Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other h...Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.展开更多
An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal d...An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal distribution of NPP along NECT and its response to climatic change were also analyzed. Results showed that the change tendency of NPP spatial distribution in NECT is quite similar to that of precipitation and their spatial correlation coefficient is up to 0.84 (P 〈 0.01). The inter-annual variation of NPP in NECT is mainly affected by the change of the aestival NPP every year, which accounts for 67.6% of the inter-annual increase in NPP and their spatial correlation coefficient is 0.95 (P 〈 0.01). The NPP in NECT is mainly cumulated between May and September, which accounts for 89.8% of the annual NPP. The NPP in summer (June to August) accounts for 65.9% of the annual NPP and is the lowest in winter. Recent climate changes have enhanced plant growth in NECT. The mean NPP increased 14.3% from 1980s to 1990s. The inter-annual linear trend of NPP is 4.6 gC·m^-2·a^-1, and the relative trend is 1.17%, which owns mainly to the increasing temperature.展开更多
The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta re...The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling.展开更多
This paper has studied the change of streamflow and the impact of climatic variability conditions on regional hydrological cycle in the headwater of the Tarim River Basin. This study investigates possible causes of ob...This paper has studied the change of streamflow and the impact of climatic variability conditions on regional hydrological cycle in the headwater of the Tarim River Basin. This study investigates possible causes of observed trends in streamflow in an environment which is highly variable in terms of atmospheric conditions, and where snow and ice melt play an important role in the natural hydrological regime. The discharge trends of three head streams have a significant increase trend from 1957 to 2002 with the Mann-Kendall test. Complex time-frequency distributions in the streamflow regime are demonstrated especially by Morlet wavelet analysis over 40 years. The purpose is to ascertain the nature of climatic factors spatial and temporal distribution, involved the use of EOF (Empirical Orthogonal Function) to compare the dominant temperature, precipitation and evaporation patterns from normally climatic records over the Tarim's headwater basin. It shows that the first principal component was dominated since the 1990s for temperature and precipitation, which identifies the significant ascending trend of spatial and temporal pattern characteristics under the condition of the global warming. An exponential correlation is highlighted between surface air temperature and mean river discharge monthly, so the regional runoff increases by 10%-16% when surface air temperature rises by 1 ℃. Results suggest that headwater basins are the most vulnerable environments from the point of view of climate change, because their watershed properties promote runoff feeding by glacier and snow melt water and their fundamental vulnerability to temperature changes affects rainfall, snowfall, and glacier and ice melt.展开更多
The characteristics of climatic change and fiver runoff, as well as the response of fiver runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over t...The characteristics of climatic change and fiver runoff, as well as the response of fiver runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over the last 50 years by the methods of Mann-Kendall nonparametric test and the nonlinear regression model. The results show that: 1) The temperature and the precipitation increased significantly in the whole northern Xinjiang, but the precipitation displayed no obvious change, or even a decreasing trend in the northern mountainous area of the northern Xinjiang. 2) River runoff varied in different regions in the northern Xinjiang. It significantly increased in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang (p = 0.05), while slightly ificreased in the west of the northern Xinjiang. 3) North Atlantic Oscillation (NAO) affects fiver runoff by influencing temperature and precipitation. The NAO and precipitation had apparent significant correlations with the fiver runoff, but the temperature did not in the northern Xinjiang. Since the mid-1990s fiver runoff increase was mainly caused by the increasing temperature in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang. Increased precipitation resulted in increased fiver runoff in the west of the northern Xinjiang.展开更多
According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between t...According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between them and their implication of rapid climatic change. The marine records show its good response to the high latitudes both for cold events and for warm ones while the continental records mainly mirror those cold Heinrich events corresponding to the North Atlantic but bear strongly a local color in reflecting warm events. The authors assume that the heat transmission style may cause the unbalanced coupling relationship.展开更多
