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20 August 2011, Volume 32 Issue 3

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Research Advances in Herbage Plant Phenology and Phenological Model of Grassland

FU Yu, PAN Xue-Biao

2011, 32(3):  319-325. 

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Grassland ecosystems are unassailable associated with global change.In this paper we summarized the research advances in herbage plant phenology and phenological model of grassland.We searched many literatures and found that the changes of plant phenology could reflect some effects of climate change directly.The environmental driving factors such as temperature,light and water would have different effects in controlling the progress of phenology.The development of plant phenological model had strong trends toward dynamic phenological model based on plant development mechanism from statistical model in the beginning.However,less was known about natural grassland phenological model.Some existing phenological models only could be used for specific species simulation,some couldn′t be used for largescale region,and the others were lack of description in development progress.Because of these problems we should enhance the research about the relationship between plant phenology and climate factors,especially water effect.We should explore all the characteristic of grass in every phenology stage and verify the phenological model step by step.An accurate natural grassland phenological model will be benefit for the study of climate change.

Temporal and Spatial Distribution of Precipitation in Summer and Autumn and Its Trend Evolution in Zhejiang Province

WU Hao min, YANG Xian min, JIANG Yan min

2011, 32(3):  326-330. 

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Droughts and floods occurred frequently in summer and autumn in Zhejiang province, so it was very important for disasters prevention to study the temporal and spatial distribution and trend evolution of precipitation in summer and autumn. The temporal and spatial distribution and trend evolution of precipitation in summer and autumn was analyzed by using trend analysis, isoline distribution, EOF method and Morlet continuous wavelet transform, based on monthly precipitation data from 65 stations in summer and autumn during 1971 to 2009. The results showed that the precipitation increased at the rate of 92mm/10y in last 39 years. The spatial distribution showed decreasing trend from southeast to other areas. There was a different periodic oscillation, but concentrated in 6 to 10 years, and the 8.7year cycle was most significant, which passed the power spectrum 95% confidence test.

Study on Spatial Interpolation Method of Annual Precipitation in Xinjiang

WANG Zhi，WU You-Jun，LIANG Feng-Chao，CHANG Shun-Li，SHI Qing-Dong

2011, 32(3):  331-337. 

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For improving the effect of annual precipitation spatial interpolation in Xinjiang area, the spatial interpolation of annual precipitation had been performed and the precision was comparatively validated by using of deterministic function and geostatistical interpolation methods, through adding some simulative meteorological stations as a supplement of spatial variability information of fact station data. The results showed that the precipitation spatial variability information and interpolation precision had effectively enhanced by establishing simulative weather stations through finding weather stations influence zone by investigating appropriate sampling interval distance of multiyear average precipitation with geostatistical analysis, and founding multiple regression equation between precipitation and longitudelatitude, elevation, slope, aspect and NDVI(normalized difference vegetation index). MRBF was the best and most appropriate method for spatial interpolation of precipitation among three interpolation methods of Inverse Distance Weighted (IDW), Multiquadratic Radial Basis Functions (MRBF) and Ordinary Kriging (OK) in Xinjiang area. By using stepwise and integrated methods, namely establishing simulative meteorological stations through multiple regression and conducted spatial interpolation of precipitation by MRBF method, considering significant factors and spatial variability, removing boundary effect of multiple regression, enhancing precipitation spatial geostatistical information, the annual precipitation spatial distribution dataset of this area with higher precision had been obtained.〖JP〗

Analysis on Characteristics of Climate Change in Last 49 Years in Southeastern Guizhou

YANG Zai Yu，LONG Xian ju

2011, 32(3):  338-345. 

