scholarly journals Distribution Pattern of Soil Organic Carbon and Its Regional Humification Constant in the Coastal Monsoon Region of Eastern China

Author(s):  
Shutian Liu ◽  
Xiansheng Xie ◽  
Xiaochuan Wang ◽  
Xinxin Feng ◽  
Xianda Hou ◽  
...  

Abstract Soils are an important pool for storing organic carbon. Soil organic carbon (SOC) content is generally considered as an important indicator to evaluate farmland soil quality. The loss of SOC causes soil degradation and reduces the sustainability of farmland. In order to reveal the distribution pattern of SOC in the coastal monsoon area of eastern China, and to clarify the macro dominant factors of SOC accumulation caused by temperature and precipitation, this paper analyzed the distribution pattern of SOC in the coastal monsoon area of eastern China by using the SOC data collected from the national soil testing and formula fertilization data set, and discussed the effects of temperature and precipitation on SOC content. According to the provincial administrative divisions, the distribution of SOC in the coastal monsoon areas of eastern China from Heilongjiang Province to Hainan Province was calculated. According to the annual average temperature < 10.18℃, 10.18 ℃ ~ 20.95℃, > 20.95℃, annual average precipitation 0 ~ 400 mm, 400 ~ 800 mm, > 800 mm, the study area was divided into different regions, and the effects of annual average temperature and annual average precipitation on SOC content were studied. In the region with annual average temperature less than 10.18℃, the temperature had a negative correlation with the accumulation of organic carbon, and the ratio of precipitation and temperature had a positive correlation with the accumulation of SOC; In the region of 10.18℃~20.95℃, the annual average temperature and annual average precipitation had a significant positive correlation, and the ratio of precipitation and temperature had a positive correlation with the accumulation of SOC; In the region > 20.95℃, the temperature had a negative correlation with the accumulation of organic carbon, and the ratio of precipitation and temperature was not related to the accumulation of SOC. In the range of 0 ~ 400 mm of annual average precipitation, the temperature had a positive correlation with the accumulation of SOC, and the ratio of precipitation and temperature had a negative correlation with the accumulation of SOC; In the range of 400 ~ 800 mm of annual average precipitation, the temperature had a negative correlation with the accumulation of SOC, and the ratio of precipitation and temperature had a positive correlation with the accumulation of SOC; In the region > 800 mm of annual average precipitation, the temperature had a positive correlation with the accumulation of organic carbon before the annual average temperature of 20.95℃, and after the annual average temperature of 20.95℃, the temperature had a negative correlation with the accumulation of organic carbon, and the ratio of precipitation and temperature had no significant effect on the accumulation of SOC. On the macro scale, the annual average temperature and precipitation had significant effects on the distribution pattern of SOC in the coastal monsoon area of eastern China. According to the influence of annual average temperature and annual average precipitation on SOC accumulation, a comprehensive model based on the annual average temperature and annual average precipitation on SOC accumulation is established. Through regression verification of the model, the correlation coefficient, r = 0.9998**, the cubic curve equation could better simulated the relationship between the predicted value and the real value of SOC, r = 0.7048**,the model can reflect the cumulative effect of annual average temperature and annual average precipitation on SOC accumulation Combined with the impact.

2019 ◽  
Vol 1 ◽  
pp. 1-3
Author(s):  
Yuzhu Wang ◽  
Haowen Yan ◽  
Xiaoping Wang ◽  
Zhuo Wang

