ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 31,Issue 10,2005 Table of Contents
2005, 31(10):3-6.
DOI: 10.7519/j.issn.1000-0526.2005.10.001
Abstract:
The impact and damages of landslide hazards on human and social economy have become more and more seriously. Landslide hazards triggered by heavy rainfall take 90% of the total amount. A review on the landslide researches is made, such as, its forecast method, its forecasting and warning, its temporal and spatial distribution, its mechanics induced by heavy rainfall, stability theory, application of GIS. Modern mathematics and physics theories have been comprehensively applied in landslide forecast, which gained quickly development for recent two decades. 3S techniques have been used to monitor and prediction of landslide, but further potential dominance should be developed. Combining degree between mechanism research and regional statistics is dissatisfied,which is necessary to have a breakthrough. Because of its local, dispersed feature and instability due to lacking sufficient data, which should be deeply discussed, the development of regional warning model is therefore emphasized. Survey of water content and pore water pressure in soil body should be more precision and available. Real-time Forecasting and Warning System of landslides based on Web-GIS need to be built for quickly getting data during extremely heavy rainfall.
The impact and damages of landslide hazards on human and social economy have become more and more seriously. Landslide hazards triggered by heavy rainfall take 90% of the total amount. A review on the landslide researches is made, such as, its forecast method, its forecasting and warning, its temporal and spatial distribution, its mechanics induced by heavy rainfall, stability theory, application of GIS. Modern mathematics and physics theories have been comprehensively applied in landslide forecast, which gained quickly development for recent two decades. 3S techniques have been used to monitor and prediction of landslide, but further potential dominance should be developed. Combining degree between mechanism research and regional statistics is dissatisfied,which is necessary to have a breakthrough. Because of its local, dispersed feature and instability due to lacking sufficient data, which should be deeply discussed, the development of regional warning model is therefore emphasized. Survey of water content and pore water pressure in soil body should be more precision and available. Real-time Forecasting and Warning System of landslides based on Web-GIS need to be built for quickly getting data during extremely heavy rainfall.
2005, 31(10):7-11.
DOI: 10.7519/j.issn.1000-0526.2005.10.002
Abstract:
With tipping bucket and self-recording rain meter, the three heavy rainfall events, in the first ten days of July in 2000, in the middle ten days of July and in the first and middle ten days of August in 2004 in Taihang mountain area, are monitored and analyzed. The monitored max rain intensity are 3mm in one minute, 17.5mm in ten minutes, 30.75mm in half an hour, 45.75mm in an hour. The rain density varied in time largely and had no clear characters. Rainfall mainly accumulated in the middle and latter period of a event, especially during heavy rain period.
With tipping bucket and self-recording rain meter, the three heavy rainfall events, in the first ten days of July in 2000, in the middle ten days of July and in the first and middle ten days of August in 2004 in Taihang mountain area, are monitored and analyzed. The monitored max rain intensity are 3mm in one minute, 17.5mm in ten minutes, 30.75mm in half an hour, 45.75mm in an hour. The rain density varied in time largely and had no clear characters. Rainfall mainly accumulated in the middle and latter period of a event, especially during heavy rain period.
2005, 31(10):12-15.
DOI: 10.7519/j.issn.1000-0526.2005.10.003
Abstract:
Based on the Doppler radar data, a technique is described with the cross correlation method to heavy rainfall nowcast. Similar patterns of radar echoes are detected by comparing tracking areas in consecutive scans. The best fit between the tracking area is found by optimizing the correlation coefficient. The displacement vector corresponding with the max correlation coefficient is used to extrapolation rainstorm for periods between～quarter and one hour. The technique is validated by the use of observational data of “China Heavy Rain Experiment and Study CHeRES”. It is showed that displacement directory of rainstorm nowcasted by cross correlation is consistent with that of radar observation, the forecast veracity is decreasing with forecast lead time.