Variation characteristics of temperature and precipitation in January and July and annual mean temperature and annual precipitation are analyzed with the help of cumulative anomalies, Mann-Kendall analysis and wavelet...Variation characteristics of temperature and precipitation in January and July and annual mean temperature and annual precipitation are analyzed with the help of cumulative anomalies, Mann-Kendall analysis and wavelet analysis. The research results indicate that January precipitation presents an increasing trend after 1990, wavelet analysis result suggests that this increasing trend will continue in the near future. The changes of July precipitation present different features. During 1900-1960, July precipitation is in a rising trend, but is in a declining trend after 1960. Wavelet analysis shows that this declining trend will go on in the near future. Temperature variations in Shanghai are in fluctuations with 2 to 3 temperature rising periods. Mann-Kendall analysis indicates that temperature variations have the obvious abrupt change time when compared with precipitation changes in Shanghai during the past 100 years. The abrupt change time of January temperature lies in 1985, and that of July temperature lies in 1931-1933 and annual mean temperature has the abrupt change time in 1923-1930. Except July precipitation, the precipitation in January, temperature in January, July and annual mean temperature, and annual precipitation are also in a rising trend in the near future. The research results in this paper may be meaningful for future further climatic changes of Shanghai and social mitigation of climatic disasters in the future.展开更多
Robust climate warming has led to significant expansion of lakes in the central Tibetan Plateau. Using remote sensing data, our quantitative analysis indicates that Siling Co, a saline lake in a characteristic endorhe...Robust climate warming has led to significant expansion of lakes in the central Tibetan Plateau. Using remote sensing data, our quantitative analysis indicates that Siling Co, a saline lake in a characteristic endorheic basin in the central region of the Plateau, has expanded more than 600 km2 in area since 1976. Particularly since 1995, the lake has signif- icantly expanded in response to increasing precipitation, decreasing water surface evaporation caused by weaker winds and less solar radiation, and increased glacier meltwater draining to the lake. Glacie^lake interactions are important in governing lake expansion and are also part of a feedback loop that influences the local climate. Worsening climatic conditions (decreased precipitation and increased temperatures) that could have caused the lake to shrink during 1976-1994 were offset by increasing glacier meltwater feeding the lake, which made the lake nearly stable. We demonstrate that this pattern changed during 1995-2009, when glacier meltwater actually decreased but participation runoff increased and evaporation decreased, leading to expansion of the lake. If climatic conditions became suitable for further lake development, which would be indicated by expansion in lake area, glacier meltwater could be saved in a stable reservoir.展开更多
Based on investigations of the Zhongwei Nanshan aeolian section situated in the southeastern margin of Tengger Desert, carbon-14 and TL (thermoluminescence) dating results and paleoclimatic proxies such as magnetic su...Based on investigations of the Zhongwei Nanshan aeolian section situated in the southeastern margin of Tengger Desert, carbon-14 and TL (thermoluminescence) dating results and paleoclimatic proxies such as magnetic susceptibility and grain size, we inferred that the northwestern margin of East Asian monsoon region experienced abrupt climatic changes during the last deglaciation. Six oscillation events were identified: Oldest Dryas, Bolling, Older Dryas, Allerod, Intra-Allerod Cold Period (IACP) and Younger Dryas (YD). The summer monsoon was weaker during Oldest Dryas and Younger Dryas when the winter monsoon was stronger. However, during the B/A (Bolling/Allerod) period, the summer monsoon strengthened, reflected by magnetic susceptibility, when the winter monsoon also became strong, which is different from the paleoclimatic pattern established in the East Asian monsoon region. Furthermore, the summer monsoon was nearly in phase with the climate changes inferred from the oxygen isotopic records of Greenland ice cores. It could be speculated that the variations of the sea ice cover in the high latitudes of the North Hemisphere affected the high pressure of Asian continent and the changes of the winter monsoon inland. On the other hand, the sea ice cover variations might have indirectly caused the occurrence of ENSO events that has tightly been related to the summer monsoon in northwest margin of East Asian monsoon region.展开更多
A number of studies indicate that global climate warming has been increasing, especially in recent decades. Climate warming greatly affects global agro-production and food security-- becoming a hotspot of global envir...A number of studies indicate that global climate warming has been increasing, especially in recent decades. Climate warming greatly affects global agro-production and food security-- becoming a hotspot of global environmental change. This paper proposes a structural and orientational framework for scientifically addressing climatic change impact on agroroduction. Through literature reviews and comparative studies, the paper systematically summarizes influencing mechanisms and impact of climate warming on such agro-production factors as light, temperature, soil quality and water environment. The impact of climate warm- ing on cultivation regions, cropping systems, crop pests, agro- production capacity, agro-economy and farm management is analyzed. Then, suitable climate-adapting agro-development strategies are put forward for different regions in China. The strategies are carefully selected from a repository of international tested climatic change countermeasures in agriculture at national or district level.展开更多
