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1.
The contingent valuation method was used with a payment card approach to estimate visitors’ willingness to pay (WTP) to conserve a traditional agricultural landscape of terraced paddy fields in coastal rural Japan. Eighty percent of participants indicated their WTP toward a conservation fund, with estimated mean and median WTP of JPY 953.5 (~?USD $8.99) and JPY 456.4 (~?USD $4.30) per visit per person. Personal income and proximity to residence both positively influenced WTP amount; visitors’ attachment to land and loyalty were positively associated with their willingness to pay for landscape conservation. Actual conservation costs are currently mostly funded by the public municipal budget (56%) and urban volunteers (43%), but government funding sources are declining and becoming unreliable. These findings suggest that visitor donations may supplement existing funding sources for the conservation of terraced paddy field landscapes. However, farmer successors are needed for farm management to sustain traditional farming and rural communities, since a living farm and a vigorous community are essential for rural tourism. 相似文献
2.
This experimental study assesses the effects of event rainfall on soil erosion characteristics in terraced rice paddy fields. A 0.75-ha terraced paddy field located in Northern Taiwan was used to investigate the soil erosion under the regular cultivation of rice during two crop seasons. The environmental changes were investigated in the neighboring areas in which terraced paddy fields have been converted to other land usages. The annual rate of soil erosion calculated from the observed rainfall runoff and suspended solid contained was 0.77 ton/ha, which is significantly less than the erosion rate associated with upland crop cultivation reported by other research conducted in Taiwan. Experimental results also showed that the terraced paddy field retained the highest percentages of clay, silt, and organic matter's content, as compared to those of other upland crops, indicating that the topsoil was less susceptible to rainfall erosion under flooded conditions of rice-cultivation. The results of this study show that the rice-planted terraced paddy offers the highest level of soil conservation. The function of soil and water conservation in terraced paddy fields could be further increased by effective maintenance of embankment and to raise the height of the bund. Poor management, abandoned cultivation, and converse to other upland crops of terraced paddy fields are regarded as major contributors to increased soil erosion in mountainous areas. The government in Taiwan should formulate effective measures and maintain sustainable rice cultivation in the terraced paddies. 相似文献
3.
Terraced paddy field rainfall-runoff mechanism and simulation using a revised tank model 总被引：1，自引：0，他引：1
Terraced paddy fields play important roles in water and soil conservation because their water storage effect reduces and delays
flood peaks. This study applies the terraced paddy field rainfall-runoff mechanism to the tank model. Though the traditional
four-section tank model can easily simulate rainfall-runoff in a terraced paddy field, it has many parameters that are difficult
to calibrate. To address the shortcomings of the traditional four-section tank model, this study develops a revised tank model
to simulate rainfall-runoff. This study selects a terraced paddy field located in Hsuing-Pu village in Hsiuing-Chu County
as the experimental field. The field under investigation was equipped with automatic monitoring stations, water-stage, and
rain gauges. These stations collected data on rainfall and water flow to simulate the rainfall-runoff model in that region.
To simulate the runoff behavior of the experimental terraced paddy field, two rainfall events were selected from the gathered
data and five normal evaluation indexes based on static and hydrological theory were applied to calculate the results of simulation
simultaneously. The revised tank model performed better than expected, and precisely predicted the variations and trends in
flow charge. Comparison with representation indexes proved that the revised tank model is an appropriate and valuable tool
for rainfall-runoff simulation. 相似文献
4.
Yumi Iwasaki Masashi Ozaki Kimihito Nakamura Haruhiko Horino Shigeto Kawashima 《Paddy and Water Environment》2013,11(1-4):551-558
There are many paddy fields and large amounts of groundwater in the Tedori River Alluvial Fan in Ishikawa Prefecture, Japan. Water infiltration from paddy fields during irrigation may significantly contribute to groundwater recharge. Groundwater recharge is known to be one outcome of paddy farming, and in general is usually related to land use. However, a decreased area of paddy fields because of socioeconomic factors such as urbanization and increasing area of fallow fields has possibly affected the groundwater environment. Evaluation of the quantitative effect of paddy fields on groundwater is necessary for groundwater conservation. This study examined the relationship between differences in the depth of groundwater from just before the irrigation period to just after the first irrigation of paddy fields (increments of groundwater levels) in observation wells and the area of paddy fields around each well. The paddy areas within circular buffer zones, which were delineated at 0.2 km intervals between 0.2 and 2.0 km centered on each observation well, were calculated. A positive relationship was found between the rise in groundwater and the area of paddy field within different buffer zones at most wells. In addition, in the middle or upper part of the fan, the effect of changes in the area of paddy fields surrounding the well on the groundwater level rise was greater than that on the lower part of the fan. 相似文献
5.
