استخدام طريقة مقلوب المسافة الموزنة IDW لإنتاج خرائط لبعض خواص التربة في محطة الابحاث الزراعية جامعة طرابلس

Abstract EN

The objective of the study was to determine the spatial differences of some physical and chemical properties of the soil samples of the research stations of the Faculty of Agricul-ture/University of Tripoli in April 2013.

The results were used to produce spatial maps in order to find out the spacial distribution for the following properties: Bulk density (BD), Gravimetric water content (GWC), soil salinity (EC) and soil pH using the inverse distance weighting (IDW) method.

The study was conducted on an area of approximately 13000 m2 and was divided into a 12 m x11 m grid to produce 100 survey units and 36 units were chosen and coordinated by a portable GPS device to collect the samples.

Tests were performed for both BD and GWC from depths 0-10 cm, 10-20 cm and 20- 30cm, while EC and pH analysis where done for samples from a depth of 30 cm.

Spatial maps were produced of continuous surfaces and quality that differed from one property to another according to the Root Mean Square Error (RMSE) values.

Based on the results, the values of RMSE varied (0.71, 0.82, and 0.86) for the GWC and (0.06, 0.13, 0.08) for the BD properties of the three depths, respectively.

Where as the RMSE values were (0.15, 0.84) for the pH and EC properties respectively.

The low RMSE values for BD maps at the first and third depths and the pH map showed a higher quality index for the maps.

While the relatively high RMSE values showed that the maps produced for both EC and GWC properties were lower quality.

This study concluded that it is possible to produce spatial maps of different quality for some soil properties within the field using IDW.

These maps can therefore be used to predict BD and pH properties in the field, while they are difficult to predict for EC and GWC.

Therefore, it is recommended to continue to explore the possibility of producing high-quality maps in other ways for these two properties, tak-ing into account the increase in the number of the samples.