青海牧区近10年牧草产量变化与气象条件的关系

利用DPS统计中的相关、回归等方法分析近10年青海高原牧区5站点牧草产量变化与气象因子的关系,并建立了牧草产量的气象条件多元回归拟合模型。结果表明：近10年来牧草产量的年最高值河南、甘德总体呈下降趋势,曲麻莱、海北、兴海总体呈上升趋势;5站点牧草产量5月变幅最大为兴海,变幅最小的为海北,6—8月变幅最大的是曲麻莱,变幅最小的是海北;5站点8月牧草产量形成期总体上日照充足,降水除河南阶段性较充沛外,其余受限制,温度除河南在牧草生长季内当光温出现匹配不当时呈负相关外,其余均受限制;气象因子与5站点年最高牧草产量的拟合模式拟合效果较好,均可通过0.01检验。     

阿克苏市冬小麦发育速度与气象条件的定量关系研究

通过几年冬小麦连续观测资料,定量分析了冬小麦各生育阶段与气象条件的关系,指出了冬小麦生育过程中栽培管理上出现的一些问题。     

归一化植被指数与降水量,土壤湿度的关系

归一化植被指数是描述植被绿度及生长状况的指数，由于植被生长依赖于环境条件因此ＮＤＶＩ与环境参量的关系是应用ＮＤＶＩ监测环境状况的基础。分别应用位于中国北部的干旱及半干旱地区的降水量资料对ＮＤＶＩ与降水量之间的关系地分析，结果表明仅在干旱半干旱地区生长季末的累积降水量与累积ＮＤＶＩ存在着显著的非线性关系，相关系数为０．７８。     

An analysis of yearly trends in growing degree days and the relationship between growing degree day values and reference evapotranspiration in Turpan area, China

The growth and development of crops is commonly regarded as a function of time alone. However, this approach can be inadequate due to temperatures which vary from year to year caused by global climate change. This prompted the development of the growing degree day concept, which incorporates information on both the passage of time and the temperature experienced by the crop plant during that time. Crop water requirements, which are estimated by multiplying reference evapotranspiration values by a crop-specific coefficient, play a crucial role in the management of hydrologic cycles on arable land. Consequently, it would be useful to identify the relationships between cumulative growing degree days and reference evapotranspiration, in order to develop new methods for predicting crop growth and development periods and calculating reference evapotranspiration. This paper describes annual trends in cumulative growing degree days values and their impact on grape growth. Three different methods for calculating cumulative growing degree days values were evaluated as well. Several key findings were achieved. First, for the period between 1952 and 1995, the cumulative growing degree days values for specific days of the year were normally distributed. Second, the relationship between the relative cumulative growing degree days value and the passage of time can be accurately described by using a cubic polynomial function. Third, the day-to-day change in the average relative cumulative reference evapotranspiration can be described using an exponential function of time, which can be used to calculate the relative cumulative reference evapotranspiration value for any given day of the year. Fourth, there was a significant correlation between the relative cumulative growing degree days and cumulative reference evapotranspiration values during the period between grape budding and maturity, which can be described using a cubic polynomial function. Finally, a new method for determining the ET0 value for any given day of the year was developed; this method requires only a knowledge of the CGDD-at-year-end and no sophisticated meteorological data.     

高CO2条件下贝加尔针毛对土壤干旱胁迫响应的试验研究

贝加尔针毛 (Stipa baicalensis) 是我国内蒙古东部和东北西部主要的地带性植被之一。通过人工模拟试验分析了CO₂浓度升高对贝加尔针毛的“施肥”效应, 结果表明:贝加尔针毛的生物量、生长量随CO₂浓度的升高而增加, 根中P的含量、叶中C、N、P的含量也随CO₂浓度的升高而增加。土壤干旱胁迫对贝加尔针毛的生物量、生长量的影响均为负效应, 且干旱程度的加重使影响更明显。干旱使针毛叶、根中的C、N含量增加。     

归一化植被指数与降水量、土壤湿度的关系

归一化植被指数是描述植被绿度及生长状况的指数，由于植被生长依赖于环境条件因此ＮＤＶＩ与环境参量的关系是应用ＮＤＶＩ监测环境状况的基础。分别应用位于中国北部的干旱及半干旱地区的降水量资料对ＮＤＶＩ与降水量之间的关系地分析，结果表明仅在干旱半干旱地区生长季末的累积降水量与累积ＮＤＶＩ存在着显著的非线性关系，相关系数为０．７８。     

西北地区玉米产量动态业务预报方法探讨

通过分析西北地区气候生产力与玉米产量的关系、土壤水分与降水量以及土壤水分与降水量和土壤初始含水量之和的关系表明:西北地区降水气候生产力与玉米产量、土壤水分与降水量和土壤初始含水量之和有着显著的相关性。在此基础上，利用玉米生长季内的降水量和播种期的土壤水分含量对Miami降水模型进行了改进，应用改进后的Miami降水模型开展以月为时间步长的玉米产量动态趋势预报，具有较为理想的业务服务效果。同时，利用此方法评价西北地区降水对玉米生长发育和产量形成的影响也非常适用。但是，由于此方法没有考虑灌溉水的作用，故不适用于灌溉农区。     

气候系统可预报性理论研究

介绍了作者近年来关于气候系统可预报性理论研究的一些工作,包括:非线性最快增长扰动理论以及在气候预测的可预报性研究中的应用;从一个新的角度研究了2类可预报性问题,并提出可预报性的3类子问题;根据计算不确定性原理,讨论了模式可预报性与机器精度的关系;探讨了可预报性与时空尺度的关系,建立了可预报性的相对观.     

黄河三角洲草场气候生产力与草业开发

分析了黄河三角洲地区主要栽培草种的气候生态适应性以及牧草生长季气候条件的优劣势。计算得出该区天然草场和人工草场的气候生产力、气候增产潜力，研究其时空分布规律，提出草场改良措施。结果表明：天然草场年气候生产力为９２１０—１１８２０ｋｇ／ｈａ。增产潜力为４５００—１０５００ｋｇ／ｈａ；种植紫花苜蓿的人工草场年气候生产力为２３７７５—２８０８０ｋｇ／ｈａ，增产潜力为６０００—１９５００ｋｇ／ｈａ。