scholarly journals Seasonal Local Temperature Responses to Paddy Field Expansion from Rain-Fed Farmland in the Cold and Humid Sanjiang Plain of China

2018 ◽  
Vol 10 (12) ◽  
pp. 2009 ◽  
Author(s):  
Tingxiang Liu ◽  
Lingxue Yu ◽  
Kun Bu ◽  
Fengqin Yan ◽  
Shuwen Zhang
Keyword(s):  
Paddy Field ◽  
Sanjiang Plain ◽  
Paddy Fields ◽  
Cooling Effect ◽  
Local Temperature ◽  
Surface Cooling ◽  
Humid Climate ◽  
The Sanjiang Plain ◽  
Near Surface ◽  
Temperature Responses

Numerous studies have documented the effects of irrigation on local, regional, and global climate. However, most studies focused on the cooling effect of irrigated dryland in semiarid or arid regions. In our study, we focused on irrigated paddy fields in humid regions at mid to high latitudes and estimated the effects of paddy field expansion from rain-fed farmland on local temperatures based on remote sensing and observational data. Our results revealed much significant near-surface cooling in spring (May and June) rather than summer (July and August) and autumn (September), which was −2.03 K to 0.73 K and −1.08 K respectively. Non-radiative mechanisms dominated the local temperature response to paddy field expansion from rain-fed farmland in the Sanjiang Plain. The contributions from the changes to the combined effects of the non-radiative process were 123.6%, 95.5%, and 66.9% for spring (May and June), summer (July and August), and autumn (September), respectively. Due to the seasonal changes of the biogeophysical properties for rain-fed farmland and paddy fields during the growing season, the local surface temperature responses, as well as their contributions, showed great seasonal variability. Our results showed that the cooling effect was particularly obvious during the dry spring instead of the warm, wet summer, and indicated that more attention should be paid to the seasonal differences of these effects, especially in a region with a relatively humid climate and distinct seasonal variations.

scholarly journals The Impact of Artificial Wetland Expansion on Local Temperature in the Growing Season—the Case Study of the Sanjiang Plain, China

2019 ◽  
Vol 11 (24) ◽  
pp. 2915
Author(s):  
Lingxue Yu ◽  
Tingxiang Liu
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Growing Season ◽  
Sanjiang Plain ◽  
Paddy Fields ◽  
Local Temperature ◽  
Night Time ◽  
Artificial Wetland ◽  
The Sanjiang Plain ◽  
The Impact

Land use and land cover change (LUCC) has been increasingly recognized as having important effects on climate systems. Paddy fields, one kind of artificial wetland, have seen a significant increase in the Sanjiang Plain, China since 2000 and have become the most typical LUCC at the regional scale. Against this background, in this paper, we discuss the effects of this artificial wetland increase on surface temperature, in addition to its driving mechanisms. Firstly, the spatiotemporal variations of land surface temperature (LST) and its two driving variables (albedo and latent heat flux (LE)) in the Sanjiang Plain are analyzed and assessed based on remote sensing observation information from 2001 to 2015. Our results from both spatial distribution difference and time series analysis show that paddy field expansion led to day-time cooling and night-time warming over the study area. However, the LST changes show different characteristics and magnitudes in the spring (May to June) compared to the other months of the growing season (July to September). The daytime cooling trend is found to be −0.3842 K/year and the warming trend at night 0.1988 K/year during the period 2001 to 2015, resulting in an overall cooling effect in May and June. In July–September, the LST changes have the same sign but a smaller magnitude, with a −0.0686 K/year temperature trend seen for the day-time and a 0.0569 K/year increase for the night-time. As a consequence, a pronounced decrease in the diurnal temperature range is detected in the growing season, especially in spring. Furthermore, albedo and LE are demonstrated to be very sensitive to land use changes, especially in the earlier periods of the growing season. Correlation analysis between LST and albedo and LE also indicates the dominant role played by evapotranspiration in paddy fields in regulating local temperature.

scholarly journals The Value of a Decrease in Temperature by One Degree Celsius of the Regional Microclimate—The Cooling Effect of the Paddy Field

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 353
Author(s):  
Ya-Wen Chiueh ◽  
Chih-Hung Tan ◽  
Hsiang-Yi Hsu
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Paddy Field ◽  
Research Area ◽  
Paddy Fields ◽  
Cooling Effect ◽  
Field Temperature ◽  
Bare Land ◽  
The Face ◽  
The Difference

