Multidecadal changes in moisture condition during climatic growing period of crops in Northeast China

In this study, the following were used to evaluate the multidecadal changes in moisture condition during climatic growth period of crops in Northeast China from 1961 to 2010: (1) the daily climate variables gathered from 101 meteorological stations in Northeast China for 1961-2010; (2) FAO (Food and Agriculture Organization) Penman-Monteith equation; (3) 80% guaranteed probability for agro-climatic indicators; and (4) the daily average temperature stably passing 0°C, which is the threshold temperature of climatic growth period for crops. Reference crop evapotranspiration (ET0) and relative moisture index were further calculated. The results showed that Northeast China’s climate in the main agricultural areas over the past 50 years was warmer and drier in general, with a growing range and intensity of drought. From 1961 to 2010, when the daily average temperature stably passed 0°C, the average annual total precipitation (P) and ET0 with 80% guaranteed probability in Northeast China both emerged as decreasing trends with averages of 555.0mm and 993.7mm, respectively. However, the decline in P was greater than that of annual total ET0. As a result, the annual relative moisture indices sharply decreased with an average of -0.44, mostly fluctuating from -0.59 to -0.25. As far as spatial distributions were concerned, the inter-regional reductions in P and relative moisture index over the past 50 years were conspicuous, especially in some agricultural areas of central Heilongjia...

Source: Physics and Chemistry of the Earth, Parts ABC - August 7, 2015 Category: Science Source Type: research