Expansion Of Paddy Fields Research Articles

Spatial and Temporal Distribution of the Ecosystem Provisioning Service and Its Correlation with Food Production in the Songhua River Basin, Northeastern China

Provisioning services are essential components of ecosystem services. Food production is usually a driver of land use change, which has the effect on altering the provisioning services of ecosystems. As one of the main areas of food production in China, the provisioning services of the Songhua River Basin (SHRB) should be taken seriously. In view of this, it is urgent to carry out a study on the assessment of provisioning services in the SHRB to provide data support and scientific reference for the optimization of the spatial pattern of land use in the basin, the sustainable development of agriculture, and the formulation of differentiated protection policies. In this study, based on the equivalent factor method for the unit area value and spatial autocorrelation with the Moran’s I, we assessed the provisioning services values (PSV) of the SHRB every ten years during the period of 2000–2020 under different land use types and analyzed the relationships between different PSV and the production of four different food types, including rice, wheat, corn, and soja. The main conclusions are as follows: (1) From 2000 to 2020, the area of paddy fields in the SHRB increased and then decreased, while the area of dry lands continued to increase. The land use transfer matrix showed a significant expansion of paddy fields (+0.55 × 104 km2), shrinkage of grassland (−0.72 × 104 km2), and loss of water body (−0.43 × 104 km2) in the SHRB from 2000 to 2020; (2) The PSV in the SHRB showed an increasing trend from 2000 to 2020, growing by 16.73 × 1010 RMB, with the growth in 2010–2020 being greater than in 2000–2010. The order of increase in each type of PSV was: water supply > food supply > raw material supply; (3) Spatially, the increase in PSV per unit and total PSV in the SHRB was lesser in the center and greater in the east and west. Meanwhile, the spatial distribution of various PSV showed that the value of unit area food supply was higher in the central and eastern plains, while the raw material supply and water supply were higher in the western and eastern hilly areas. (4) In terms of spatial correlation, the distribution of soja production with the total PSV, food supply, raw materials supply, and water supply services values were positively spatially correlated. However, the production of rice, wheat, and corn with the total PSV, food supply, and raw materials supply services values were negatively spatially correlated. Cluster analysis revealed that changing the crop cultivation structure could protect the ecosystem and increase the value of ecosystem services.

Assessment and projection of the groundwater drought vulnerability under different climate scenarios and land use changes in the Sanjiang Plain, China

Study RegionA district of the Sanjiang Plain, China. Study focusAiming at assessing the likelihood of groundwater exposure to drought in the present and future, a comprehensive evaluation framework based on the groundwater drought vulnerability index (GDVI) is proposed. Firstly, nine influencing factors are selected in terms of groundwater dependence, hydrogeology, and meteorology, and the current drought vulnerability is assessed by combining the analytic hierarchy process (AHP) and random forest (RF) models. Afterwards, by projecting land use and future climate under the shared socioeconomic pathways of SSP1–2.6, SSP2–4.5, and SSP5–8.5, the GDVI is calculated for three future periods, i.e., 2015–2039, 2040–2064, and 2065–2089. New hydrological insights for the regionMore than 30% of the groundwater experiences high and very high vulnerability during the baseline period, concentrated in areas with arable land and a thick clay cover. With rising temperatures and the rapid expansion of paddy fields, areas of high-vulnerability will continue to expand and will exceed 50% by the middle of the 21st century. If the groundwater irrigation and the agricultural land development are not restricted, the groundwater drought will be exacerbated. The proposed evaluation framework can be used in other areas with high groundwater use or where groundwater resources are at risk of depletion, and the findings provide guidance for agricultural development planning and joint surface water-groundwater scheduling.