In the face of climate change, extreme climates are becoming more frequent. There were severe droughts in Taiwan in 2020, 2014–2015, and 2002. In these years, the paddy fields were kept fallow to save water and transfer agricultural water to non-agricultural use. On the other hand, with global warming, the existence of paddy fields may be one of the natural solutions to regional temperature mitigation. This study used remote sensing to quantify the difference in temperature between paddy fields and urban areas. The result of overall surface temperature deductive analysis revealed that the temperature in the whole Taoyuan research area was 1.2 °C higher in 2002 than in 2003 because of fallowing of the paddy field, while in the Hsinchu research area, it was 1.5 °C higher in 2002 than in 2003, due to the same reason described above. In terms of the difference in land use, for the Hsinchu research area, the surface temperature deductive result showed that the average paddy field temperature in 2002 was 22.3 °C (sample area average), which was 7.7 °C lower than that of the building and road point and 4.3 °C lower than that of the bare land point. The average paddy field temperature in 2003 was 19.2 °C (sample area average), which was 10.1 °C lower than that of the building and road point and 8.3 °C lower than that of the bare land point. Then this study evaluated the economic valuation of the paddy field cooling effect using the contingent valuation method. Through the paddy field cooling effect and in the face of worsening extreme global climate, the willingness to pay (WTP) of the respondents in Taiwan for a decrease of 1 °C with regard to the regional microclimate was evaluated. It was found that people in Taiwan are willing to pay an extra 8.89 USD/per kg rice/year for the paddy for a decrease in temperature by 1 °C in the regional microclimate due to the paddy field. Furthermore, this study applied the benefits transfer method to evaluate the value of a decrease of 1 °C in the regional microclimate in Taiwan. The value of a decrease of 1 °C in the regional microclimate in Taiwan is 9,693,144,279 USD/year. In this regard, the economic value of 1 °C must not be underestimated. In conclusion, more caution is needed while making decisions to change the land use of paddy fields to other land uses.

scholarly journals Sources, Influencing Factors, and Pollution Process of Inorganic Nitrogen in Shallow Groundwater of a Typical Agricultural Area in Northeast China

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3292
Author(s):  
Xinqiang Du ◽  
Jing Feng ◽  
Min Fang ◽  
Xueyan Ye
Keyword(s):  
Influencing Factors ◽  
Paddy Field ◽  
Northeast China ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Shallow Groundwater ◽  
Development Planning ◽  
Sanjiang Plain ◽  
Nitrogen Compounds ◽  
The Sanjiang Plain

As one of the largest agricultural areas, the Sanjiang Plain of Northeast China has faced serious inorganic nitrogen pollution of groundwater, but the sources and the formation mechanism of pollution in the regional shallow groundwater remain unclear, which constrains the progress of pollution control and agricultural development planning. An investigation on potential nitrogen sources, groundwater inorganic nitrogen compounds (NH4+, NO3−, NO2−), and topsoil total nitrogen concentration (TN) was conducted in a typical paddy irrigation area of Sanjiang Plain. Multivariate statistical analysis combined with geospatial-based assessment was applied to identify the sources, determine the governing influencing factors, and analyze the formation process of inorganic nitrogen compounds in shallow groundwater. The results show that the land use type, oxidation-reduction potential (Eh), groundwater depth, NO2− concentration, and electrical conductivity (EC) are highly correlated with the NO3− pollution in groundwater, while DO and Eh affected the distribution of NH4+ most; the high concentrations of NO3− in sampling wells are most likely to be found in the residential land and are distributed mainly in densely populated areas, whereas the NH4+ compounds are most likely to accumulate in the paddy field or the lands surrounded by paddy field and reach the highest level in the northwest of the area, where the fields were cultivated intensively with higher fertilization rates and highest values of topsoil TN. From the results, it can be concluded that that the NO3− compounds in groundwater originated from manure and domestic waste and accumulated in the oxidizing environment, while the NH4+ compounds were derived from N fertilization and remained steady in the reducing environment. NO2− compounds in groundwater were the immediate products of nitrification as a result of microorganism activities.