Based on the Doppler radar data, a technique is described with the cross correlation method to heavy rainfall nowcast. Similar patterns of radar echoes are detected by comparing tracking areas in consecutive scans. The best fit between the tracking area is found by optimizing the correlation coefficient. The displacement vector corresponding with the max correlation coefficient is used to extrapolation rainstorm for periods between～quarter and one hour. The technique is validated by the use of observational data of “China Heavy Rain Experiment and Study CHeRES”. It is showed that displacement directory of rainstorm nowcasted by cross correlation is consistent with that of radar observation, the forecast veracity is decreasing with forecast lead time.
2005, 31(10):16-19.
DOI: 10.7519/j.issn.1000-0526.2005.10.004
Abstract:
Based on the NCEP reanalysis data from 1996 to 2000, the main synoptic features of summer heat wave events in Beijing area and the mechanisms of Hetao high pressure are analyzed by composite method. The analyses show that the strong downward motion in the Hetao high pressure and solar radiation heating cause the heat wave in Beijing area. Finally, a conceptual model is developed.
Based on the NCEP reanalysis data from 1996 to 2000, the main synoptic features of summer heat wave events in Beijing area and the mechanisms of Hetao high pressure are analyzed by composite method. The analyses show that the strong downward motion in the Hetao high pressure and solar radiation heating cause the heat wave in Beijing area. Finally, a conceptual model is developed.
2005, 31(10):20-23.
DOI: 10.7519/j.issn.1000-0526.2005.10.005
Abstract:
Based on the observation and NCAR/NCEP reanalysis data, the advection term and perpendicular term of local temperature variation are estimated, and the non-adiabatic term is estimated too. The advection term varies with comparative complication, but its role is very weak. The perpendicular term leads to increase 1%—5%. The local temperature increment in Anhui is mainly from non-adiabatic term, and it takes significant role in local temperature increment.
Based on the observation and NCAR/NCEP reanalysis data, the advection term and perpendicular term of local temperature variation are estimated, and the non-adiabatic term is estimated too. The advection term varies with comparative complication, but its role is very weak. The perpendicular term leads to increase 1%—5%. The local temperature increment in Anhui is mainly from non-adiabatic term, and it takes significant role in local temperature increment.
2005, 31(10):24-27.
DOI: 10.7519/j.issn.1000-0526.2005.10.006
Abstract:
Based on geographic, geologic, as well as climatic background, whole China was divided into 28 geognosy disaster warning regions. In addition, using historical geognosy disaster records and related meteorological data, regional meteorological geognosy disaster forecast model is developed for each region. Since July 1,2003, the models have been put into operational forecast and have a good overall forecast and service effect. For further development, the forecast model should be optimized with the help of related scientific research.
Based on geographic, geologic, as well as climatic background, whole China was divided into 28 geognosy disaster warning regions. In addition, using historical geognosy disaster records and related meteorological data, regional meteorological geognosy disaster forecast model is developed for each region. Since July 1,2003, the models have been put into operational forecast and have a good overall forecast and service effect. For further development, the forecast model should be optimized with the help of related scientific research.
2005, 31(10):28-31.
DOI: 10.7519/j.issn.1000-0526.2005.10.007
Abstract:
The synthesis waves of ultra-long and long waves in different latitudes are calculated based on the grid-data of the 500hPa geopotential height and 850hPa temperature from 1975 to 2004, as a data base for wind forecasting. A forecasting model of multi-time scale and multi-space spectrum analogy is developed together with a new concept of analogue deviation on basis of the principal of harmonic analysis and a combination with coefficient analogy and distance analogy. Test results show that the model works well for the last two years and proved a very useful reference for the forecasts of wind that obey the geostrophic relation. The model, which involves factors of local topography and geography, provides a simple method to forecast the wind direction and velocity under large-scale weather background. As the multi-time scale and multi-space spectrum analogy takes into account of the spatial variety of physical fields as well as the continuous temporal processes, it is meaningful for medium-range weather events. The method needs to be improved in the future for forecasts of the strong winds produced by cold air at high latitudes or tropical cyclone, and other supplementary methods are required in condition of meso-scale system or thunder storms.