The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air te...The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air temperatureand decreased by 5% in annual precipitation over 1951-1990. Regionally, temperature change has varied from acooling of 0.3℃ in Southwest China to a'warming of 1 .0℃ in Northeast China. With the exception of South China,all regions of China have shown a declination in precipitation. Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation. Under doubled CO2 concentration,climatic change in China will tend to be warmer and moister, with increases of 4.5℃ in annual mean air temperatureand 11% in annual precipitation on the national scale. Future climatic change will reduce the temporal and spatialdifferences of climatic factors.展开更多
Through analyzing statistically metrological observation data from 1971 to 2010 and pasture data from 1983 to 2012 at 6 animal husbandry meteorological testing stations of Inner Mongolia grassland, the conclusions wer...Through analyzing statistically metrological observation data from 1971 to 2010 and pasture data from 1983 to 2012 at 6 animal husbandry meteorological testing stations of Inner Mongolia grassland, the conclusions were drawn. Those were that annual average temperature rose in a straight line in Inner Mongolia grassland, and the increase rates of annual average temperature in meadow steppe and typical steppe were 0.40 and 0.34 ℃/10 a respectively. Annual rainfall had 10-year cyclical characteristics, and precipitation in the 1990s was the most but reduced significantly after 2000. Climate experienced the cold wet -cold dry -warm wet -warm dry periods. Warm and dry climate made the average heights of pasture in meadow steppe and typical steppe of Inner Mongolia cut down 2.4 and 9.3 cm in nearly 12 years than that in the 1990s; the average coverage of herbage decreased by 11% and 13%; the average hay yields reduced by 1 019.8 and 671.4 kg/hm^2.展开更多
The world is facing a big challenge of climatic change, mainly due to increasing concentrations of GHGs (greenhouse gases) in the atmosphere. Many researches indicated that the climate change occurred disproportiona...The world is facing a big challenge of climatic change, mainly due to increasing concentrations of GHGs (greenhouse gases) in the atmosphere. Many researches indicated that the climate change occurred disproportionately on developing countries such as MENA (Middle East and North Africa) countries. The climatic model CGCM3.1 (T47) 2 is used in this research to explain the changes in average temperatures and the rainfall on the MENA region with special emphases on Iraq. Historical records (1900-2009) and future (2020-2099) were studied and compared; each period was divided to four sub-periods of thirty years. The results showed that the average monthly temperature for the four historical periods fluctuated between the lowest and highest value as follows: 9.2-32.9, 10.3-32.7, 9.3-32.8 and 8.6-33.9 (℃). The rainfall for historical periods kept on the same distribution during the past 109 years, and fluctuated between the lowest and highest value of 21.3 mm and 37.6 mm with an average that reached up to 26.51 mm. For the future period, the maximum average monthly temperature reached up to 37.41 (℃) during June and minimum average monthly temperature reached up to 4.24 (℃) during January. The average monthly temperature fluctuated giving a clear impression that the future portends a higher temperature. The average monthly rainfall, for the future period, fluctuated between the lowest and highest value of 12.91 mm and 20.63 mm with an average that reached 16.84 mm which represent a reduction percentage of about 36.47% relative to the historical record of rainfall for the sanae months.展开更多
[ Objective] The research aimed to establish SWAT distributed hydrologic model and analyze influence of the climatic change on runoff in Beijiang River basin. [ Method] Beijiang River basin as research object, SWAT mo...[ Objective] The research aimed to establish SWAT distributed hydrologic model and analyze influence of the climatic change on runoff in Beijiang River basin. [ Method] Beijiang River basin as research object, SWAT model was used to simulate runoff in basin. Monthly water flow in Shijiao station from 1961 to 1980 was used to determine model parameter, while monthly water flow from 1981 to 1990 was used to verify. Setting 15 kinds of climate change scenarios, SWAT model was used to simulate influence of the future climatic change on runoff in Beijiang River basin. [Result] Simulated accuracy of the SWAT model was high, and it could be used to simulate runoff in Beijiang River basin. Under the situation of in- variable rainfall, temperature rise made that evaporation capacity increased, and runoff depth decreased. When temperature unchanged, rainfall increase made that evaporation capacity and runoff depth increased somewhat. [ Conclusion] The research could provide reference basis for water re- source management in Beijiang River basin.展开更多
The opening and many years of research of magnetic spinor particles (real magnetic charges) in atoms and substance have enabled the author to formulate the conception of the Physical Triad, according which the real Wo...The opening and many years of research of magnetic spinor particles (real magnetic charges) in atoms and substance have enabled the author to formulate the conception of the Physical Triad, according which the real World consists of three fundamental phases: Matter, Antimatter and Energo-phase (Energo-medium). Particles of Matter are called spinors and particles of Antimatter are called antispinors. Energo-medium is a gasiform phase of high density that fills by himself all the infinite space of the real World. It consists of spinless and massless particles-energions. Spinor fields can be both flows energions (fields of Matter), so and anti-flow energions (fields of Antimatter). Atomic-shaped structures consisting of