Disentangling the relative effects of climate change and anthropogenic activities on paddy expansion in the northern Sanjiang Plain of China

Since the changes in paddy areas would significantly affect food security and agricultural sustainability, it has received worldwide attention guided by the United Nations 2030 Sustainable Development Goals. However, the process of paddy field change was complex, which was affected by both climate change and anthropogenic activities. Most existing studies focused on the spatial–temporal evolution of paddy field in different regions, while the quantitative separation of climatic and anthropogenic contributions to paddy field expansion was rare but imperative. This study adopted the patch-generating land use simulation (PLUS) model to simulate the paddy field expansion under different scenarios. Based on satellite-based land use data, meteorological data, socioeconomic data, physical geographical data, and transport data, it proposed four indicators, including ACI (anthropogenic contribution index), CCI (climatic contribution index), RII (relative importance index), and CEI (combined effects index) to quantitatively disentangle the climatic and anthropogenic contribution at different scales, and further determined the relative importance and combined effects of climate change and anthropogenic activities. These indicators were applied to the case of northern Sanjiang Plain of China and found that the total area of paddy fields in this area expanded greatly from 2638.88 km2 in 1995 to 19363.80 km2 in 2020. 1) At the regional scale (the northern Sanjiang Plain of China), the effect of climate change was slightly larger than that of anthropogenic activities on the paddy field expansion, with an inhibitory interactive effect of climate change and anthropogenic activities. 2) At the city scale (Hegang, Jiamusi and Shuangyashan), the effect of climate change was slightly stronger than anthropogenic activities in Hegang and Jiamusi, whereas Shuangyashan was the opposite. 3) At the county scale (15 counties), paddy field expansion of the central NSP was dominated by anthropogenic activities, while the northern part was disturbed more by climate change. 4) At the grid scale (30-m resolution), 51.17% of the grids had anthropogenic activities contributing more than climate change to paddy field expansion, and 88.60% of the grids presented an inhibitory interactive effect of climate change and anthropogenic activities. Thus, the indicators established for in this study can not only provide a better understanding of the relative effects of climate change and anthropogenic activities on paddy field expansion, but also give some policy implications for sustainable agricultural practice in both China and other developing countries.

The Effectiveness of Remote Sensing Techniques for Land use Classification in Kota Belud, Sabah

The objective of this study was to evaluate the effectiveness of remote sensing techniques in classifying land use types in Kota Belud, Sabah. Two classification techniques, unsupervised and supervised, were employed to ensure high accuracy of the land use data. Six land use types were classified, including paddy fields, bare land, water bodies, forest, urban areas, and oil palm plantations. This study found that the accuracy of land use classification for the years 1990, 2000, 2010, and 2020 was 94%, 86%, 98.30%, and 91.60%, respectively. These results suggest that the supervised classification method was more effective in accurately classifying land use types compared to the unsupervised classification method. The final maps generated by both classification methods showed significant changes in land use over time. For instance, the expansion of paddy fields was observed in the study area, particularly from 1990 to 2020. The conversion of forest areas and bare land to paddy cultivation was in line with the National Agro-Food Policy 2021-2030, which aims to make Kota Belud a paddy granary. Overall, the study highlights the importance of remote sensing techniques in monitoring land use changes. The results provide valuable insights for policymakers and land use planners in making informed decisions to manage land resources sustainably.

Transformation of Agricultural Landscapes and Its Consequences for Natural Forests in Southern Myanmar within the Last 40 Years

Kyunsu township comprises coastal regions and a multitude of small islands covered by vast tropical evergreen and mangrove forests, and a large water body in the Adman Sea of Myanmar. Due to population growth, residents have increasingly expanded their agricultural land areas into natural tropical evergreen and mangrove forests, leading to deforestation. Understanding the processes and consequences of landscape transformation for surrounding ecosystems is crucial for local policy making and for fostering sustainable crop production in this area. Landsat datasets from 1978, 1989, 2000, 2011, and 2020 were used in a time-series post-classification approach to investigate land use land cover (LULC) changes in the Kyunsu township of Southern Myanmar across the last 40 years. Our study also attempted to assess the effects of the transformation of LULC on carbon stocks. Between 1978 and 2020, major LULC changes occurred with the expansion of Paddy Fields (+90%), Plantations (+11%), Open Forests (+81%), Settlement Areas (+115%), Aquaculture Areas (+1594%), and Others (+188%) while the area covered with Closed Forests shrunk by 44% and with Mangrove Forests by 9%. Water Bodies expanded by 0.13%. Our analyses show that between 1978 and 2020 2453 ha of Paddy Fields expanded into Plantations, 1857 ha to Open Forests, and 1146 ha to Mangrove Forests. Additionally, 12,135 ha of Open Forests, 8474 ha of Closed Forests, and 2317 ha of Mangrove Forests became Plantations. Across the 40 year study period, a total of 40,523 ha of Closed Forests were transformed to Open Forests. Our findings show that transformation of agricultural landscapes in the study area significantly affected deforestation and forest degradation of tropical evergreen rain forests and mangrove forests which are vital sources of ecosystem services. These transformations led to estimated losses of carbon stocks between 1978 and 2020 ranged from 89,260–5,106,820 Mg (average of 1,723,250 Mg) in our study area. Our findings call for sustainable resource intensification to increase production efficiency in existing cultivated areas rather than crop land expansion into natural forests. In addition, our data highlight the need for rigorous policies to conserve and protect tropical natural evergreen and mangrove forest, as key local resources providing multiple ecosystem services.