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The climate characteristics including temperature, precipitation, relative humidity and sunshine hours was analyzed by using conventional statistical methods and Mexican hat wavelet transform, based on the daily meteorological data of 16 meteorological stations in southeastern Guizhou from 1961 to 2009，The results showed that the annual average minimum temperature increased at the rate of 0 146℃ per 10 years，while the average temperature and average maximum temperature had no significant change trend. The annual average temperature decreased gradually from southeast to northwest, and its oscillation period was 3 years, 17 years and 36 years. The annual average precipitation had no significant change trend but the days with rainstorm had a increasing trend. The annual precipitation decreased gradually from east to south and from west to north. Its oscillation period was 3 years and 18 years.〖JP+2〗 The annual average relative humidity had no significant change trend but its oscillation period was 3 years, 8 years and 11 years. The average sunshine hours decreased at the rate of 25 835 hours per 10 years, and its oscillation period was 4 years, 10 years and 20 years. Totally, climate changed warmer and drier in last 49 years in southeastern Guizhou

Comparison of Soil Respiration Variation Characteristics between Quercus variabilis Plantation and Abandoned Land in the South Hilly Region of North China

WANG Ping, ZHANG Jin-Song, MENG Ping, LU Sen, GAO Jun, LV Hai-Yan

2011, 32(3):  346-349. 

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During the growing season of 2010, in order to find the difference of soil respiration between the 29 yearold quercus variabilis plantation and abandoned land, soil respiration rate were measured with the static chamber gas chromatography method in the south hilly region of North China.The main results were as follows: (1)the seasonal variation curves of soil respiration on the plantation and abandoned land both had a single peak during the studying period. The largest soil respiration rate occurred in the July. Average soil respiration on the plantation during the studying period was 601.69 mg/m² less than the abandoned land (1007.96mg/m²  , about 40.3% lower.(2) Both for the abandoned land and quercus variabilis plantation, soil respiration were controlled mostly by soil temperature and there was no significant correlation between the soil respiration rate and soil water content in the studied abandoned land.At the depth of 5cm, Q of the abandoned land and quercus variabilis plantation were 2.702 and 2.573,respectively.

Variation of Sunshine Hours and Its Influence Factors in Last 50 Years in Fujian Province

PENG Yun-Feng，WANG Qiong

2011, 32(3):  350-355. 

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The meteorological data including monthly sunshine hours and total cloud amount, lowlevel cloud amount, vapor pressure and relative humidity, from 64 observational stations in Fujian province from 1961 to 2008 was analyzed, based on climate tendency rate method. The results showed that annual sunshine hours decreased in Fujian province at the rate of 71.7 h/10y in last 50 years, in southern Fujian particularly. The sunshine hours in four seasons decreased at the rate between 13.8 h/10y to 26.5 h/10y, of which the maximum was in summer and the minimum was in autumn, in latest 30 years particularly. From decadal variation, four seasons had sufficient sunshine during 1960s to 1970s, with positive anomaly. But only summer sunshine hours had positive anomaly in 1980s, while negative anomaly for the other three seasons. In 1990s, three seasons had more sunshine except spring. The annual sunshine hours were extremely excessive in 1963 or 1971, but never extremely deficient. Annual and seasonal sunshine hours decreased with the increasing of low level cloud amount, and the reduction of sunshine hours increased along with vapor pressure in winter.

Measurement of Ammonia and GHGs Concentration of Hoop Structure Barnfor Finishing Pigs in Summer and Spring Season

ZHU Zhiping，KANG Guohu，DONG Hongmin，TAO Xiuping

2011, 32(3):  356-361. 

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To investigate ammonia and greenhouse gas concentration condition in swine barn,a hoop structure barn as experiment barn and typical swine barn with brickconcrete floor as control were chose at a confined swine farm in Beijing,gases concentration were measured for 3 consecutive days during spring and summer seasons using INNOVA 1312 multigas monitor. The results showed that the average NH₃、CO ₂、  N ₂ O concentration in experiment barn was by 40%,70%,77%,respectively,compared with control barn (P＜0.05).The average  CH₄  concentration in hoop structure was higher than that in the control barn in summer,but lower in spring.The concentrations of CH₄、CO ₂、  N ₂ O had significant different(P＜005) between summer and spring season in the hoop structure,but NH₃ had no significant different,the CO ₂ concentration was lower in summer,NH₃、CH ₄、  N ₂ Oconcentration was higher in summer than that in spring. The hoop structure barn could improve indoor environment and mitigate gases emission.

Simulation and Forecast of Air Temperature inside the GreenhousePlanted Myica rubra Based on BP Neural Network

JIN Zhifeng,FU Guohuai,HUANG Haijing,PAN Yongdi,YANG Zaiqiang,LI Renzhong

2011, 32(3):  362-367. 

