Studies on the Relationship between Occurrence Degree of Cotton Bollworm and Rainfall

[Objective] The aim of the study is to investigate the factors causing the outbreak of cotton bollworm and to provide effective measures for controlling cotton bollworm. [Method] Based on the analysis of the data about insect and weather situation in Luyi County in 32 years,the meteorological prediction model was established for monitoring the quarterly or monthly occurrence trend of cotton bollworm. [Result] The cotton bollworm occurred slightly in the years with rainfalls of 3 months over 500 nm and severely in the years with rainfalls of 3 months less than 400 nm. The results of correlation analysis show that annual occurrence degrees of cotton bollworm and occurrence degrees of 4th generation of cotton bollworm are extremely negatively correlated with rainfall during June-August; the occurrence degrees of 3rd and 4th generations of cotton bollworm are also extremely negatively correlated with rainfall in July. [Conclusion] The occurrence of cotton bollworm in field is heavily influenced by rainfall in at its occurrence stage,moreover,the rainfall during June-August is the decisive factors influencing the occurrence of cotton bollworm.     

SCS模型在紫色土坡地降雨径流量估算中的运用

为了合理利用紫色土流域的水土资源,对紫色土坡地的降雨产生的径流量进行模拟,为农田非点源污染物输出模拟提供科学依据。此次试验地位于四川盆地中部,独特的紫色土资源与亚热带气候的最佳组合成为四川农业的主体区域,运用SCS模型计算试验小区在2005年的三场降雨产生的径流量,通过校正Ia和CN参数,小区计算值和实测值的误差分别为6.46%,10.22%和8.40%,得到了可信度较高的结果,同时说明了SCS模型在估算紫色土流域径流量的可行性。     

雷达-雨量计-粒子激光探测仪联合估测辽宁试验区降水量业务系统

利用雷达-雨量计-粒子激光探测仪联合校准法,设计了雷达-雨量计-粒子激光探测仪联合估测辽宁试验区降水量业务系统。结果表明,该系统可以提高缺乏雨量计或雨量计网密度较小地区降水量的观测精度,更好地预测洪涝、风暴等灾害的范围和强度。     

云南黄金走廊烟区气候类型分区研究（英文）

为了进一步评价气候条件对云南黄金走廊烟区烤烟生产的影响,通过对云南黄金走廊烟区10个州53个县1971-2004年共34年的光照、温度、降雨量等主要气象因子数据进行分析,以烤烟生育期均温、生育期最高气温、生育期最低气温、生育期累积日照时数、生育期降水量、生育期蒸发量、生育期平均相对湿度等为指标,基于SPSS系统聚类方法将云南黄金走廊烟区划分为4个气候类型区域,并分析了各类型的气候特点,结果表明生育期均温、最高温、累计日照和平均相对湿度在4个气候类型区之间差别较小,而生育期最低温、降雨量和蒸发量在4个气候类型区之间具有明显差异,可能是影响黄金走廊烟区特色烤烟品质的关键。     

聊城市春季人工增雨作业天气条件分析

利用1970～2005年聊城市春季降水和高空探测资料,分析了春季降水的气候特征、主要影响天气系统及降水云系的变化。结果表明：西北冷锋和黄淮气旋是聊城市春季适合实施人工增雨作业的最为有利和作业机会最多的天气系统,3月以层状云为主要作业对象,4～5月则以层积混合云为主要作业对象。     

