Therefore, in the planning of greenhouse greenhouses, it is necessary to combine the local conditions to consider the geographical latitude, the slope and slope direction of the ground, the construction orientation of the greenhouse, the time of use and the time of sunshine. In short, the factors that determine the distance of greenhouse greenhouses can be summarized as the following six points: (1) Geographic latitude The higher the geographic latitude, the smaller the solar elevation angle, the larger the shadow length, and the greater the distance required for greenhouses. However, blindly seeking a large distance will also cause the entire park area to be underutilized to form land dross.

Therefore, under the condition of agreement, according to the different requirements of the cultivation crops on the number of illumination hours, the sunshine hours without occlusion can be appropriately reduced to reduce the distance of the greenhouse; (2) The influence of the ground slope on the greenhouse greenhouse distance It is remarkable, so when constructing a solar greenhouse, try to choose a land with a flat terrain or a southward slope. If the site has a northward slope, the greenhouse greenhouse distance should be properly added, but the general slope should not be greater than 9 degrees;

(3) When the ground slope is punctual to the local upper slope, the influence of the ground slope on the greenhouse greenhouse distance is small, but when the site is selected, the south slope direction should be selected as much as possible to reduce the greenhouse shed along the east-west length. The height difference; (4) The increase of the sunshine time with the increase of the sunshine time requires the distance of the greenhouse to increase, so that the greenhouse greenhouse distance will not be too large and combined with crop growth requirements.

Generally, when the sun angle is low on the winter solstice day, the illumination is ensured to be 6 to several hours, and the growth requirements of different crops can be appropriately reduced. (5) The orientation of the construction of the greenhouse is to be the orientation of the greenhouse, although the orientation does not affect the cost. But it will directly affect the distance of greenhouse greenhouses. When the greenhouse shed is facing south, the distance is small; with the addition of the east or west, the greenhouse shed distance increases. How to judge the orientation and size of the greenhouse, and to consider the factors such as the local climatic conditions. Generally, in the cold regions of high latitudes, the temperature in the early morning is relatively low and the temperature in the evening is relatively high. The morning curtains are generally late and the afternoon curtains are also late. In order to obtain more light, the greenhouse is usually 1 to a few degrees south to the south. As a matter of course, it is generally not appropriate to exceed 31 degrees

(6) The season changes the change at any time. The solar declination angle will also change. The declination angle of the winter solstice is -degree, and the declination angle of the spring or winter is -degree. The distance from the declination angle to the greenhouse can be appropriately reduced, but the seasonality of different crops should be considered when considering the influence of the solar declination angle on the distance.