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The minimum and maximum temperature prediction model inside greenhouse planted Myica rubra was established based on BP neural network,by using meteorological data both inside and outside the greenhouse from December 2009 to June 2010 in Wenzhou of Zhejiang province. Using the independent experimental data and simulation back generations to verify the model,the results indicated that the root mean square error(RMSE) between the predicted value and measured value based on 1 line for the minimum and maximum and hourly inside air temperature were 0.8℃,1.4℃ and 0.7℃,respectively. The precision of BP neural network model was higher than that of the stepwise regression model obviously. The model,with few parameters,could predict the greenhouse temperature more accurately,which could provide scientific basis for facility meteorological service and environment regulation of greenhouse Myrica rubra cultivation.

Effects of Plastic Film Mulching Patterns on Soil Moisture and Spring Wheat Yields in Drought Years

ZHANG Shufang, CHAI Shouxi,LIN Yanchun,CHANG Lei，YANG Changgang

2011, 32(3):  368-374. 

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An experiment was conducted to study effect of different plastic film mulching on soil moisture of spring wheat and further to explore approaches of increasing wheat yield and improve water use efficiency. The effect of plastic film mulching with three methods on soil moisture were investigated under semiarid rain fed conditions in the Northwest of China. The results showed that the plastic film mulching could increase the moisture content of soil surface layer (0-20cm) significantly,however,after jointing stage,the moisture content of soil surface layer was obviously lower than the open field treatments. The water consumption of the mulched land was generally less than the control,viewed by the average moisture condition during the whole period of growth of soil body (2m). The moisture conditions of Gansu and Gansu Models among the six were markedly higher than that of open ground. The yield from the land mulched with plastic mulch was higher than that from the open ground,with an average increase of 44.45% and by 711.45kg\hm². The yield from the land mulched in autumn was higher than that from the land mulched in spring. Water assured and the stimulation mechanism of higher yields were the effective use of deep soil moisture and the ability to transport the deep moisture to surface in spring mulching under the more arid soil.

Sensitivity Analysis of the Reference Crop Evapotranspiration duringGrowing Season in the Northwest China in Recent 49 Years

CAO Wen,SHEN Shuanghe,DUAN Chunfeng

2011, 32(3):  375-381. 

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Based on the FAO Penman-Monteith equation,sensitivity coefficients of ET₀ in growing season to air temperature,wind speed,relative humidity and shortwave radiation were studied in 126 stations in Northwest China using a 49-year dataset. The temporal-spatial variations of sensitivity coefficients of ET₀ were also analyzed. The results showed that shortwave radiation was the most sensitive variable to ET₀ in general for the region,followed by relative humidity and air temperature. Wind speed had the least impact. The sensitivity coefficients to all climate variables indicated large spatial variability. The high value area of sensitivity coefficients to air temperature and wind speed was in the westerly climatic region,while the high value area of sensitivity coefficients to relative humidity was in the relatively moist region. The sensitivity coefficients to shortwave radiation were higher in the south study area than in the north. In the growing season,the highest sensitivity coefficients to air temperature and shortwave radiation were in July,while the lowest sensitivity coefficient to wind speed was in July. The absolute sensitivity coefficients to relative humidity increased from April to October. The sensitivity coefficients to shortwave radiation and relative humidity indicated significant increasing and decreasing trends respectively during the 49 years. But the yearly change trends of sensitivity coefficients to air temperature and wind speed were not obvious.

Climate Suitability and Regionalization of Lychee Planting inGuangdong Based on GIS

DING Lijia，WANG Chunlin，ZHENG Youfei，LING Liangxin，XIE Songyuan

2011, 32(3):  382-387. 

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In the support of GIS technology, climatic and regionalization for lychee with different maturing was performed based on 1980-2009 climate data in Guangdong. The result could provide scientific guidance to Guangdong lychee production layout and variety selection. Based on the relationship of lychee growth and local climate conditions in Guangdong, four climatic division index，including annual average temperature，extreme minimum temperature for multiyears, average temperature in flower bud differentiation critical period and precipitation in flowering and fruiting period，had been established for early，middle and late maturing lychee. Each index had three levels, corresponding to suitable, subsuitable and inappropriate.A spatial analysis model for climate division had been produced in terms of those indexes. Using the spatial model and GIS, a smaller grid calculation was conducted and climate division for early, middle and late maturing lychee was achieved. The result showed that in Guangdong, the midmaturity lychee had largest favorable areas of 6.6653×10⁶ha,〖JP2〗followed by the early maturing variety, it was 5.2745×10⁶ha. Late maturing lychee, which was constrained by temperature and precipitation, had smallest size of suitable area of 4.2525×10⁶ha.

