Autographic rain-gauge networks are designed to provide the density and distribution of stations so that

characteristics of the rainfall events both in time and over the region can be determined with sufficient

precision. Development and application of scientific methods for network design is probably one of the

most complex issues of hydrology.

In this study, annual rainfall data for rain-gauge stations of khorasan province consisting of Northern,

Razavi and Southern Khorasan were collected from Khorasan Regionl Water authority and geostatistical

analysis was made for finding the spatial correlation of them.

Finally, some additional rain-gauge stations were suggested based on errors of kriging method.

Geostatistical studies in Razavi Khorasan province show that adding 15 rain-gauges, decreases coefficient

of variation (CV) values from 14% to 17% in vast central parts and decreases approximately 7% in

western parts. Also, the results of mentioned analysis of whole provinces including North, South and

Razavi Khorasan show that 15 added rain-gauges, decreased CV values about 8% to 9% just in central

northern and eastern parts and approximately 23% in Western parts.