scholarly journals ON-SITE EXPERIMENTS AND HYDRAULIC EVALUATION ON RUNOFF CONTROL BY RAINWATER STORAGE IN PADDY FIELDS

2008 ◽  
Vol 52 ◽  
pp. 469-474 ◽  
Author(s):  
Morihiro HARADA ◽  
Mikio OHMORI ◽  
Tomio MORI ◽  
Satoru FUJISAWA
Keyword(s):  
Paddy Fields ◽  
Runoff Control

Reduction of nitrogen fertilizer application under different crop rotation systems in paddy fields of Taihu Area

2011 ◽  
Vol 19 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Jun QIAO ◽  
Ting-Mei YAN ◽  
Feng XUE ◽  
Lin-Zhang YANG ◽  
Ping LU
Keyword(s):  
Crop Rotation ◽  
Nitrogen Fertilizer ◽  
Fertilizer Application ◽  
Paddy Fields

Evaluation of an improvement in runoff control by means of a construction of an infiltration sewer pipe under a porous asphalt pavement

1997 ◽  
Vol 36 (8-9) ◽  
pp. 397-402
Author(s):  
Yasuhiko Wada ◽  
Hiroyuki Miura ◽  
Rituo Tada ◽  
Yasuo Kodaka
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Asphalt Pavement ◽  
Considerable Effect ◽  
Rainfall Infiltration ◽  
Sewer Pipe ◽  
Porous Asphalt ◽  
Runoff Control

We examined the possibility of improved runoff control in a porous asphalt pavement by installing beneath it an infiltration pipe with a numerical simulation model that can simulate rainfall infiltration and runoff at the porous asphalt pavement. From the results of simulations about runoff and infiltration at the porous asphalt pavement, it became clear that putting a pipe under the porous asphalt pavement had considerable effect, especially during the latter part of the rainfall.

The inspection of actual runoff control facilities five years after construction

1997 ◽  
Vol 36 (8-9) ◽  
pp. 373-377
Author(s):  
Yuzo Akagawa ◽  
Yasutoshi Matsumoto ◽  
Mitsuyoshi Zaizen
Keyword(s):  
Return Period ◽  
Social Background ◽  
Groundwater Table ◽  
Control Functions ◽  
Design Rainfall ◽  
The Social ◽  
Athletic Field ◽  
Runoff Control

This report describes runoff control facilities (five years after construction) which are basically an athletic field consisting of tennis courts, constructed in an area of about four hectares in Tokyo. The report is divided into three parts. The first part deals with the social background of the fact that the athletic field has come to have runoff control functions. The second part concerns the summary of these facilities, and then the last part relates to the effects of runoff control. Concerning the effects of the facilities, the return period of design rainfall for runoff control facilities is ten years, but stormwater has been stored on the tennis courts twice in five years after construction. Though these two cases of rainfall were very extraordinary, as the outcome of the inspection of the runoff control facilities we were able to confirm the effects of runoff control by means of simulating under the condition of those two cases of rainfall. In addition, we were able to confirm the effect of groundwater cultivation by means of researching the transition of the groundwater table.

scholarly journals Response of Vertical Migration and Leaching of Nitrogen in Percolation Water of Paddy Fields under Water-Saving Irrigation and Straw Return Conditions

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 868 ◽  
Author(s):  
Chengxin Zheng ◽  
Zhanyu Zhang ◽  
Yunyu Wu ◽  
Richwell Mwiya
Keyword(s):  
Vertical Migration ◽  
Growth Stage ◽  
Nitrogen Leaching ◽  
Water Saving ◽  
Paddy Fields ◽  
N Leaching ◽  
Leaching Losses ◽  
Leaching Loss ◽  
Straw Return ◽  
Percolation Water

