Precipitation variability in Northeast China from 1961 to 2008

Variability in precipitation plays an important role in the way it influences ecological and agricultural water requirements. This is especially true for semi-humid and semi-arid regions exemplified in certain regions in Northeast China. The temporal variation and spatial distribution of precipitation in Northeast China from 1961 to 2008 was investigated in this study by means of a linear fitted model, the Mann–Kendall test, the moving t-test, and the Morlet wavelet and Kriging (exponential) interpolation methods. Results indicate that: (a) the monthly precipitation rate varied considerably wherein summer precipitation accounted for 65.7% of the annual total value; (b) a decreasing trend in precipitation was found in the data obtained from 77 (annual) and 80 (summer) of the 98 meteorological stations throughout a 48 year period (from 1961 to 2008) while climate jumps were detected in 77% (annual) and 67% (summer); (c) three climate jumps and periods of 2.3 and 3.3 years (significant at a 95% confidence level) were detected on a regional scale; (d) the mean annual and summer precipitation rates decreased in a southeastern to northwestern trajectory throughout the 48 year period due both to the influence of the East Asian monsoon and to topography. All these findings can help provide rational regulatory and managerial policy in relation to water resources to maintain the health of the various ecosystems that make up Northeast China.