-dimensional surface and subsurface coupling hydrological model of the Sakuragawa River watershed. This watershed is located in the Kanto Plain in Japan and includes the hillside of Mt. Tsukuba. Therefore, this watershed includes both steep mountainous areas and rice paddy-dominated flat land. Thus, water management of rice paddies is important and was calculated separately using a paddy model. The use of groundwater for rice paddy irrigation was considered as well as a water supply from outside of the watershed (Kasumigaura Lake). The model parameters were calibrated and validated with reference to the predictability of river water flow and the groundwater level. Using the calibrated model, three-dimensional streamlines, water travel time distributions, and water balance in some grids were clarified. The developed model will facilitate sustainable water resource management in the watershed.
2
Fujii, Shinji, Masao Omura, Shogo Sugahara, Hiroshi Kamiya, and Masumi Yamamuro. "Effect of Herbicides in Paddy Runoff on Seed Germination of Vallisneria asiatica and Ammannia multiflora." Aquatic Science and Technology 5, no. 1 (January 5, 2017): 1. http://dx.doi.org/10.5296/ast.v5i1.10556.
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Although rice production provides stable environments for aquatic plants, the wide use of herbicides is a concern for wild plants inhabiting the surroundings of rice paddies. Because commercial herbicides are typically a cocktail of chemicals, they may pose a threat to wild plants even when the constituent chemicals do not individually have detrimental effects. We sampled water from a rice paddy and a river receiving the paddy drainage immediately after the transplanting period to identify and compare the concentrations of herbicides. We also examined the effect of the sampled water on the germination of two plants: Ammannia multiflora (hygrophyte) and Vallisneria asiatica (submerged). We found that the concentrations of glufosinate in the paddy and river waters were 0.0015 and 0.0013 mg L-1, respectively, and those of pyraclonil were 0.0010 and 0.0009 mg L-1 in the same waters, indicating that these chemicals persist outside the rice paddy. The germination rate of A. multiflora was significantly diminished with exposure to river and paddy water under fluctuating temperature conditions, whereas no difference was observed for V. asiatica. For a comprehensive understanding of the influences of residual herbicides on wetland biodiversity, it is necessary to analyse the effects of herbicides on a wide range of aquatic plants and at various stages of growth.
3
Marchesan, Enio, Renato Zanella, Luis Antonio de Avila, Edinalvo Rabaioli Camargo, Sérgio Luiz de Oliveira Machado, and Vera Regina Mussoi Macedo. "Rice herbicide monitoring in two Brazilian rivers during the rice growing season." Scientia Agricola 64, no. 2 (2007): 131–37. http://dx.doi.org/10.1590/s0103-90162007000200005.
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Irrigated rice production can involve environmental contamination with pesticides due to the proximity of the fields to rivers and to management problems. During three years (2000 to 2003) the rice herbicides clomazone, propanil and quinclorac were quantified in water during the rice growing season, in the Vacacaí and Vacacaí-Mirim Rivers, located in Rio Grande do Sul (RS) State, Brazil. Water samples were taken at several locations in each river, selected by their importance in terms of rice drainage area. The samples were analyzed by HPLC-UV. At least one herbicide was detected in 41% of the samples from the Vacacaí River and 33% from the Vacacaí-Mirim River. The most frequent herbicide in both rivers and in each year was clomazone. The amount of herbicides in the river water was dependent on the rainfall regime. River water contamination by rice herbicides is probably caused by the rice water management used in the fields. The maintenance of flooded areas makes herbicides prone to contaminate the environment. To reduce the environmental contamination risk it is necessary to adopt measures to avoid overflow of flooded rice fields, keeping paddy water in the field for time enough to reduce the herbicide concentration before its release and enhancing the quality of the levees to reduce the probability of paddy rice overflow.
4
Li, He, Dongjie Fu, Chong Huang, Fenzhen Su, Qingsheng Liu, Gaohuan Liu, and Shangrong Wu. "An Approach to High-Resolution Rice Paddy Mapping Using Time-Series Sentinel-1 SAR Data in the Mun River Basin, Thailand." Remote Sensing 12, no. 23 (December 3, 2020): 3959. http://dx.doi.org/10.3390/rs12233959.
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Timely and accurate regional rice paddy monitoring plays a significant role in maintaining the sustainable rice production, food security, and agricultural development. This study proposes an operational automatic approach to mapping rice paddies using time-series SAR data. The proposed method integrates time-series Sentinel-1 data, auxiliary data of global surface water, and rice phenological characteristics with Google Earth Engine cloud computing platform. A total of 402 Sentinel-1 scenes from 2017 were used for mapping rice paddies extent in the Mun River basin. First, the calculated minimum and maximum values of the backscattering coefficient of permanent water (a classification type within global surface water data) in a year was used as the threshold range for extracting the potential extent. Then, three rice phenological characteristics were extracted based on the time-series curve of each pixel, namely the date of the beginning of the season (DBS), date of maximum backscatter during the peak growing season (DMP), and length of the vegetative stage (LVS). After setting a threshold for each phenological parameter, the final rice paddy extent was identified. Rice paddy map produced in this study was highly accurate and agreed well with field plot data and rice map products from the International Rice Research Institute (IRRI). The results had a total accuracy of 89.52% and an F1 score of 0.91, showing that the spatiotemporal pattern of extracted rice cover was consistent with ground truth samples in the Mun River basin. This approach could be expanded to other rice-growing regions at the national scale, or even the entire Indochina Peninsula and Southeast Asia.
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Matsui, Y., T. Inoue, T. Matsushita, T. Yamada, M. Yamamoto, and Y. Sumigama. "Effect of uncertainties in agricultural working schedules and Monte-Carlo evaluation of the model input in basin-scale runoff model analysis of herbicides." Water Science and Technology 51, no. 3-4 (February 1, 2005): 329–37. http://dx.doi.org/10.2166/wst.2005.0607.
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In the prediction of time-series concentrations of herbicides in river water with diffuse-pollution hydrological models, farming schedules (the dates of herbicide application and drainage of irrigation water from rice paddies) greatly affect the runoff behavior of the herbicides. For large catchments, obtaining precise data on farming schedules is impractical, and so the model input inevitably includes substantial uncertainty. This paper evaluates the effectiveness of using the Monte-Carlo method to generate sets of estimated farming schedules to use as input to a GIS-based basin-scale runoff model to predict the concentrations of paddy-farming herbicides in river water. The effects of using the Monte-Carlo method to compensate for uncertainty in the evaluated parameters for herbicide decomposition and sorption were also evaluated.
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Fujii, S., H. Tanaka, and I. Somiya. "Quantitative comparison of forests and other areas with dry weather input loading in the Lake Biwa catchment area." Water Science and Technology 45, no. 9 (May 1, 2002): 183–93. http://dx.doi.org/10.2166/wst.2002.0235.
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For the evaluation of pollutants loading to Lake Biwa, comprehensive river surveys on river mouths and forest sites were conducted 9 times from 1996 to 1999, on 25–40 main rivers in the Lake Biwa watershed. The main results obtained are as follows. (1) River water quality reflects regional characteristics of their catchment areas, and the concentration difference among rivers ranged between 2–3 fold. (2) Concentration variation shows different patterns with time and location depending on water quality indices used. (3) Indices related to organic matter and nutrients have lower correlation between forests and river mouths, but those related to ionic species showed strong correlation. (4) Flux comparison of forest and river mouth sites suggests that pollutants from catchment areas are conveyed to the lake not only through rivers but also underground. (5) In dry weather conditions, forests contribute 30% to the whole pollutants (TN, TP, and TCODMn) loading, and the remainder is derived mainly from paddy fields and residential/commercial zones. (6) Unit loading factors from forests are estimated as 640, 57 and 1200 kg/km2/y, respectively for TN, TP and TCODMn, while those from other areas are estimated as 2,500, 208 and 4,200 kg/km2/y.