Impact of paddy field landscape on the local thermal environment in the Sanjiang Plain

2021 ◽  
Vol 41 (5) ◽  
Author(s):  
金翠，李欣涛，佟欣羽，曾令辉，李凤秀 JIN Cui
Keyword(s):  
Paddy Field ◽  
Thermal Environment ◽  
Sanjiang Plain ◽  
The Sanjiang Plain

scholarly journals Land Use and Landscape Pattern Changes in the Sanjiang Plain, Northeast China

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 637 ◽  
Author(s):  
Xiaohui Liu ◽  
Yu An ◽  
Guihua Dong ◽  
Ming Jiang
Keyword(s):  
Land Use ◽  
Landscape Pattern ◽  
Northeast China ◽  
Temporal Dynamics ◽  
Sanjiang Plain ◽  
Paddy Fields ◽  
Dynamic Monitoring ◽  
The Sanjiang Plain ◽  
Relative Change ◽  
Landscape Level

Agricultural reclamation has been the major threat to land use changes in the Sanjiang Plain, Northeast China, over the past decades. However, spatial and temporal dynamics of land use and landscape, especially in the recent years, are not well known. In this study, land use and landscape pattern changes from 1982 to 2015 were analyzed using remote sensing data by splitting the period into five periods. The results indicated that the largest reduction of forestland area was 648.70 km2 during 1995–2000, and the relative change was −1.84%. The converted area of forestlands to dry farmlands in this period was about 90% of the total reduced forestland area. Marshland areas decreased remarkably by 63.29% and paddy fields increased by 1.78 times from 1982 to 2015. Paddy fields experienced large conversion into dry farmlands during 2005–2010 (1788.57 km2), followed by a reverse conversion from 1995 to 2000 (2379.60 km2). The difference of relative change revealed development speed of paddy field was faster than that of dry farmlands among the five periods. Landscape pattern was analyzed using class- and landscape-level metrics. The landscape diversity index and number of patches increased, which showed that the degrees of the forestland, marshland, and cropland landscape fragmentation were aggravated. Our study provides the effective means of land use dynamic monitoring and evaluation at the landscape level for the existing forestlands and marshlands protection.

scholarly journals Is groundwater sufficient to support sustainable irrigation agriculture in a reclaimed wetland region?

2016 ◽  
Author(s):  
Zhonghe Pang ◽  
Lianghua Lv ◽  
Jie Li ◽  
Lijuan Yuan ◽  
Yanlong Kong ◽  
...  
Keyword(s):  
Water Resources ◽  
Rice Paddy ◽  
Sanjiang Plain ◽  
Paddy Fields ◽  
Environmental Tracers ◽  
The Sanjiang Plain ◽  
Quaternary Aquifer ◽  
Sustainable Irrigation ◽  
Irrigation Agriculture ◽  
Rice Paddy Fields

Abstract. Water resources management is the key to sustainable agriculture and wetlands ecosystems. Understanding whether agriculture with groundwater-dominated irrigation is sustainable is sometimes difficult due to complex hydrological conditions, e.g. in the case of a wetland region. To investigate this issue we have chosen a wetland and rice paddy fields co-existing area with a groundwater-dominated irrigation scheme in the Sanjiang Plain, NE China, which has been reclaimed from lake-swamp type of natural wetlands since the 1950s. Using a multi-tracer approach involving water chemistry and isotopes (2H, 18O, 3H, 13C, 14C), integrated with data on groundwater regime, we demonstrate that it is possible to delineate the mechanism of hydraulic interactions between groundwater and river, ponds and rice paddy fields in the wetlands terrain. Regional variations in hydrogeology have been found to be the main factors controlling groundwater recharge and regime. Groundwater in the confined Quaternary aquifer with ages over 50 years and evidenced by depleted heavy isotopes is recharged by lateral flow from nearby mountains. The groundwater is in general not affected by surface activities, however, its yield is limited. Groundwater alone is not sufficient to support sustainable irrigation agriculture. On the contrary, the unconfined Quaternary aquifer is recharged by rainfall or riverbank infiltration, especially at localities near the rivers. It is more likely for the groundwater to be affected by agricultural activities, though its yield is rather abundant. This paper also indicates that utilization and planning of water resources for reclaimed agriculture can be improved through hydrological studies using environmental tracers.

scholarly journals Erratum to: Ecosystem Service Comparison before and after Marshland Conversion to Paddy Field in the Sanjiang Plain, Northeast China

Wetlands ◽  
2017 ◽  
Vol 37 (3) ◽  
pp. 601-601
Author(s):  
Xiaohui Liu ◽  
Ming Jiang ◽  
Guihua Dong ◽  
Zhongsheng Zhang ◽  
Xigang Wang
Keyword(s):  
Ecosystem Service ◽  
Paddy Field ◽  
Northeast China ◽  
Sanjiang Plain ◽  
The Sanjiang Plain ◽  
Before And After
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