Paddy and Water Environment - Traditional agricultural practices, including paddy farming on terraced uplands, have garnered renewed interest in recent years in response to increasing concerns on... 相似文献
6.
F. Agus I. Irawan H. Suganda W. Wahyunto A. Setiyanto M. Kundarto 《Paddy and Water Environment》2006,4(4):181-188
Industrial and urban developments in Indonesia focus on the economic merits, but neglect agricultural services that, when disappear, will destabilize the environmental and livelihood systems. A series of 5-year study has evaluated various aspects of multifunctionality and implications of paddy field conversion on the disappearance of multifunctionality. Soil loss from a series of 18 terraced paddy fields in central Java is negligible. Only a few terraces located along the streams directly caused sedimentation. The functions of flood mitigation, water-resource conservation, erosion reduction, organic waste disposal, heat mitigation, and rural amenity of paddy fields in Citarum watershed in West Java were significant. The ‘replacement costs’ of such functions was about 51% ($92.67 million yr−1) of the total price of rice of $181.34 million yr−1 produced in the 156,000 ha paddy field. This amount could be considered as free services by the farmers to the society. However, because of society's negligence and unawareness, conversion has been accelerating while development of new paddy fields has been decelerating in the last few years. Low and fluctuating price of agricultural products, unavailability or non-affordability of agricultural supplies and inaccessibility to market are among the major disincentives faced by farmers. Because of appreciable multifunctionality they produce, farmers deserve various incentives for the sake of environmental sustainability and other services. 相似文献
7.
We investigated the soil and soil water chemistry in abandoned terraced paddy fields (reed stand) and a thicket of deciduous
broad-leaved trees (thicket stand) on the same slope in Sado Island, Japan. The soils gathered from these plots were incubated
under different water conditions to examine the dynamics of dissolved ions. The organic carbon pool in the soil in the reed
stand at the lower slope position was greater than the thicket stand at the middle slope position. The high concentration
of base cations and an almost neutral pH of the soil water at the reed stand corresponded with the high exchangeable cation
concentrations and base saturation in the soil. These results reflect the mineral-rich groundwater percolating down the slope,
which may be produced by chemical weathering. An in situ sulfate reduction in the reed stand at deeper soil horizons was identified.
The different water conditions in the incubated soils affected the soil pH(H2O), transformation of Fe, and dominant anions (NO3
−, HCO3
−, and SO4
2−). These biogeochemical processes were more conspicuous in the reed stand at the lower slope position where the concentrations
of organic matter and base cations were high. When the abandoned terraced paddy field is developed for the conservation of
the Japanese crested ibis (Nipponia nippon) habitat in Sado Island, the reductive subsoil at the lower slope position should be kept waterlogged to limit sulfuric acid
generation. 相似文献
8.
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10.
Converting rice paddy to dry land farming in the Tai Lake Basin,China: toward an understanding of environmental and economic impacts 总被引：1，自引：0，他引：1
Water pollution is a well-known major problem in the Tai Lake Basin, China. Compared to industries and domestic sewage, non-point pollution from agriculture is more difficult to detect, measure, and control. Therefore, a range of policies has been formulated, among which is that of ‘adjustment of the planting structure.’ However, this policy during implementation has been used to simply convert paddy fields to dry land and food crops to cash crops. More surprisingly, to date, no research has provided evidence that such an agricultural land-use change contributes to the reduction of agricultural nutrient pollution. Based on an extensive farm survey, this research finds that conversion of rice paddy to dry land farming has not generated a positive effect on nutrient pollution control. It is estimated that nitrogen runoff from agricultural land has increased by 11 %, while phosphorus runoff has increased more than two times since land-use patterns changed, as farmers are inclined to apply more fertilizer on dry land than in paddy fields. However, this agricultural land-use change is economically effective as land-use conversion increases the net profits of farming in a significant way. It is demonstrated that, compared to environmental concerns, economic considerations are seen to have greater benefits after such an adjustment in the planting structure. These findings have important implications for policy making by local authorities in their efforts to improve environmental management and pollution control in their territories. 相似文献
11.