7
Kawara, Osami, Katsuya Hirayma, and Takao Kunimatsu. "A study on pollutant loads from the forest and rice paddy fields." Water Science and Technology 33, no. 4-5 (February 1, 1996): 159–65. http://dx.doi.org/10.2166/wst.1996.0500.
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The eutrophication of Lake Biwa, which is the largest lake in Japan and one of the most important fresh water resources, has been warned since 1960s. In order to improve the water quality of the lake, it is inevitable to reduce the pollutant loads from the river basins. The Hino river and the Soma river basins are considered in the present study and models which predict the influence of pollutant load generation on the discharged pollutant loads through the rivers. These basins mainly consist of forests and rice paddy fields. The identified models reproduce the observed water quality relatively well. Evaluation of loads from point-sources and non-point sources indicates that the loads from non-point sources occupy the most of pollutant loads from the basins. Especially, the loads from rice paddy fields occupy most of the pollutant loads from the basisn. Therefore, controlling non-point source pollutant loads in the Hino and Soma river basins is an important step in checking the eutrophication of Lake Biwa.
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Nakajima, J., Y. Murata, and M. Sakamoto. "Comparison of several methods for BAP measurement." Water Science and Technology 53, no. 2 (January 1, 2006): 329–36. http://dx.doi.org/10.2166/wst.2006.067.
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It has been more important for management of water quality to estimate the amount of bioavailable phosphorus (BAP) in suspended solids (SS) entering lakes and estuaries. AGP test or extraction by 0.1 mol l−1 NaOH (C-BOD) is widely used. Recently, highly bioavailable phosphorus (HBAP) was introduced to indicate a more easily soluble and bioavailable fraction using successive extraction by 0.1 mol l−1 HCl and 0.1 mol l−1 NaOH. New biologically measured BAP (B-BAP) using bacterial respiration activity was introduced in this paper. B-BAP was estimated from oxygen uptake rate (OUR), which was measured by a respiratory meter for BOD measurement using a pressure sensor. B-BAP is useful for a rapid and direct measurement of phosphorus bioavailability. B-BAP, HBAP and C-BAP in river SS were measured and compared with each other. The percentages of HBAP and B-BAP to PP were large in the urban river, while the percentage of NaOH-P or C-BAP was large in the rivers flowing in agricultural areas. By comparison with phosphorus fractions in paddy soil and activated sludge it was suggested that SS in the rivers flowing in agricultural areas mainly consisted of clay, silt or sand, while the SS in the urban river consisted of a large percentage of organic particles as well. Phosphorus in SS was suggested to be more easily bioavailable in the urban river than the rivers in agricultural areas. The ratio of C-BAP/B-BAP was large in the rivers in agricultural areas and small in the urban river. As HBAP contents were almost similar to B-BAP contents in the river SS, HBAP can be a suitable index of phosphorus indicating easily and rapidly the bioavailable fraction in SS. Keywords Bacterial respiration; bioavailable phosphorus; eutrophication; lake water management; oxygen uptake rate; phosphate analysis
9
Rau Alexey,, Kadasheva Zhanar,, Rau Genadiy,, Anuarbekov Kanat,, and Meranzova Rossitza,. "GEOLOGICAL STRUCTURE OF SOILS AND RICE YIELD IN THE ILI RIVER BASIN." NEWS of National Academy of Sciences of the Republic of Kazakhstan 5, no. 443 (October 15, 2020): 165–71. http://dx.doi.org/10.32014/2020.2518-170x.117.
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Rice irrigation systems in Kazakhstan are located on river terraces and levees of the Syr Darya, Ile, and Karatal rivers’ basins. The geological structure and lithological composition of soils in the aeration zone is characterized by a wide variety, differing in soil fertility, mechanical composition, water and physical properties, water availability and salinity. Alluvial-meadow and takyr soils consist of light and heavy loam, sandy loam, and clay [1,2,3]. Melioration errors of the rice irrigation systems, built in the period from 60s to 80s of the last century, can be described by the fact that the Kubanskaya rice sowing map was built on all soils of river terraces and river banks, with the same parameters of irrigation and drainage, with the share of rice 57.5% and 63% [4]. At the rice irrigation systems, where the geological structure and lithological composition of the aeration zone soils correspond to the irrigation and drainage parameters of the Kubanskaya rice sowing map, the soil fertility and ameliorative status of irrigated land has remained high for many decades. The salt content in the 100 cm soil layer is 0.3-0.4%; in the autumn-winter period ground water is at a depth of 2.0-2.5 m, its mineralization is 5-7 g/l. During the rice irrigation period, ground water does not connect with the water of rice paddies, and the filtration of water from rice paddies is permitted and comprises 12 – 17 mm/day. Rice is grown without flow and discharge of water from rice paddies, the irrigation rate is 21,400 m3/ha, and the yield is 5.2 t/ha. At the rice irrigation systems, where the geological structure and lithological composition of the soil in the aeration zone does not correspond to the irrigation and drainage parameters of the Kubanskaya rice sowing map, the land is saline. During the rice irrigation period, the ground water connects with the water on the rice paddies. On these paddies, due to the convective diffusion of salts from the soil and from ground water, water salinity increases and reaches the critical threshold of toxicity of 2.5 g/l [5]. It is necessary to discharge water to reduce the salinity of water on the rice paddies, which is followed by flooding of water from the irrigation channel. The irrigation rate is 23,500 m3/ha, and the yield is 4.7 t/ha.
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Oda, Masato, and Huu Chiem Nguyen. "Methane emissions in triple rice cropping: patterns and a method for reduction." F1000Research 8 (February 15, 2021): 1675. http://dx.doi.org/10.12688/f1000research.20046.6.
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The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies because total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after the annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that avoiding rice straw incorporating into soil and decomposing rice straw in paddy surface-water reduces methane emissions.
11
FUTATSUGAWA, S., J. ITOH, Y. SAITOH, K. DOI, S. GOTO, S. HATAKEYAMA, and K. SERA. "ANNUAL CHANGE OF THE CONCENTRATION OF ELEMENTS IN ENVIRONMENTAL SAMPLES SURROUNDING RADIOISOTOPE WASTE TREATMENT LABORATORY." International Journal of PIXE 15, no. 03n04 (January 2005): 277–84. http://dx.doi.org/10.1142/s0129083505000623.
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Environmental samples (rice, soil, river soil and water, running water, pine needle, milk and grass) are collected from the area surrounding Kaya Memorial Takizawa Laboratory (radioisotope waste management laboratory) neighboring Nishina Memorial Cyclotron Center for detection of radionuclides in them. Rice, which is the most important diet for Japanese, was prepared using a nitric acid ashing and analyzed using ordinary vacuum PIXE for detection of the elemental concentration. Comparison of potassium-40 between the detected value using Ge radiation detector and the analyzed value using PIXE was carried out for accuracy. We examine the change of elemental concentration in rice samples harvested in the different rice paddies in 2001 and in the same rice paddy during 13-year period. There is little change in those.
12
Leonard, C. Christopher. "Ricer Paddy." Anthropology News 36, no. 3 (March 1995): 35. http://dx.doi.org/10.1111/an.1995.36.3.35.2.