electric and magnetic spinor particles represent a Physical Mass (atoms, nucleons, etc.). The main characteristic of all varieties of Mass is its ability radiate gravitational field, which is a vortex electromagnetic field. All spinor particles are massless so as individually generate a gravitational field they can’t. All primary forces in the real World are implemented by means of Energo-medium, i.e. contact pressure its particles—energions. The spinor fields, including the gravitational field, myself the real of the power significance, have not. They are only intermediaries, inducing in Energo-medium its active (power) education, which is called “Dark Energy”. “Dark Energy” can be both positive, so and negative. Namely, a positive “Dark Energy”, which is associated with the technical activity of man, is responsible for stable climatic changes on Earth. Greenhouse gases are not the main “culprit” of climatic changes on our planet. However, these gases are the simplest indicator of the overall level of irreversible physical processes that stimulate the growth of the positive “Dark Energy” and are responsible for the negative thermal scenario on Earth.展开更多
Climatic change and urbanization effect in China during the last 39 years were investigated. It is found that a warming of about 0.23℃ for the annual temperature has been noticed from 1951 to 1989. The warmings of ab...Climatic change and urbanization effect in China during the last 39 years were investigated. It is found that a warming of about 0.23℃ for the annual temperature has been noticed from 1951 to 1989. The warmings of about 0.78 ℃ in winter and 0.34 3℃ in spring have been shown. It is also presented that a cooling of about -0.27℃ in summer has been indicated. The bigger cities are warmer than smaller cities in China. The dried trends in the annual precipitation during the last 39 years were presented. The precipitation decreased obviously in summer all over China. The bigger cities were drier than smaller cities.展开更多
Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated resul...Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in China .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2-5℃ in summer in China as simulated by the GCMs induced by doubling CO2 have been found. There are getting drier or wetter regions in China due to doubled CO2 as simulated by most of models. Comparing the simulated results with the observed data in China, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.展开更多
The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface env...The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface environments were analyzed.The impact indices of climatic factors,along with their corresponding ranks,were used to characterize the responses of different types of surface environments to climate change.Results show that in the past 20 years,the surface environments of the study area have been deteriorating.Furthermore,there is a positive relationship between the changes in surface environments and those in climatic factors.Various climatic factors influence surface environments in different ways and at different levels.The most sensitive factor is relative humidity,followed by precipitation and evaporation.Overall,moisture is the key factor that affects the changes in surface environments of arid and semi-arid areas.展开更多
The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced...The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced about 44 Ma in the polar re- gions as the seas cooled following the loss of the circum-equatorial ocean. Before then, a mega warm period lasted for more than 200 Ma. The frequency of the major cold events within the present mega cold period is increasing, with each continent being un- der the influence of a different set of climatic controls. There are many causes of these shifts in climate, ranging from fluctuating meridional ocean currents, rearrangement of tectonic plates, and changes in ocean gateways. These are enhanced by a combination of Milankovitch cycles and many other medium to small oscillations and cyclic controls that cause the daily, monthly, and season- al fluctuations in weather. Examples are given of how these can cause a change from cold to warm events, or vice versa, at pre- sent-day or mega scales, aided by eustatic changes in sea levels and changes in the distribution of air masses, sea ice, and snow.展开更多
The acronym C6 means "Climatic Changes and Carbon Cycle in Canyons and Caves". It is a monitoring project, for the evaluation of climate change signals, based on measuring sites located inside canyons and caves; it ...The acronym C6 means "Climatic Changes and Carbon Cycle in Canyons and Caves". It is a monitoring project, for the evaluation of climate change signals, based on measuring sites located inside canyons and caves; it merged in the year 2005, under the scientific supervision of the Palermo Branch of the Italian National Institute for Geophysics and Volcanology (INGV), two different monitoring programs active since 1999. The choice of these environments is based on their morphological structure: being them more or less segregated respect the outer atmosphere, they act as low-pass filters respect the variations of the monitored parameters, which are rainfall and dropping water amounts and rates, air temperatures and relative humidity and carbon dioxide concentrations in the atmosphere. On the basis of the preliminary data, reported and discussed in the paper, the C6 network seems to be capable to give useful information on the local effects of global changes, even if at the moment the monitored parameters concern only the abiotic components of the studied ecosystems.展开更多
文摘Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.
