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Nitrogen interception in floodwater of rice field in Taihu region of China 被引量:16
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作者 LIANG Xin-qiang CHEN Ying-xu LI Hua TIAN Guang-ming ZHANG Zhi-jian NI Wu-zhong HE Miao-miao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第12期1474-1481,共8页
A field experiment located in Taihu Lake Basin of China was conducted, by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen (N) export in a typical rice field through "... A field experiment located in Taihu Lake Basin of China was conducted, by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen (N) export in a typical rice field through "zero-drainage water management" combined with sound irrigation, rainfall forecasting and field drying. N concentrations in floodwater rapidly declined before the first event of field drying after three split fertilizations, and subsequently tended to rearm to the background level. Before the first field drying, total particulate nitrogen (TPN) was the predominant N form in floodwater of plots with no N input, dissolved inorganic nitrogen (DIN) on plots that received urea only, and dissolved organic nitrogen (DON) on plots treated with the mixture of urea and manure. Thereafter TPN became the major form. No N export was found from the rice field, but total nitrogen (TN) of 15.8 kg/hm^2 was remained, mainly due to soil N sorption. The results recommended the zero-drainage water management for full-scale areas for minimizing N export. 展开更多
关键词 NITROGEN paddy field surface floodwater INTERCEPTION Taihu region
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Study of Dynamics of Floodwater Nitrogen and Regulation of Its Runoff Loss in Paddy Field-Based Two-Cropping Rice with Urea and Controlled Release Nitrogen Fertilizer Application 被引量:12
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作者 JI Xiong-hui ZHENG Sheng-xian +1 位作者 LUYan-hong LIAO Yu-lin 《Agricultural Sciences in China》 CAS CSCD 2007年第2期189-199,共11页
The article deals with the effects of urea and controlled release nitrogen fertilizer (CRNF) on dynamics of pH, electronic conductivity (EC), total nitrogen (TN), NH4^+-N and NO3 -N in floodwater, and the regul... The article deals with the effects of urea and controlled release nitrogen fertilizer (CRNF) on dynamics of pH, electronic conductivity (EC), total nitrogen (TN), NH4^+-N and NO3 -N in floodwater, and the regulation of runoff TN loss from paddy field-based two-cropping rice in Dongting Lake, China, and probes the best fertilization management for controlling N loss. Studies were conducted through modeling alluvial sandy loamy paddy soil (ASP) and purple calcareous clayey paddy soil (PCP) using lysimeter, following the sequence of the soil profiles identified by investigating soil profile. After application of urea in paddy field-based two-cropping rice, TN and NHa+-N concentrations in floodwater reached peak on the 1st and the 3rd day, respectively, and then decreased rapidly over time; all the floodwater NO3--N concentrations were very low; the pH of floodwater gradually rose in case of early rice within 15 d (late rice within 3 d) after application of urea, and EC remained consistent with the dynamics of NH4^+-N. The applied CRNF, especially 70% CRNF, led to significantly lower floodwater TN and NH4^+ concentrations, pH, and EC values compared with urea within 15 d after application. The monitoring result for N loss due to natural rainfall runoff indicated that the amount of TN lost in runoff from paddy field- based two-cropping rice with urea application in Dongting Lake area was 7.47 kg ha^-1, which accounted for 2.49% of urea- N applied, and that with CRNF and 70% CRNF application decreased 24.5 and 27.2% compared with urea application, respectively. The two runoff events, which occurred within 20 d after application, contributed significantly to TN loss from paddy field. TN loss due to the two runoffs in urea, CRNF, and 70% CRNF treatments accounted for 72, 70, and 58% of the total TN loss due to runoff over the whole rice growth season, respectively. And the TN loss in these two CRNF treatments due to the first run-off event at the 10th day after application to early rice decreased 44.9 and 44.2% compared with urea, respectively. In conclusion, the 15-d period after application of urea was the critical time during which N loss occurred due to high floodwater N concentrations. But CRNF decreased N concentrations greatly in floodwater and runoff water during this period. As a result, it obviously reduced TN loss in runoff over the whole rice growth season. 展开更多
关键词 controlled release nitrogen fertilizer paddy field-based two-cropping rice floodwater NITROGEN loss due to runoff
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An experimental study on embankment failure induced by prolonged immersion in floodwater
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作者 Yu-long Luo Cheng Zhang +2 位作者 Min Nie Mei-li Zhan Jin-chang Sheng 《Water Science and Engineering》 EI CAS CSCD 2016年第1期81-86,共6页
