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 Cooling Effect of Paddy on Land Surface Temperature in Cold China Based on MODIS Data: A Case Study in Northern Sanjiang Plain

2019 ◽  
Vol 11 (20) ◽  
pp. 5672 ◽  
Author(s):  
Du ◽  
Liu ◽  
Pan ◽  
Yang ◽  
Wang
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Growing Season ◽  
Rice Paddy ◽  
Sanjiang Plain ◽  
Paddy Fields ◽  
Landsat Images ◽  
The Impact ◽  
The Relationship

Fast-growing crops have been evolved in North China, accompanied by intense paddy expansion, leading to dramatic impacts on the agricultural environment. Among these environmental issues, the impact of paddy expansion on land surface temperature is still unclear. In the present study, based on Landsat images and MODIS land surface temperature (LST) products, the crop pattern and monthly LST in the northern Sanjiang Plain are obtained. A 1 km scale grid unit is built to investigate the relationship between LST and paddy expansion. The results obtained from the study are as follows. Firstly, for crop patterns, cropland planting is given priority to paddy fields, accompanied by an aggregated pattern, while upland crops present a discrete pattern. Secondly, for LST changes during the growing season, the maximum LST occurs in June, and the lowest values occur in October across the whole region. In addition, the LST of paddy fields is lower compared with that of upland crops for the whole growing season. Thirdly, at the 1 km grid scale, the relationship between monthly LST and paddy field ratio is significantly negative, and better represented by a cubic function rather than a linear fit. Finally, LST decreases with the increased fraction of the rice paddy area more rapidly when rice paddy is aggregated and accounted for by more than 80% of each study grid. The findings of this study are important to guide agricultural production and to better understand the environmental effects of paddy expansion in cold regions.

scholarly journals DOC concentrations and spectroscopic characteristics in surface runoff from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China

2012 ◽  
Vol 9 (6) ◽  
pp. 7919-7945
Author(s):  
L. L. Wang ◽  
C. C. Song ◽  
G. S. Yang
Keyword(s):  
Land Use ◽  
Surface Runoff ◽  
Rice Paddy ◽  
Sanjiang Plain ◽  
Natural Wetland ◽  
Artificial Wetland ◽  
The Sanjiang Plain ◽  
Wetland Ecosystems ◽  
Wetland Site ◽  
Spectroscopic Characteristics

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. In this study, we examined the concentrations and spectroscopic characteristics of DOC in surface runoff from contrasting wetlands along the lower Amur River Basin in the Sanjiang Plain, Northeastern China. Surface runoff from seven sites (two natural phialiform wetlands, three natural riparian wetland, one degraded wetland, and one artificial wetland i.e. rice paddy) were monitored during the growing seasons of 2009 and 2010. Surface runoff from the natural wetland sites exhibited a wide range of DOC concentrations (10.06–48.73 mg l−1) during the two-year sampling period. The specific ultraviolet absorbance (SUVA) and color values of DOC in surface runoff were also highly variable at different natural wetland sites. Our analysis also found that DOC values were significantly lower in the surface runoff at the artificial wetland site compared with those from surface runoff at the five natural wetland sites and one degraded wetland site (P < 0.01). The colour per carbon unit (C / C) ratio in surface runoff at the artificial wetland site was one to three times lower, while the E4 / E6 ratio (Abs465 / Abs665) was reduced by 42.07% to 55.36%, compared to those from runoff water at the five natural wetland sites. The C / C ratios in surface runoff at the natural wetland sites were higher than that from surface runoff at the degraded wetland, which in turn has greater values than that from surface runoff at the artificial wetland site. Meanwhile, the E4 / E6 ratio in the surface runoff from the artificial wetland was lower compared to that in surface runoff at the degraded wetland site (P < 0.05). This implies that disturbance to DOC concentrations and spectroscopic characteristics in surface runoff is stronger from natural wetland conversion to rice paddy land than that from wetland degradation. The dataset from this study can provide insightful points for understanding the underlying mechanisms of aquatic DOC dynamics from wetland ecosystems, and improve land use policy and management strategies in the future.

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 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 Simulating Land-Use Changes and Predicting Maize Potential Yields in Northeast China for 2050

2021 ◽  
Vol 18 (3) ◽  
pp. 938
Author(s):  
Luoman Pu ◽  
Jiuchun Yang ◽  
Lingxue Yu ◽  
Changsheng Xiong ◽  
Fengqin Yan ◽  
...  
Keyword(s):  
Land Use ◽  
Food Security ◽  
Northeast China ◽  
Land Use Changes ◽  
Sanjiang Plain ◽  
Potential Production ◽  
Potential Yield ◽  
The Sanjiang Plain ◽  
Ecological Zones ◽  
The Future

Crop potential yields in cropland are the essential reflection of the utilization of cropland resources. The changes of the quantity, quality, and spatial distribution of cropland will directly affect the crop potential yields, so it is very crucial to simulate future cropland distribution and predict crop potential yields to ensure the future food security. In the present study, the Cellular Automata (CA)-Markov model was employed to simulate land-use changes in Northeast China during 2015–2050. Then, the Global Agro-ecological Zones (GAEZ) model was used to predict maize potential yields in Northeast China in 2050, and the spatio-temporal changes of maize potential yields during 2015–2050 were explored. The results were the following. (1) The woodland and grassland decreased by 5.13 million ha and 1.74 million ha respectively in Northeast China from 2015 to 2050, which were mainly converted into unused land. Most of the dryland was converted to paddy field and built-up land. (2) In 2050, the total maize potential production and average potential yield in Northeast China were 218.09 million tonnes and 6880.59 kg/ha. Thirteen prefecture-level cities had maize potential production of more than 7 million tonnes, and 11 cities had maize potential yields of more than 8000 kg/ha. (3) During 2015–2050, the total maize potential production and average yield decreased by around 23 million tonnes and 700 kg/ha in Northeast China, respectively. (4) The maize potential production increased in 15 cities located in the plain areas over the 35 years. The potential yields increased in only nine cities, which were mainly located in the Sanjiang Plain and the southeastern regions. The results highlight the importance of coping with the future land-use changes actively, maintaining the balance of farmland occupation and compensation, improving the cropland quality, and ensuring food security in Northeast China.

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 Impact of Multitemporal Land Use and Land Cover Change on Land Surface Temperature Due to Urbanization in Hefei City, China

2021 ◽  
Vol 10 (12) ◽  
pp. 809
Author(s):  
Jing Sun ◽  
Suwit Ongsomwang
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Urban Areas ◽  
Decomposition Analysis ◽  
Lulc Change ◽  
Main Components ◽  
The Impact

Land surface temperature (LST) is an essential parameter in the climate system whose dynamics indicate climate change. This study aimed to assess the impact of multitemporal land use and land cover (LULC) change on LST due to urbanization in Hefei City, Anhui Province, China. The research methodology consisted of four main components: Landsat data collection and preparation; multitemporal LULC classification; time-series LST dataset reconstruction; and impact of multitemporal LULC change on LST. The results revealed that urban and built-up land continuously increased from 2.05% in 2001 to 13.25% in 2020. Regarding the impact of LULC change on LST, the spatial analysis demonstrated that the LST difference between urban and non-urban areas had been 1.52 K, 3.38 K, 2.88 K and 3.57 K in 2001, 2006, 2014 and 2020, respectively. Meanwhile, according to decomposition analysis, regarding the influence of LULC change on LST, the urban and built-up land had an intra-annual amplitude of 20.42 K higher than other types. Thus, it can be reconfirmed that land use and land cover changes due to urbanization in Hefei City impact the land surface temperature.

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