基金This paper was supported by the National Natural Sci-ence Foundation of China (Grant No. 40371001) and the Youth Foundation of Beijing Normal University
文摘An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal distribution of NPP along NECT and its response to climatic change were also analyzed. Results showed that the change tendency of NPP spatial distribution in NECT is quite similar to that of precipitation and their spatial correlation coefficient is up to 0.84 (P 〈 0.01). The inter-annual variation of NPP in NECT is mainly affected by the change of the aestival NPP every year, which accounts for 67.6% of the inter-annual increase in NPP and their spatial correlation coefficient is 0.95 (P 〈 0.01). The NPP in NECT is mainly cumulated between May and September, which accounts for 89.8% of the annual NPP. The NPP in summer (June to August) accounts for 65.9% of the annual NPP and is the lowest in winter. Recent climate changes have enhanced plant growth in NECT. The mean NPP increased 14.3% from 1980s to 1990s. The inter-annual linear trend of NPP is 4.6 gC·m^-2·a^-1, and the relative trend is 1.17%, which owns mainly to the increasing temperature.
文摘The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling.
基金Foundation: National Natural Science Foundation for Distinguished Young Scholar of China, No.40225004 World Bank Cooperative Project, No.THSD-7
文摘This paper has studied the change of streamflow and the impact of climatic variability conditions on regional hydrological cycle in the headwater of the Tarim River Basin. This study investigates possible causes of observed trends in streamflow in an environment which is highly variable in terms of atmospheric conditions, and where snow and ice melt play an important role in the natural hydrological regime. The discharge trends of three head streams have a significant increase trend from 1957 to 2002 with the Mann-Kendall test. Complex time-frequency distributions in the streamflow regime are demonstrated especially by Morlet wavelet analysis over 40 years. The purpose is to ascertain the nature of climatic factors spatial and temporal distribution, involved the use of EOF (Empirical Orthogonal Function) to compare the dominant temperature, precipitation and evaporation patterns from normally climatic records over the Tarim's headwater basin. It shows that the first principal component was dominated since the 1990s for temperature and precipitation, which identifies the significant ascending trend of spatial and temporal pattern characteristics under the condition of the global warming. An exponential correlation is highlighted between surface air temperature and mean river discharge monthly, so the regional runoff increases by 10%-16% when surface air temperature rises by 1 ℃. Results suggest that headwater basins are the most vulnerable environments from the point of view of climate change, because their watershed properties promote runoff feeding by glacier and snow melt water and their fundamental vulnerability to temperature changes affects rainfall, snowfall, and glacier and ice melt.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-127, KZCX2-XB2-03-01, KZCX2-Q10-5-4)
文摘The characteristics of climatic change and fiver runoff, as well as the response of fiver runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over the last 50 years by the methods of Mann-Kendall nonparametric test and the nonlinear regression model. The results show that: 1) The temperature and the precipitation increased significantly in the whole northern Xinjiang, but the precipitation displayed no obvious change, or even a decreasing trend in the northern mountainous area of the northern Xinjiang. 2) River runoff varied in different regions in the northern Xinjiang. It significantly increased in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang (p = 0.05), while slightly ificreased in the west of the northern Xinjiang. 3) North Atlantic Oscillation (NAO) affects fiver runoff by influencing temperature and precipitation. The NAO and precipitation had apparent significant correlations with the fiver runoff, but the temperature did not in the northern Xinjiang. Since the mid-1990s fiver runoff increase was mainly caused by the increasing temperature in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang. Increased precipitation resulted in increased fiver runoff in the west of the northern Xinjiang.
基金The study is supported by the National Key Project ( No. 19980 40 80 0 ) and National Natural Science Foundation of China( Nos.
文摘According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between them and their implication of rapid climatic change. The marine records show its good response to the high latitudes both for cold events and for warm ones while the continental records mainly mirror those cold Heinrich events corresponding to the North Atlantic but bear strongly a local color in reflecting warm events. The authors assume that the heat transmission style may cause the unbalanced coupling relationship.