The use of water-saving irrigation techniques has been encouraged in rice fields in response to irrigation water scarcity. Straw return is an important means of straw reuse. However, the environmental impact of this technology, e.g., nitrogen leaching loss, must be further explored. A two-year (2017–2018) experiment was conducted to investigate the vertical migration and leaching of nitrogen in paddy fields under water-saving and straw return conditions. Treatments included traditional flood irrigation (FI) and two water-saving irrigation regimes: rain-catching and controlled irrigation (RC-CI) and drought planting with straw mulching (DP-SM). RC-CI and DP-SM both significantly decreased the irrigation input compared with FI. RC-CI increased the rice yield by 8.23%~12.26%, while DP-SM decreased it by 8.98%~15.24% compared with FI. NH4+-N was the main form of the nitrogen leaching loss in percolation water, occupying 49.06%~50.97% of TN leaching losses. The NH4+-N and TN concentration showed a decreasing trend from top to bottom in soil water of 0~54 cm depth, while the concentration of NO3−-N presented the opposite behavior. The TN and NH4+-N concentrations in percolation water of RC-CI during most of the rice growth stage were the highest among treatments in both years, and DP-SM showed a trend of decreasing TN and NH4+-N concentrations. The NO3−-N concentrations in percolation water showed a regular pattern of DP-SM > RC-CI > FI during most of the rice growth stage. RC-CI and DP-SM remarkably reduced the amount of N leaching losses compared to FI as a result of the significant decrease of percolation water volumes. The tillering and jointing-booting stages were the two critical periods of N leaching (accounted for 74.85%~86.26% of N leaching losses). Great promotion potential of RC-CI and DP-SM exists in the lower reaches of the Yangtze River, China, and DP-SM needs to be further optimized.

scholarly journals Ecological and Environmental Effects of Estuarine Wetland Loss Using Keyhole and Landsat Data in Liao River Delta, China

2021 ◽  
Vol 13 (2) ◽  
pp. 311
Author(s):  
Hongyan Yin ◽  
Yuanman Hu ◽  
Miao Liu ◽  
Chunlin Li ◽  
Jiujun Lv
Keyword(s):  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Ecological Risk ◽  
Potential Ecological Risk ◽  
Wetland Loss ◽  
Ecological Effects ◽  
Paddy Fields ◽  
Suitable Habitat ◽  
Estuarine Wetland

An estuarine wetland is an area of high ecological productivity and biodiversity, and it is also an anthropic activity hotspot area, which is of concern. The wetlands in estuarine areas have suffered declines, which have had remarkable ecological impacts. The land use changes, especially wetland loss, were studied based on Keyhole and Landsat images in the Liao River delta from 1962 to 2016. The dynamics of the ecosystem service values (ESVs), suitable habitat for birds, and soil heavy metal potential ecological risk were chosen to estimate the ecological effects with the benefit transfer method, synthetic overlaying method, and potential ecological risk index (RI) method, respectively. The driving factors of land use change and ecological effects were analyzed with redundancy analysis (RDA). The results showed that the built-up area increased from 95.98 km2 in 1962 to 591.49 km2 in 2016, and this large change was followed by changes in paddy fields (1351.30 to 1522.39 km2) and dry farmland (189.5 to 294.14 km2). The area of wetlands declined from 1823.16 km2 in 1962 to 1153.52 km2 in 2016, and this change was followed by a decrease in the water area (546.2 to 428.96 km2). The land use change was characterized by increasing built-up (516.25%), paddy fields (12.66%) and dry farmland (55.22%) areas and a decline in the wetland (36.73%) and water areas (21.47%) from 1962–2016. Wetlands decreased by 669.64 km2. The ESV values declined from 6.24 billion US$ to 4.46 billion US$ from 1962 to 2016, which means the ESVs were reduced by 19.26% due to wetlands being cultivated and the urbanization process. The area of suitable habitat for birds decreased by 1449.49 km2, or 61.42% of the total area available in 1962. Cd was the primary soil heavy metal pollutant based on its concentration, accumulation, and potential ecological risk contribution. The RDA showed that the driving factors of comprehensive ecological effects include wetland area, Cd and Cr concentration, river and oil well distributions. This study provides a comprehensive approach for estuarine wetland cultivation and scientific support for wetland conservation.

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