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Oda, Masato, and Huu Chiem Nguyen. "Methane emissions in triple rice cropping: patterns and a method for reduction." F1000Research 8 (September 23, 2019): 1675. http://dx.doi.org/10.12688/f1000research.20046.1.
Full textAbstract:
The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.
14
Oda, Masato, and Huu Chiem Nguyen. "Methane emissions in triple rice cropping: patterns and a method for reduction." F1000Research 8 (November 12, 2019): 1675. http://dx.doi.org/10.12688/f1000research.20046.2.
Full textAbstract:
The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.
15
Oda, Masato, and Huu Chiem Nguyen. "Methane emissions in triple rice cropping: patterns and a method for reduction." F1000Research 8 (February 26, 2020): 1675. http://dx.doi.org/10.12688/f1000research.20046.3.
Full textAbstract:
The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.
16
Oda, Masato, and Huu Chiem Nguyen. "Methane emissions in triple rice cropping: patterns and a method for reduction." F1000Research 8 (March 12, 2020): 1675. http://dx.doi.org/10.12688/f1000research.20046.4.
Full textAbstract:
The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.
17
Oda, Masato, and Huu Chiem Nguyen. "Methane emissions in triple rice cropping: patterns and a method for reduction." F1000Research 8 (June 26, 2020): 1675. http://dx.doi.org/10.12688/f1000research.20046.5.
Full textAbstract:
The Mekong Delta paddies are known as hotspots of methane emission, but these emissions are not well studied. We analyzed methane emission patterns based on monitoring data from typical triple rice cropping paddies collected over 5 years. We found that the total emissions in a crop season doubled in the second crop, tripled in the third crop, and reset after the annual natural flood of the Mekong River. The emission peaks occurred around 0 to 3 weeks after starting irrigation, then gradually decreased. This suggests that methane was generated by the soil organic matter, because the small rice plants provide little carbon for methanogenesis. In general, the main source of emitted methane is rice-derived carbon by current-season photosynthates and the emission peaks at the rice heading stage. However, the contribution of the rice-derived carbon is negligible in the hotspot paddies while total emission is high. The increase in emission levels from the first to the third crop can be explained by the accumulation of rice residue from the preceding crops, especially rice straw incorporated into the soil. The reset of emission levels after annual flood means that the rice straw is decomposed without methanogenesis in water with dissolved oxygen. Thus, the annual emission pattern shows that decomposing rice straw in paddy surface-water is an effective method to reduce methane emissions.
18
Nakasone, H., H. Kuroda, T. Kato, and T. Tabuchi. "Nitrogen removal from water containing high nitrate nitrogen in a paddy field (wetland)." Water Science and Technology 48, no. 10 (November 1, 2003): 209–16. http://dx.doi.org/10.2166/wst.2003.0576.
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Nowadays, it has become very common to find in Japan that nitrate nitrogen concentrations are very high in spring water and in well water where the land use of a watershed is agricultural. We have often observed around 50 mg/L of nitrate nitrogen in the spring water where we live. Crops produced in those fields are mainly vegetables such as celery, cabbage, lettuce, carrots, and so on. Green tea is also popular in Japan. In order to produce good quality green tea, farmers apply a great amount of nitrogen fertilizer. This amount can reach up to 1,000 kg/ha in some areas, although the average application amounts to 628 kg/ha in Japan. As a result, ground water that is rich in nitrate flows into the river, which results in a high nitrogen concentration in river water and ground water. Further, this causes a low pH in river water in some tributary rivers in Japan, though this kind of case is very rare. We knew from field tests that if water contained a high nitrogen concentration and was introduced into paddy fields, high nitrogen removal would be performed. This paper presents the outline and results of a system on how to remove nitrogen using paddy fields (wetlands). Further, this paper presents the evaluated results of the removal quantity at the watershed level.
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Jha, Sasinath. "Status and Conservation of Lowland Terai Wetlands in Nepal." Our Nature 6, no. 1 (March 1, 2009): 67–77. http://dx.doi.org/10.3126/on.v6i1.1657.
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Known as "Simsar" in Nepal, wetlands are those areas which lie between the land and deepwater and remian waterlogged or submerged under water, seasonally or throughout the year. Generally the land is so muddy that one cannot easily walk over it, and water is so deep that one can neither swim nor get drowned. River floodplains, shallow margins of lakes and reservoirs, shallow and seasonal ponds, islands in rivers, deepwater paddy fields, and sea-coasts are typical examples of wetlands.Keywords: Lowland wetland, Nepaldoi: 10.3126/on.v6i1.1657Our Nature (2008)6:67-77
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Yoshioka, Y., K. Nakamura, H. Horino, T. Nakano, K. C. Shin, and S. Kawashima. "Evaluation of groundwater qualities in a paddy-dominated alluvial fan." Water Supply 15, no. 6 (June 25, 2015): 1236–43. http://dx.doi.org/10.2166/ws.2015.088.
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Analytically assessing groundwater quality is indispensable for sustainable use of groundwater and its effective pollution controls. A large volume of groundwater is stored in the Tedori River alluvial fan one of which of the predominant land uses being irrigated paddy fields. Much groundwater under the fan is used for drinking and industrial purposes. For assessing agricultural activities at the paddy and upland fields on groundwater quality during an irrigation period, multiple water quality items were measured in several water types, including groundwater, river water, and paddy water. Water quality indicators, such as major dissolved ions, a number of trace elements, and some isotopes were measured. The concentrations of nutrients and some elements related to the environmental standards indicated that pollution in the groundwater in the fan was not severe. Concentrations of the tracers (Mg, Na, δD, δ18O) in the shallow groundwater were low along the Tedori River and increased with distance from the river; this trend would be caused by dilution effect by the river water. It was also shown that the paddy field also affects groundwater quality by the infiltration of irrigation water.
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Khasanah, Ni’matul, Lisa Tanika, Lalu Deden Yuda Pratama, Beria Leimona, Endro Prasetiyo, Fitri Marulani, Adis Hendriatna, Mukhammad Thoha Zulkarnain, Alix Toulier, and Meine van Noordwijk. "Groundwater-Extracting Rice Production in the Rejoso Watershed (Indonesia) Reducing Urban Water Availability: Characterisation and Intervention Priorities." Land 10, no. 6 (June 1, 2021): 586. http://dx.doi.org/10.3390/land10060586.
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Production landscapes depend on, but also affect, ecosystem services. In the Rejoso watershed (East Java, Indonesia), uncontrolled groundwater use for paddies reduces flow of lowland pressure-driven artesian springs that supply drinking water to urban stakeholders. Analysis of the water balance suggested that the decline by about 30% in spring discharge in the past decades is attributed for 47 and 53%, respectively, to upland degradation and lowland groundwater abstraction. Consequently, current spring restoration efforts support upland agroforestry development while aiming to reduce lowland groundwater wasting. To clarify spatial and social targeting of lowland interventions five clusters (replicable patterns) of lowland paddy farming were distinguished from spatial data on, among other factors, reliance on river versus artesian wells delivering groundwater, use of crop rotation, rice yield, fertiliser rates and intensity of rodent control. A survey of farming households (461 respondents), complemented and verified through in-depth interviews and group discussions, identified opportunities for interventions and associated risks. Changes in artesian well design, allowing outflow control, can support water-saving, sustainable paddy cultivation methods. With rodents as a major yield-reducing factor, solutions likely depend on more synchronized planting calendars and thus on collective action for effectiveness at scale. Interventions based on this design are currently tested.