基金Chinese Post-D octoralFoundation Wang,K C Post-doctoralEducation Foundation (H ong K ong)
文摘Variation characteristics of temperature and precipitation in January and July and annual mean temperature and annual precipitation are analyzed with the help of cumulative anomalies, Mann-Kendall analysis and wavelet analysis. The research results indicate that January precipitation presents an increasing trend after 1990, wavelet analysis result suggests that this increasing trend will continue in the near future. The changes of July precipitation present different features. During 1900-1960, July precipitation is in a rising trend, but is in a declining trend after 1960. Wavelet analysis shows that this declining trend will go on in the near future. Temperature variations in Shanghai are in fluctuations with 2 to 3 temperature rising periods. Mann-Kendall analysis indicates that temperature variations have the obvious abrupt change time when compared with precipitation changes in Shanghai during the past 100 years. The abrupt change time of January temperature lies in 1985, and that of July temperature lies in 1931-1933 and annual mean temperature has the abrupt change time in 1923-1930. Except July precipitation, the precipitation in January, temperature in January, July and annual mean temperature, and annual precipitation are also in a rising trend in the near future. The research results in this paper may be meaningful for future further climatic changes of Shanghai and social mitigation of climatic disasters in the future.
基金funded by the Major State Basic Research Development Program of China (973 Program) under Grant No. 2010CB951701by the Natural Science Foundation of China (No. 41071042)supported by the Innovation Project of Chinese Academy of Sciences (KZCX2-YW-BR-22)
文摘Robust climate warming has led to significant expansion of lakes in the central Tibetan Plateau. Using remote sensing data, our quantitative analysis indicates that Siling Co, a saline lake in a characteristic endorheic basin in the central region of the Plateau, has expanded more than 600 km2 in area since 1976. Particularly since 1995, the lake has signif- icantly expanded in response to increasing precipitation, decreasing water surface evaporation caused by weaker winds and less solar radiation, and increased glacier meltwater draining to the lake. Glacie^lake interactions are important in governing lake expansion and are also part of a feedback loop that influences the local climate. Worsening climatic conditions (decreased precipitation and increased temperatures) that could have caused the lake to shrink during 1976-1994 were offset by increasing glacier meltwater feeding the lake, which made the lake nearly stable. We demonstrate that this pattern changed during 1995-2009, when glacier meltwater actually decreased but participation runoff increased and evaporation decreased, leading to expansion of the lake. If climatic conditions became suitable for further lake development, which would be indicated by expansion in lake area, glacier meltwater could be saved in a stable reservoir.
基金Under the auspices of the National Natural Science Foundation of China (No. 40271114, 40301051)
文摘Based on investigations of the Zhongwei Nanshan aeolian section situated in the southeastern margin of Tengger Desert, carbon-14 and TL (thermoluminescence) dating results and paleoclimatic proxies such as magnetic susceptibility and grain size, we inferred that the northwestern margin of East Asian monsoon region experienced abrupt climatic changes during the last deglaciation. Six oscillation events were identified: Oldest Dryas, Bolling, Older Dryas, Allerod, Intra-Allerod Cold Period (IACP) and Younger Dryas (YD). The summer monsoon was weaker during Oldest Dryas and Younger Dryas when the winter monsoon was stronger. However, during the B/A (Bolling/Allerod) period, the summer monsoon strengthened, reflected by magnetic susceptibility, when the winter monsoon also became strong, which is different from the paleoclimatic pattern established in the East Asian monsoon region. Furthermore, the summer monsoon was nearly in phase with the climate changes inferred from the oxygen isotopic records of Greenland ice cores. It could be speculated that the variations of the sea ice cover in the high latitudes of the North Hemisphere affected the high pressure of Asian continent and the changes of the winter monsoon inland. On the other hand, the sea ice cover variations might have indirectly caused the occurrence of ENSO events that has tightly been related to the summer monsoon in northwest margin of East Asian monsoon region.
基金Supported by National Natural Science Foundation of China(Grant No.40871257,40635029)State Key Development Program of Basic Research of China(973Program)(Grant No.2006CB400505)
文摘A number of studies indicate that global climate warming has been increasing, especially in recent decades. Climate warming greatly affects global agro-production and food security-- becoming a hotspot of global environmental change. This paper proposes a structural and orientational framework for scientifically addressing climatic change impact on agroroduction. Through literature reviews and comparative studies, the paper systematically summarizes influencing mechanisms and impact of climate warming on such agro-production factors as light, temperature, soil quality and water environment. The impact of climate warm- ing on cultivation regions, cropping systems, crop pests, agro- production capacity, agro-economy and farm management is analyzed. Then, suitable climate-adapting agro-development strategies are put forward for different regions in China. The strategies are carefully selected from a repository of international tested climatic change countermeasures in agriculture at national or district level.