Prolonged immersion in floodwater is one of the main causes of embankment failure or dam breaks, although failure mechanisms have not been extensively studied. In this study, an embankment model was constructed to inv... Prolonged immersion in floodwater is one of the main causes of embankment failure or dam breaks, although failure mechanisms have not been extensively studied. In this study, an embankment model was constructed to investigate the influence of prolonged immersion in floodwater on the failure of an embankment. The results indicate that: (1) the phreatic surface gradually rises and negative pore pressures gradually dissipate with the time of prolonged immersion in floodwater, and, finally, a stable and fully saturated state is reached; (2) observable cracks and a heave phenomenon are found near the downstream toe and in the top stratum of the foundation, which are attributed to the large uplift pressure on the interface between the top stratum and the pervious substratum, the tremendous impact effect induced by the rapid rise in water level, and the reduction of shear strength of heavy silt loam. The present study enhances our in-depth knowledge of the mechanisms of embankment failure induced by floodwater, and provides experimental data for validation of mathematical models of the embankment seepage failure. 展开更多
关键词 EMBANKMENT floodwater Seepage failure Prolonged immersion Heave phenomenon
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Floodwater utilization of the Three Gorges Project
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作者 董前进 《Journal of Chongqing University》 CAS 2009年第2期82-88,共7页
Floods are both risks and resources. Floodwater utilization is an important part of flood management. Considering the rising shortage of water resources, serious water pollution, and undersupply of electric power, it... Floods are both risks and resources. Floodwater utilization is an important part of flood management. Considering the rising shortage of water resources, serious water pollution, and undersupply of electric power, it’s imperative to strengthen flood management. In light of the hydrological characteristics of the Three Gorges Project (TGP) on the Yangtze River in P. R. China, we investigated the necessity and feasibility of TGP floodwater utilization, proprosed dynamic control of limited water level during flood season of the reservoir and basin-wide integrated floodwater management as strategies, and identified problems that might occur in practice. 展开更多
关键词 flood control flood managementi floodwater utilization limited water level in flood seasons Three Gorges Project .
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Influence of floodwater irrigation on vegetation composition and vegetation regeneration in a Taklimakan desert oasis 被引量:7
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作者 ARNDT S. K. 《Chinese Science Bulletin》 SCIE EI CAS 2008年第S2期156-163,共8页
Naturally occurring floods in the summer months are the main source of surface water application in the foreland of Qira oasis, which is characterized by a hyperarid climate and is located at the southern fringe of th... Naturally occurring floods in the summer months are the main source of surface water application in the foreland of Qira oasis, which is characterized by a hyperarid climate and is located at the southern fringe of the Taklimakan Desert. We investigated the impact of repeated artificial flood irrigation on seedling recruitment and growth of Alhagi sparsifolia and Karelinia caspica plant communities which are part of the dominant vegetation in Qira oasis. Flood irrigation was applied three times during the growing season and we studied the effect of irrigation on species recruitment, vegetation growth, spe- cies composition, and changes in soil water and nutrient concentrations in the soil profile. Results show that (1) repeated flood irrigation had a positive effect on seedling recruitment of the two species, with vegetative recruitment via root tillers being more important than seed recruitment for both species. (2) Irrigation promoted the germination and establishment of herbaceous weed species, which in- creased species diversity as well as ground coverage. (3) Irrigation also increased soil water and soil nutrient concentrations in the upper soil layer and changed the soil nutrients in the vertical profile. Available N, P, K and the total P and K increased in the soil profile. Our study demonstrates that naturally occurring flood irrigation has significant ecological benefits and plays an important role in promoting the renewal of desert vegetation and a short-term increase of soil nutrients. Our study also highlights the potential negative consequences for vegetation composition and rejuvenation if naturally occurring floods in the study area are diminished by either the effects of climate change or human management. 展开更多
关键词 floodwater IRRIGATION Alhagi.sparsifolia Karelinia caspica species RECRUITMENT VEGETATION composition soil NUTRIENTS
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Specific detection of the floodwater mosquitoes Aedes sticticus and Aedes vexans DNA in predatory diving beetles
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作者 Thomas Z. Persson Vinnersten Peter Halvarsson Jan O. Lundstrom 《Insect Science》 SCIE CAS CSCD 2015年第4期549-559,共11页
