农业地形气候区划的方法及其应用

本文论述了山区农业地形气候区划的原则,方法、指标和等级单位系统,监以福建省沙溪流域为例作了具体应用。文中介绍的山区农业气候资源空间分布的推算方法能有效地揭示山区农业气候资源的宏观与微观分异规律,从而为山区农业地形气候区划的开展创造了先决条件。

METHOD OF AGROTOPOCLIMATIC DIVISION AND ITS PRACTICE

Agrotopoclimatology is concerned with the local differences in climate arising from topography(including soil and vegetation influences), within a nominally uniform macroclimtic zone-insofar as these differences affect agriculture, In scale it lies between macroclimatology and microclimatology. Therefore the agrotopoclimatological method is very suitable for the agroclimatic analysis and division in mountainous area under the county(or even prefecture) in China. This paper consists of three parts: 1 It introduced the methods calculating the spatial distribution of agroclimatic resources(temperature, humidity, precipitation and wind speed) in mountainous area, proposed by the authors. The accuracy of these calculating methods is very satisfactory. They may effectively disclose the macro and micro variations of spatial distribution of agroelimatie resurces in mountainous area, creating the precondition for agrotopoelimatie division. 2 It discussed the methodology of agrotopoelimatie division, such as the principles, indices and classification system of division. The authors consider the formation of agrotopoclimate is governed mainly by the non-zonal element-elevation and local topography-on the basis of the horizontal agroclimatie zone(basal zone), and the task of agrotopoelimatie division is to disclose the spatial differentiation of climatic resources and its relation to the agriculture and forestry, serving the rational exploitation and utilization of agroclimatic resources in mountainous area. From this viewpoint they suggest that for the leading index of divison the thermal condition(such as accumulated temperature, annual mean temperature, etc.) may be adopted in the humid region, but in the arid region the water condition(such as annual precipitation, aridity, etc.)may be adopted at lower elevation and thermal condition at higher elevation. And the agrotopoclimatic division may be divided into four levels, i.e. belt, layer, sublayer and microtopograhieal environment type. 3 As an example of practice, the agrotopoelimatie division in the Shaxi River basin of Fujian Province is made. Because the studied region has a relatively large area(about 11800 km~2), the division is only developed at three levels, The whole basin is divided into 3 belts(the mountain subtropical, mountain warm-temperate and mountain frigid-temperate belts), 4 layers(the hot, warm, mild and cool layers)and 8 sublayers(in each layer there are two sublayers, the upper and the lower)as shown Fig. 1. In Table 3 the value of climatic effect of major microtopographical environment types is given, it provided the basis for selecting the optimum habitat of crop and forest. Finally, the evaluation of agroclimatic condition for the rational arrangement of crop and forest is also made.