Water is a primary driver of the physical, geochemical and biological evolution of the Earth. The near-surface hydrosphere (exosphere) includes the atmosphere, cryosphere (glacial and polar ice), the biosphere, surface water, groundwater, and the oceans. The amounts of water in these various reservoirs of the hydrologic cycle have likely varied significantly over the past 700 Ma, with the cryosphere and continental biosphere reservoirs likely showing the most dramatic variations relative to the modern. For example, 700 Ma, during snowball-Earth conditions, the planet may have been almost entirely enveloped in ice, whereas throughout much of the Phanerozoic, greenhouse conditions predominately prevailed and the Earth had a much smaller cryosphere. Similarly, before about 444 Ma and the proliferation of land plants, the continental biosphere reservoir would have effectively non-existent. However, today, plants play a critical role in storage and transfer of water within the hydrologic cycle. Because the amount of water in the exosphere is thought to have remained relatively constant during the past 700 Ma, variations in the amounts of water held by the in the various exogenic reservoirs exert concomitant effects on other reservoirs in the exosphere. We present a conceptual and numerical model that examines variations in the amount of water in the various reservoirs of the near-surface hydrologic cycle (exosphere) during the past 700 Ma and quantify variations in the rates of exchange of water between these reservoirs in deep time. Variations in the sizes of major reservoirs are primarily controlled by changes in global average temperature, and the movement of water between the atmosphere, surface water, and ocean reservoirs varies in concert with the waxing and waning of the cryosphere. We find that variations in the sizes of major reservoirs are primarily controlled by changes in global average temperature, and the flux of water between the atmosphere, surface water, and ocean reservoirs varies in concert with the waxing and waning of the cryosphere, with some fluxes decreasing to 0.0 kg/yr during snowball-Earth conditions. We find that the amount of water precipitated from the atmosphere to the cryosphere increases from greenhouse conditions to -10.5°C and decreases from -10.5°C to snowball-earth conditions, highlighting "tipping-point" behavior due to changes in temperature and cryosphere surface area. The amount of surface runoff to the oceans varies in proportion to the amount of water removed from the surface water reservoir and transferred into the continental biosphere. Variations in the movement of water between near-surface reservoirs that are driven by the waxing and waning of the cryosphere and emergence and growth of plant life thus have significant implications for the transfer of weathering products to the oceans and could contribute to short-term (<1 Ma) variations in seawater composition and isotopic signatures. / Ph. D. / Water drives the evolution of the planet, and the distribution of water throughout Earth’s atmosphere and surface has varied during the geologic past. The amounts of water in the atmosphere, polar ice, the biosphere, surface water, groundwater, and the oceans have changed during the past 700 million years, and the polar ice and biosphere reservoirs have undergone the most significant changes during that time. For example, at extremely cold conditions the planet may have been covered in ice, and during warmer conditions the planet may have been covered in little to no ice. Similarly, before 444 million years ago, the biosphere on Earth’s continental surface was almost non-existent. The evolution of land plants after 444 Ma resulted in an increase in the amount of water in the biosphere. Changes in the amounts of water in one reservoir of water over time will have effects on the other reservoirs of water in the water cycle. We produce a numerical model that examines changes in the sizes of water cycle reservoirs and the movement of water between those reservoirs during the past 700 million years. Variations in reservoir sizes are primarily controlled by changes in global average temperature, and the movement of water between the atmosphere, surface water, and ocean reservoirs varies with changes in the amount of polar ice on Earth. We find that total annual precipitation to polar ice increases from greenhouse temperatures to - 10.5°C and decreases from -10.5°C to cold snowball-earth temperatures due to changes in both temperature and the surface area of polar ice. The amount of surface runoff to the oceans varies in proportion to the amount of water removed from the surface water reservoir and transferred into the continental biosphere. Variations in the movement of water between reservoirs that are driven by the waxing and waning of polar ice and the growth of plant life have significant implications for the movement of dissolved material to the oceans and could contribute to short-term (<1 Ma) variations in seawater chemistry.

From the Proceedings of the 1975 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 11-12, 1975, Tempe, Arizona / The importance of water resources and an increasing interest on improvement of out environment have identified the urgent need for methods to predict river response due to various changes resulting from proposed water resource planning. Fluvial geomorphology and hydraulic elements that are related to the interpretation and modeling of response to the problem are presented. Interpretation of alluvial rivers should be preceded by a qualitative analysis and information is presented which should be adequate to carry this out in most cases. This should be followed by a quantitative evaluation of channel response and water sediment routing using theory supplemented by physical and mathematical model studies of the system.

From the Proceedings of the 1973 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 4-5, 1973, Tucson, Arizona / All groundwater in fort valley is presently found in perched aquifers. The regional water table in the area is estimated to lie at a depth of approximately 1750 feet. Groundwater reservoirs are perched on impermeable clay zones located at the base of alluvial units. Groundwater is also found in highly fractured volcanic zones overlaying impermeable clay zones. Perched aquifers also occur in interflow zones above either impermeable clays or unfractured volcanics. Groundwater in fort valley is the result of infiltration or runoff and from precipitation. This recharge water infiltrates the alluvium or fractured volcanic rocks until an impermeable zone is reached where it becomes perched groundwater. Greatest well yields come from these recharge aquifers; their reliability is largely dependent on precipitation and runoff. Most wells in the fort valley area supply adequate amounts of water for domestic use.

From the Proceedings of the 1973 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 4-5, 1973, Tucson, Arizona / The geohydrology of a portion of the Santa Catalina Mountains including the definition of aquifer systems in the foothills was studied in order to calculate groundwater recharge to the Tucson basin. This underlying groundwater aquifer is the only source of Tucson, Arizona's water supply. A well network, well logs, geologic profiles, and a water level contour map were used as source information. Recharge was found to occur in some sections of washes and close to the mountains where washes cross or coincide with faults. Significant recharge to sand and gravel aquifers occurs directly through faults and joints. Little of the surface runoff is thought to recharge local aquifers because of low permeability layers beneath the alluvium and the short duration of the flows. Recharge calculation using the Darcy equation was subject to considerable error; but flow net analysis showed the total recharge to be 336 acre-feet per year representing about 50 acre feet per mile of mountain front per year.