Spearman's correlation coefficient in statistical analysis

In our research, we present a study to determine the required sample size (the water body) to estimate the Spearman correlation coefficient in terms of its strength and direction for the variables of the total annual evaporation and annual humidity so that we have a symbol for the total annual evaporation (a) and the annual total humidity (b) for three provinces in Iraq, which are Baghdad, Najaf and Babel for a period of ten Years 1991 to 2000, we know that the Simple Linear Correlation Coefficient (Spearman) is a tool for people who work in statistical analysis. The result of the correlation of total annual evaporation and annual total humidity in Baghdad governorate was negative and strong, and the result of the correlation of total annual evaporation with the humidity of Najaf Governorate was positive and weak, and the result of the correlation between total annual evaporation and annual humidity in Babil Governorate was positive and weak.