<p><strong>Abstract.</strong> Research purpose: To master the spatial-temporal evolution of precipitation and temperature in Xinjiang, and to provide reference for industrial, agricultural and transportation industries in the study area. Date and Rrsearch methods: Based on monthly precipitation and temperature data of 64 weather stations in Xinjiang in recent 50 years,the spatial-temporal variation of precipitation and temperature were analyzed by the methods of simple linear regression, 5-year moving average, radial basis function interpolation, sliding -t test, accumulated variance analysis, Mann-Kendall and morlet wavelet transform.</p><p>Research conclusion:</p><p>(1) The annual average precipitation (8.65&amp;thinsp;mm/10&amp;thinsp;a) in Xinjiang showed a significant increasing trend, and the increasing trend in local areas was:Northern Xinjiang (14.83&amp;thinsp;mm/10&amp;thinsp;a) &amp;gt; Southern Xinjiang(7.76&amp;thinsp;mm/10&amp;thinsp;a) &amp;gt; Eastern Xinjiang (3.37&amp;thinsp;mm/10&amp;thinsp;a).</p><p>(2) The spatial distribution of tendency rate of annual precipitation is basically the same as the spring, summer and autumn in Xinjiang, the tendency rate decreases from northwest to southeast, but the tendency rate of winter precipitation decreases from north to south.</p><p>(3) The precipitation of Xinjiang changed abruptly in 1989, Southern Xinjiang was relatively earlier (1986), Northern Xinjiang (1991) and Eastern Xinjiang (1990) were relatively delay.</p><p>(4) The main cycle of precipitation was 26&amp;ndash;30&amp;thinsp;a in Xinjiang and local areas, which predicts that the next 10 years will be a wet season.</p><p>(5) The annual average temperature (0.44&amp;thinsp;°C / 10&amp;thinsp;a) in Xinjiang is very significant, and the temperature increase trend in local areas is: Eastern Xinjiang (0.58&amp;thinsp;°C / 10&amp;thinsp;a) &amp;gt; Northern Xinjiang (0.45&amp;thinsp;°C / 10&amp;thinsp;a) &amp;gt; Southern Xinjiang (0.31&amp;thinsp;°C / 10&amp;thinsp;a).</p><p>(6) The spatial distribution of tendency rate of annual average temperature is basically the same as the four seasons in Xinjiang, and the tendency rate showed a decreasing trend from northeast to southwest.</p><p>(7) The temperature change of Xinjiang occurred in 1988,Northern Xinjiang was 1988 (relatively earlier), Southern Xinjiang and Eastern Xinjiang were 1992 (relatively delay).</p><p>(8) The main cycle of temperature in Xinjiang and local areas was 25&amp;ndash;30&amp;thinsp;a. It was predicted that the next 10 years would be high temperature period.</p>


2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Lin ◽  
Jingying Fu ◽  
Dong Jiang ◽  
Jianhua Wang ◽  
Qiao Wang ◽  
...  

Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5dataset, this paper explores the relationship between PM2.5concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5had a strong and stable correlation with meteorological parameters. In particular, PM2.5had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010.


2012 ◽  
Vol 616-618 ◽  
pp. 1496-1499
Author(s):  
Guo Wei Xu ◽  
Xin Tian Yuan ◽  
Shu Ling Huang ◽  
Yang Gao

Selecting 50 years temperature observation data from1959 to 2008 and using statistical analysis, this paper revealed the characteristics of temperature variation in Hefei city. The results show that in past 50 years, the annual average temperature in Hefei city greatly increased, tendency rate of temperature change was 0.246°C/10 a, especially after 1993, the temperature increased significantly; the temperature in four seasons all increased somewhat, warming was most prominent in spring. The most significant temperature increase was in spring, winter following behind, temperature increase in autumn was not obvious, and the average summer temperature increased the most unobvious.


2015 ◽  
Vol 9 (2) ◽  
pp. 2367-2395 ◽  
Author(s):  
S. Yang ◽  
Y. Shi

Abstract. Ice caves exist in locations where annual average temperature in higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively explain the mechanism of formation and preservation of the ice cave, we use Finite Element Method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside, very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice–water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, etc. for sustainable development of ice cave as tourism resource. In some other ice caves in China, managers installed air-tight doors at these ice caves entrance intending to "protect" these caves, but this prevent cooling down these caves in winters and these cave ices will entirely melt within tens of years.


2011 ◽  
Vol 137 ◽  
pp. 286-290 ◽  
Author(s):  
Xi Chun ◽  
Mei Jie Zhang ◽  
Mei Ping Liu

The objective of this study is to analyse the climate changing patterns chronologically for exposing the coincident relationships between the lake area fluctuation and the climate change in Qehan lake of Abaga county of Inner Mongolia. The results show that there’s highly interrelation between the changes of the lake area and the climatic factors here, the annual average temperature and annual evaporation are negatively interrelate to the lake area fluctuation, and the annual precipitation interrelate to it is positive. The lake area has descended about 75 km2 during the nearly past 40 years. There were about two considerable lake expansions in 1973, 1998 through the generally lake area descending process.


