The Study On Climatic Regionalization Of Alfalfa Based On GIS Technology In China

The alfalfa is not only a perennial leguminous grass but also one of the largest planting grass varieties ranging from the nation even to the world.Due to its advantages of widely adaptability,highly yields,good quality and some others,it is commonly called the "king of the pasturage".Dexter(1930),Heinrishs(1960),Lanson(1963)and Smith(1961) and other scientists from the U.S.A have found that there is a definite link between fall dormancy and cold resistance of the Alfalfa.The former tends to indicate the latter. Moreover,the lower the fall dormancy of the Alfalfa is,the stronger the cold resistance is. It proved to be a highly correlation among fall dormancy of the Alfalfa,regeneration,productivity and cold resistance.As the understanding about alfalfa's fall dormancy characteristic is rather superficial,also the introduction and extension region of the alfalfa in china has not been the similarly main introduction basis for fall dormancy in the USA,the problems like blindly introducing a fine variety,promoting planting in inaptitude areas brings the negative effect of the alfalfa production.The research combines Chinese alfalfa's different fall dormancy characteristics with the regional climate characteristics with the help of GIS technology thereby bringing up the reasonable planting programmers of alfalfa,reducing the climate risk of alfalfa production in line with international practice. Also it can bring the production of Chinese alfalfa stepping into a Scientific,pecialization's new realm.In summing up predecessors' experimental and research results,the research makes sure of the effect of alfalfa's geographical distribution of five major ecological indicators of climate and the weight via consultanting experts and using AHP model.Moreover it establishes climate of alfalfa Index System Division.Through the space superimposed in GIS analysis,it enables the division of Chinese alfalfa in five climatic indicators to make the spatial database stack space.Also it makes the use of the space module statistics of GIS integrate Chinese alfalfa's climate and climatic division.The study draws several conclusions as follows:1.According to the average climax database of 2300 meteorological stations from abroad,established five main ecological index factor stations respectively.The database which includes the information as follows:annual accumulated temperatures above zero centigrade,the annual precipitation,the extremely lowest temperature,frost-free days and the annual average temperature.2.The Chinese alfalfa integrated climate is divided into seven regional divisions:the areas of regionâ… accounts for about 2297997 square meters which represents 23.8%of the whole national areas;the areas of regionâ…¡accounts for about 2276993 square meters which represents 23.6%of the whole national areas;the areas of regionâ…¢accounts for about 1233065 square meters which represents 12.8%of the whole national areas;the areas of regionâ…£accounts for about 1746247 square meters which represents 18.1%of the whole national areas;the areas of regionâ…¤accounts for about 868017 square meters which represents 9.0%of the whole national areas;the areas of regionâ…¥accounts for about 567015 square meters which represents 5.9%of the whole national areas;the areas of regionâ…¦accounts for about 652825 square meters which represents 6.8%of the whole national areas.3.The climatic characteristics of Huanghuai region is considered to be most favorable to the plantation and development of alfalfa which is also an important production base to develop the production of alfalfa.The cold resistance of the variety should be paid more attention in the northeast region.The resisting hotness and wetness of the variety should be used in the Yangtze River basin which is fir for the alfalfa plantation in Part of Qingzang altiplano region while adaptable variety needs to be adopted.Whereas in northwest region,there must be conditions of irrigation for the growth of alfalfa,and in the meanwhile should select the variety of resisting cold.In other words,we should select the variety of resisting cold.4.We summarize the performance test and fall dormancy characteristics of all the variety of alfalfa from each region according to the description of the climate condition which is fit for all kinds of the variety of alfalfa.Then,the variety of alfalfa which is fit for planting in each region will be recommended.