文摘The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air temperatureand decreased by 5% in annual precipitation over 1951-1990. Regionally, temperature change has varied from acooling of 0.3℃ in Southwest China to a'warming of 1 .0℃ in Northeast China. With the exception of South China,all regions of China have shown a declination in precipitation. Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation. Under doubled CO2 concentration,climatic change in China will tend to be warmer and moister, with increases of 4.5℃ in annual mean air temperatureand 11% in annual precipitation on the national scale. Future climatic change will reduce the temporal and spatialdifferences of climatic factors.
基金Supported by Science Technology Innovation Item of Inner Mongolia Meteorological Bureau,China(nmgqxkjcx201115)
文摘Through analyzing statistically metrological observation data from 1971 to 2010 and pasture data from 1983 to 2012 at 6 animal husbandry meteorological testing stations of Inner Mongolia grassland, the conclusions were drawn. Those were that annual average temperature rose in a straight line in Inner Mongolia grassland, and the increase rates of annual average temperature in meadow steppe and typical steppe were 0.40 and 0.34 ℃/10 a respectively. Annual rainfall had 10-year cyclical characteristics, and precipitation in the 1990s was the most but reduced significantly after 2000. Climate experienced the cold wet -cold dry -warm wet -warm dry periods. Warm and dry climate made the average heights of pasture in meadow steppe and typical steppe of Inner Mongolia cut down 2.4 and 9.3 cm in nearly 12 years than that in the 1990s; the average coverage of herbage decreased by 11% and 13%; the average hay yields reduced by 1 019.8 and 671.4 kg/hm^2.
文摘The world is facing a big challenge of climatic change, mainly due to increasing concentrations of GHGs (greenhouse gases) in the atmosphere. Many researches indicated that the climate change occurred disproportionately on developing countries such as MENA (Middle East and North Africa) countries. The climatic model CGCM3.1 (T47) 2 is used in this research to explain the changes in average temperatures and the rainfall on the MENA region with special emphases on Iraq. Historical records (1900-2009) and future (2020-2099) were studied and compared; each period was divided to four sub-periods of thirty years. The results showed that the average monthly temperature for the four historical periods fluctuated between the lowest and highest value as follows: 9.2-32.9, 10.3-32.7, 9.3-32.8 and 8.6-33.9 (℃). The rainfall for historical periods kept on the same distribution during the past 109 years, and fluctuated between the lowest and highest value of 21.3 mm and 37.6 mm with an average that reached up to 26.51 mm. For the future period, the maximum average monthly temperature reached up to 37.41 (℃) during June and minimum average monthly temperature reached up to 4.24 (℃) during January. The average monthly temperature fluctuated giving a clear impression that the future portends a higher temperature. The average monthly rainfall, for the future period, fluctuated between the lowest and highest value of 12.91 mm and 20.63 mm with an average that reached 16.84 mm which represent a reduction percentage of about 36.47% relative to the historical record of rainfall for the sanae months.
基金Supported by Open Research Fund Program of State Key Laboratory of Water Resources and Hydropower Engineering Science,China(2010B065)National Natural Science Foundation,China(10972080)Fundamental Research Funds for the Central Universities,SCUT,China (2009ZM0186)
文摘[ Objective] The research aimed to establish SWAT distributed hydrologic model and analyze influence of the climatic change on runoff in Beijiang River basin. [ Method] Beijiang River basin as research object, SWAT model was used to simulate runoff in basin. Monthly water flow in Shijiao station from 1961 to 1980 was used to determine model parameter, while monthly water flow from 1981 to 1990 was used to verify. Setting 15 kinds of climate change scenarios, SWAT model was used to simulate influence of the future climatic change on runoff in Beijiang River basin. [Result] Simulated accuracy of the SWAT model was high, and it could be used to simulate runoff in Beijiang River basin. Under the situation of in- variable rainfall, temperature rise made that evaporation capacity increased, and runoff depth decreased. When temperature unchanged, rainfall increase made that evaporation capacity and runoff depth increased somewhat. [ Conclusion] The research could provide reference basis for water re- source management in Beijiang River basin.