Effect of Climate Change on Early Rice Yield in Last 30 Years in Ganzhou

2011, 32(3):  388-393. 

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The characteristics of climate change during early rice growth period was analyzed, and correlation analysis between meteorological yield and meteorological factors during early rice growth period was conducted, based on daily temperature, precipitation and sunshine hours data from 1980 to 2009 in Ganzhou. The results showed that there was an increasing trend of early rice yield during last 30 years with linear increase before 1990, but yield growth rate slowed down obviously after late 1990s. Temperature increased at the rate of 0.35℃/10y during last 30 years. Temperature was significantly negatively relationship with rice yield, and climate warming restrained early rice yield increasing. Precipitation decreased at the rate of 157.6mm/10y during last 30 years. Precipitation was obviously positive correlation with rice yield, and precipitation decreasing could be affected early rice yield in future. The sunshine hours change not obviously during last 30 years, but the interannual and interdecadal change a lot. A sunshine hour was a negative correlation with early rice yield, and oversunshine was not benefit to rice yield. Temperature increased obviously during early rice grouting milky stage, the meteorology of high temperature urging maturity was significantly increasing since the late 1990s in particular. Temperature was negatively relationship with early rice yield, and heat damage could be affected yield and quality of early rice.

Sensitivity Analysis on the Growth of Potato Stemleaf to Meteorology Factors

SONG Yuzhi，JIN Xin，MA Guofei，YUAN Haiyan，WANG Lianxi，LI Jianping

2011, 32(3):  394-398. 

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Field experiment of different sowing date for potatoes, taking Ning4 and Long3 varieties, was conducted, which were planted on April 13 and 20, 2008. The relationship between the dry weight of stemleaf per plant potato every 10d in the whole growing period and meteorology factors, such as accumulated temperature, precipitation and sunshine hours, was analyzed. The results showed that the related coefficient between the dry weight of stemleaf per plant and the accumulated temperature, precipitation and sunshine hours of Ning4 no mulching sowed on April 13 was higher than Long3 (P<0.01), which indicated that the sensitivity of Ning4 was higher. The sensitivity to accumulated temperature of Ning4 no mulching sowed on April 20 was higher than Long3, the correlation of Ning4 mulching sowed on April 13 was higher than that sowed on April 20(P<0.01), which indicated that Ning4 sowed on April 13 had more sensitive to meteorological factors. Ning4 sowed on April 20, was sensitive to the accumulated temperature, and the dry weight of stemleaf per plant of Ning4 mulching increased 0.6g than that of no mulching when the accumulated temperature increased 100℃, which indicated that Ning4 mulching had more sensitive. To sum up, the optimum sowing date for Ning4 potato mulching was April 13 in Xiji County.

Climatic Suitability of Winter Wheat and Its SpatialtemporalChanges in Hebei Province

2011, 32(3):  399-406. 

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For evaluating quantitative effect of meteorological factors to crop yield, the climatic suitability model of winter wheat during growing season in Hebei province was established, based on the daily climatic data and statistics methods, and the temporalspatial changing characteristics of the climatic suitability was analyzed. The results showed that the precipitation suitability degree was obviously lower than that of sunshine and temperature, but the coefficient of variation of precipitation suitability was the largest. The sunshine suitability during the tillering period was the lowest and the coefficient of variation was the largest, the precipitation suitability during the period from jointing to heading was the lowest and the coefficient of the variation was the largest, the temperature suitability during the period from overwintering to double ridge was the lowest, the coefficient of the variation of tillering stage was the largest. The area with highvalue of temperature suitability degree was in Northwest, while the lowvalue area was in Southeast. The area with highvalue of precipitation suitability degree was in Northeast, while the lowvalue area was in Southeast. The area with highvalue of sunshine suitability degree was in North, while the lowvalue area was in South. The climatic suitability showed that, from 1981 to 2010, the sunshine suitability degree of winter wheat growing period decreased obviously, climate suitability degree decreased slowly, and temperature and precipitation suitability no changed. The main reason to climate suitability decreasing was temperature suitability decreasing during overwintering period and grain filling period, and the sunshine suitability decreasing during each development stage.