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Piranti, Agatha Sih, Soedarmadji Soedarmadji, Gentur Waluyo, and Suwardi Suwardi. "Transport Nutrien penyebab Eutrofikasi dari Daerah Tangkapan Air Waduk Mrica Banjarnegara." Biosfera 32, no. 1 (January 10, 2015): 66. http://dx.doi.org/10.20884/1.mib.2015.32.1.297.
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The transport of nutrien causing eutrophication in water from catchment area especially fosforus (P) through runoff is determined by type of landuses, slop, soils type, and land cover (Jeje,2006) . The research was conducted using a survey method. The sampling technique was done by a purposive sampling on any flooding in the rivers that pass through areas with specific land use (settlement, forest, plantations, agricultural fields and rice field). The main parameters were river discharge and the content of nutrients causing eutrophication that was phosphorus (P) in rivers. The P loadingfrom cacthment area to Mrica reservoir was 11,526,706.14 kg/year and the load allocation (LA) was 3,833,587.70 kg/year. The reservoir operational of power generating dan flushing activity were able to manage the LA up to 1,147,329.09kg/year, so the TMDL of Mrica reservoir become 4,980,916.78kg/year. It was concluded that the highest transport of P was from paddy field and then followed by respectivelly agricultural (potato) field, plantation (perhutani) field, settlement area, and forest area.
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Ebise, S., and T. Inoue. "Runoff characteristics of pesticides from paddy fields and reduction of risk to the aquatic environment." Water Science and Technology 45, no. 9 (May 1, 2002): 127–31. http://dx.doi.org/10.2166/wst.2002.0221.
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Simultaneous rice-transplanting and subsequent application of pesticides to the paddy fields in the catchment of a rural river on weekends from late May to mid June caused high concentrations and high loadings of pesticides in the river. Imperfections in irrigation water management and the overflow discharge from paddy fields during heavy storm events increased the risk of drinking water contamination and threatened the aquatic ecosystems. Several pesticides were detected at nearly ten ppb in the biofilms on the river bed. In order to reduce the risks due to runoff pesticides, it is necessary to improve the management of irrigation and to strengthen the biodegradation capacity of biofilms on the river bed by maintaining a long retention time in drainage channels.
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Nagafuchi, O., T. Inoue, and S. Ebise. "Runoff pattern of pesticides from paddy fields in the catchment area of Rikimaru reservoir, Japan." Water Science and Technology 30, no. 7 (October 1, 1994): 137–44. http://dx.doi.org/10.2166/wst.1994.0327.
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Patterns of runoff behaviours in concentration and loading of pesticides from paddy fields have been intensively observed in the catchment area of Rikimaru Reservoir, mainly during the regular application period of fungicide during the summer. The runoff characteristics of three pesticides (pyroquilone, isoprothiolane and flutolanil) from paddy fields to the drainage river differed from one another due to their water solubilities. The linear correlation between the water solubilities and the amounts of pesticide runoff loadings from paddy fields to the drainage river and reservoir during dry weather days was confirmed as good on log-log paper. To reduce the risk to raw water for drinking in the reservoir the method of irrigation water management for paddy fields should be improved.
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Singkran, Nuanchan, Pitchaya Anantawong, Naree Intharawichian, and Karika Kunta. "The Chao Phraya River Basin: water quality and anthropogenic influences." Water Supply 19, no. 5 (October 10, 2018): 1287–94. http://dx.doi.org/10.2166/ws.2018.167.
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Abstract Land use influences and trends in water quality parameters were determined for the Chao Phraya River, Thailand. Dissolved oxygen (DO), biochemical oxygen demand (BOD), and nitrate-nitrogen (NO3-N) showed significant trends (R2 ≥ 0.5) across the year, while total phosphorus (TP) and faecal coliform bacteria (FCB) showed significant trends only in the wet season. DO increased, but BOD, NO3-N, and TP decreased, from the lower section (river kilometres (rkm) 7–58 from the river mouth) through the middle section (rkm 58–143) to the upper section (rkm 143–379) of the river. Lead and mercury showed weak/no trends (R2 < 0.5). Based on the river section, major land use groups were a combination of urban and built-up areas (43%) and aquaculture (21%) in the lower river basin, paddy fields (56%) and urban and built-up areas (21%) in the middle river basin, and paddy fields (44%) and other agricultural areas (34%) in the upper river basin. Most water quality and land use attributes had significantly positive or negative correlations (at P ≤ 0.05) among each other. The river was in crisis because of high FCB concentrations. Serious measures are suggested to manage FCB and relevant human activities in the river basin.
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Harada, Sayoko, and Takeshi Noro. "Creation of continuity between river and paddy field in Onga River." Landscape Ecology and Management 25, no. 1 (2020): 19–24. http://dx.doi.org/10.5738/jale.25.19.
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Gustinasari, Kiki, Joni Hermana, and Ellina S. Pandebesie. "Water Bodies Quality along Paddy Field in Karang Ploso Sub District, Malang City, Indonesia." E3S Web of Conferences 125 (2019): 04007. http://dx.doi.org/10.1051/e3sconf/201912504007.
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Agricultural activities cannot be separated from the use of agrochemical, both chemical fertilizer and pesticides. As the largest water user sector, agricultural activities are a source of water pollution. This study was carried out in Brantas’ upper stream along paddy fields, Karangploso Subdistrict, Malang District. The river water samples were collected along the paddy field. The samples were collected when ahead of the harvest season. During the harvest season, pesticides were not sprayed but the concentration of pesticides in the river is quite high. Because no studies have previously measured Organochlorine Pesticide levels in the river along paddy fields, this study is an important contribution to the knowledge of organochlorine contaminants present in surface water in Karang Ploso Subdistrict. The river water has a high concentration of organochlorine pesticides of 400.000 ppt, Total Dissolved Solids (TDS) of 226,8 mg/L, Biological Oxygen Demand (BOD) of 10,2 mg/L, Dissolved Oxygen (DO) of 3,8 mg/L, Chemical Oxygen Demand (COD) of 36,4 mg/L, total phosphate (PO4-) of 0,2 mg/L, nitrate (NO3-N) of 0,7 mg/L, Total Suspended Solids (TSS) of 53 mg/L, and potential of Hydrogen (pH) in lab and field of 8 and 7,08, respectively.
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Inoue, T., S. Ebise, A. Numabe, O. Nagafuchi, and Y. Matsui. "Runoff characteristics of particulate pesticides in a river from paddy fields." Water Science and Technology 45, no. 9 (May 1, 2002): 121–26. http://dx.doi.org/10.2166/wst.2002.0220.
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Runoff characteristics of particulate pesticides from paddy fields have been intensively observed in the Koise River in Japan. The 8 pesticides that are applied to paddy fields were analyzed in both particulate and dissolved forms. The concentrations and the detection frequencies of particulate pesticides were lower than those of dissolved pesticides. The particulate pesticide concentrations in the river water were evaluated based on the soil sorption coefficient, particulate organic carbon concentration, and dissolved pesticide concentrations. The particulate pesticide concentrations in the river were higher than evaluated concentrations because the paddy soil contained more pesticides than did suspended solids in the river water discharged during rain events, and because the desorption rates of pesticides were slow. In observations made during rains, the particulate pesticide concentrations increased with the increases in both the discharge rate and the concentrations of suspended solids. The particulate loading was slight compared with dissolved loading, but particulate pesticides may be influenced by enclosed areas such as a lake or estuary because under such conditions particulate matter settles vertically and the pesticide decomposition rate in sediment is slow compared with that in water.
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Goda, Takeshi. "Management and Status of Japanese Public Waters." Water Science and Technology 23, no. 1-3 (January 1, 1991): 1–10. http://dx.doi.org/10.2166/wst.1991.0395.