Floodwater mosquitoes (Diptera: Culicidae) are associated with periodically flooded wet meadows, marshes, and swamps in floodplains of major rivers worldwide, and their larvae are abundant in the shallow parts of f... Floodwater mosquitoes (Diptera: Culicidae) are associated with periodically flooded wet meadows, marshes, and swamps in floodplains of major rivers worldwide, and their larvae are abundant in the shallow parts of flooded areas. The nuisance caused by the blood-seeking adult female mosquitoes motivates mosquito control. Larviciding with Bacillus thuringiensis israelensis is considered the most environmentally safe method. However, some concern has been raised whether aquatic predatory insects could be indi- rectly affected by this reduction in a potential vital prey. Top predators in the temporary wetlands in the River Dal/ilven floodplains are diving beetles (Coleoptera: Dytiscidae), and Aedes sticticus andAe, vexans are the target species for mosquito control. For detailed stud- ies on this aquatic predator-prey system, we developed a polymerase chain reaction (PCR) assay for detection of mosquito DNA in the guts of medinm-sized diving beetles. Primers were designed for amplifying short mitochondrial DNA fragments of the cytochrome C oxidase subunit I (COI) gene in Ae. sticticus and Ae. vexans, respectively. Primer speci- ficity was confirmed and half-life detectability ofAe. sticticus DNA in diving beetle guts was derived from a feeding and digestion experiment. The Ae. sticticus DNA within diving beetle guts was detected up to 12 h postfeeding, and half-life detectability was estimated to 5.6 h. In addition, field caught diving beetles were screened for Ae. sticticus and Ae. vexans DNA and in 14% of the diving beetles one or both mosquito species were detected, showing that these mosquito species are utilized as food by the diving beetles. 展开更多
关键词 Aedes sticticus DYTISCIDAE floodwater mosquitoes gut content analysis half-life detectability PCR
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Fighting Floodwaters
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作者 ZHANG ZHIPING 《Beijing Review》 2010年第26期2-2,共1页
Since May, the southern area of China has been ravaged by heavyrainfalls causing massive flooding and triggering landslides—and thereis more to come.
关键词 Fighting floodwaters
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Abkhandari (Aquifer Management): a Green Path to the Sustainable Development of Marginal Drylands
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作者 Sayyed Ahang Kowsar 《Journal of Mountain Science》 SCIE CSCD 2005年第3期233-243,共11页
Recurrent droughts and occasional floods are the facts of life in drylands. The presence of innumerable societies in deserts is the living proof that even the extremely dry environments are livable; the secret is how ... Recurrent droughts and occasional floods are the facts of life in drylands. The presence of innumerable societies in deserts is the living proof that even the extremely dry environments are livable; the secret is how to adapt to the situation. Floodwater management, the most important art of sedentarized desert dwellers, is the secret of living with deserts. Floodwater irrigation alone, or in combination with the artificial recharge of groundwater (ARG), has sustained the Persians for millennia. The scientists at the Kowsar Floodwater Spreading and Aquifer Management Research, Training and Extension Station in the Gareh Bygone Plain have been working since January 1983 to revive this ancient art and upgrade it to the level of science. A summary of important findings is provided as follows: 1. Debris cones and coarse alluvial fans are the best places for the ARG as they provide the potential aquifer for groundwater storage. The recharged water may be used for irrigation on the lower lying, fine alluvium; 2. Flood is not a proverbial curse but a blessing in disguise, and the turbid floodwater is the best resource for the sustainable development of drylands; 3. Translocation of fine clay minerals eventually makes the vadose zone impermeable. Planting deep-rooted, drought-resistent trees and shrubs, and introducing sowbugs (Hemilepistus shirazi Schuttz) are reliable methods to increase infiltration rate and the saturated hydraulic conductivity of the ARG systems; 4. The moving sand stabilization is best achieved by spreading turbid floodwater onto them. Establishing of living windbreaks and planting of fodder trees and shrubs turn a sand menace into a verdant pasture; 5. The 10 year average of native forage yield in the ARG systems has been 445 kg·ha^-1·year^-1 as opposed to 92 kg·ha^-1.year^-1 for the control. At 4×4 m^2 spacing, Atriplex lentiformis (Torr.) Wats. can annually yield 1500 kg ha^-1 of dry matter and support 3 heads of sheep; 6. The stem- and fuel wood yield of 18 year old Eucalyptus camaldulensis Dehnh. in the ARG system have been 4,684 and 781 kg·ha^-1.year^-1, respectively. The mean annual carbon sequestration of this tree has been 2.975 tons per ha; 7.Up to 80% of the diverted floodwaters reach the unconfined aquifer. As evaporation practically wastes large volumes