2018 ◽  
Vol 36 (2) ◽  
pp. 555-564 ◽  
Author(s):  
Everton Frigo ◽  
Francesco Antonelli ◽  
Djeniffer S. S. da Silva ◽  
Pedro C. M. Lima ◽  
Igor I. G. Pacca ◽  
...  

Abstract. Quasi-periodic variations in solar activity and galactic cosmic rays (GCRs) on decadal and bidecadal timescales have been suggested as a climate forcing mechanism for many regions on Earth. One of these regions is southern Brazil, where the lowest values during the last century were observed for the total geomagnetic field intensity at the Earth's surface. These low values are due to the passage of the center of the South Atlantic Magnetic Anomaly (SAMA), which crosses the Brazilian territory from east to west following a latitude of ∼ 26∘. In areas with low geomagnetic intensity, such as the SAMA, the incidence of GCRs is increased. Consequently, possible climatic effects related to the GCRs tend to be maximized in this region. In this work, we investigate the relationship between the ∼ 11-year and ∼ 22-year cycles that are related to solar activity and GCRs and the annual average temperature recorded between 1936 and 2014 at two weather stations, both located near a latitude of 26∘ S but at different longitudes. The first of these stations (Torres – TOR) is located in the coastal region, and the other (Iraí – IRA) is located in the interior, around 450 km from the Atlantic Ocean. Sunspot data and the solar modulation potential for cosmic rays were used as proxies for the solar activity and the GCRs, respectively. Our investigation of the influence of decadal and bidecadal cycles in temperature data was carried out using the wavelet transform coherence (WTC) spectrum. The results indicate that periodicities of 11 years may have continuously modulated the climate at TOR via a nonlinear mechanism, while at IRA, the effects of this 11-year modulation period were intermittent. Four temperature maxima, separated by around 20 years, were detected in the same years at both weather stations. These temperature maxima are almost coincident with the maxima of the odd solar cycles. Furthermore, these maxima occur after transitions from even to odd solar cycles, that is, after some years of intense GCR flux. The obtained results offer indirect mathematical evidence that solar activity and GCR variations contributed to climatic changes in southern Brazil during the last century. A comparison of the results obtained for the two weather stations indicates that the SAMA also contributes indirectly to these temperature variations. The contribution of other mechanisms also related to solar activity cannot be excluded. Keywords. Meteorology and atmospheric dynamics (climatology)


Author(s):  
Seonghee Kho ◽  
Jayoung Ki ◽  
Myoungcheol Kang

Since around 70°C of geothermal water exists in Seokmo-do of Republic of Korea, this study is to assess the feasibility of electricity generation by utilizing ORC system, and the pertinent economic impact. It is generally believed that economic feasibility can be secured only when the source of geothermal water is above 100°C in order to generate electricity by operating ORC system. However, there was an exceptional case that ORC system was commercialized by Pratt-Whitney for around 70 °C of geothermal water in the hot springs of Chena, Alaska. The annual average temperature in the hot springs of Chena, Alaska is approximately 1°C whereas that of Seokmo-do is around 11°C, which makes 10°C of annual average temperature difference in operational environment between the two. Thus, the 2 phases of absorption refrigerating machine is considered for the ORC generation system. With establishing ORC system in consideration of operational environment, the feasibility of the development of ORC system in Seokmo-do is assessed by performance analysis and economic feasibility. As a result of the assessment, it is identified that the economic feasibility can be secured if the price of electricity is over $0.42/kWh same as that of photovoltaic generation as an incentive of the RPS program granted by the Korean government.


2020 ◽  
Vol 28 ◽  
pp. 157-165
Author(s):  
Karine Rabelo Oliveira ◽  
Williams Pinto Marques Ferreira ◽  
Humberto Paiva Fonseca ◽  
Cecília Fátima Souza