Analysis on Effects of Global Warming on Three Major CropYields in Inner Mongolia

GAO Tao, CHEN Yancai, YU Xiao

2011, 32(3):  407-416. 

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The impact of droughts on yields was analyzed by using the statistical regression model, based on yields data of wheat, maize and potato from 10 cities or leagues of Inner Mongolia, and temperature and precipitation data (1961-2008) from 58 meteorological stations. The results showed that the temperature increased during crop growth season in last 48 years. The average temperature of 10 cities during 2001-2008 increased 0.9℃ comparing to that during 1971-2000, the average precipitation reduced 489mm at the same time. The aridity index of wheat, maize and potato increased 1.29, 1.82 and 1.49, respectively.Additionally,it has been also revealed in the outcomes of pre-estimated yield that most of the regions would have a declining yield with increase intervals of the temperature at 0.2℃,0.5℃ and 1.0℃ .while the precipitation keeps at the climatological mean level.The more temperature rising,the more yield would decrease. Furthermore,the yield would increase with more rainfall while the temperature going up by 0.2℃ above the climatological mean temperature.Only with more than 20 percent increase amount of precipitation would the yield increase possibly when the rising temperature interval reaches to 0.5℃ With the temperature interval goes up to 1.0℃,most regions perform a decrease yield even with 30 percent increase of precipitation,just few of the regions show a little increase yield

Vegetation Changes in Xilingol Grassland Based on NOAA/AVHRR Data

HE Junjie

2011, 32(3):  417-422. 

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Vegetation change and its causes were discussed through analyzing the relationship between herbage yield and the Normalized Difference Vegetation Index (NDVI) in August and precipitation in early May to middle July during 2005-2008. The results showed that NDVI changed significantly in most regions, the region with increasing NDVI extended, and vegetation grew better than last year. Regions with decreasing NDVI mainly distributed in middle and east of the Grassland, which indicated that herbage degradation was serious. Grassland vegetation changes and herbage yield fluctuation were significantly to precipitation in late June.

Initial Exploration of Maize Phenological Stage Based on Image Recognition

LU Ming, SHEN Shuanghe,WANG Chunyan,LI Maosong

2011, 32(3):  423-429. 

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Through the observation and research of whole phenological stage of summer maize in agrometeorological station in Hebi city, Henan province and by means of field monitoring image capture device to collect different maize image data and analyzing image feature of group images as well as parameters with a variety of colors, the identification of the main phenological stage can be attained. For different phenological stage, RGB color space to extract green pixel value and HSL color space to extract yellow pixel value are used to determine the proportion of developmental period. For the weed effect on the extraction image color, proposed using small area elimination algorithm based on region labeling to eliminate weed impact in pictures. For wet soil on the extraction of the interference of the yellow pixel value in pictures, proposed combining S value of HSL color space to eliminate the color of wet soil. After comparison with the manual observation, the results showed that it is available to identify maize developmental period by using color parameters. The correct recognition rate reaches 94.26%.

Precipitation；Spatiotemporal change；DEM；Urumqi river basin

ZHANG Shanqing，PU Zongchao

2011, 32(3):  437-443. 