文摘The opening and many years of research of magnetic spinor particles (real magnetic charges) in atoms and substance have enabled the author to formulate the conception of the Physical Triad, according which the real World consists of three fundamental phases: Matter, Antimatter and Energo-phase (Energo-medium). Particles of Matter are called spinors and particles of Antimatter are called antispinors. Energo-medium is a gasiform phase of high density that fills by himself all the infinite space of the real World. It consists of spinless and massless particles-energions. Spinor fields can be both flows energions (fields of Matter), so and anti-flow energions (fields of Antimatter). Atomic-shaped structures consisting of electric and magnetic spinor particles represent a Physical Mass (atoms, nucleons, etc.). The main characteristic of all varieties of Mass is its ability radiate gravitational field, which is a vortex electromagnetic field. All spinor particles are massless so as individually generate a gravitational field they can’t. All primary forces in the real World are implemented by means of Energo-medium, i.e. contact pressure its particles—energions. The spinor fields, including the gravitational field, myself the real of the power significance, have not. They are only intermediaries, inducing in Energo-medium its active (power) education, which is called “Dark Energy”. “Dark Energy” can be both positive, so and negative. Namely, a positive “Dark Energy”, which is associated with the technical activity of man, is responsible for stable climatic changes on Earth. Greenhouse gases are not the main “culprit” of climatic changes on our planet. However, these gases are the simplest indicator of the overall level of irreversible physical processes that stimulate the growth of the positive “Dark Energy” and are responsible for the negative thermal scenario on Earth.
文摘Climatic change and urbanization effect in China during the last 39 years were investigated. It is found that a warming of about 0.23℃ for the annual temperature has been noticed from 1951 to 1989. The warmings of about 0.78 ℃ in winter and 0.34 3℃ in spring have been shown. It is also presented that a cooling of about -0.27℃ in summer has been indicated. The bigger cities are warmer than smaller cities in China. The dried trends in the annual precipitation during the last 39 years were presented. The precipitation decreased obviously in summer all over China. The bigger cities were drier than smaller cities.
文摘Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in China .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2-5℃ in summer in China as simulated by the GCMs induced by doubling CO2 have been found. There are getting drier or wetter regions in China due to doubled CO2 as simulated by most of models. Comparing the simulated results with the observed data in China, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.
基金supported by the National Natural Science Foundation of China (Grant No. 50869005 and 50669002)the National Natural Science Foundation of China (Grant No. 50869005)supported by the National Natural Science Foundation of China (Grant No. 50669002)
文摘The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface environments were analyzed.The impact indices of climatic factors,along with their corresponding ranks,were used to characterize the responses of different types of surface environments to climate change.Results show that in the past 20 years,the surface environments of the study area have been deteriorating.Furthermore,there is a positive relationship between the changes in surface environments and those in climatic factors.Various climatic factors influence surface environments in different ways and at different levels.The most sensitive factor is relative humidity,followed by precipitation and evaporation.Overall,moisture is the key factor that affects the changes in surface environments of arid and semi-arid areas.
文摘The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced about 44 Ma in the polar re- gions as the seas cooled following the loss of the circum-equatorial ocean. Before then, a mega warm period lasted for more than 200 Ma. The frequency of the major cold events within the present mega cold period is increasing, with each continent being un- der the influence of a different set of climatic controls. There are many causes of these shifts in climate, ranging from fluctuating meridional ocean currents, rearrangement of tectonic plates, and changes in ocean gateways. These are enhanced by a combination of Milankovitch cycles and many other medium to small oscillations and cyclic controls that cause the daily, monthly, and season- al fluctuations in weather. Examples are given of how these can cause a change from cold to warm events, or vice versa, at pre- sent-day or mega scales, aided by eustatic changes in sea levels and changes in the distribution of air masses, sea ice, and snow.
文摘The acronym C6 means "Climatic Changes and Carbon Cycle in Canyons and Caves". It is a monitoring project, for the evaluation of climate change signals, based on measuring sites located inside canyons and caves; it merged in the year 2005, under the scientific supervision of the Palermo Branch of the Italian National Institute for Geophysics and Volcanology (INGV), two different monitoring programs active since 1999. The choice of these environments is based on their morphological structure: being them more or less segregated respect the outer atmosphere, they act as low-pass filters respect the variations of the monitored parameters, which are rainfall and dropping water amounts and rates, air temperatures and relative humidity and carbon dioxide concentrations in the atmosphere. On the basis of the preliminary data, reported and discussed in the paper, the C6 network seems to be capable to give useful information on the local effects of global changes, even if at the moment the monitored parameters concern only the abiotic components of the studied ecosystems.