延安地区太阳高度角和方位角建模及核桃树阴影变化分析
Modeling Solar Altitude and Azimuth, and Analyzing Walnut Tree Shadow Patterns in Yan’an Region

本研究利用天文学和数学模型，结合MATLAB编程，通过分析树木的受光情况，建立了太阳高度角和太阳方位角模型，并构建了锥形树冠模型来近似树冠形状，对延安地区核桃树阴影的高度、方向和面积变化情况进行了详尽的分析。首先，根据延安的经纬度计算出时角和方位角，并建立太阳高度角和太阳方位角模型，得出了一年中每日每时的太阳高度角和太阳方位角数据。随后，利用影长公式和阴影方向角公式，得到核桃树每小时的阴影高度、方向变化和面积变化情况。本研究为了解核桃树的生长环境提供了重要的参考价值，有助于优化核桃树种植布局和光照条件，提高核桃林的产量和质量，同时也为类似植物的生长环境分析提供了新的研究思路。
This study utilized astronomical and mathematical models, combined with MATLAB programming, to analyze the sunlight conditions of trees. We established models for solar altitude and azimuth, and constructed a conical tree crown model to approximate the shape of the tree crown. A detailed analysis of the changes in height, direction, and area of shadows cast by walnut trees in the Yan’an region was conducted. Initially, the solar hour angle and azimuth were calculated based on the lati-tude and longitude of Yan’an, and the models for solar altitude and azimuth were established to obtain the data on daily and hourly solar altitude and azimuth throughout the year. Subsequently, using the shadow length formula and shadow direction angle formula, we determined the hourly changes in shadow height, direction, and area for the walnut trees. This study provides significant reference value for understanding the growth environment of walnut trees, aiding in the optimiza-tion of walnut tree planting layout and lighting conditions to enhance the yield and quality of wal-nut forests. Furthermore, it offers a new research approach for analyzing the growth environment of similar plants.