| This article, based on GIS technology, has a research on the grid distributing (500mx500m) of the Agricultural Climate Resource in Viet Nam and builds the crop climate delimitation on Viet Nam with high-resolution data. The content and the result are as follow:1. having a research on the climate changing characteristics within the recent 50 years in Viet Nam, and the yearly changing characteristics of the Viet Nam climate with the atmospheric background of global warming. The result shows that the temperature is increasing in Viet Nam and the precipitation is tremendously decreasing in the recent 50 years. The changing climate, pointing to agriculture, will have a remarkable influence on the crop producing. Hence, it is highly necessary to have a sophisticate research on agricultural climate resource and its delimitation, and to improve and have a better exploitation of agricultural environment, and to readjust the agricultural configuration.2. building the grid-framed DEM of Viet Nam and the grid-layer chart with the properties of gradient and direction with geographical information system technology (GIS) and contour line with rate of 1:500,000. Based on the theory of mountainous region climatology, this article measures out the solar radiation amount in different period (monthly, seasonly and yearly) in Viet Nam with resolution of 500m x 500m. The amount of solar radiation in different period is figured out through the climatologic method of radiation. The interpolation model of temperature and precipitation of Viet Nam is built by using different inserting methods according to the elements that reflect the climate in different dimension scales. With the model and the GIS technology, the high-resolution dimensional grid-layer chart of monthly temperature and precipitation in Viet Nam is built.3. Several characteristics of resources of solar radiation, temperature and precipitation are found out based on grid analysis. The distinct monsoon climate results in the seasonly and regional characteristics of crop producing in Viet Nam. The high temperature and rain come in the same season. This enables to expand the growth of temperature-relying crops. The various agricultural climate resources are beneficial for the crops producing in Viet Nam.4. As a test, the research also deals with evaluating and analyzing thequality of agricultural climate resource by using information from crop producing model. Through the measurement on the delimitation of climate productivity and Miami model, the national yearly plant yield in Viet Nam is about 7.86x108t. The average plant yield per square kilometer is 1983t. But for the divergences on the temperature and precipitation, the general plant yield is different. The climate productivity across Viet Nam can be divided into six zones and smaller superposed region also exist between these big zones according to the result from the grid. This show the influences different terrains have on climate.5. Lining out the regional delimitation for different crops in Viet Nam according to the actual unit productivity and producing index, by using analysis method such as relative analysis, multianalysis and sequence statistic analysis. According to the real practice, the paddy rice in Viet Nam is planted in summer and winter-spring. Although the regions for them are different, the total area for both of them occupies 72% of the whole country. The corn is mainly planted in spring and autumn because of the soil and irrigation condition. The area for corn planted in spring occupies 76% of the country while there is only 70.31% for corn in autumn. Beans, for its short budding period and lower requirement for heat, can be planted four times a year. The level and growth area are all different at each time. The area for beans planted in summer comes to the top rate and it occupies 87.18% of the country, while it is only 66.32% as the minimum rate for the bean planted in spring.
|
PDF Full Text Request