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The management and status of public water bodies in Japan is discussed. The environmental quality standards which have been set and the levels of compliance with these standards are shown. The water quality of Japanese rivers, lakes, reservoirs, wetlands and coastal waters is described, and eutrophication problems are mentioned. The effects of changes in population density and levels of recycling of industrial wastewaters on the quality of water bodies are discussed. Almost 75% of industrial wastewater is now recycled. Per capita availability of freshwater in Japan is comparatively low, and the construction of 530 dams, in addition to the 2393 dams already in operation, is planned. Irrigation effluents from paddy fields are a major factor which influences river water quality in Japan. The improvement of water quality using various methods is discussed.
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Fitriani, Dini, Widya Utami, Kartika Hajar Kirana, Eleonora Agustine, and Siti Zulaikah. "Magnetic Signatures on River Sediments and Agricultural Soils as Proxy Indicators of Anthropogenic-derived Pollution (Case Study: Cikijing River, Rancaekek, West Java)." Jurnal Penelitian Pendidikan IPA 7, no. 3 (June 23, 2021): 381. http://dx.doi.org/10.29303/jppipa.v7i3.697.
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A number of activities occur around the Cikijing River in Rancaekek area, West Java, such as industrial and domestic activities. The various activities could decrease the quality of the river and surrounding environment due to anthropogenic pollutants that might be produced. Since the Cikijing River is also used as the source of irrigation, paddy fields around the river could be also be affected. The presence of pollutants in river sediments and agricultural soils over a long period could change their magnetic properties. Magnetic susceptibility of Cikijing River sediments and soils of the paddy fields in the surrounding have been examined considering that magnetic properties could represent environmental conditions. The results show that river sediments have magnetic susceptibility (cLF) in range of 356.2-456.3 (×10-8) m3kg-1, whereas soils samples have cLF varying from 94.1 to 347.1 (×10-8) m3kg-1, suggesting domination of ferrimagnetic minerals. The cFD (%) is <4% indicating the anthropogenic origin of magnetic minerals. Electron microscopy images show the imperfect octahedral and spherules shapes of magnetic grains that supports magnetic susceptibility analysis about the source of magnetic minerals. Elemental composition analysis reveals Fe and O’s content as main elements, including minor elements of Ca, Mg, Al. Si, Ti and Cr
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Zheng, Kan, Jian Cheng, Junfang Xia, Guoyang Liu, and Lei Xu. "Effects of Soil Bulk Density and Moisture Content on the Physico-Mechanical Properties of Paddy Soil in Plough Layer." Water 13, no. 16 (August 21, 2021): 2290. http://dx.doi.org/10.3390/w13162290.
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For paddy-upland rotation areas in the middle and lower reaches of the Yangtze River, the paddy soil has undesired physico-mechanical properties of tillage during the dry season. The purpose of this study is to determine the effects of soil bulk density and moisture content on the physico-mechanical properties of paddy soil in the plough layer. The bulk density and moisture content were selected as experimental factors, and the cohesion, tangential adhesion, plasticity index, and soil swelling rate were chosen as experimental indices from physico-mechanical properties of paddy soil in the plough layer. The experimental factors were quantitatively analyzed to explore the change characteristics of the physico-mechanical properties of paddy soil in the plough layer. Conclusions were obtained that show that when the bulk density increased in the range of 1 to 1.6 g·cm−3, the cohesion, tangential adhesion, plasticity index, and swelling rate of paddy soil increased in different degrees. Between 15% and 35% moisture content, the cohesion increased first and then decreased with the increase of moisture content, while the peak cohesion value occurred at the moisture content of 20%. Moisture content was positively correlated with tangential adhesion and negatively correlated with soil swelling rate. This study provides a reference for the regulation of paddy soil tillability in the middle and lower reaches of the Yangtze River Basin.
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Stelck, C. R., and Dale A. Leckie. "Biostratigraphy of the Albian Paddy Member (Lower Cretaceous Peace River Formation), Goodfare, Alberta." Canadian Journal of Earth Sciences 27, no. 9 (September 1, 1990): 1159–69. http://dx.doi.org/10.1139/e90-123.
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Thirty-seven taxa of arenaceous foraminifera, recovered from cores of the upper part of the Paddy Member (Peace River Formation) and the superjacent lower Shaftesbury Formation in the Goodfare area of northwestern Alberta, are assigned to the lower part of the Verneuilina canadensis Subzone of the Miliammina manitobensis Zone of the Lower Cretaceous (upper Albian). A stratigraphic hiatus of eight foraminiferal subzones is implied between the Paddy Member and subjacent Cadotte Member. Progressive transgression of the M. manitobensis sea is reflected by a succession of four faunules of foraminifera and trace fossils. Shallow-water facies and reduced salinity are indicated for the Paddy environment, and a return to normal salinity during deposition of the overlying Shaftesbury Formation. A distinctive Miliammina–Ammotium faunule is figured from the upper part of the Paddy Member.
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Jung, Shin Hye, Han-Pil Rhee, Ha Sun Hwang, and Chun Gyeong Yoon. "A Study on the Applicability of HSPF Paddy-RCH for Calculating the Reduction of Agricultural Non-point Pollutants." Journal of Korean Society of Environmental Engineers 42, no. 12 (December 31, 2020): 593–602. http://dx.doi.org/10.4491/ksee.2020.42.12.593.
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Objectives:Non-point source pollution (NPS) reduction has been considered as the first priority in South Korea to achieve acceptable water quality. Among many NPS pollutions, agricultural NPS is one of the major NPS contributor due to its vast area. However, agricultural NPS characterization has not been successful because agricultural NPS has inconsistent water and mass balances, thus has lacking NPS reduction measures. This study assesses applicability of HSPF Paddy-RCH method to estimate agricultural NPS loads in paddy rice field.Methods:HSPF Paddy-RCH method was developed to simulate water and mass balance in paddy rice field(s). Applicability of the developed method was tested in Gyeseongcheon watershed in Nakdong River basin, South Korea. The study area was selected because there is no other major pollutant source except the paddy fields, but has simple drainage system. HSPF Paddy-RCH method was calibrated in control paddy field with conventional fertilizing condition and applied to two small scale paddy fields (89% and 76% fertilizing condition). The calibrated HSPF Paddy-RCH method was then tested in small watershed (subbasin) including small paddy fields applied earlier for applicability study of watershed scale.Results and Discussion:Calibrated HSPF Paddy-RCH method well represented observed flow rates (R2=0.825) and water-quality (BOD, T-N, T-P, relative differences [%diff]<7.52%). Water-quality parameters for the control paddy field showed slower decaying rate than river and stream. The calibrated HSPF Paddy-RCH well represented water and mass balance for the small scale paddy fields with varying fertilizing condition (R2>0.689 for flow rate, %diff<12.20% for water quality), as well as for the small scale watershed with large scale paddy fields (R2>0.693 for flow rate, %diff<19.29% for water quality) could promise.Conclusions:This applicability study results would suggest that HSPF Paddy-RCH method is a feasible tool to quantify agricultural NPS pollution and to develop reduction measured for paddy rice field.
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Singkran, Nuanchan. "Water budget analysis and management for Bangkok Metropolis, Thailand." Water Science and Technology 76, no. 6 (June 12, 2017): 1545–54. http://dx.doi.org/10.2166/wst.2017.350.