The synthesis waves of ultra-long and long waves in different latitudes are calculated based on the grid-data of the 500hPa geopotential height and 850hPa temperature from 1975 to 2004, as a data base for wind forecasting. A forecasting model of multi-time scale and multi-space spectrum analogy is developed together with a new concept of analogue deviation on basis of the principal of harmonic analysis and a combination with coefficient analogy and distance analogy. Test results show that the model works well for the last two years and proved a very useful reference for the forecasts of wind that obey the geostrophic relation. The model, which involves factors of local topography and geography, provides a simple method to forecast the wind direction and velocity under large-scale weather background. As the multi-time scale and multi-space spectrum analogy takes into account of the spatial variety of physical fields as well as the continuous temporal processes, it is meaningful for medium-range weather events. The method needs to be improved in the future for forecasts of the strong winds produced by cold air at high latitudes or tropical cyclone, and other supplementary methods are required in condition of meso-scale system or thunder storms.
2005, 31(10):32-34.
DOI: 10.7519/j.issn.1000-0526.2005.10.008
Abstract:
From the view of effective rainfall, in consideration of the times and the amount of the rainfall, especially the temporal distribution of the rainfall and its effectiveness, a new drought index is developed. The result is useful in the detection and estimation and making decisions of drought.
From the view of effective rainfall, in consideration of the times and the amount of the rainfall, especially the temporal distribution of the rainfall and its effectiveness, a new drought index is developed. The result is useful in the detection and estimation and making decisions of drought.
2005, 31(10):35-38.
DOI: 10.7519/j.issn.1000-0526.2005.10.009
Abstract:
With the SVD(Singular Value Decomposition), wavelet transform, the multiple temporal scale feature of coupling relationship between rainfalls in the first flood season in South China and 500hPa geopotential height is investigated. Results indicate that rainfall-height coupled mode appears pronounced interannual difference, and various periodic variability. Characterized by the multiple level and multiple temporal scale, a lot of coincident periods between rainfall and Height field indicate the closed couple relationship between them, besides, they all appear decadal abrupt.
With the SVD(Singular Value Decomposition), wavelet transform, the multiple temporal scale feature of coupling relationship between rainfalls in the first flood season in South China and 500hPa geopotential height is investigated. Results indicate that rainfall-height coupled mode appears pronounced interannual difference, and various periodic variability. Characterized by the multiple level and multiple temporal scale, a lot of coincident periods between rainfall and Height field indicate the closed couple relationship between them, besides, they all appear decadal abrupt.
2005, 31(10):39-41.
DOI: 10.7519/j.issn.1000-0526.2005.10.010
Abstract:
The breakdowns of the Lianyungang CINRAD/SA weather radar are analyzed. Each kind of reason is taken apart from both hardware side and software side, and some methods and steps are brought out accordingly.
The breakdowns of the Lianyungang CINRAD/SA weather radar are analyzed. Each kind of reason is taken apart from both hardware side and software side, and some methods and steps are brought out accordingly.
2005, 31(10):42-46.
DOI: 10.7519/j.issn.1000-0526.2005.10.011
Abstract:
Doppler radar data is used in rocket rain enhancement. The methods sach as, the target clouds choice,catalyzing potential estimation,catalyzing opportunity identification and catalyzing points determination are discussed. Within trajectory curve parameter,the projecting elevation,azimuth angle and projecting quantity are discussed, too.
Doppler radar data is used in rocket rain enhancement. The methods sach as, the target clouds choice,catalyzing potential estimation,catalyzing opportunity identification and catalyzing points determination are discussed. Within trajectory curve parameter,the projecting elevation,azimuth angle and projecting quantity are discussed, too.
2005, 31(10):47-50.