of water in surface reservoirs, storing water underground is logical in deserts; 8. The high evaporation rate, the large sediment load, the environmental hazards, the undesirable social costs, the long time needed for the different phases of study, and the very large price tag make dam building the most hydro-illogical choice in deserts where the ARG is practicable; 9. Each 5.5 ha of the irrigated farm provides income for a family of 7.64 member and 0.38 employment opportunities for a farm hand. On average, 4-ha of an ARG system provides one full time job for irrigation farmers. The benefit: cost ratio for this project is 22; 10. The number of wells in the area affected by the ARG activities has increased lo-fold to 130 wells, the irrigated area has increased 8-fold to 1,193 ha, and 345 job opportunities have been created in 4 villages that surround the Station. 展开更多
关键词 floodwater artificial recharge of groundwater (ARG) DRYLANDS sustainable development
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Runoff Management, Wetland Hydrology, and Biodiversity Relations in Minnesota's Red River Basin Wetlands
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作者 StevenI.Apfelbaum John. D. Eppicht James A. Solstada 《Journal of Environmental Science and Engineering(A)》 2012年第1期107-124,共18页
The authors assessed if wetlands can contribute to flood damage reduction in the Red River Basin, Minnesota, by providing reliable flood water storage. Hydrology and biodiversity in 28 natural and restored wetlands su... The authors assessed if wetlands can contribute to flood damage reduction in the Red River Basin, Minnesota, by providing reliable flood water storage. Hydrology and biodiversity in 28 natural and restored wetlands suggested uncontrolled natural wetlands provided the highest mean annual flood storage at 15 cm of runoff while single and 2-stage outlet controlled wetlands provided 3.0 and 8.1 cm of runoff control. Natural controlled wetlands, followed by 2-stage and single stage outlet controlled restorations provided 10.2, 6.6, and 2.2 cm of storage for early summer storm events. Two years of recorded water levels and a 20-year continuous meteorological record were used to model "temporary water level increases" in each wetland. Species diversity, hydrology, and watershed land use variables are inversely related where high quality and diverse wetlands had the lowest amplitude and frequency of water level increases, while low quality wetlands had the highest. Uncontrolled natural wetlands had the highest biological diversity and the lowest frequency and magnitude of temporary water levels increased. A significant biodiversity declines were measured where water level increases were greater than 2.7 meters. Strong multi-linear relationships between watershed land uses and watershed/wetland ratio explained wetland hydraulic performance and biodiversity relations (r2 ranging from 0.6-0.8). Non-native wetland plant diversity increased with greater water level dynamics. 展开更多
关键词 Diversity and hydrology floodwater in wetlands water level dynamics.
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Straw Application Altered CH_4 Emission,Concentration and ^(13)C-Isotopic Signature of Dissolved CH_4 in a Rice Field 被引量:8
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作者 ZHANG Xiao-Yan ZHANG Guang-Bin +3 位作者 JI Yang MA Jing XU Hua CAI Zu-Cong 《Pedosphere》 SCIE CAS CSCD 2012年第1期13-21,共9页
CH4 emission and the concentration of dissolved CH4 in soil solution and floodwater in a rice field and their stable carbon isotopic signatures as affected by straw application were investigated in 2009 in a field exp... CH4 emission and the concentration of dissolved CH4 in soil solution and floodwater in a rice field and their stable carbon isotopic signatures as affected by straw application were investigated in 2009 in a field experiment at Jurong, Jiangsu Province, China. Straw application increased CH4 emission and CH4 concentration in the soil solution and floodwater. A positive seasonal correlation was also observed in the variation between CH4 flux and CH4 concentration in soil solution. The seasonal total CH4 emission (51.6 g CH4 m^-2) in Treatment WS (straw applied) was about 168% higher than that in Treatment CK (without straw). The emitted CH4 and CH4 in soil solution were initially relatively enriched, then depleted and finally enriched again in 13C in both treatments, while CH4 in floodwater became isotopically heavier. The carbon isotopic signature of emitted CH4 and CH4 in floodwater averaged around -62%o and -45%0 for both treatments, respectively, and was not significantly influenced by the application of straw. However, straw application caused the CH4 in soil solution to be significantly depleted in lac during the middle of the rice season, and the mean δ13C value was lower in WS (-57.5‰) than in CK (-49.9‰). Calculation from the isotopic data showed that straw application increased the fraction of CH4 oxidized, causing no significant difference in the δ13C value of the emitted CH4 between the two treatments. 展开更多
关键词 δ13CH4 CH4 flux CH4 oxidation floodwater soil solution
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