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The water budget of the Bangkok Metropolis system was analyzed using a material flow analysis model. Total imported flows into the system were 80,080 million m3 per year (Mm3 y–1) including inflows from the Chao Phraya and Mae Klong rivers and rainwater. Total exported flows out of the system were 78,528 Mm3 y–1 including outflow into the lower Chao Phraya River and tap water (TW) distributed to suburbs. Total rates of stock exchange (1,552 Mm3 y–1) were found in the processes of water recycling, TW distribution, domestic use, swine farming, aquaculture, and paddy fields. Only 21% of the total amount of wastewater (1,255 Mm3 y–1) was collected, with insufficient treatment capacity of about 415 Mm3 y–1. Domestic and business (industrial and commercial sectors) areas were major point sources, whereas paddy fields were a major non-point source of wastewater. To manage Bangkok's water budget, critical measures have to be considered. Wastewater treatment capacity and efficiency of wastewater collection should be improved. On-site wastewater treatment plants for residential areas should be installed. Urban planning and land use zoning are suggested to control land use activities. Green technology should be supported to reduce wastewater from farming.
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Sthiannopkao, S., S. Takizawa, and W. Wirojanagud. "Effects of soil erosion on water quality and water uses in the upper Phong watershed." Water Science and Technology 53, no. 2 (January 1, 2006): 45–52. http://dx.doi.org/10.2166/wst.2006.037.
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The main objective of this paper is to simulate the effects of soil erosion on river water quality and on agricultural production as a result of the transformation of forestlands in the catchment of the upstream Phong River. Suspended solids carry down attached nutrients and agricultural chemicals causing water pollution in the downstream. There are four different types of land use in this simulation, namely forestlands, flatland and highland sugarcane plantation areas, and paddy fields. The highest mean annual amount of soil erosion is from paddy fields (585,700 tons/year), followed by highland (73,800 tons/year) and flatland (63,950 tons/year) sugarcane plantation areas and forestlands (41,800 tons/year), respectively. However, as most of paddy fields are located in a low land and are wet type cultivations, the soil erosion occurred has less impact on river water quality and its production compared to the soil erosion from the steeper slopes of highland plantation areas. Under the resource-based agriculture, the sugarcane production is mainly increased by expanding the plantation areas leading to a significant loss of topsoil and a considerable reduction of agricultural production. Soil erosion contributes to an increase in the average annual suspended solids concentration by 72 mg/l.
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HANKAWA, Yoshiyuki. "Behavior of Molinate in Paddy and River Water." Journal of Pesticide Science 10, no. 1 (1985): 107–12. http://dx.doi.org/10.1584/jpestics.10.107.
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Yorozu, K., and Y. Tachikawa. "The effect on river discharge estimation by considering an interaction between land surface process and river routing process." Proceedings of the International Association of Hydrological Sciences 369 (June 11, 2015): 81–86. http://dx.doi.org/10.5194/piahs-369-81-2015.
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Abstract. There is much research assessing the impact of climate change on the hydrologic cycle. However, it has often focused on a specific hydrologic process, without considering the interaction among hydrologic processes. In this study, a distributed hydrologic model considering the interaction between flow routing and land surface processes was developed, and its effect on river discharge estimation was investigated. The model enables consideration of flow routing, irrigation withdrawal from rivers at paddy fields, crop growth depending on water and energy status, and evapotranspiration based on meteorological, soil water and vegetation status. To examine the effects of hydrologic process interaction on river discharge estimation, a developed model was applied to the Chao Phraya river basin using near surface meteorological data collected by the Japanese Meteorological Research Institute's Atmospheric General Circulation Model (MRI-AGCM3.2S) with TL959 spatial resolution as forcing data. Also, a flow routing model, which was part of the developed model, was applied independently, using surface and subsurface runoff data from the same GCM. In the results, the developed model tended to estimate a smaller river discharge than was estimated by the river routing model, because of the irrigation effect. In contrast, the annual maximum daily discharge calculated by the developed model was 24% greater than that by the flow routing model. It is assumed that surface runoff in the developed model was greater than that in the flow routing model because the soil water content was maintained at a high level through irrigation withdrawal. As for drought discharge, which is defined as the 355th largest daily discharge, the developed model gave a discharge 2.7-fold greater than the flow routing model. It seems that subsurface runoff in the developed model was greater than that in the flow routing model. The results of this study suggest that considering hydrologic interaction in a numerical model could affect both flood and drought estimation.
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Wang, L. L., C. C. Song, and G. S. Yang. "Dissolved organic carbon characteristics in surface ponds from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China." Hydrology and Earth System Sciences 17, no. 1 (January 29, 2013): 371–78. http://dx.doi.org/10.5194/hess-17-371-2013.
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Abstract. Dissolved organic carbon (DOC) is a significant component of carbon and nutrient cycling in fluvial ecosystems. Natural wetlands, as important DOC sources for river and ocean ecosystems, have experienced extensive natural and anthropogenic disturbances such as climate change, hydrological variations and land use change in recent years. The DOC characteristics in surface ponds from contrasting wetlands in the Sanjiang Plain, Northeastern China were investigated. Surface ponds at seven sites (two natural phialiform wetlands, three natural riparian wetlands, one degraded wetland and one artificial wetland, i.e., rice paddy) were monitored during the growing seasons of 2009 and 2010. The results show that the surface ponds at the five natural wetland sites exhibited a wide range of DOC concentrations (10.06–48.73 mg L−1) during the study period. The DOC concentrations showed no annual differences (P > 0.05) at all the wetland sites, except one of the phialiform wetland sites. The two phialiform wetlands exhibited higher DOC concentrations than the three riparian wetlands (P < 0.05). The DOC concentration in the surface pond at the artificial wetland site was relatively low (P < 0.05) compared to that at the degraded wetland site. The C/C ratios (the color per carbon unit ratio, Abs400/DOC concentration) showed inconsistent variations among these seven wetland sites, while the E4/E6 ratio (Abs465/Abs665, fulvic acid/humic acid) from the surface pond in the rice paddy land exerted 42.07–55.36% reductions (P < 0.05), compared to those at the five natural wetland sites. Furthermore, the E4/E6 ratio in the surface pond at the rice paddy site was significantly lower compared to that at the degraded wetland site (P < 0.05), which indicated that disturbance to wetland DOC in surface ponds might be stronger when natural wetlands were converted to rice paddies in comparison with wetland degradation. This study could not only provide insightful points for understanding the aquatic DOC dynamics from different wetland ecosystems, but also support data information for incorporating the aquatic DOC into the model for regional carbon budgets in the future.
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Song, Dan, Shuang Yi Li, Chen Feng, Jiu Bo Pei, and Jing Kuan Wang. "Evaluation of Carbon Sequestration Potential in Cropland Soil of Lower Reaches of Liaohe River Plain." Advanced Materials Research 726-731 (August 2013): 4938–44. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.4938.
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Lower reaches of Liaohe River Plain is one of the areas where has a long history of planting in China, thus the enhancement of the capacity of soil carbon sequestration in cropland of this area has an important influence on global green house gases mitigation.Based on the 2nd National Soil Inventory data and the latest results from cropland productivity evaluation,the statistical model of soil carbon sequestration potential established by Qin et al. [, the soil organic carbon (SOC) sequestration potential was estimated and the differences of carbon sequestration ability between dry land and paddy field were compared according to the SOC spatio-temporal changes in cropland of Lower reaches of Liaohe River Plain over the last 30 years.The results show that the organic carbon density (SOCP) is 4.95 kg m-2 when the cropland soil organic carbon is saturated. The organic carbon storage in soil surface is 127.33 Tg in this area with an increase of 57.52 Tg. The organic carbon sequestration ability in paddy field is bigger than dry land in Lower reaches of Liaohe River Plain.