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Based on the monthly precipitation data of nine meteorological stations in 19612009 in Urumqi river basin，the refinement spatialtemporal variation characteristics of annual precipitation change trend rate, annual precipitation increment after and before it sudden change, mean precipitation of annual and monthly，the variation coefficient of annual precipitation in recent 49 years were analyzed by using methods of threedimensional and quadratic trend surface simulation and against distance square weighting residual error revising based on DEM. The main results were as follows. (1)The average annual precipitation of nine meteorological stations was increasing by the change rate of 1529mm/10y,and the annual precipitation had the discontinuity ascension in 1987,but the change rate and annual precipitation increment after and before annual precipitation sudden change was different in each region in Urumqi river basin, generally, the increase rate and increment of annual precipitation was more in higher altitude areas than in lower altitude areas and plain in Urumqi river basin.(2)The spatial variation of annual precipitation was very obvious, precipitation was less than 250mm at the end of Urumqi river basin,to the south,along with the increase of altitude, precipitation was increasing, the most annual precipitation occurd at altitude of 1900 to 2200m,and the most precipitation was 550mm to 600mm correspondly.After this,precipitation had a decreasing trend with the altitude continues rise, to the river source area of above 3500m,the precipitation was less than 450mm.（3）Annual precipitation variation coefficient was smaller in higher altitude mountain than in lower altitude areas and plain in Urumqi river basin.（4）The spatial distribution of monthly precipitation in a year performance for the obvious periodical change characteristics. Precipitation was less in winter (December to February),the area of the most precipitation was mainly in the lower altitude mountain and the piedmont plain, and the least precipitation zone was mainly in elevation above 2500m.In spring (March to May),precipitation was more than winter, the most precipitation zone was moving up to higher altitude mountain, and the least precipitation zone was moving from higher altitude mountain to the plains migration gradually. Summer (June to August) is the season of greatest precipitation in a year, the most precipitation zone move up to medium and higher altitude mountain belt of 20004000m,and the least precipitation zone in northern plains. In autumn (September to November),the precipitation was reducing gradually, the most precipitation zone was also moving to lower altitude area, and the least precipitation zone was moving up to medium and higher altitude mountain belt gradually, to November, the most precipitation zone revert to lower altitude area and piedmont flood impact basin deposition,and the least precipitation zone rising up to higher altitude mountain belt of above 2500m again.

Analysis on S Drought Index Variation in Warm Season for Altay Area in Xinjiang

ZHUANG Xiaocui, ZHAO Zhengbo, YANG Sen, ZHANG Linmei

2011, 32(3):  444-450. 

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S drought index was established and analyzed by using MannKendall drift test method and Morlet small wave transformation, based on monthly precipitation and nonprecipitation day′s number from 7 meteorological stations in warm season (April to October) from 1961 to 2009 in Altay, Xinjiang. The results showed that S drought index accorded with drought condition in Altay. There were 3 extreme drought years and 1 extreme wetness year in last 49 years, there were extreme drought years except for 2 east stations. There were 1 extreme wetness year in Burgin and 2 extreme wetness years in Jimunai, and not in other stations. There were 2 extreme drought years in spring and 1 extreme drought year in autumn, but no extreme wetness years. There were 2 extreme drought years and 3 extreme wetness years in summer. Wetness dominated in warm season during 1980s and 1990s, and drought usually in other time; drought dominated in spring during 1960s and wetness usually in other time. Decadal change in summer was similar to warm season, wetness dominated during 1960s and 1980s, and drought usually in other time. Small wave analysis results indicated that S drought index changed as decadal and annual cycle.

Prediction on Drought Risk for Maize in Different Growing Stages in Chaoyang City

ZHANGQi, ZHANG Jiquan, YAN Denghua, TONG Zhijun, LIU Xingpeng

2011, 32(3):  451-455. 

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he prediction model to drought risk for maize in different growing stages was established, by using multiscale SPI, discriminant analysis and linear sliding average method, based on the data of precipitation during each ten days and maize yield in Chaoyang city, Liaoning province. The results showed that the accuracy of the model increased with the growing stages promoted and got to 83.8%. Accuracy of the model for highrisk group, lowrisk group, and normal group were different, which was highest and could be 90.9% to highrisk group, and was lowest and could be 78.9% to normal group. It had highest accuracy at milkyripening stage, which increased to 83.8%from 67.6% at former stage. It indicated that the milkyripening stage was the key growing stage for maize, had more prominent influence on the final yields. The results indicated that the prediction model had high accuracy, could meet the demand of business service, especially for the regions where drought was the main disaster.

Analysis on the Change of Dryhot Wind Hazard for Winter Wheat inLast 47 Years in Henan Province

CHENG Lin, ZHANG Zhihong, CHANG Jun

2011, 32(3):  456-460. 

