نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار پژوهش مؤسسه تحقیقات کشور برنج، رشت، ایران
2 کارشناس ارشد مؤسسه تحقیقات کشور برنج، رشت، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The sampling design, samples size, and their distances have important roles in determining the quality of the environmental variables map. This study was conducted to optimize sampling management (size, distance, and sampling design) with integrating of the scale invariant, variability, and the balance of the cost of measurement-estimation variance. The soil studied variables were total nitrogen, available phosphorous (P) and available potassium (K) in paddy fields of Guilan province. Four different sampling scales were considered in a paddy field of 306 ha. The scales consisted of 357 soil samples with dimensions of 100 × 50 m; 127 soil samples with dimensions of 200 × 100 m; 74 soil samples with dimensions of 400 × 200 m; and the fourth scale consisted of 43 soil samples with dimensions of 800 × 400 m. The spatial structure and scale invariance were assessed using variogram and the Hurst parameter, respectively. The strategy of the balance between the costs of measurement- variance estimation was economically efficient in the measurements of these variables, which showed self-similarity and scale invariance. The optimum size and distance for available P and K were 240 samples with a rectangular network pattern (75m × 150m) along the 44° north-west direction. However, the strategy of the balance between the costs of measurement- variance estimation is not suitable for those variables that show heterogeneity and scale variance, e.g. total nitrogen in the studied region.
کلیدواژهها [English]