Salt Balance of Moderately Saline-Alkaline Rangeland Soil and Runoff Water Quality from Rainfall Simulation Studies near Moab,Utah U.S.A.

A Walnut Gulch rainfall simulator was used to determine runoff water quality and salt balance of a Sandy Loam moderately saline-alkaline site containing 0.27%of gypsum near Moab,Utah.Four rainfall intensities corresponding to 2,10,25 and 50-year storm return intervals were applied to dry soil.During each rainfall simulation,time-stamped runoff samples were also collected for the determination of ions concentration.Soil water and solute content by depth increments were determined before and after simulations.All correlation coefficients between the applied simulation water and the amounts of Cl-,SO42-,NO3-and sum of anions in runoff water were positive and ranged between 0.922 and 0.999.The correlation coefficients for Ca2+,Mg2+,Na+,K+and sum of cations ranged between 0.783 and 0.983.We concluded from the data analysis that:(1)The amounts of ions in simulation water and in runoff water represent less than 1%of sum of the soil soluble content before rainfall simulation.(2)The CEC contained about 250%the sum of cation in saturated extract.(3)The very small amount of gypsum in the soil contained 50%the sum of saturated extract ions.This means that special attention should be paid to CEC and gypsum content in the management of such soils.Moreover,when modeling runoff and water quality from soils with these properties the modelers must include suitable subroutines considering gypsum and CEC of the soil for accurate prediction of runoff water quality.

Rangeland restoration in Jordan:Restoring vegetation cover by water harvesting measures

Restoration of the degraded rangelands in Jordan using mechanized water harvesting and native species planting has become key to enhancing and maintaining the productivity and resilience of fragile ecosystems.A balanced interaction between the rangeland's hydrology and vegetation states is vital for achieving long-term sustainability.To gain a better insight into the impact of restoration on surface runoff and erosion and its role in recovering the ecosystem functions,we used the Rangeland Hydrological and Erosion Model(RHEM)to simulate various vegetation scenarios.Our research aims to understand the rangelands'water and sediment dynamics and the vegetation transition states of the ecosystem through evaluating the current(degraded)situation,assess the restoration approach on improving the degraded status(restored),and investigate the long-term sustainability of the restoration approach compared with historical rangeland conditions(baseline).Several scenarios were developed with rangeland experts,local community representatives,and measurements at protected and restored areas to represent the rangeland conditions.We found that restoration of the degraded Badia areas will decrease annual surface runoff from an average of 23.5 to 19.1 mm/year and soil erosion rate from 3.3 to 1.3 tons/ha.With time,restoration can bring back rangeland water and sediment dynamics closer towards the baseline conditions,which were 16.9 mm/year runoff rates and 0.85 ton/ha/year soil loss.The results indicate that restoration is a promising methodology to restore the degraded ecosystem and approximate the environment's historical hydrological regime.