为了预测未来气候变化对中国东北三省玉米需水量的影响,该文在对中国东北三省近26a来玉米生育期内参考作物蒸散量变化及玉米需水量分析的基础上,结合《排放情景特别报告》(Special Report on Emissions Scenarios,SRES)的两种排放情景A2...为了预测未来气候变化对中国东北三省玉米需水量的影响,该文在对中国东北三省近26a来玉米生育期内参考作物蒸散量变化及玉米需水量分析的基础上,结合《排放情景特别报告》(Special Report on Emissions Scenarios,SRES)的两种排放情景A2(强调经济发展)和B2(强调可持续发展)预估的未来气候情景,研究探讨了未来气候情景下中国东北三省玉米需水量的变化趋势。结果表明,未来气候变化情景下,东北三省玉米需水量距平百分率大多表现为增加的趋势,最高可增加77.8%,而且不同地理环境及气候差异下,各地空间分布上也不尽相同。A2情景下,到2040年玉米需水量距平百分率平均增加27.2%,到2070年玉米需水量距平百分率平均增加34.5%,到2100年玉米需水量距平百分率平均增加42.9%;B2情景下,到2040年玉米需水量距平百分率平均增加28.6%,到2070年玉米需水量距平百分率平均增加33.3%,到2100年玉米需水量距平百分率平均增加37.3%。可见,未来中国东北三省水资源可能更趋于短缺状况。展开更多
新疆维吾尔自治区地域辽阔,气候特征空间差异性显著。准确估算各地区的参考作物腾发量(ET0)是新疆节水灌溉设计的基础。该文选用6种计算公式利用新疆4个典型气候区的气象资料计算了ET0。并以Penm an-M on te ith方法作为标准,对其它方...新疆维吾尔自治区地域辽阔,气候特征空间差异性显著。准确估算各地区的参考作物腾发量(ET0)是新疆节水灌溉设计的基础。该文选用6种计算公式利用新疆4个典型气候区的气象资料计算了ET0。并以Penm an-M on te ith方法作为标准,对其它方法进行评价。结果表明在新疆各气候区1948Penm an法估算的ET0值较FAO-24 Penm an与FAO-24R ad iation方法更接近于P-M法的计算结果;在缺少资料的地区,H argreaves方法或湿润区用P riestley-T ay lor方法均可以得到与P-M法估值相当的结果;同时分析了P-M法计算的ET0值和水面蒸发量之间的关系,为利用水面蒸发资料估算新疆地区ET0值提供参考。展开更多
参照腾发量ET0的实时预测对实时灌溉预报很重要。通过对普通天气预报信息进行解析,取得可用的合理数据,利用Penm an-M on te ith方法估算了北京大兴试区近10年逐日参照腾发量,最后与由实测气象数据计算的结果进行了对比分析。结果表明:...参照腾发量ET0的实时预测对实时灌溉预报很重要。通过对普通天气预报信息进行解析,取得可用的合理数据,利用Penm an-M on te ith方法估算了北京大兴试区近10年逐日参照腾发量,最后与由实测气象数据计算的结果进行了对比分析。结果表明:解析气象因子与实测数据中,日照时数的相关系数为0.99,风速为0.90;t检验值日照时数为376.9042,风速为122.4295,远远大于t分布相应临界值2.576(α=0.01),表明其可以认为是来自一个近似的总体样本。由日最低气温确定的实际水汽压和由实测相对湿度计算的实际水汽压,二者相关系数达到0.93,t检验值为153.3015。运用天气预报信息计算预测的ET0与实测数据用Penm an-M on te ith方法计算的ET0相比,相关系数达到0.9613,t检验值为209.1194,说明二者具有高度显著的线性相关性。如果日常天气预报准确度能够达到90%以上,用此理论预测参照腾发量将具有较大的参考价值和实际意义。展开更多
Despite the observed increase in global temperature, observed pan evaporation in many regions has been decreasing over the past 50 years, which is known as the ＂pan evaporation paradox＂. The ＂pan evaporation parado...Despite the observed increase in global temperature, observed pan evaporation in many regions has been decreasing over the past 50 years, which is known as the ＂pan evaporation paradox＂. The ＂pan evaporation paradox＂ also exists in the Tibetan Plateau, where pan evaporation has decreased by 3.06 mm a-2 （millimeter per annum）. It is necessary to explain the mechanisms behind the observed decline in pan evaporation because the Tibetan Plateau strongly influences climatic and environmental changes in China, Asia and even in the Northern Hemisphere. In this paper, a derivation based approach has been used to quantitatively assess the contribution rate of climate factors to the observed pan evaporation trend across the Tibetan Plateau. The results showed that, provided the other factors remain constant, the increasing temperature should have led to a 2.73 mm a-2 increase in pan evaporation annually, while change in wind speed, vapor pressure and solar radiation should have led to a decrease in pan evaporation by 2.81 mm a-2, 1.96 mm a-2 and 1.11 mm a-2 respectively from 1970 to 2005. The combined effects of the four climate variables have resulted in a 3.15 mm a-2 decrease in pan evaporation, which is close to the observed pan evaporation trend with a relative error of 2.94%. A decrease in wind speed was the dominant factor for the decreasing pan evaporation, followed by an increasing vapor pressure and decreasing solar radiation, all of which offset the effect of increasing temperature across the Tibetan Plateau.展开更多
