Study on the Change Character of Double Rice Cold Damage in Hunan and Hubei Province during the Past 50 Years

Based on the meteorological data of representative meteorological stations in Hunan and Hubei from 1961 to 2008 years,the change character of double rice cold damage under the background of climate change were analyzed adopting 30 years glide accumulation method.The analysis showed that the 30 years sliding cumulative days of mild low-temperature during spring sowing in Hunan and Hubei were decreased in the recent 50 years,as well as the 30 years sliding cumulative days of moderate low-temperature in central south Hubei,northern and western Hunan.However,there was an increase in southern Hunan,so was the 30 years sliding cumulative days of severe low-temperature.The 30 years sliding cumulative days of mild low-temperature in May reduced in Hunan and Hubei.Instead,that of moderate low-temperature in May in central south Hubei was on the rise,and it was opposite in northern and southern Hunan,but there was no obvious change in western Hunan.The 30 years sliding cumulative days of severe low-temperature showed a decreasing tendency in May in central south Hubei,northern and western Hunan,and southern Hunan showed a contrary tendency.The 30 years sliding cumulative days of mild cold dew wind in Hunan and Hubei were decreased,that of moderate cold dew wind in central south Hubei,northern and western Hunan had the same tendency,but there was a contrary tendency in southern Hunan.The 30 years sliding cumulative days of severe cold dew wind was decreased in central south Hubei and increased in western Hunan,without cold dew wind in northern and southern Hunan.

Monitoring and Early Warning of Paddy Rice Low Temperature Cold Damage in Ningxia with the Support of GIS and RS

The low temperature cold damage of paddy rice is the major agricultural meteorological disaster in Ningxia.The real-time monitoring and early warning of low temperature cold damage are very important to develop the advantages,avoid the disadvantages and reduce the disaster losses.Based on the prior researches on the low temperature cold damage indexes of paddy rice,we improved the small grid reckoning method of temperature and the reckoning precision with the support of GIS.By using the multitemporal remote sensing data,the paddy rice planting zone was picked.The calculation results of low temperature cold damage monitoring indexes were combined with the paddy rice planting zone,which judged the grade distribution and zone of low temperature cold damage in real time.Meanwhile,the low temperature cold damage of paddy rice was done the early warning,and the automatic monitoring early warning system was developed by using the weather forecast data.This method and system were applied to the business works,and the monitoring and early warning products of paddy rice low temperature cold damage business were made.The monitoring results basically corresponded with the actual situation,and the better monitoring service effect was gained.

Study on the Monitoring and Pre-warning of Cold Damage of Early Rice in Summer Based on GIS

Based on GIS techniques,a climatology model,and several types of geographic data such as longitude,latitude,altitude,cold damage data in Guangxi were corrected according to specific geographic details of 1 km×1 km.Considering growing conditions and cold-index of rice in Guangxi,the real-time monitoring and pre-warning on the occurrence,development and intensity and scope of rice in Guangxi were realized.The monitoring effects of damage process in middle and late May of 2009 was comparatively accordant with the actual situations.

Cold Damage Risk Assessment of Double Cropping Rice in Hunan, China

Combined with remote sensing data and meteorological data, cold damage risk was assessed for planting area of double cropping rice （DCR） in Hunan Province, China. A new methodology of cold damage risk assessment was built that apply to grid and have clear hazard-affected body. Each station cold damage annual frequency and average annual intensity of cold damage was calculated by using 1951-2010 station daily mean temperature and simple cold damage identification index. On this basis, average annual cold damage risk index was obtained by their product. The spatial analysis models of cold damage risk index about double-season early rice （DSER） and double-season later rice （DSLR） were established respectively by the relation of average annual cold damage risk index and its geographic factors. Critical threshold of level of average annual cold damage risk index for DSER and DSLR were respectively divided by the correlative equation of cold damage annual frequency and average annual intensity of cold damage. 2001-2010 planting area of DCR, acquired by time series analysis of MOD09AI 8-d composite land surface reflectance product, was as target of assessment. The results show average annual intensity of cold damage is exponential function of cold damage annual frequency, average annual cold damage risk index is directly proportional to cold damage cumulant and cold damage annual frequency, and is inversely proportional to happen times of cold damage and the square of statistical time sequence length. Cold damage risk of DSER is higher than DSLR in Hunan Province. In the 10-yr stacking map, DCR planting in low risk area accounted for 11.92% of total extraction area, in moderate risk area accounted for 69.62%, in high risk area accounted for 18.46%. According to the cold damage risk assessment result, DCR production can be guided to reduce cold damage losses.

Risk Assessment of Maize Cold Damage in Heilongjiang Province in Recent 30 Years

In order to make the relevant risk departments and the agricultural producers have a clearer understanding of maize cold damage, the data of daily average temperature of 83 meteorological stations in Heilongjiang Province from 1986 to 2015, and the risk assessment model of maize cold damage in northeast China were used, and the risk index values of maize cold damage in Heilongjiang Province from 1986 to 2015 were calculated. And according to the risk index values, Heilongjiang Province was divided into five risk areas. The results showed that the high risk areas and the sub-high risk areas of maize cold damage in Heilongjiang Province in recent 30 years were in Daqing and Suihua cities, the medium risk areas were located in the center of the Songnen Plain and other regions, the sub-low risk areas were located in the Songnen Plain, and most of the rest were the low risk areas.