Future warming-induced phosphorus loss mitigated by land conversion and degradation

Under the context of global climate change, it is critical to understand future soil organic carbon (SOC) dynamics and the corresponding diffuse phosphorus pollution, and to explore their driving factors to facilitate sustainable soil and water management in agricultural watersheds. With the integrated application of the Denitrification-Decomposition (DNDC) and Soil and Water Assessment Tool (SWAT) models, we simulated the long-term changes in SOC and diffuse phosphorus loss during the 2011–2100 period in Naoli River watershed, which is a typical agricultural watershed in northeastern China. The results showed that approximately 14.71 % of the study area will be converted from natural land (i.e., forest, pasture, and wetland) into agricultural land, and 23.50 % of the uplands will be converted into paddy fields under future climate change conditions. Without additional carbon input, the SOC will decrease at an annual rate of 0.37 % from 24.48 g/kg in 2011 to 17.77 g/kg in 2100, indicating serious land degradation in the future. As a result, watershed diffuse phosphorus loss will increase in the first 40 years (from 2011 to 2050), but show a decreasing trend in the later 50 years (from 2051 to 2100). Overall, watershed diffuse phosphorus loss will decrease from 2.75 kg/ha to 2.24 kg/ha during the 2011–2100 period. According to the scenario comparison, the logarithmic mean Divisia index and structural equation model analysis indicated that climate-induced land-use changes was the dominant factor causing SOC changes and diffuse phosphorus pollution, rather than climate change alone. The expansion of paddy fields could mitigate diffuse phosphorus pollution in the future, and improving agronomic management, such as increasing carbon inputs and integrating water and fertilizer management, are suggested to be adopted to mitigate land degradation by increasing SOC sequestration.

Farmers’ perception and objective validation of the impact of climate change on farming activities in Northeast Thailand

In general, there is a gap between people’s subjective and objective assessment of risk and resilience and objective resilience is larger than a subjective one. The aim of this paper is to analyze farmers’ perception of climate change comparing with objective data. We conducted the questionnaire survey in Khon Kaen Province in Northeast Thailand and clarified the farmers’ profile, agricultural management, and perception of climate change. In addition, comparing to questionnaire result and objective data, we discussed how much the actual farmers’ perception of climate change is different from the objective data. As a result, the farmers perceptions to the rainfall amount in 10 years and trend of objective data were not consistent. This gap suggests that farmers perceived changes in short-term rainfall as climate change rather than changes in long-term rainfall, and that farmers may perceive their production as decreasing due to the increased amount lost due to the expansion of paddy fields into unsuitable areas.

On the Chronology and A Social Communities of the Songguk-ri Settlement in the Korean Bronze Age