文摘为了预测未来气候变化对中国东北三省玉米需水量的影响,该文在对中国东北三省近26a来玉米生育期内参考作物蒸散量变化及玉米需水量分析的基础上,结合《排放情景特别报告》(Special Report on Emissions Scenarios,SRES)的两种排放情景A2(强调经济发展)和B2(强调可持续发展)预估的未来气候情景,研究探讨了未来气候情景下中国东北三省玉米需水量的变化趋势。结果表明,未来气候变化情景下,东北三省玉米需水量距平百分率大多表现为增加的趋势,最高可增加77.8%,而且不同地理环境及气候差异下,各地空间分布上也不尽相同。A2情景下,到2040年玉米需水量距平百分率平均增加27.2%,到2070年玉米需水量距平百分率平均增加34.5%,到2100年玉米需水量距平百分率平均增加42.9%;B2情景下,到2040年玉米需水量距平百分率平均增加28.6%,到2070年玉米需水量距平百分率平均增加33.3%,到2100年玉米需水量距平百分率平均增加37.3%。可见,未来中国东北三省水资源可能更趋于短缺状况。
文摘新疆维吾尔自治区地域辽阔,气候特征空间差异性显著。准确估算各地区的参考作物腾发量(ET0)是新疆节水灌溉设计的基础。该文选用6种计算公式利用新疆4个典型气候区的气象资料计算了ET0。并以Penm an-M on te ith方法作为标准,对其它方法进行评价。结果表明在新疆各气候区1948Penm an法估算的ET0值较FAO-24 Penm an与FAO-24R ad iation方法更接近于P-M法的计算结果;在缺少资料的地区,H argreaves方法或湿润区用P riestley-T ay lor方法均可以得到与P-M法估值相当的结果;同时分析了P-M法计算的ET0值和水面蒸发量之间的关系,为利用水面蒸发资料估算新疆地区ET0值提供参考。
文摘参照腾发量ET0的实时预测对实时灌溉预报很重要。通过对普通天气预报信息进行解析,取得可用的合理数据,利用Penm an-M on te ith方法估算了北京大兴试区近10年逐日参照腾发量,最后与由实测气象数据计算的结果进行了对比分析。结果表明:解析气象因子与实测数据中,日照时数的相关系数为0.99,风速为0.90;t检验值日照时数为376.9042,风速为122.4295,远远大于t分布相应临界值2.576(α=0.01),表明其可以认为是来自一个近似的总体样本。由日最低气温确定的实际水汽压和由实测相对湿度计算的实际水汽压,二者相关系数达到0.93,t检验值为153.3015。运用天气预报信息计算预测的ET0与实测数据用Penm an-M on te ith方法计算的ET0相比,相关系数达到0.9613,t检验值为209.1194,说明二者具有高度显著的线性相关性。如果日常天气预报准确度能够达到90%以上,用此理论预测参照腾发量将具有较大的参考价值和实际意义。
基金The European Commission (Call FP7-ENV-2007-1), No.212921National Basic Research Program of China, No.2010CB428406
文摘Despite the observed increase in global temperature, observed pan evaporation in many regions has been decreasing over the past 50 years, which is known as the ＂pan evaporation paradox＂. The ＂pan evaporation paradox＂ also exists in the Tibetan Plateau, where pan evaporation has decreased by 3.06 mm a-2 （millimeter per annum）. It is necessary to explain the mechanisms behind the observed decline in pan evaporation because the Tibetan Plateau strongly influences climatic and environmental changes in China, Asia and even in the Northern Hemisphere. In this paper, a derivation based approach has been used to quantitatively assess the contribution rate of climate factors to the observed pan evaporation trend across the Tibetan Plateau. The results showed that, provided the other factors remain constant, the increasing temperature should have led to a 2.73 mm a-2 increase in pan evaporation annually, while change in wind speed, vapor pressure and solar radiation should have led to a decrease in pan evaporation by 2.81 mm a-2, 1.96 mm a-2 and 1.11 mm a-2 respectively from 1970 to 2005. The combined effects of the four climate variables have resulted in a 3.15 mm a-2 decrease in pan evaporation, which is close to the observed pan evaporation trend with a relative error of 2.94%. A decrease in wind speed was the dominant factor for the decreasing pan evaporation, followed by an increasing vapor pressure and decreasing solar radiation, all of which offset the effect of increasing temperature across the Tibetan Plateau.
