A Study on the Evolution Characteristics of Agricultural Climate Resources and Wheat and Rice Potential Productivity During the Last 30 Years in Jianghuai Region
|School||Nanjing Agricultural College|
|Course||Crop Cultivation and Farming System|
|Keywords||Jianghuai region Climatic change Potential productivity GIS (Geographic Information System)|
The Intergovernmental Panel on Climate Change Fourth Assessment Report issued during 1906-2005 global mean surface temperature rose higher(0.74±0.18℃),over the past 50 years of warming rate 0.13±0.03℃/10a,this is almost the past 100 years twice the rate of warming. Climate change trend of China and the general trend of global climate change is the same. Nearly China has a temperature rise 1.1℃in 100 years. The northwest, north China, northeast China warming is most obvious in winter; our country the most warm period in the eighties of the 20th in 100 years,In order to study the impacts of climatic changes on agriculture, we selected Jianghuai as an example, and 32 meteorological stations in Jianghuai China were covered, the climatic factors including light, temperature, precipitation as well as data about the growing periods and yields of the main crops in Jinaghuai China were collected. Based on Geographic Information System(GIS), we analyzed the spatial-temporal patterns annual、wheat and rice growing seasons of temperature, radiation and precipitation from 1981 to 2008 in Jianghuai China. Based on Mechanism Method, we gradually Corrected crop potential productivity models on the parameters of light, heat, and calculated the photo synthetic potential, light-heat potential, and climatic Potential of main crops, e.g. wheat and rice Jianghuai China.The main research results were summarized as follows:(1) Recent 30 years annual、wheat and rice growing seasons and earing and maturing detes mean temperature、earing and maturing detes mean maximum temperature and earing and maturing detes mean minimum temperature has increased trend in Jianghuai region. Recently 30 years annual mean temperature is 15℃, Annual、Wheat and rice growing season mean temperature per ten years increasing rate is respectivety 0.6℃、0.7℃and 0.4℃.Wheat and rice earing and maturing dates mean temperature per ten years increasing rate is respectivety 0.5℃and 0.2℃. Wheat and rice earing and maturing dates mean maximum temperature and earing and maturing detes mean minimum temperature per ten years increasing rate is respectivety0.35 ℃、.0.38℃and 0.63℃、0.58℃.Annual mean temperature and the wheat and rice whether growing seasons mean temperature or earing and maturing dates mean temperature、earing and maturing dates mean maximum temperature and earing and maturing detes mean minimum temperature the spatial distribution is increasing gradually from north to south in Jianghuai region; (2) Recent 30 years annual、wheat and rice growing seasons solar radiation,annual、wheat and rice growing seasons sunshine hours are reduce trend in Jianghuai region. Annual solar radiation decreasing rate is 6.9 MJ/a,wheat and rice growing seasons solar radiation decreasing rate is respectivety 2.8 MJ/a、1.9 MJ/a, wheat and rice earing and maturing dates solar radiation decreasing rate is respectivety 2.5 MJ/a、1.6 MJ/a.Annual、wheat and rice growing seasons sunshine hours decreasing rate is respectivety 4.4 h/a、4.7 h/a、4.3 h/a, wheat and rice earing and maturing dates sunshine hours decreasing rate is respectivety 1.1 h/a、0.7 h/a.Annual、wheat and rice growing seasons solar radiation,annual、wheat and rice growing seasons sunshine hours are gradually reduce in the spatial distribution from north to south, (3) Recent 30 years annual、wheat and rice growing seasons precipitation are mild increasing trend in Jianghuai region, annual、wheat and rice growing seasons precipitation per ten years increasing rate is respectivety 10 mm、17 mm and 15 mm.The wheat and rice precipitation whether annual or growing seasons the spatial distribution is increasing gradually from north to south in Jianghuai region. (4) Recent 30 years wheat and rice photosynthetic potential productivity regression rate is respectivety 18 kg/ha and 61 kg/ha, wheat light-heat potential productivity is linear rising trend, its increasing rate is 52 kg/ha,but rice light-heat potential productivity is linear downward trend, its regression rate is 24 kg/ha.Wheat and rice whether photosynthetic potential productivity or light-heat potential productivity are presented reduce trend gradually in Jianghuai region, and in the same area, photosynthetic potential productivity is reduce different decades. (5) The south of Anhui is increment larger space, and increment smaller area in Jiangsu Dafeng of wheat. Jiangsu Xuzhou and Anhui northern Dangshan、Haozho、Suxian and Anhui southern Hefei、Chaohu and Anqing, such area with a greater increment space of rice, Jiangsu Huai’an、Lvsi、Changzhou、Wuxian and so on, such area with a lesser increment space.