Implementation of Southern Arizona Soil Moisture Observational Network

May 22, 2006

The NOAA Earth System Research Laboratory will implement a Soil Moisture Observational Network across southern Arizona's San Pedro River Basin. At each of the six sites, soil moisture and temperature will be measured as well as basic meteorological parameters at the surface (temperature, humidity and rainfall). The objective is to work with the Colorado River Basin Forecast Center and National Weather Service (NWS) Office of Hydrologic Development to improve flash flood forecasting and better understand how soil information (i.e. moisture, texture, and temperature) can be included in hydrologic models. Operations are scheduled to commence 1 June 2008, ahead of the onset of the North American Monsoon season. These data will then be shared with the NWS Colorado Basin River Forecast Center in real time.

Southern Arizona’s San Pedro River recharges ground water storage, and provides water for human needs and those of agriculture. However, during the North American monsoon season (July-September), heavy precipitation events can cause severe flooding in the San Pedro basin. The goals of the project include providing a data set that can be used to evaluate the performance of the operational hydrological models, and in particular distributed hydrologic models. The closely nested stations located in the headwaters of the Babocomari River will be used to examine the impact of land use and soil type heterogeneity on scales smaller than the spacing of a model grid cell. Overall model evaluation will utilize the stations, which cross cut the San Pedro River Basin. Because long-term soil measurements are of interest from a climatological standpoint, the sites will be installed as permanent installations.

With a dry climate and a rapidly growing population, the state of Arizona is facing a growing risk for the impacts of flash floods and drought. Accurate soil information is needed to support flash flood forecasts and warnings and can be of use to water resource management studies. The Soil Moisture Observational Network originates from NOAA’s cross-cutting goal of Integrated Water Resource Services, and will be a long-term project to support NWS R&D on distributed hydrologic model as well as daily operations.

Contact: Robert Zamora