Climate change and its effect on reference crop evapotranspiration in central and western Inner Mongolia during 1961–2009

Water resource is one of the major constraints to agricultural production in central and western Inner Mongolia, where are characteristic by arid and semi-arid climate. Reference crop evapotranspiration (ET0) is an important part of water cycle in agricultural ecosystem, which has a direct effect on crop growth and yield. The implications of climate change on ET0 are of high importance for agriculture regarding water management and irrigation scheduling. The aim of this study was to analyze the variations in climate and its effect on ET0 in central and western Inner Mongolia over the period 1961 to 2009. For this purpose, data in ten meteorological stations across study area were collected and the FAO Penman-Monteith 56 method was used. Results showed that the average temperature, maximum temperature and minimum temperature increased by 0.49°C, 0.31°C and 0.70°C per decade during 1961–2009, respectively. In comparison, the daily temperature range decreased by 0.38°C per decade. The air relative humidity, sunshine hour, and 10-m wind speed decreased generally by 0.58%, 40.11 h, and 0.35 m/s per decade, respectively. Annual mean ET0 decreased significantly at a rate of 12.2 mm per decade over the periods, this was mainly due to the decrease in wind speed in the study area. The decrease in wind speed may balance the effect of the increase in air temperature on ET0. Variations in spatial distribution of ET0 and its main controlling factor were also detected among ten stations. Our results suggested that spatial and temporal distribution of ET0 should be considered regarding the optimization of water resource management for agriculture in central and western Inner Mongolia under foreseen climate change.

[1]  H. B. Mann.  Nonparametric Tests Against Trend , 1945 .

[2]  Wayne C. Palmer,et al.  A GRAPHICAL TECHNIQUE FOR DETERMINING EVAPOTRANSPIRATION BY THE THORNTHWAITE METHOD , 1958 .

[3]  M. Kendall,et al.  Rank Correlation Methods , 1949 .

[4]  T. Peterson,et al.  Evaporation losing its strength , 1995, Nature.

[5]  Yongkang Xue,et al.  The Impact of Desertification in the Mongolian and the Inner Mongolian Grassland on the Regional Climate , 1996 .

[6]  B. Itier.  Measurement and Estimation of Evapotranspiration , 1996 .

[7]  Mike Hulme,et al.  Evaporation and potential evapotranspiration in India under conditions of recent and future climate change , 1997 .

[8]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .

[9]  Axel Thomas,et al.  Spatial and temporal characteristics of potential evapotranspiration trends over China , 2000 .

[10]  Pradeep Kashyap,et al.  Evaluation of evapotranspiration estimation methods and development of crop-coefficients for potato crop in a sub-humid region , 2001 .

[11]  J. Palutikof,et al.  Climate change 2007 : impacts, adaptation and vulnerability , 2001 .

[12]  M. Roderick,et al.  The cause of decreased pan evaporation over the past 50 years. , 2002, Science.

[13]  Gerald Stanhill,et al.  Evaporative climate changes at Bet Dagan, Israel, 1964–1998 , 2002 .

[14]  P. Shi,et al.  Daily precipitation changes in the semi-arid region over northern China , 2004 .

[15]  J. Jacobs,et al.  Utility of Penman–Monteith, Priestley–Taylor, reference evapotranspiration, and pan evaporation methods to estimate pasture evapotranspiration , 2005 .

[16]  H. Zuo,et al.  Characteristics of climatic trends and correlation between pan-evaporation and environmental factors in the last 40 years over China , 2005 .

[17]  S. Regional,et al.  Characteristics of the Changes in Pan Evaporation over Northern China during the Past 45 Years and the Relations to Environment Factors , 2006 .

[18]  Liao Yao-ming,et al.  Spatial and temporal variations and controlling factors of potential evapotranspiration in China: 1956-2000 , 2006 .

[19]  Zhaodong Feng,et al.  Dry or humid? Mid-Holocene humidity changes in arid and semi-arid China , 2006 .

[20]  Michael L. Roderick,et al.  On the attribution of changing pan evaporation , 2007 .

[21]  J. Klaus,et al.  Recent climate trends and implications for water resources in the Catskill Mountain region, New York, USA , 2007 .

[22]  D. Rayner,et al.  Wind Run Changes: The Dominant Factor Affecting Pan Evaporation Trends in Australia , 2007 .

[23]  Vincent R. Gray.  Climate Change 2007: The Physical Science Basis Summary for Policymakers , 2007 .

[24]  Sam Drake,et al.  Soil properties, crop productivity and irrigation effects on five croplands of Inner Mongolia , 2007 .

[25]  Klaus Fraedrich,et al.  Changes of pan evaporation and reference evapotranspiration in the Yangtze River basin , 2007 .

[26]  T. Wilbanks,et al.  Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , 2007 .

[27]  F. Evrendilek,et al.  Implications of climate change for evaporation from bare soils in a Mediterranean environment , 2008, Environmental monitoring and assessment.

[28]  Z. Dawei,et al.  Analysis of Grain Production Changes and Food Security Problem in Inner Mongolia , 2009 .

[29]  Hossein Tabari,et al.  Evaluation of Class A Pan Coefficient Models for Estimation of Reference Crop Evapotranspiration in Cold Semi-Arid and Warm Arid Climates , 2010 .

[30]  P. Ciais,et al.  The impacts of climate change on water resources and agriculture in China , 2010, Nature.

[31]  Tao Sun,et al.  The temporal trends of reference evapotranspiration and its sensitivity to key meteorological variables in the Yellow River Basin, China , 2010 .

[32]  E. Dai,et al.  Attribution analyses of potential evapotranspiration changes in China since the 1960s , 2010 .

[33]  Causes of decreased reference evapotranspiration and pan evaporation in the Jinghe River catchment, northern China , 2012, The Environmentalist.

[34]  H. Tabari,et al.  Trend analysis of reference evapotranspiration in the western half of Iran , 2011 .

[35]  H. Tabari,et al.  Spatial distribution and temporal variation of reference evapotranspiration in arid and semi‐arid regions of Iran , 2012 .

[36]  Vijay P. Singh,et al.  Trends in reference evapotranspiration in the humid region of northeast India , 2012 .