청동기시대 후기의 송국리유적은 수전농경민이 거주한 초기 취락이다. 순서배열보충법으로 3개의 획기를 설정하였다. Ⅰ기부터 구릉을 4개소로 분할하여 거주하였는데, 구릉의 계곡부를 메워서 대지를 조성하였다. 아마도 소규모의 수전을 곡저부에 개간하였을 것이다. Ⅱ기에는 각 가족체 혹은 농업공동체 단위로 주 능선상에 대형의 고상건물을 만든 시기이다. 이 고상건물은취락을 관통하듯이 일렬로 배치되며 가옥처럼 짧은 시간동안에만 사용되었다. 수전농경민으로서의 정체성을드러내기 위한 위세적인 기념물이라고 판단된다. Ⅲ기는 수장이 등장하면서 취락은 통합된다. 수전의 확대로 식량의 잉여생산을 이루었으며, 청동기를 생산하고 또 무덤에 부장하였다. 울타리로 구획된 곡물창고 2동과 수전농경의 조상신을 모신 초대형의 사당을 조성하여, 분립된 조상의례를 통합하여 취락 구성원을 결집하고 의례의 주관자로서 수장의 지위를 강화하였다. 묘지는 독립된 구릉 말단부에 입지하며 성인묘 6기와 유아묘 2기가 분포한다. 2열을 이루면서 순차적으로 매장되었고 마지막 Ⅲ기에는 퇴장유물로서 청동기와 옥 등이 매납되었다.Songguk-ri site, in the Late Bronze Age, exemplifies the early form of communities settled by the first paddy-field agricultural tribes in the Korean peninsular. In Period I of Songguk-ri culture when the hill was divided into four for residence, the site was developed by filling up the valley area of the hill. It is assumed that a small scale of paddy fields was cultivated at the lower spot of the valley at this time. Period II is characterized as the time when large raised buildings were constructed on the main ridge of the hill by each family or an agricultural community. These buildings were aligned in a row across the settlement, and each of them was persisting only for one generation like other houses. They are assumed to be built as monumental edifices to express the authority and identity of paddy-field agricultural tribes. In Period III, the settlement was unified by the chiefs who appeared this time. The expansion of paddy fields resulted in surplus productions. Bronzeware began to be produced and buried as grave goods. Two granaries cordoned off by fences and one large shrine for ancestor gods were constructed as the means to unify the hitherto divided communities. The graveyard was located at the end-point of the hill and consisted of six adult graves and two child graves, which had been arranged along the two lines in sequential order. The first grave was a chief’s and buried with bronzeware, jades, and stone blades as grave goods.

Impacts of Saline-Alkali Land Improvement on Regional Climate: Process, Mechanisms, and Implications

Studying land use change and its associated climate effects is important to understand the role of human activities in the regulation of climate systems. By coupling remote sensing measurements with a high-resolution regional climate model, this study evaluated the land surface changes and corresponding climate impact caused by planting rice on saline-alkali land in western Jilin (China). Our results showed that paddy field expansion became the dominant land use change in western Jilin from 2015 to 2019, 25% of which was converted from saline-alkali land; this percentage is expected to increase in the near future. We found that saline-alkali land reclamation to paddy fields significantly increased the leaf area index (LAI), particularly in July and August, whereas it decreased albedo, mainly in May and June. Our simulation results showed that planting rice on saline-alkali land can help decrease the air temperature and increase the relative humidity. The temperature and humidity effects showed different magnitudes during the growing season and were most significant in July and August, followed by September and June. The nonradiative process, rather than the radiative process, played a dominant role in regulating the regional climate in this case, and the biophysical competition between evapotranspiration (ET) and albedo determined the temperature and relative humidity response differences during the growing season.

The spatiotemporal changes of\xa0marshland and the driving forces in the Sanjiang Plain, Northeast China from 1980 to 2016

BackgroundWetland loss is a global concern due to its enormous ecosystem services. Marshland, a typical natural wetland, which is concentrated in the Sanjiang Plain, has undergone dramatic loss in the last several decades. The spatiotemporal changes in marshland were studied based on Landsat images of the Sanjiang Plain from 1980 to 2016 with the land use maps in 1980, 1995, 2000, 2005, 2010, and 2016 using land use dynamic degree and landscape indices. The driving forces of marshland loss, including biophysical factors, socio-economic factors, and land management, were analyzed with boosted regression trees (BRTs) methods.ResultsThe area of marshland loss was 7372 km2, which accounted for 65.7% of the area of marshland in 1980; however, the paddy field area was expanded by 22,313 km2. The lost marshland was mainly converted to dry farmland (47.5%) and paddy field (47.2%) during 1980–2016. Both the landscape pattern of the study area and marshland became increasingly fragmented. The relatively important factors responsible for marshland loss were biophysical factors, socio-economic factors, and land management, which accounted for 65.2%, 25.5%, and 8.4%, respectively. The most important driving forces with high “relative influence” were “distance to river,” which accounted for 20.6% of the total variance explained. The “relative influence” of potential crop yield and ditch density reached 20.2% and 8.4%, respectively.ConclusionSignificant land use changes have occurred in the Sanjiang Plain over the past 37 years, with characteristics of rapid paddy field expansion and drastic marshland loss. Meanwhile, marshland fragmentation continued to increase. Reclamation was the main reason for the large-scale marshland loss. Biophysical factors influenced the decisions regarding the locations of marshland loss. Moreover, climate factors (i.e., average annual precipitation and average annual temperature) also played an important role in marshland loss. These results can provide helpful knowledge for understanding the patterns and reasons for marshland loss and protecting and managing strategies for wetlands restoration.