Coffee is among the most significant products in Brazil. Minas Gerais is the largest state producer of Arabica coffee. Coffee activity has excellent growth potential, which justifies the identification of new areas for expansion of the culture. This study aimed to determine factors that affect the spatial distribution of coffee plantations the most, as well as to identify areas with a greater aptitude for its expansion in the region of the Matas de Minas (63 municipalities). The MaxEnt software was used to elaborate a model capable of describing the area with the highest potential for estimating the probability of coffee adequacy. The elaboration of the model considered the records of occurrence, climatic and topographic variables of Matas de Minas, the second largest state producing region. The area under the curve (AUC), the omission rate and the Jackknife test were used for validation and analysis of the model. The model was accurate with an AUC of 0.816 and omission rate of 0.54% for the ‘test’. It was identified that the potential distribution of coffee in Matas de Minas is determined by changes in the annual maximum temperature, although it did not generate a significant gain when omitted, accounting for a considerable loss in the model. However, the most influential variables on the delineation of distribution were, the altitude and the annual average temperature. The most favorable areas for expansion of coffee culture in the Matas de Minas were found in the vicinity of the region of Alto Caparaó.Abbreviations used: A1 (altitude); A2 (maximum annual temperature); A3 (annual minimum temperature); BIO 1 (annual average temperature 1); BIO 4 (temperature seasonality), BIO 12 (annual precipitation); BIO 15 (precipitation seasonality); csv (comma-separated values); AUC (area under the curve).


2007 ◽  
Vol 32 ◽  
pp. 161-200 ◽  
Author(s):  
Manuel Becerra Parra ◽  
Estrella Robles Domínguez

RESUMEN. Catálogo florístico del macizo de Líbar (Parques Naturales Sierra de Grazalema y losAlconocales, Málaga-Cádiz, España). El Macizo de Líbar es uno de los conjuntos montañosos másimportantes de la Serranía de Ronda y Andalucía Occidental. Su principal característica orográficaes la presencia de dos alineaciones montañosas que encierran una gran depresión intramontañosadenominada genéricamente los Llanos de Líbar. La vegetación dominante en los terrenos de naturalezacaliza la constituye el encinar, mientras que el alcornocal lo es de aquellas zonas donde afloran lasareniscas del Aljibe. A estas formaciones vegetales se suman otras como los quejigales, acebuchales,algarrobales, fresnedas, olmedas, adelfares y diversas formaciones de matorral. La climatología quedamarcada por ser una de las zonas con mayor precipitación de la Península Ibérica y por unastemperaturas bastante suaves durante todo el año, aunque en las zonas más altas la media anual seaproxima a los 10 ºC. Para llevar a cabo el estudio florístico del Macizo de Líbar se han realizadorecolecciones durante cinco años, en las que se ha pretendido herborizar la mayor parte del macizo,además de una revisión bibliográfica y consultas de los pliegos depositados en herbarios. El catálogoflorístico del Macizo de Líbar está formado por 826 taxones. De estos, 128 son endemismos, repartidosen endemismos ibéricos, ibero-mauritanos, bético, béticos-mauritanos, y rondeños. Son endemismosRondeños Linaria platycalyx, Reseda gayana subsp. undata, Saxifraga bourgeana, entre otros. Treceespecies están protegidas según la Ley de Flora y Fauna Silvestres de Andalucía y 32 taxones estánincluidos en la lista Roja de la Flora Vascular de Andalucía.Palabras claves. Flora, Catálogo, Macizo de Líbar, Sierra de Grazalema, Los Alcornocales, Málaga,Cádiz.ABSTRACT. Floristic catalogue of the Macizo of Libar (Natural Parks of Sierra de Grazalema andLos Alcornocales. Malaga-Cadiz, Spain). The Mountain of Líbar is one of the most important rangesof the mountainous area of Ronda and Western Andalusia. Its main orographic characteristic is thepresence of two mountainous alignments that delimit a great intramountainous depression denominatedLlanos de Líbar. The Quercus rotundifolia wood is the main vegetation in limestone lands, whereasthe Q. suber forest is dominant in sandstone zones. Other plants communities present in this area aredominated by Q. faginea, Olea europaea, Ceratonia siliqua, Fraxinus angustifolia, Ulmus minor,Nerium oleander and other shrublands. This is one of the zones with highest rainfall in the IberianPeninsula and with mild temperatures, although in the summits, the annual average temperature, decreases near 10 ºC. In order to carry out the botanical study, samplings have been made during fiveyears, in addition to a bibliographical revision and review of biodiversity databases. The botanicalcatalogue of Líbar is composed by 826 species, 128 are endemic species with different distributionarea. Linaria platycalyx, Reseda gayana subsp. undata or Saxifraga bourgeana are endemic from thearea of Ronda. 13 species are protected according to the Law of Wild Flora and Fauna of Andalusiaand 32 species are included in the plants Red List of Andalusia.Key words. Flora, Catalogue, Macizo de Líbar, Sierra de Grazalema, Los Alcornocales, Málaga,Cádiz.


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