Spatio-temporal Analysis of Changes in Winter Wheat Cold Damage with Meteorological Elements in Huang-Huai-Hai Plain from 2011 to 2020

The Huang-Huai-Hai Plain is one of the typical agri-ecosystems in China,which suffers from cold damage frequently resulting in substantial economic losses.In order to monitor the changes in the occurrence of cold damage in an effective and large-scale manner,and to determine their meteorological causes,this paper collected low temperature data from the agricultural meteorological stations and remote sensing data of MODIS from 2005 to 2015,and constructed a monitoring model of cold damage to winter wheat in Huang-Huai-Hai Plain based on the Logistic regression model.This model was used to analyze the spatio-temporal changes of cold damage of winter wheat in Huang-Huai-Hai Plain from 2011 to 2020,and correlation analysis was performed with the spatio-temporal changes of meteorological factors to ascertain how they affect cold damage.The results show that the harm from cold damage in winter wheat has been gradually decreasing from 2011 to 2020,and the cold damage areas with high probability and high frequency are moving from north to south.The meteorological elements with the greatest impacts on the degree of cold damage from stronger to weaker are heat,precipitation and sunshine duration,whose influence has spatial variability.

Application of TERRA/MODIS images, TM images and weather data to assess the effect of cold damage on rice yield

Data assimilation is extensively applied in agricultural remote sensing application.However,integration of multi-temporal and high spatial resolution images with crop growth model to evaluate the effect of cold damage on paddy rice was still lacking.In this paper,authors applied data assimilation combining LANDSAT/TM,a series of terra MODIS images with SIMRIW model to detect how cold damage affected paddy rice yield per unit in the Wuchang county,Heilongjiang province for the year 2006.In the study,MODIS images selected corresponding to a series of the key rice growth phases were utilized to retrieve daily LAI values that were needed in the SIMRIW model.Meanwhile,TM was applied to accurately extract paddy rice sown areas.The study results showed that the yield per unit was 10,628.5840 kg/ha under cold damage condition,which was little less than 10,768.3210 kg/ha under optimal condition.Moreover,the ratio of the calculated yield per value under cold damage condition to the actual value of paddy rice yield per unit was 0.56.The result was better than that acquired in USA and Japan.The results of this study expected to provide suggestions to policy-makers and reference to related research.

Mitigative Effects of Foliage Spraying and Root Irrigation of ALA on Banana Plantlets Exposed to Cold Stress

[Objective] This study aimed to investigate the effect of ALA applied by foliage spraying and root irrigation on banana plantlets exposed to cold stress. [Method] After applied by foliage spraying and root irrigation with 5-aminolevulinic acid （ALA） at four different concentrations, ＂Brazil banana＂ plantlets were placed in artificial climate boxes at 7 ℃ to imitate low-temperature stress. [Result] The results showed that ALA application by both foliage spraying and root application can significantly increase SOD and POD activities, and reduce O2- generation rate, MDA content and relative conductivity in leaves of banana plantlets, as well as raising proline content, soluble protein content and relative water content, and maintaining the stability of chlorophyll. Foliage application of ALA within concentration range of 0.505.00 mg/L had best effect, which increased the chlorophyll content and reduced the relative conductivity and MDA content significantly compared to root irrigation at the same concentration, and raised SOD and POD activities by 64.5% and 12.3% respectively at 5 mg/L compared to their counterparts by root irrigation. [Conclusion] Foliage spraying of ALA can better mitigate the injuries to banana plantlets caused by low-temperature stress.

Application of surface-defect detector in CDCM at Baosteel

The continuous descaling and cold rolling mill（ CDCM） is renow ned for its high capacity and high speed,which makes it very difficult to manually check the surface quality of steel strips. A surface-defect online detector and its components,which are employed in a CDCM at Baosteel,are introduced,including the electrical,imaging,processing and softw are systems. To evaluate the effectiveness of the application of this detector,and to reduce the number of false alarms,the optimal number of defect samples is determined,pre- and post-processing rules are established,and talking-voice and color-changing alarms are employed.

Quantifying Multi-hazards and Impacts Over Different Growth Periods of Maize:A Study Based on Index Construction

Owing to the complexity and variability of global climate,the study of extreme events to ensure food security is particularly critical.The standardized precipitation requirement index(SPRI)and chilling injury index(I_(Ci))were introduced using data from agrometeorological stations on the Songliao Plain between 1981 and 2020 to identify the spatial and temporal variability of drought,waterlogging,and low-temperature cold damage during various maize growth periods.Compound drought and low-temperature cold damage events(CDLEs)and compound waterlogging and low-temperature cold damage events(CWLEs)were then identified.To measure the intensity of compound events,the compound drought and low-temperature cold damage magnitude index(CDLMI),and compound waterlogging and low-temperature cold damage magnitude index(CWLMI)were constructed by fitting marginal distributions.Finally,the effects of extreme events of various intensities on maize output were examined.The findings demonstrate that:(1)There were significant differences in the temporal trends of the SPRI and ICiduring different maize growth periods.Drought predominated in the middle growth period(MP),waterlogging predominated in the early growth period(EP)and late growth period(LP),and both drought and waterlogging tended to increase in intensity and frequency.The frequency of low-temperature cold damage showed a decreasing trend in all periods.(2)The CDLMI and CWLMI can effectively determine the intensity of CDLEs and CWLEs in the study area;these CDLEs and CWLEs had higher intensity and frequency in the late growth period.(3)Compared to single events,maize relative meteorological yield had a more significant negative correlation with the CDLMI and CWLMI.