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

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.

Study of The Potential Expansion of New Rice Fields in Central Maluku District to Support Food Security in Maluku Province

Central Maluku district is one of the priorities region in the development of paddy fields in the province of Maluku. Maluku province was only able to meet the needs of 58% of the rice. Fulfillment needs rice is one of the Government’s efforts in food self-sufficiency. Increased agricultural productivity through the extension of new rice fields became one alternative settlement in fulfilment of rice. The increase in rice production through the expansion of rice fields is still possible. The success of the process of the expansion of paddy fields depend on the expansion of the activities in the rice production. The process of the expansion of rice fields is preceded by feasibility investigation location. Feasibility study of the site was conducted to find out the feasibility of potential land with the observations in the field which is then processed and spatial dianalis in using ArcGIS software. Results of a survey investigating the Central Maluku with the total area of 594.29 ha based on the suitability of the land for the potential expansion of new acres of rice paddies 587.35 ha from 2 (two) subdistricts include North Eastern Seram Subdistrict Kobi m2 170.87 ha and North Seram Subdistrict covering 416.82 ha.

Perubahan Penggunaan Lahan dan Potensi Perluasan Lahan untuk Sawah di Kabupaten Cianjur

Pertumbuhan penduduk, peningkatan pendapatan, dan pesatnya pembangunan menjadikan permasalahan penggunaan lahan semakin kompleks. Lahan berperan sebagai penyedia pangan, namun di sisi lain permintaan lahan di luar sektor pertanian terus meningkat secara signifikan untuk memenuhi kebutuhan penduduk. Kabupaten Cianjur merupakan kabupaten dengan luas sawah terbesar pertama di bagian selatan Provinsi Jawa Barat. Namun, konversi lahan sawah menjadi lahan pertanian lain atau lahan non-pertanian menyebabkan penurunan luas baku sawah. Penelitian yang bertujuan untuk: (1) menganalisis pola perubahan penggunaan dan penutupan lahan, (2) mengevaluasi kesesuaian lahan untuk sawah, dan (3) menganalisis potensi perluasan penggunaan lahan untuk sawah. Pola perubahan penggunaan dan penutupan lahan diidentifikasi menggunakan citra Landsat tahun perekaman 2000 dan 2015 dengan teknik fusi citra. Kesesuaian lahan untuk sawah dianalisis menggunakan metoda faktor pembatas minimum. Potensi perluasan lahan untuk sawah mengacu pada kesesuaian lahan dan alokasi lahan pada Rencana Tata Ruang Wilayah (RTRW). Hasil penelitian menunjukkan bahwa pada periode analisis, lahan sawah paling banyak terkonversi menjadi pemukiman. Lahan di Kabupaten Cianjur memiliki tingkat kesesuaian lahan untuk sawah sesuai (S2) (9.53%), sesuai marjinal (S3) (29.28%) dan tidak sesuai (N) (61.19%). Saat ini, masih tersedia potensi lahan untuk perluasan sawah di Kabupaten Cianjur seluas 148,980 ha.
 Kata kunci: Perubahan penggunaan lahan, prioritas potensi sawah, kesesuaian lahan untuk sawah

Land Surface Temperature Response to Irrigated Paddy Field Expansion: a Case Study of Semi-arid Western Jilin Province, China