Potential rainwater storage capacity of irrigation ponds 总被引：1，自引：1，他引：1
From antiquity to the present, Japan has irrigated many paddy fields from irrigation ponds. There are some 64,000 such irrigation ponds with a benefit area of over 2 ha each. These irrigation ponds not only function as a water-source for the stable production of food, but also are thought to reduce flooding in lower regions through temporary storage of rainwater and catchment runoff because they are located upstream of paddy fields, upland fields and residential land. Centering our research on Kagawa and Osaka Prefectures, we assessed the potential of rainwater storage capacity created by free space in irrigation ponds resulting from irrigation at a macro level as an indicator of flood mitigation. In these prefectures, potential rainwater storage capacity of irrigation ponds in early September was 2.1 and 1.4 times that of the potential storage capacity of associated paddy fields in an ordinary year. 相似文献
12.
The groundwater recharge function, one example of the multifunctionality of agriculture, is closely related to hydrogeological phenomena and socioeconomic factors such as pumpage and land use. A long-term evaluation of the groundwater recharge function is necessary to understand its role among the multiple functions of agriculture. The Nobi Plain, one of the largest coastal plains in Japan, was selected as the study area because it has experienced typical socioeconomic changes. We conducted a long-term evaluation of the groundwater recharge function based on simple water-balance equations using long-term data on groundwater levels and river flows. Leakage recharge from paddy fields in 1975 was about 2.8×108 m3/year, decreased to 0.6×108 m3/year in 1984, and ceased in 1985. Its monetary value of the function in 1975 was estimated by the replacement cost method, was about $56 million for 20 ha×103 ha of paddy fields. The value per unit area of paddy fields was calculated as $2820/ha and that in Japan was calculated as $400/ha. Paddy fields in suburbs of big cities have a higher value than the average paddy field in Japan. However, this recharge value is no longer produced because no leakage recharge occurs at present owing to socioeconomic changes. 相似文献
13.
Flood mitigation in irrigation tanks and paddy fields is their favorable aspect though its practical effect is not known very
well. A dynamic and systematic approach is presented to assess flood mitigation in a tank irrigated paddy fields area in the
worst case where no static buffer function is expected. Based on the linear control theory, transfer function models for runoff
process in catchments are identified. Hydraulic models are developed to represent flood dynamics in irrigation tanks, paddy
fields, and drainage channels. These models are integrated as an ordinary differential equations system. Then, using the perturbed
linear system, flood mitigation in each component of the system is examined in terms of frequency response. An application
example demonstrates that a tank irrigated paddy fields area has a significant flood mitigation effect as a low-pass filter.
This method has the advantage of assessing flood mitigation even in the case of an increase in the total runoff ratio. 相似文献
14.
A new method for assessing land leveling to produce high quality consolidated paddy fields 总被引：1，自引：1，他引：0
The quality of leveling of 0.3-ha consolidated paddy fields in Japan was investigated. The leveling of normal consolidated
plots was accurate to within 7 cm from a horizontal plane, with an average standard deviation of about 18 mm for the points
measured throughout the plot. The investigated paddy fields had inclinations ranging from horizontal to quite steep; the average
inclination was 0.56‰ (1/1,718). The traditional assessment method is based on a horizontal plane. Because it is difficult
to use this method to assess the leveling conditions of paddy fields that have an inclined surface, a new assessment method
that accurately evaluates the sloped plane of a paddy field is proposed. The new method assesses the leveling conditions within
a field by means of a "state index" that considers both the inclination and the surface roughness. Using this state index
not only allowed the conditions to be effectively evaluated, but also helped reduce the extra workload needed to level the
field to the farmers' requirements after the initial consolidation.
Electronic Publication 相似文献
15.
Effect of N-fertilizer application on return flow water quality from a terraced paddy field in Northern Taiwan 总被引：1，自引：0，他引：1
Shih-Kai Chen Cheng-Shin Jang Shu-Ming Chen Kun-Hung Chen 《Paddy and Water Environment》2013,11(1-4):123-133
Intensive use of chemical fertilizer for crops may be responsible for nitrogen and phosphate accumulation in both groundwater and surface waters. The return flow polluted by nutrients not only results in the limitation of water reuse goals but also creates many environmental problems, including algal blooms and eutrophication in neighboring water bodies, posing potential hazards to human health. This study is to evaluate the N-fertilizer application of terraced paddy fields impacting return flow water quality. Water quality monitoring continued for two crop-periods around subject to different water bodies, including the irrigation water, drainage water at the outlet of experimental terraced paddy field, and shallow groundwater were conducted in an experimental paddy field located at Hsin-chu County, Northern Taiwan. The analyzed results indicate that obviously increasing of ammonium-N (NH4 +-N) and nitrate-N (NO3 ?-N) concentrations in the surface drainage water and ground water just occurred during the stage of basal fertilizer application, and then reduced to relatively low concentrations (<0.1 mg/l and <3 mg/l, respectively) in the remaining period of cultivation. The experimental results demonstrate the potential pollution load of nitrogen can be reduced by proper drainage water control and fertilizer application practices. 相似文献
16.