DOI: 10.7519/j.issn.1000-0526.2005.10.012
Abstract:
The trend forecast of air quality of winter is made based on the climatic character and the weather background and elements from January to July. Combined with both methods of the short-term climatic forecast and the stitistical analysis of the weather elements and the air quality forecast, the tendency of air pollution during the winter from November in 2003 to March in 2004 was attenpted. That is, at first, the pollution potential and the meteorological parameter is established with the statistic and analytical result of the ground weather background and pollution-weather conditions in analogical years matching the heating season of 2003 on the basis of the climate prediction of the winter. Then, the day-by-day consistency of aerial pollutant is calculated by the forecast equation of aerial pollutant consistency. Finally, the air-pollution trend prediction of heating days is acquired after generally analyzing the results of climate forecast in 2003 winter and daily air quality.
The trend forecast of air quality of winter is made based on the climatic character and the weather background and elements from January to July. Combined with both methods of the short-term climatic forecast and the stitistical analysis of the weather elements and the air quality forecast, the tendency of air pollution during the winter from November in 2003 to March in 2004 was attenpted. That is, at first, the pollution potential and the meteorological parameter is established with the statistic and analytical result of the ground weather background and pollution-weather conditions in analogical years matching the heating season of 2003 on the basis of the climate prediction of the winter. Then, the day-by-day consistency of aerial pollutant is calculated by the forecast equation of aerial pollutant consistency. Finally, the air-pollution trend prediction of heating days is acquired after generally analyzing the results of climate forecast in 2003 winter and daily air quality.
2005, 31(10):51-55.
DOI: 10.7519/j.issn.1000-0526.2005.10.013
Abstract:
Based on the data of acid rain in the main cities of Guangxi ,the result shows that the acid rain frequency in Guangxi is high and its acidity is strong which means pH value is low. The frequency of strong acid rain whose pH is lower than 4.5 is high too, acid rain frequency is relative low in summer half year while relative high in winter half year. The conclusion are also drawn that acid rain has relation with atmosphere circulation, 76 percents of acid rain in Guangxi has relation with weather system of height trough, shear and frontogenesis, while 24 percents of acid rain has relation with others weather systems.
Based on the data of acid rain in the main cities of Guangxi ,the result shows that the acid rain frequency in Guangxi is high and its acidity is strong which means pH value is low. The frequency of strong acid rain whose pH is lower than 4.5 is high too, acid rain frequency is relative low in summer half year while relative high in winter half year. The conclusion are also drawn that acid rain has relation with atmosphere circulation, 76 percents of acid rain in Guangxi has relation with weather system of height trough, shear and frontogenesis, while 24 percents of acid rain has relation with others weather systems.
2005, 31(10):56-61.
DOI: 10.7519/j.issn.1000-0526.2005.10.014
Abstract:
The mesoscale numerical model MM5(V3) is used to simulate the heavy rain process (occurred) in North China in Autumn. Based on the model products the environment parameters such as convective available potential energy (CAPE), storm relative helicity(SRH) and (energy)-helicity index(EHI) are calculated and analyzed. The results show that the three parameters (indicate) the occurrence and development of the heavy rain. Much energy is accumulated before the heavy rain, and the rainstorm center lies in the isoline denseness which is in the south of the (low-layer) helicity center, at the same time, the severe storm take place under the condition of (big-SRH) and small-CAPE.
The mesoscale numerical model MM5(V3) is used to simulate the heavy rain process (occurred) in North China in Autumn. Based on the model products the environment parameters such as convective available potential energy (CAPE), storm relative helicity(SRH) and (energy)-helicity index(EHI) are calculated and analyzed. The results show that the three parameters (indicate) the occurrence and development of the heavy rain. Much energy is accumulated before the heavy rain, and the rainstorm center lies in the isoline denseness which is in the south of the (low-layer) helicity center, at the same time, the severe storm take place under the condition of (big-SRH) and small-CAPE.
2005, 31(10):61-67.
