Long-term water balance and conceptual model of a semi-arid mountainous catchment

Abstract. To achieve water resources sustainability in the water-limited Southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basin-wise stream flows. In Arizona, the Four Forest Restoration Initiative (4FRI) is being developed with the goal of restoring 2.4 million acres of ponderosa pine along the Mogollon Rim. Using the physically based, spatially distributed tRIBS model, we examine the potential impacts of the 4FRI on the hydrology of Tonto Creek, a basin in the Verde–Tonto–Salt (VTS) system, which provides much of the water supply for the Phoenix Metropolitan Area. Long-term (20 year) simulations indicate that forest removal can trigger significant shifts in the spatio-temporal patterns of various hydrological components, causing increases in net radiation, surface temperature, wind speed, soil evaporation, groundwater recharge, and runoff, at the expense of reductions in interception and shading, transpiration, vadose zone moisture and snow water equivalent, with south facing slopes being more susceptible to enhanced atmospheric losses. The net effect will likely be increases in mean and maximum stream flow, particularly during El Niño events and the winter months, and chiefly for those scenarios in which soil hydraulic conductivity has been significantly reduced due to thinning operations. In this particular climate, forest thinning can lead to net loss of surface water storage by vegetation and snow pack, increasing the vulnerability of ecosystems and populations to larger and more frequent hydrologic extreme conditions on these semi-arid systems.

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Spatial and temporal variability of soil horizons and long-term solute transport under semi-arid conditions

Canadian Journal of Soil Science ◽

10.4141/cjss2012-082 ◽

2013 ◽

Vol 93 (2) ◽

pp. 173-191 ◽

Cited By ~ 3

Author(s):

S. A. Woods ◽

M. F. Dyck ◽

R. G. Kachanoski

Keyword(s):

Spatial Distribution ◽

Water Balance ◽

Soil Water ◽

Temporal Variability ◽

Soil Water Balance ◽

Spatial And Temporal Variability ◽

Soil Horizons ◽

Deep Drainage ◽

Semi Arid

Woods, S. A., Dyck, M. F. and Kachanoski, R. G. 2013. Spatial and temporal variability of soil horizons and long-term solute transport under semi-arid conditions. Can. J. Soil Sci. 93: 173–191. Characterizing the spatial and temporal variability of deep drainage is required for quantifying risks to groundwater resources associated with chemicals released into the soil. A variety of approaches are available to characterize the spatial variability of deep drainage, including complex, spatially explicit hydrological models or simpler, distributed soil water balance models. There is no clear understanding which approach is most appropriate for a given landscape. In this paper we compare the spatial distribution of an applied chloride tracer to pedogenic nitrate and sulphate salts, subject to transport in the soil over decadal to millennial time scales, to characterize the relative spatial and temporal differences in deep drainage at a site in southern Saskatchewan. Comparison of the spatial distribution of the salts with differing soil residence times showed that the soil water balance and deep drainage fluxes have changed significantly over time in some parts of the landscape because of infilling of surface depressions as indicated by the presence of buried A horizons. At larger scales, the distribution of the salts showed very little correspondence to the spatial distribution and thicknesses of soil horizons (often used to infer spatial variability in soil water balance), but was more consistent with the scale of the surface topography. Thus it was concluded that spatial and temporal changes in surface topography (i.e., catchment area) were the primary factors responsible for the observed transport of the salts. We propose that this site is representative of the cold, semi-arid prairies and that these conclusions likely apply to this region.

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Assessing the performances of low impact development alternatives by long-term simulation for a semi-arid area in Tianjin, northern China

Water Science & Technology ◽

10.2166/wst.2014.228 ◽

2014 ◽

Vol 70 (11) ◽

pp. 1740-1745 ◽

Cited By ~ 16

Author(s):

Jinhui Jeanne Huang ◽

Yu Li ◽

Shuai Niu ◽

Shu H. Zhou

Keyword(s):

Water Balance ◽

Environmental Protection Agency ◽

Flood Control ◽

Hydrological Cycle ◽

Low Impact Development ◽

Northern China ◽

Evaluation Methods ◽

Important Place ◽

Semi Arid

For areas that are urbanized rapidly, the practice of low impact development (LID) has gained an important place in stormwater management and urban planning due to its capability and beneficial effects in restoring the original hydrological cycle. The performances of LID alternatives can vary substantially due to different climate conditions. This study investigated the performances of five LID alternatives under a semi-arid climate in northern China on water balance and flood control. A numerical model, Storm Water Management Model version 5 (US Environmental Protection Agency), was employed to run 10 years’ rainfall events for these objectives. Two evaluation methods were proposed in this study: the efficiency index for water balance and a performance radar chart. The investigation of the five LID alternatives revealed that these LID alternatives functioned differently in flood control and water balance, and porous pavement performed best in all indices except the lag time. The two evaluation methods, in conjunction with the long-term numerical simulation, can facilitate design and decision making by providing a clear picture of the performance and functions for these LID alternatives.

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Modeling the distributed effects of forest thinning on the long-term water balance and streamflow extremes for a semi-arid basin in the southwestern US

Hydrology and Earth System Sciences ◽

10.5194/hess-20-1241-2016 ◽

2016 ◽

Vol 20 (3) ◽

pp. 1241-1267 ◽

Cited By ~ 8

Author(s):

Hernan A. Moreno ◽

Hoshin V. Gupta ◽

Dave D. White ◽

David A. Sampson

Keyword(s):

Water Balance ◽

Ponderosa Pine ◽

Forest Restoration ◽

Snow Water Equivalent ◽

Water Balance Components ◽

Forest Thinning ◽

Physically Based ◽

Streamflow Extremes ◽

Semi Arid

Abstract. To achieve water resource sustainability in the water-limited southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basinwise streamflows. In Arizona, the Four Forest Restoration Initiative (4FRI) is being developed with the goal of restoring 2.4 million acres of ponderosa pine along the Mogollon Rim. Using the physically based, spatially distributed triangulated irregular network (TIN)-based Real-time Integrated Basin Simulator (tRIBS) model, we examine the potential impacts of the 4FRI on the hydrology of Tonto Creek, a basin in the Verde–Tonto–Salt (VTS) system, which provides much of the water supply for the Phoenix metropolitan area. Long-term (20-year) simulations indicate that forest removal can trigger significant shifts in the spatiotemporal patterns of various hydrological components, causing increases in net radiation, surface temperature, wind speed, soil evaporation, groundwater recharge and runoff, at the expense of reductions in interception and shading, transpiration, vadose zone moisture and snow water equivalent, with south-facing slopes being more susceptible to enhanced atmospheric losses. The net effect will likely be increases in mean and maximum streamflow, particularly during El Niño events and the winter months, and chiefly for those scenarios in which soil hydraulic conductivity has been significantly reduced due to thinning operations. In this particular climate, forest thinning can lead to net loss of surface water storage by vegetation and snowpack, increasing the vulnerability of ecosystems and populations to larger and more frequent hydrologic extreme conditions on these semi-arid systems.

Download Full-text