放牧对典型草原区土壤水分及其对降雨响应规律的影响

为研究放牧对典型草原区土壤水分及其对降雨响应规律的影响,通过在内蒙古西乌珠穆沁旗设置试验,对禁牧区和放牧区5cm、10cm、15cm、30cm层土壤体积含水率和降雨量进行监测和分析。分析表明:放牧会导致草原地上生物量减少,植被抑制土壤蒸发的作用减弱,降雨转化率降低;放牧会破坏0~15cm层植被根系,根系吸水能力减弱,上层土壤水分向下运移,从而放牧区0~15cm层含水量小于禁牧区,30cm层却大于禁牧区;禁牧区与放牧区5cm、10cm和15cm层土壤水分对降雨的响应相似,单次或累积降雨量大于10mm时,土壤含水量即有显著增加,但会因干旱间隔(两次降雨事件之间无降雨日数)时间的不同而变化,禁牧区含水量更加敏感,增加幅度较大;禁牧区30cm层土壤水分对降雨的响应有滞后现象,单次降雨量大于30mm或累积降雨量大于20mm且干旱间隔时间≤3d时,才有显著增加,放牧区30cm层只在干旱间隔较短(≤2d)的连续大降雨后有明显波动;禁牧区0~30cm层土壤水分的增加都与降雨量、降雨强度极显著相关,放牧区0~15cm层与降雨量极显著相关,0~10cm层与降雨强度极显著相关。     

4种常用气象作图软件在绘制站点雨量图中的应用

使用ArcGIS、Surfer、GrADS、NCL 4种气象常用的作图软件进行了站点雨量图绘制,介绍了其较为详细的操作步骤、部分源程序及所得的图像,并对每种软件在绘制站点雨量图时的优劣进行了比较。结果表明,4种软件在绘图中各有优势,使用者可根据喜好自行选择。推荐使用NCL和Surfer软件来绘制站点雨量图,这2种软件在站点数据的插值和图像的绘制中相对更为便捷,绘制的图形也极为美观。     

2000—2015年中国土地荒漠化连续遥感监测及其变化

以植被覆盖度作为荒漠化评价的指标,利用2000—2015年序列影像计算的年均植被覆盖度和气温、降水等数据,分析不同地区荒漠多年间荒漠化动态的变化过程、自然因素对土地荒漠化动态的影响以及人类活动对土地荒漠化的贡献。结果表明:我国土地荒漠化呈整体得到初步遏制,荒漠化土地持续减少,但局部地区呈扩大的趋势;全国大部分地区气象因子未发生显著变化,西藏东部和云南山区气温上升和降水下降对土地荒漠化起到了促进作用;国家的政策和人工造林、退耕还林和保护天然林等重大工程对遏制我国土地荒漠化具有重要作用。     

Rainfall concentration for increasing corn production under semiarid climate

The ridge and furrow farming of rainfall concentration (RC) system is being promoted to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. In the system, plastic-covered ridges serve as rainfall harvesting zones and furrows serve as planting zones. In recent years, however, the current RC practices are still confined to rural family units for very limited supplemental irrigation purposes. To adopt this system for large-scale use in the semiarid region and bring it into full play, it is necessary to test the befitting rainfall range for RC farming. A field study (using corn as an indicator crop) combined with rainfall simulation was designed to determine the effects of RC practices on soil water content, crop yield and water use efficiency (WUE) under three rainfall levels (230 mm, 340 mm and 440 mm) during the growing seasons of 2006 and 2007. The results indicated that with the rainfalls ranging within 230-440 mm, RC system can increase soil water content in 0-100 cm and temperature conditions in the topsoil (0-10 cm) in furrows by 5-12% and 0.7-1 °C, respectively. The corn seedlings emerged 1-2 days earlier, the developmental stages generally occurred earlier, and the plant height and total dry matter all significantly increased (P < 0.05). In 2006, compared to conventional flat (CF) practice, the grain yield and WUE in the RC system increased by 75.4% and 73.3%, respectively at 230 mm rainfall, and by 36.7% and 40.2%, respectively at 340 mm rainfall, but there was no significant difference between the RC₄₄₀ and CF₄₄₀ patterns. In 2007, the grain yield and WUE were 82.8% and 77.4%, respectively higher in the RC₂₃₀ plots than in the CF₂₃₀ plots, 43.4% and 43.1%, respectively higher in the RC₃₄₀ plots than in the CF₃₄₀ plots, and 11.2% and 9.5%, respectively higher in the RC₄₄₀ plots than in the CF₄₄₀ plots. Combining yield and WUE, it could be concluded that the optimal rainfall upper limit for RC system is below 440 mm rainfall in the experiment. In the case of corn, the adoption of RC practice in the 230-440-mm rainfall area will make the system more attractive during the whole growth period and offer a sound opportunity for sustainable farming under semiarid climate.