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Jothiprakash, V., and R. Mohandoss. "A weekly operational planning model for a run-off-the-river system: some simulation results from the Tambiraparani river, Tamil Nadu, India." Water Policy 12, no. 3 (November 9, 2009): 318–35. http://dx.doi.org/10.2166/wp.2009.094.
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In the present study, a weekly operational planning model has been developed using a simulation technique for the Tambiraparani river system in Tamil Nadu, India. A planning model has been developed incorporating the important features of the existing operational policy. Paddy is the main crop cultivated in three seasons, although banana is cultivated to an appreciable extent, it has not been recognized in the existing operational policy. The major task of the water resources manager is to find the area under paddy during the third season namely, the Advance Kar season. The main objective of the present study is to simulate the temporal distribution of the available water in the Tambiraparani river system. Simulation is carried out for various possible extents of Advance Kar area and banana area for various initial storage conditions. It is found that the entire Tambiraparani river system could be managed without deficit by reducing the release of water by 10–25% during the non-stress crop periods and also by lagging the starting period of the season by one or two weeks. If this management is practiced during average inflow years, it is possible to maintain the same final storage as the initial storage during the start of the season. Thus the polices derived using the present study would be more useful to the system managers enabling them to authorize the area under paddy during the Advance Kar season and also to help them to maintain the required storage for the next season.
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Luo, Xier, Yu Zhou, Bing Zhang, Yi Zhang, Xiaobo Wang, Tong Feng, Zhipeng Li, et al. "Understanding divergent domestication traits from the whole-genome sequencing of swamp- and river-buffalo populations." National Science Review 7, no. 3 (February 17, 2020): 686–701. http://dx.doi.org/10.1093/nsr/nwaa024.
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Abstract Domesticated buffaloes have been integral to rice-paddy agro-ecosystems for millennia, yet relatively little is known about the buffalo genomics. Here, we sequenced and assembled reference genomes for both swamp and river buffaloes and we re-sequenced 230 individuals (132 swamp buffaloes and 98 river buffaloes) sampled from across Asia and Europe. Beyond the many actionable insights that our study revealed about the domestication, basic physiology and breeding of buffalo, we made the striking discovery that the divergent domestication traits between swamp and river buffaloes can be explained with recent selections of genes on social behavior, digestion metabolism, strengths and milk production.
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Cao, Z. H., X. C. Wang, D. H. Yao, X. L. Zhang, and M. H. Wong. "Selenium geochemistry of paddy soils in Yangtze River Delta." Environment International 26, no. 5-6 (May 2001): 335–39. http://dx.doi.org/10.1016/s0160-4120(01)00009-5.
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Han, Long Fei, You Peng Xu, and Yi Shi. "The Effect of Land Use and Land Cover Change on the Stream Structure: Case Study in the Qinhuai River Basin, China." Applied Mechanics and Materials 212-213 (October 2012): 186–92. http://dx.doi.org/10.4028/www.scientific.net/amm.212-213.186.
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The effect of land use and cover change (LUCC) aroused heated topic in the field of hydrogen. Change of LUCC and its effect on the stream structure in the study area are analyzed in paper. The land use transfer matrix from 1979 to 2006 was built through GIS and RS technique to perform an analysis on the characteristic of the LUCC, and its effect on river system is discussed using river structure indices. Result shows that (1) the loss of the forest, paddy field and dry land has contributed most to the increase of the urban area (16.76%, 7.11% and 10.75% respectively). (2) Length and density of river are decreasing by 41% and stability of river (SR) is shortening, especially in the moderately urbanised area, whose SR reach to 0.67. The low-grade river disappears more and the stream structure is not as complex as before.
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Matsui, Y., K. Narita, T. Inoue, and T. Matsushita. "Using precise data sets on farming and pesticide properties to verify a diffuse pollution hydrological model for predicting pesticide concentration." Water Science and Technology 56, no. 1 (July 1, 2007): 71–80. http://dx.doi.org/10.2166/wst.2007.437.
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Verification of a diffuse pollution model involves comparing results actually observed with those predicted by precise model inputs. Acquisition of precise model inputs is, however, problematic. In particular, when the target catchment is large and substantial estimation uncertainty exists, not only model verification but also prediction is difficult. Therefore, in this study, rice-farming data were collected for all paddy fields from all farmers in a catchment and pesticide adsorption and degradation rates in paddy field soil samples were measured to obtain precise model inputs. The model inputs successfully verified the model's capability to predict pesticide concentrations in river water. Sensitivity analyses of the model inputs elucidated the processes significantly affecting pesticide runoff from rice farms. Pesticide adsorption and degradation rates of the soil did not significantly affect pesticide concentrations, although pesticide discharge to river water accounted for less than 50% of the total quantity of pesticide applied to fields, possibly owing to pesticide adsorption and degradation. The timing of increases in pesticide concentrations in river water was affected mostly by the farming schedule, including the time of pesticide application and irrigation, and secondarily by rainfall events.
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Liu, Guoyang, Junfang Xia, Kan Zheng, Jian Cheng, Jun Du, and Dong Li. "Effects of moisture content and tillage methods on creep properties of paddy soil." PLOS ONE 16, no. 6 (June 24, 2021): e0253623. http://dx.doi.org/10.1371/journal.pone.0253623.
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The rheological properties parameters of paddy soil affect the interaction between the tillage tools and soil, thus influencing the operation quality and power consumption. In order to study the effects of tillage methods and moisture content on the rheological properties parameters of paddy soil in the middle and lower reaches of the Yangtze River, uniaxial compression creep tests of paddy soils with four moisture contents under no tillage (moisture contents: 26.71%, 24.52%, 23.26%, 21.28%) and plough tillage (moisture contents: 26.77%, 25.55%, 23.40%, 20.56%) were carried out using a TMS-PRO texture analyzer. The creep properties curves obtained from the tests, and the rheological constitutive equation of paddy soil under compression was established by Burgers viscoelastic model. Respectively, the quantitative change rules of creep properties of paddy soil with different moisture contents under different tillage methods and the correlation between these parameters were explored. The results showed that the moisture content under the three-year plough tillage and no tillage methods had significant influence on the rheological properties parameters of paddy soil (P < 0.05). The instantaneous elastic modulus, delay elastic modulus, and viscosity coefficient of the two paddy soils (no tillage and plough tillage soils) decreased with the increase of moisture content. However, the variation rules of relaxation time and delay viscosity coefficient with moisture content differed between these two paddy soils. Specifically, the strain rate of the two paddy soils decreased as moisture content decreased, where the total strain combines elastic strain, viscous strain, and viscoelastic strain. The initial strain rate and steady strain rate of the plough tillage paddy soils were lower than that of the no tillage paddy soils. The established creep model equation could be used to obtain viscoelastic rheological parameters of paddy soil in a wide range. The fitting equations between rheological parameters and moisture content were introduced into Burgers model, and the coupling equations between creep deformation and moisture content and time were derived, which could be used to predict the creep properties and deformation behavior of paddy soil in a certain range of no tillage and ploughed field. Overall, this study has a certain theoretical significance for the development and improvement of paddy soil rheology theory, and can also provide theoretical basis and technical support for the research of agricultural machinery design optimization, field water, soil conservation, soil tillage and compaction related simulation analysis in the middle and lower reaches of the Yangtze River.
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Bahagia, Bahagia, Fachruddin Majeri Mangunjaya, Zuzy Anna, and Rimun Wibowo. "INDIGENIOUS KNOWLEDGE OF URUG SOCIETIES FOR AGRICULTURE IRRIGATION IN BOGOR WEST JAVA." JURNAL SOSIAL HUMANIORA 11, no. 2 (October 12, 2020): 169. http://dx.doi.org/10.30997/jsh.v11i2.3226.