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According to the meteorological occupation standard for dryhot wind hazard of winter wheat, daily meteorological element data from 1961 to 2007 in later growth stage of winter wheat at 118 stations in Henan province was taking used for analyzing the variation of range and frequency, et al for high temperature and low humid type of dryhot wind hazard. The results showed that： in the recent 47 years, the wind speed at 14:00, which was closely relate to the hazard declined conspicuously, and a climatic mutation point was found near 1983, while other meteorological elements varied insignificantly. In view of the overall weakening trend of the hazard, the range and days that different grades of the hazard occurred was increasing after 1990s, especially the increasing speed of ratio of stations that light hazard occurred reached to 2.01%,and the days that the hazard happened reached to 0.07. According to running mean statistic，the frequency of all grades of dryhot wind hazard was decreasing, however, it showed a trend of accelerating in the late 30 years.

Risk Division of Drought Disaster for Rice Production in Hunan Province

LUO Boliang, HUANG Wanhua, SHUAI Xiqiang, XIE Baicheng, PENG Li

2011, 32(3):  461-465. 

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The evaluation model on drought disasters for middle and later rice in Hunan province was established by using the human survival environmental risk assessment method, based on the factors, such as the frequency of disasters, the area and the intensity of disasters and rice production. Furthermore, risk division on drought disasters for rice production in Hunan province was conducted by using GIS technology. The results showed that the high risk region was south Hunan and Huaihua region, and others were low or slight risk region.

Forecasting Model of Meteorological Grades of Calamity Caused by Psylla Chinese Yang et Li in Kuerle Region

HUANG Jian,GUO Tiequn

2011, 32(3):  466-470. 

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Psylla Chinese Yang et Li was a new introduction fatalness pest in Xinjiang, China. In order to reduce loss，we measured off meteorological grades of calamity caused byPsylla ChineseYang et Li. A forecasting model of eggs of Psylla Chinesewas built by using meteorological conditions which were firmly connected with the development of Psylla Chinese through actual investigation data and historical meteorological data. The results showed that high temperature was the major meteorological factor that could obstacle the development of  Psylla Chinesefrom 2000 to 2002 and in 2010. The development rate of Psylla Chineseincreased quickly with temperature increased under 22.5℃, and increased slowly with temperature increased above 22.5℃, restraining when temperature increased to 35℃.The model was tested and confirmed well with the occurrence of Psylla Chinesefrom 2000 to 2002 and in 2010.This provided scientific basis for effective prevention on  Psylla Chinese. And it had important guidance significance for prevention and reduction disaster and sustainable development of agriculture practice.

Prediction of Meteorological Condition Suitability for Emergence ofCorn Borer in Inner Mongolia

WU Rongsheng| CHEN Suhua

2011, 32(3):  471-474. 

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It was supposed that meteorological suitability for emergence of core borer was the sum of product of suitability level determined by meteorological conditions and the corresponding weights. Prediction equation of meteorological suitability for emergence grade of corn borer in Inner Mongolia was established by using correlation method, based on meteorological data and the emergence data of corn borer from 1971 to 2005 in Inner Mongolia, considering physiology meteorological index of corn borer. The experiment results, from 2006 to 2010, showed that it was consistent between prediction and emergence, which indicated that the prediction equation could be used for monitoring and prediction of emergence grade of corn borer.

Study of Drought Prediction Based on Support Vector Machine

FAN Gaofeng,ZHANG Yong,LIU Miao,MAO Yanjun

2011, 32(3):  475-478. 

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Support Vector Machine(SVM)is an intellectual learning method based on the statistics theory. The SVM can solve problems of complicated nonlinear pattern recognition of spatial samples. Drought is a respond of water deficit that resulted from the complicated nonlinearity interrelationship of climate factors. Examined fifteen climate factors (southern oscillation index, subtropical high strength index and polar vortex strength index, etc.) by using the SVM method, this study had developed Zhejiang autumn drought prediction model which was based on the RBF kernel function of SVM. The best parameters of SVM for Zhejiang were determined by applying the cross validation method. The autumn droughts predicted by the model of this study agreed well with the truth facts. These results demonstrated the autumn drought prediction model with a better accuracy rate could act as an effective approach of switching climate factor prediction to meteorological hazard prediction.