DOI: 10.7519/j.issn.1000-0526.2005.10.015
Abstract:
The heavy rain in north-west region of Hunan province is analyzed. Result shows as follows. The heavy rain is related to the southwest jet at the low and middle troposphere and the block in the high latitude area of the Eurasia. The maintaining block keeps two cyclones motionless at the middle troposphere, so the northeast dry and cold air develops and meets the warm and wet air from southwest region, and the northeast and southwest shear line came into being. Evolution and development of the deep mesoscale cyclone on the shear line is the reason why the rain becomes so heavy. As the big vorticity and the big diver of Q-vector in the low troposphere and the potential vorticity on 345K isentropic surface move from south to north, the heavy rain begins from south to north, so this characteristic can be used as the sign of forecasting heavy rain. The coupling of the strong diver and vorticity cylinder and the steep θse structure are the fundamental dynamic mechanism of vertical motion and the heavy rain cause and persistence.
The heavy rain in north-west region of Hunan province is analyzed. Result shows as follows. The heavy rain is related to the southwest jet at the low and middle troposphere and the block in the high latitude area of the Eurasia. The maintaining block keeps two cyclones motionless at the middle troposphere, so the northeast dry and cold air develops and meets the warm and wet air from southwest region, and the northeast and southwest shear line came into being. Evolution and development of the deep mesoscale cyclone on the shear line is the reason why the rain becomes so heavy. As the big vorticity and the big diver of Q-vector in the low troposphere and the potential vorticity on 345K isentropic surface move from south to north, the heavy rain begins from south to north, so this characteristic can be used as the sign of forecasting heavy rain. The coupling of the strong diver and vorticity cylinder and the steep θse structure are the fundamental dynamic mechanism of vertical motion and the heavy rain cause and persistence.
2005, 31(10):68-71.
DOI: 10.7519/j.issn.1000-0526.2005.10.016
Abstract:
Analysis of sudden heavy rain in the middle and south of Fujian Province on Sept. 20, 2003 is made. Results show that Typhoon Choi-wan, turning to north far away, plays an important role of organizer and promoter in the formation of the heavy rain. Through the adjustment of the general circulation, the typhoon makes an orographic depression and a westerly trough develop. As a result, the cold air invades southwards more intensively, which is a key trigger for the heavy rain. The outflows downward at the west side of the typhoon enhanced the low level inflows of a mesoscale vortex and constituted a secondary circulation together with the updrafts over the heavy rain area, which strengthen the development of the convective cloud clusters.
Analysis of sudden heavy rain in the middle and south of Fujian Province on Sept. 20, 2003 is made. Results show that Typhoon Choi-wan, turning to north far away, plays an important role of organizer and promoter in the formation of the heavy rain. Through the adjustment of the general circulation, the typhoon makes an orographic depression and a westerly trough develop. As a result, the cold air invades southwards more intensively, which is a key trigger for the heavy rain. The outflows downward at the west side of the typhoon enhanced the low level inflows of a mesoscale vortex and constituted a secondary circulation together with the updrafts over the heavy rain area, which strengthen the development of the convective cloud clusters.
2005, 31(10):72-75.
DOI: 10.7519/j.issn.1000-0526.2005.10.017
Abstract:
Based on the routine data and Doppler radar echo etc, a continuous heavy rain event in Weihai, Shandong Province from 4 to 6 August 2004 is diagnosed. The meso-β-scale heavy rain in the evening on August 5 is analyzed on emphases. It shows that the event occurred in the area of high energy accumulation at the edge of the west Pacific subtropical high. And the main reason of the heavy rainfall in the first period is the cold air invasion. Surface convergence is the primary trigger mechanism to lead the heavy rainfall again. The rich moisture transmission and the concentrated CAPE (convection available potential energy) provided the physics mechanism for the occurring and development of mesoscale heavy rainfall system.
Based on the routine data and Doppler radar echo etc, a continuous heavy rain event in Weihai, Shandong Province from 4 to 6 August 2004 is diagnosed. The meso-β-scale heavy rain in the evening on August 5 is analyzed on emphases. It shows that the event occurred in the area of high energy accumulation at the edge of the west Pacific subtropical high. And the main reason of the heavy rainfall in the first period is the cold air invasion. Surface convergence is the primary trigger mechanism to lead the heavy rainfall again. The rich moisture transmission and the concentrated CAPE (convection available potential energy) provided the physics mechanism for the occurring and development of mesoscale heavy rainfall system.
