From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona / Structural models for single family residential water demand in Tucson, Arizona are identified using cross-sectional data from the 1980 census. Indoor and outdoor water usage are modeled separately. Indoor water demand appears to be a simple function of household size and fraction of the population that are children. Outdoor water demand is a function of several variables, including length of residence in the area and lot size. The indoor and outdoor models are shown to be significantly different. The impact of the results on forecasting water demand is discussed.

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona

Complete issue of the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona / Flood flows and water quality in the Southwest are roust dramatically influenced by short, intense rainstorms. Runoff from these storms has been modeled with some success. One key element that has often been overlooked, however, is the importance of intra-storm rainfall distribution on runoff response. Actual storms were modeled for small experimental watersheds in the Southwest using different time increments of intra-storm rainfall. Increments of 5 minutes or less proven satisfactory for accurate hydrograph simulation. As increments became longer than 5 minutes, the ability to simulate actual hydrographs became increasingly difficult. Increments of 30 minutes or longer proved unacceptable for most storms. Hydrologic models must be sensitive to short time increments of intra-storm rainfall to accurately predict peak flows in the Southwest. Watershed treatments will be more cost-effective if their design considers intense bursts of intra-storm rainfall in addition to total storm volume.

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona / The Beaver Creek Watershed is located in southern Coconino and southeastern Yavapai Counties, Arizona. This 472 square mile watershed contributes to Beaver Creek which flows into the Verde River. The objectives of this study were: 1) to monitor a network of stock tanks in the watershed on a bi-weekly basis to document seasonal fluctuations in water levels over one year; 2) to investigate the impact of stock tanks on local hydrology by determining the number of times the tanks fill during one year; and 3) to determine a set of dependent variables which would quantify stock tank performance, and a set of independent variables representing characteristics of the tanks and their drainage basins which could affect the performance of the tanks. The relative importance of each of these independent variables in influencing tank performance was then determined through statistical analysis.

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona / Almost all runoff from small rangeland watersheds in the Southwest is the result of intense thunderstorm rainfall, and the variability of this rainfall is an important runoff-influencing factor in such areas where high intensity rainfall dominates watershed hydrology. Thunderstorm runoff estimates for small rangeland watersheds can be made using a multitude of estimating techniques ranging from simple table and graph procedures to utilizing high-speed computers, and even the most sophisticated models greatly simplify the rainfall input. In this paper, the combined effects of rainfall quantity and intensity, and the rainfall energy factor, EI, in the Universal Soil Loss Equation (USLE), were analyzed, and simple procedures for estimating semiarid rangeland runoff volumes were developed. Equally good correlations with runoff volumes were found for EI, and for total storm rainfall times maximum rainfall intensities for 5, 10, and 30 minutes and the square of the maximum 60-minute rainfall.

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona / Forest openings affect a snowpack during both accumulation and melt phases. At any point in time, a snowpack is the integrated result of all accumulation, redistribution, and melt processes that have taken place before the time of measurement. Since snowpacks do not always have distinct accumulation and melt phases, it is difficult to determine the effect that an opening will have on a snowpack regime. This paper describes an analysis of the effects of openings in Arizona ponderosa pine forests on snowpacks in and adjacent to the openings, using readily available input variables.

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona / A discrete form of the water balance equation is used to illustrate the interaction among precipitation, runoff, percolation below the root zone, bare soil evaporation, plant transpiration, and plant available soil moisture. Under rangeland conditions, water availability is often the limiting factor in plant survival and growth. Therefore, the water balance equation is used, together with soils data and water use efficiency factors, to estimate annual aboveground net primary production of perennial vegetation.

From the Proceedings of the 1983 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1983, Flagstaff, Arizona