Michiko Hayano Naoki Horikawa Tsuneo Kuwagata Jun Furuya Yasushi Ishigooka Toshihiro Hasegawa Tomoyuki Taniguchi Akira Shimizu Hitoshi Toritani Minoru Tada Takao Masumoto 《Paddy and Water Environment》2008,6(1):15-23
This paper introduces the Agriculture, Forestry and Fisheries Research Council of Japan (AFFRC) model, an integrated model
that predicts future rice production in the Mekong River basin by taking into account the effect of global warming on both
the water cycle and the rice economy. The model focuses especially on the water balance of paddy fields for different farmland
water use systems. We defined six categories of irrigated paddies and three categories of rain-fed paddies on the basis of
their systems of water usage. We included a process-based model to predict future rice production, accounting for daily changes
in available water resources such as precipitation. Many models of crop production treat rice in the same way as other crops;
the particular characteristics of rice farming are considered in more detail in our model. Our results show that it is possible
to estimate future rice production in the Mekong River basin by taking into account changes in available water, and to model
the resultant effects on the grain market. 相似文献
17.
18.
Sooyong Shim Bomchul Kim Yoshihiko Hosoi Takanori Masuda 《Paddy and Water Environment》2005,3(4):211-218
The aim of this study is to quantify the dissolved organic carbon (DOC) of drainage water from paddy fields in agricultural
areas of Tottori prefecture, Japan. In four experimental paddy fields, DOC concentration varied much from 1.1 to 10.1 mg C l−1, and was the highest during heavy runoff that occurred in April when there was a non-agricultural period. However, variation
in DOC concentration did not always correspond to rainfall, but depended more on cultivation-activity events such as tilling,
planting, draining in summer, and final draining in autumn. The water discharge rate from each experimental field was estimated
by using a hydrologic model (the Tank Model and a genetic algorithm). Daily DOC export rate per unit area of three experimental
paddy fields was calculated to be 0.0074, 0.0052, and 0.0081 kg a−1 day−1, respectively. The daily DOC export rate showed large seasonal variation with the highest value in May and June. It can be
concluded that DOC export from paddy fields can be a substantial source of DOC in receiving waters, and the export rate depends
much on cultivation method practice. It might be suggested that DOC export from paddy fields can be controlled by a better
water management practice of farmers. 相似文献
19.
The multi-functionality of paddy farming in Korea 总被引：3，自引：3，他引：0
The multi-functionality of paddy field and irrigation water has become a hot issue recently in Asian monsoon regions. Asian people know why they have to conserve the paddy farm where the sustainable functions have been historically inherited and maintain the rural community where the unique cultures have been traditionally created. But, the real value of multi-functionality has not been clearly highlighted as much worthy as it has. We should evaluate the characteristics of multi-functionality of paddy farming correctly and transmit them to the people of Western countries under quite different conditions of upland fields. In Korea, several studies on the multi-functionality of paddy farming have been performed with positive and negative viewpoints. This paper shows the results and the discussion of the researches to get global recognition on the multi-functionality of paddy farming.
相似文献
| Tai-Cheol KimEmail: |
20.
Sirirat Kiatpathomchai P. Michael Schmitz T. S. Amjath Babu Sutonya Thongrak 《Paddy and Water Environment》2008,6(3):319-326
Rice and shrimp farming are two important economic activities in rural southern Thailand that compete each other in land allocation
leading to land use conflicts. Moreover, it can be observed that the conversion of rice fields to shrimp farms is already
extended from coastal areas to the inlands. These conversions are making more area be saline which is essential condition
for shrimp cultivation but deleterious for rice farming. We are looking at the unidirectional externalities originating from
the conversion which brings the productivity of adjacent rice fields further down. This study attempts to quantify the external
effects on rice yield and efficiency of rice farming by constructing three models. Model I, we assess the rice yield function
by using the multiple linear regression while in Model II, we attempt to delineate the technical efficient frontier of rice
farms by using an input oriented non-parametric approach, so called data envelopment analysis. Model III, we probe into the
factors influencing technical efficiency scores using the Tobit regression. Database of the study is constituted by primary
survey data from 120 rice farms in Songkhla province for the crop year 2004/2005. The 30 out of 120 sample farms have been
affected by externality of shrimp farming. The empirical results of all three models show that shrimp farming externalities
caused a production drop of 467–515 kg paddy rice per ha and significantly affect the technical efficiency of rice farms.
The measures of internalizing this externality are discussed. 相似文献