Variation Characteristics and Trends of Temperature and Evaporation in Huanren County in Recent 60 Years

Based on the data of daily average temperature and evaporation in Huanren County from 1953 to 2012, the changing characteristics and trends of temperature and evaporation were analyzed by using climatic tendency rate and sliding Ttest method. The results showed that annual av- erage temperature in Huanren County showed a significant increasing trend in recent 60 years, and its linear tendency rate was 0.26 ℃/10 a. Tem- perature increase was in other seasons except for summer. There was a sudden change in annual average temperature in 1987, and winter average temperature changed suddenly in 1969 and 1985, while there were no sudden changes in average temperature in other seasons. Annual average evaporation also decreased, and its linear trend rate was -8.19 mm/10 a; average evaporation tended to decrease in spring and summer and in- creased in autumn and winter. In a word, the climate tended to be warm and dry in Huanren County.

Analysis on Changing Trends of Temperature and Precipitation in Huanren County over the Past 58Years

Based on data of temperature and precipitation in Huanren County from 1953 to 2010, linear trend analysis and mutation detection of temperature and precipitation sequence were carried out using linear trend, Mann-Kendall detection and dryness of the de Martonne method. The results showed that during 1953-2010, annual average temperature, annual average maximum and minimum temperature in Huanren County showed an increasing trend; annual precipitation showed a decreasing trend; there was a downward trend in annual dryness. The mutation of annu- al average temperature, annual average maximum and minimum temperature appeared in 1978, 1987 and 1982 respectively; there was no mutation of annual precipitation and dryness. On the whole, the climate of Huanren County tended to be warm and dry over the past 58 years.

Response of Plant Climatic Productivity to the Warming and Drying Trend in Huanren in the Past 58 Years

[Objective]The research aimed to study the response of plant climatic productivity to warming and drying tendency in Huanren in the past 58 years.[Method]Based on the temperature and precipitation data in Huanren from 1953 to 2010,using trend analysis,Thornthwaite Memorial model and Mann-Kendall detection method,change characteristics of climate and plant climatic productivity in Huanren were analyzed,and the regression evaluation model between plant climatic productivity and temperature and precipitation was established.[Result]Annual average temperature in Huanren presented a significant upward trend,and its linear tendency rate was 0.29℃/10 a;annual precipitation presented a decreasing trend,and its linear tendency rate was-13.29 mm/10 a;dryness presented a declining trend.The warming and drying trend was obvious in Huanren.Plant climatic productivity presented a significant increasing trend,and its linear tendency rate was 8.39 g/（m2·10 a）.Plant climatic productivity was closely related to precipitation and temperature.[Conclusion]The research could provide basis and reference for the adjustment of agricultural structure and sufficiently playing the advantages of climate resources in Huanren.