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The objective of this research to investigate traditional agricultural irrigation based on indigenious knowledge of customary urug societies in Bogor West Java. The research method use is Ethnoecology qualitative approach. This method is implemented because research have conection among human (cultural & social) and environment including traditional agriculture water management as well as the knowledge about environment. Data are collected by in-depth interview, observation and documentation. In order to determine respondents as major sources information use purposive sampling technique. The outcome is analized with combination numerous of method such as in-dept interview, observation, and documentation (triangulation data). There are some results including rice paddy field in Urug societies exert traditional terrascering for inventing land for cultivating of paddy because geograhpycally location of wet land paddy is mountainious. The another is traditional irrigation of Urug slue river water (main sources of irrigation) to to susukan (traditional reservoir). After that water is flowed to Selokan and continue to rice paddy field. The person who have mandatory for water agriculture management is mentioned as Ulu-ulu. Ulu-ulu is pivotal person because have chores for ensuring all farmer received water from river, Susukan and selokan. The other finding is Urug customary societies applicate gotong royong (mutual cooperation) among member of societies typically in traditional agriculture irrigatin activity. Keywords: Indigenious Knowledge, Susukan, Ulu-ulu, Traditional irrigation, traditional agriculture
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Ibrahim, Irini, Norazlina Abdul Aziz, Faridah Hussain, Syuhaeda Aeni Mat Ali, and Azhani Arshad. "COVID-19 AND THE ENVIRONMENT: THE ISSUES AND ADVERSE EFFECTS TO WETLANDS GLOBALLY." Journal of Tourism, Hospitality and Environment Management 6, no. 23 (June 10, 2021): 60–70. http://dx.doi.org/10.35631/jthem.623007.
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The Covid-19 pandemic causes chaotic situations globally. Many cities around the world are facing improved better fresh air and experiencing cooler weather due to reduced carbon emission which normally raises temperatures. The environment, as a whole, experience the same. In this paper, the author's emphasis on the visibility, the effects of the pandemic on wetlands globally. There are a few aspects that will be looked at, for example to wetlands effect specifically, to the wildlife, to humans or wetlands, and the effect on the environment generally. This is a conceptual paper. The data collected are from the internet and books and also from some observations. This study adopted a doctrinal analysis, where legal research forms as part of analytical study of existing laws, related cases, and authoritative materials as a whole, on some specific matter. It works as knowledge-building research in the legal field. For example, the Ganga River in India is so clean that reports suggest that it is fit for drinking. The Yamuna River is showing improved water quality and quantity. This is the first time in years that its surface is not covered in plastic and froth, but reflects the sky and scenic beauty around. Wetlands are the most vulnerable ecosystems, including freshwater rivers, lakes, paddies, marshes and peatlands, and saltwater estuaries, mangroves, coral reefs, seagrass beds, and lagoons. 87% of the wetlands globally were lost over the past 300 years. They provide an estimated $47 trillion worth of services annually and a livelihood for one billion people. The issue is on the Covid-19 pandemic and how seriously it effects the livelihood of all species including humans in wetlands areas.
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Emiyati, Eko Kusratmoko, and Sobirin. "THE EFFECT OF HYDROLOGIC RESPONSE UNIT ON CI RASEA WATERSHED STREAMFLOW BASED ON LANDSAT TM." International Journal of Remote Sensing and Earth Sciences (IJReSES) 12, no. 2 (June 21, 2017): 97. http://dx.doi.org/10.30536/j.ijreses.2015.v12.a2689.
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. This paper discusses spatial pattern of Hydrologic Response Unit (HRU), which is a unit formed of hydrological analysis, including geology and soil type, elevation and slope, and also land cover in 2009. This paper also discusses the impact of HRU on streamflow of Ci Rasea watershed, West Java. Ci Rasea watershed is located at the upstream part of Ci Tarum watersheds in West Java Province, Indonesia. This research used SWAT (Soil and Water Assessment Tool) model to obtain spatial HRU and river flow. The method used Landsat TM data for land cover and daily rainfall for river flow modeling. The results have shown spatial pattern of HRU which was affected by land cover, soil type and slope. In 2009, accumulated surface runoff and streamflow changes were spatially affected by HRU changes. The large amount accumulation of river flow discharge happened in HRU with landcover paddy field, silty clay soil, and flat slope. While the low discharge of river flow happened in HRU with plantation, clay soil, and slightly steep slopes as HRU dominant. It was found that accumulation of surface runoff in Ci Rasea watershed can be reduced by changing the land cover type in some areas with clay and slightly steep slope to become plantation area and the areas with sandy loam soil and flat slope can be used for paddy fields. Beside affected by HRU, the river flow discharge was also affected by the distance of sub watershed to the outlet. By using NS model and statistical t-student for calibration and validation, it was obtained that the accuracy of river flow models with HRU was 70%. It meant that the model could better simulate water flows of the Ci Rasea watershed.
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Zhou, Lin Fei, Cheng Ming Li, Qi Xin Chen, and Yu Long Zhang. "Forecasting Analysis of Land Use Dynamic Change in Liaohe River Delta Wetlands." Advanced Materials Research 726-731 (August 2013): 3313–19. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.3313.
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The paper supported by 3S technology, based on the remote sensing images in different periods within the 7 years from 1988 to 2009 in Liaohe River Delta wetlands, conducts the following researches :(1) establish single dynamic degree model and comprehensive dynamic degree model, extract the data of different types of land , and analyze the reason of the changes in this region. Results indicate that: the area of residential land use in this region is increasing remarkably, reed-swamp resources is deceasing slightly, and the comprehensive land use degree is increasing stably.(2)establish the Liaohe River Delta wetlands transition probability matrix, and forecast the land use area of Liaohe River Delta in 2030 using Markov model. The results indicate that: the area of forest, reed-swamp, shoals shows a downward trend, paddy field, glebe, river/channel, reservoir/pond/lake, residential land shows an upward trend in 2030 in Liaohe River Delta wetlands. It is obvious that the area of wetlands shrunk severely. Ecological balance and quality will face crisis seriously in Liaohe River Delta wetlands in the future.
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Numabe, A., and S. Nagahora. "Estimation of pesticide runoff from paddy fields to rural rivers." Water Science and Technology 53, no. 2 (January 1, 2006): 139–46. http://dx.doi.org/10.2166/wst.2006.047.
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The runoff characteristics of pesticides from paddy fields to rural rivers were investigated over a period of three years in Hokkaido Prefecture, Japan. High pesticide concentrations were usually observed in rivers during pesticide application periods. In one year, the growth of rice seedlings slowed down after transplantation owing to low temperatures and lack of sunshine, and many farmers delayed herbicide application. In that year, high-concentration runoff of herbicides in rivers was observed 1–3 weeks later than in average years. The pesticide runoff rates ranged from 0.3% for fenthion to 42% for benfuresate. The runoff rates of pesticides applied post-flood were large. Furthermore, the larger the water solubility of the pesticide, the larger the runoff rate. The highest concentrations of herbicides in paddy water were observed on the day of application or 1–2 days later, and the concentrations decreased exponentially afterwards. The half-lives of the herbicides ranged from 1.2 days for pretilachlor and esprocarb to 5 days for simetryn; the concentrations of the herbicides in paddy water had decreased to 1/10 of their initial concentrations by about 7 days after application. Therefore, the runoff amounts of pesticides from paddy fields could be decreased by improving irrigation-water management.