2005, 31(10):76-79.
DOI: 10.7519/j.issn.1000-0526.2005.10.018
Abstract:
Based on the historical data of drought and flood from 1470 to 1979,the grade data of drought and flood are obtained and then extended to 2003. With the methods of wavelet analysis, t-test and low-pass filter,the occurrence laws,periodicity, phases and sudden-change of drought /flood are analyzed for the last 543years in Zhejiang. The results show that (1) Middle-intensity drought/flood events occurred every 3—4 years and serious drought/flood occurred about every 10 years. (2)Zhejiang drought/flood has obvious 30-year,50-year and 70—80-year oscillation periods,then about 10—20-year. (3) The fluctuation of drought/flood appears three ascending stages mainly characterized by much drought and three descending stages mainly characterized by much flood. (4)Drought/flood have three obvious sudden-change points including 1636,1708 and 1963, which represent climate evolution characteristics from lack of rain, stage of rich rain to stage of lack of rain.
Based on the historical data of drought and flood from 1470 to 1979,the grade data of drought and flood are obtained and then extended to 2003. With the methods of wavelet analysis, t-test and low-pass filter,the occurrence laws,periodicity, phases and sudden-change of drought /flood are analyzed for the last 543years in Zhejiang. The results show that (1) Middle-intensity drought/flood events occurred every 3—4 years and serious drought/flood occurred about every 10 years. (2)Zhejiang drought/flood has obvious 30-year,50-year and 70—80-year oscillation periods,then about 10—20-year. (3) The fluctuation of drought/flood appears three ascending stages mainly characterized by much drought and three descending stages mainly characterized by much flood. (4)Drought/flood have three obvious sudden-change points including 1636,1708 and 1963, which represent climate evolution characteristics from lack of rain, stage of rich rain to stage of lack of rain.
2005, 31(10):79-82.
DOI: 10.7519/j.issn.1000-0526.2005.10.019
Abstract:
The monitoring data in a small area is analyzed with NOAA/AVHRR data in a parallel way. NOAA/AVHRR data gets applied to winter wheat growth monitoring of the small area. The relationship between the agricultural index and the degree of greenness by remote sensing is set up with the developing equation in the satellite remote figures of crop classification. So a set of practical methods of classifying crops by means of satellite remote sensing are provided for the local area.
The monitoring data in a small area is analyzed with NOAA/AVHRR data in a parallel way. NOAA/AVHRR data gets applied to winter wheat growth monitoring of the small area. The relationship between the agricultural index and the degree of greenness by remote sensing is set up with the developing equation in the satellite remote figures of crop classification. So a set of practical methods of classifying crops by means of satellite remote sensing are provided for the local area.
2005, 31(10):83-85.
DOI: 10.7519/j.issn.1000-0526.2005.10.020
Abstract:
Based on the weather data in the period of seedtime for winter wheat from 1961 to 2003 in the Zhumadian, Henan Province, a correlation analysis is made. The result shows that the temperature of conventional seedtime in the southern area of Henan Province gradually rises. The suitable seedtime for winter wheat is gradually postponed. Rainfall during the period of conventional seedtime has decreased. The conclusion is that the output of suitable late seeding winter wheat will be increased.
Based on the weather data in the period of seedtime for winter wheat from 1961 to 2003 in the Zhumadian, Henan Province, a correlation analysis is made. The result shows that the temperature of conventional seedtime in the southern area of Henan Province gradually rises. The suitable seedtime for winter wheat is gradually postponed. Rainfall during the period of conventional seedtime has decreased. The conclusion is that the output of suitable late seeding winter wheat will be increased.
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ISSN:1000-0526 CN:11-2282/P