The irrigated paddy fields have expanded greatly at semi-arid western Jilin province of China in recent over ten years, the sources of which are rain-fed cornfields, swamp meadow and saline alkali land mainly. Based on regional land use data, remote sensing data and meteorological data, this paper evaluates the land surface temperature changes response to land surface biophysical processes changes resulting from land use change (LUC), and dissociates the effect of radiative change (albedo) and non-radiative change (evapotranspiration and turbulent process) quantitatively using the energy redistribution factor. The results show that, the total land surface temperature changes based on energy redistribution factor are consistent with that based on remote sensing data on the whole, which have significant and different seasonal variations for agriculture adjustment of rain-fed cornfields to irrigated paddy fields and nature land reclamation. Generally, the largest Land surface temperature changes (ΔTs) are most pronounced in May and June for agriculture adjustment of rain-fed cornfields to irrigated paddy fields, which is −1.85 K averagely. Notable decline of albedo from saline alkali land to irrigated paddy fields in April to June greatly counteracts the cooling effect of non-radiative processes changes, while the largest ΔTs is found of −2. 54 K in dry summer months of July and August. For swamp meadows to irrigated paddy fields, non-radiative process is strengthened from June to September, the cooling effect of which is −1.69 K averagely. This study provides a case reference of local temperature change and obvious changes of land surface non-radiative terms at semi-arid area for adjustment of agricultural activities and land use changes.

Variations in ecosystem services in response to paddy expansion in the Sanjiang Plain, Northeast China

ABSTRACT The ecosystem of the Sanjiang Plain in China has dramatically changed in the past four decades. This study investigated the history of paddy field expansion in the Sanjiang Plain and discovered the ecosystem service variations in response to paddy expansion. Integrating a series of Landsat images, we obtained the paddy expansion history from 1976 to 2015. Then, we calculated ecosystem service values (ESVs) to estimate the ecosystem service variations caused by paddy expansion in the Sanjiang Plain. The results indicate that the paddy area increased from 404,789–2,598,449 ha during 1976–2015, leading to a decline in the total ecosystem service values by 11288.04 million dollars. The largest decline in ESVs in response to paddy expansion was caused by wetland reclamation (9998.54 million dollars). Apart from agricultural products and gas regulation functions, the ESVs provided by other functions all showed a declining trend. Paddy expansion in the Sanjiang Plain increased agricultural product function at the expense of the decline of other functions. In future management practices, the rational allocation of water resources and paddy distribution are necessary in order to achieve sustainable development of both water resources and agricultural production. Some suggestions including coculture systems, restoring habitats for aquatic species, farm management that fosters biodiversity in paddy fields are provided for future sustainability.

Impacts of Wetland Reclamation and Paddy Field Expansion on Observed Local Temperature Trends in the Sanjiang Plain of China

AbstractThe warming or cooling effects on regional climate in response to early land use change may be strengthened, weakened, or eliminated by the same or opposite effect in the subsequent land use/management period. Taking the Sanjiang Plain in China as our study area, this paper analyzed the surface temperature change due to land use/land management changes from the mid‐1950s to 2015, based on the land surface temperature response model and the observation minus reanalysis (OMR) method using remote sensing data, meteorological observation data, and reanalysis data. Results revealed a magnitude of monthly mean land surface warming up to 1.31 °C due to the land use change from wetland to rain‐fed farmland and a cooling effect of −1.32 °C caused by the land management change from rain‐fed farmland to paddy fields during the growing season. The trends were confirmed using OMR method. Land surface temperature change based on remote sensing data was divided into radiative and nonradiative forcing. The nonradiative processes play a dominant role in regulating the local surface temperature. The monthly mean temperature differences in response to land use changes differ greatly during the growing season. The temperature difference was greater in May and June (spring) than in July and August (summer). Our study shows that the land use impact on regional climate could be switched dramatically, and it would be basically consistent with the impact of natural wetlands before reclamation in our study area right now, which provides important information for mitigating and adapting to global climate change at regional scale.

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

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, −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.

