Soil Surface Temperature

As an atmospheric parameter, air temperature plays an important role in providing energy for plants during their phonological stages. Soil surface temperature affects plants chemical reactions which is an important factor in its nutrient absorption. Therefore soil surface temperature is an essential parameter in the quality and quantity of agricultural products. Advances in artificial intelligence and their applications in every branch of science, provide us with tools to calculate and predict climatology parameters more accurately. In this paper we use artificial neural networks to predict future soil temperature from five measured parameters, namely ‘minimum soil temperature’, ‘moisture’, 'minimum and maximum air temperature’, and ‘total sunny hours per day’. The data is collected from Isfahan synoptic center and includes statistics from 1968 to 2005. From those, 80 percent is used as the training set and the rest is used as the validation data. Data analysis was performed through standard statistical methods using MATLAB. Learning methods employed are linear regression and artificial neural networks. Results show that a neural network, performs slightly better than linear regression but the amount of improvement does not justify the use of the more complicated models.

Keywords: forecast, air temperature, soil temperature, linear regression, artificial neural network, synaptic data.

1. Introduction

Quality and quantity of food production is considered as one of the most important problems in our world. Since agricultural capability of a region in food production depends on climate, studying factors affecting climate is of paramount importance. One of the major threats to food production is frost. For this reason, protecting pla...

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...s, east. Isfahan, with an area of 15.825 square kilometers and altitude of 1550.4 meters above sea level is located in the central Iranian plateau (VP of strategic planning and supervising the Statistical Center of Iran, 1385: 300). In order to check the temperature status of the city, the available period of record (2005-1951) of synoptic station in Isfahan has been used. The annual average temperature of the city is 16.2° degree Celsius. The average minimum and maximum temperature is 9.1 and 23.4 degree Celsius respectively which are corresponding to the months of January and July. Temperature difference between the warmest and the coldest month is 25.5 degree Celsius. The average monthly relative humidity is 40 percent, according to the station's long-term statistics. Overall annual precipitation is 122.8 mm and the average annual air pressure is 841.3 millibars.