Assessing environmental impacts and change in Myanmar's mangrove ecosystem service value due to deforestation (2000–2014)

Myanmar is one of the mangrove-richest countries in the world, providing valuable ecosystem services to people. However, due to deforestation driven primarily by agricultural expansion, Myanmar's mangrove forest cover has declined dramatically over the past few decades, while what remains is still under pressure. To support management planning, accurate quantification of mangrove forest cover changes on a national scale is needed. In this study, we quantified Myanmar's mangrove forest cover changes between 2000 and 2014 using remotely sensed data, examined the environmental impacts of such changes, and estimated the changes in the economic values of mangrove ecosystem services in the country. Results indicate that Myanmar had a net mangrove loss of 191,122ha over the study period. Since 2000, Myanmar has been losing mangrove forest cover at an alarming rate of 14,619ha/year (2.2%/year). The loss was predominant in Rakhine and Ayeyarwady. The observed mangrove forest cover loss has resulted in decreased evapotranspiration, carbon stock, and tree cover percentage. Due to deforestation, Myanmar also suffered a net loss of 2,397million US$/year in its mangrove ecosystem service value (i.e. 28.7% decrease from 2000), in which maintenance of fisheries nursery populations and habitat and coastal protection were among those services that were greatly affected. We suggest that intensive reforestation and mangrove protection programs be implemented immediately. Agroforestry and community forestry programs are encouraged in areas that are under immense pressure from paddy field expansion, fuelwood extraction, charcoal production, and fish and shrimp farming activities. Potential alternative sustainable solutions should include intensive government-led private forest plantations or community-owned forest plantations to be developed with care by local farmers, nongovernmental organizations, and business owners.

Study of the potential expansion of new rice fields in Central Maluku District to support food security in Maluku Province

Maluku province is one of the Islands in Indonesia. Seram island is one of the largest islands in the Maluku province lies the Central Maluku Regency. Central Maluku district is one of the priorities regions in the development of paddy fields in the province of Maluku. According to the BPS Maluku province in the year 2015, Government Maluku province was only able to meet the needs of 58% of the rice. Fulfillment needs rice is one of the Government's efforts in food self-sufficiency, it is because of the availability of food is one of the primary needs. Increased agricultural productivity through the extension of new rice fields became one alternative settlement in fulfillment of rice. The increase in rice production through the expansion of rice fields is still possible, because of the potential land is suitable for the expansion of rice fields was still quite spacious. The success of the process of the expansion of paddy fields depend on the expansion of the activities of the mechanism of the rice is done. The process of the expansion of rice fields is preceded by feasibility investigation location. Feasibility study of the site was conducted to find out the feasibility of potential land with the observations in the field which is then processed and spatial dianalis in using ArcGIS software. Results of a survey investigating the Central Maluku district region with a total area of 594.29 achieved ha based on the suitability of the land for the potential expansion of new acres of rice paddies 587.35 ha from 2 (two) subdistricts include North Eastern Seram Subdistrict Kobi m2 170.87 ha and North Seram Subdistrict covering 416.82 ha. Keywords: The Expansion Of New Rice Fields, Agricultural Land Suitability Evaluation, Islands

Paddy Field Expansion and Aggregation Since the Mid-1950s in a Cold Region and Its Possible Causes

Over the last six decades, paddy fields on the Sanjiang Plain have experienced rapid expansion and aggregation. In our study, land use and land cover changes related to paddy fields were studied based on information acquired from topographic maps and remote-sensing images. Paddy field expansion and aggregation were investigated through landscape indices and trajectory codes. Furthermore, the possible causes of paddy field expansion and aggregation were explored. Results indicated that such fields have increased by approximately 42,704 ha·y−1 over the past six decades. Approximately 98% of paddy fields in 2015 were converted from other land use types. In general, the gravity center moved 254.51 km toward the northeast, at a rate of approximately 4.17 km·y−1. The cohesion index increased from 96.8208 in 1954 to 99.5656 in 2015, and the aggregation index grew from 91.3533 in 1954 to 93.4448 in 2015, indicating the apparent aggregation of paddy fields on the Sanjiang Plain. Trajectory analyses showed that the transformations from marsh as well as from grassland to dry farmland and then into paddy fields were predominant. Climate warming provided a favorable environment for rice planting. Meanwhile, population growth, technological progress, and government policies drove paddy field expansion and aggregation during the study period.