UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Water Resources Division A SUMMARY OF METHODS FOR THE COLLECTION AND ANALYSIS OF BASIC HYDROLOGIC DATA FOR ARID REGIONS By s. E. Rantz and T. E. Eakin Prepared in cooperation with the California Department of Water Resources OPEN-FILE REPORT 7}- JoS N o I tI') o Menlo Park, California o ~ February 16, 1971 CONTENTS Page Abstract------------------------------------------------------------- 1 Introduction--------------------------------------------------------- 2 Purpose and scope----------------------------------------------- 2 Acknowledgments------------------------------------------------- 5 Description of the Basin and Range province-------------------------- 5 Physical setting------------------------------------------------ 5 Climate--------------------------------------------------------- 7 Hydrologic classification of valleys---------------------------- 8 Current methods of studying the elements of the hydrologic budget---- 10 Precipitation--------------------------------------------------- 10 Soil moisture-------------------------------~------------------- 18 Evapotranspiration---------------------------------------------- 21 Evapotranspiration by phreatophytes------------------------ 21 Evaporation from bare soil---------------------------- 28 Evapotranspiration by irrigated crops---------------------- 30 Evaporation from open-water surfaces---------------------------- 31 Water yield----------------------------------------------------- 36 Streamflow-correlation method------------------------------ 37 Crippen method--------------------------------------------- 38 Langbein-Nace method--------------------------------------- 40 Langbein method-------------------------------------------- 40 Bagley method---------------------------------------------- 42 Riggs-Moore method----------------------------------------- 43 Oltman-Tracy method---------------------------------------- 43 Mundorff method-------------------------------------------- 44 Hely-Peck method------------------------------------------- 44 Burnham method--------------------------------------------- 47 Channel-geometry method------------------------------------ 48 Evapotranspiration method---------------------------------- 49 Discussion of methods-------------------------------------- 49 Surface water-------------------------------------------------------- 52 Problems in determining discharge------------------------------- 52 Determination of discharge from stage-discharge relation--- 54 Determination of discharge during pulsating flow----------- 57 Determination of peak discharge by indirect methods-------- 58 Snowmelt runoff------------------------------------------------- 59 Flood frequency------------------------------------------------- 60 Reservoirs and lakes-------------------------------------------- 62 Sediment movement and deposition-------------------------------- 63 Chemical, thermal, and biological quality----------------------- 68 Data for studies of fluvial morphology-------------------------- 70 . I I I IV CONTENTS Page Ground water--------------------------------------------------------- 71 Description of ground-water basins------------------------------ 71 Basic elements of a ground-water study-------------------------- 72 Storage---------------------------------------------------- 72 Boundaries of the ground-water reservoir-------------- 73 Gross volume of lithologic units within the ground-water reservoir------------------------------ 74 Specific yield---------------------------------------- 75 Determination of storage changes from long-term water-level fluctuations---------------------------- 77 Conclusions------------------------------------------- 78 Transmissivity--------------------------------------------- 78 Estimating transmissivity in developed valleys-------- 78 Estimating transmissivity in undeveloped valleys------ 81 Recharge--------------------------------------------------- 82 Seepage from streams---------------------------------- 83 Direct infiltration of precipitation------------------ 85 Subsurface inflow from consolidated rocks------------- 85 Determination of average annual total recharge from precipitation-recharge relation---------------- 86 Computation of average annual total recharge as a residual in the hydrologic budget----------------- 87 Conclusions------------------------------------------- 87 Discharge-------------------------------------------------- 88 Evapotranspiration losses from ground water----------- 88 Surface outflow--------------------------------------- 88 Subsurface outflow------------------------------------ 90 Withdrawal by pumping--------------------------------- 90 Chemical quality------------------------------------------- 92 Areal investigations------------------------------------------------- 95 Reconnaissance investigations----------------------------------- 98 Detailed investigations----------------------------------------- 105 Summary and conclusions---------------------------------------------- 114 Selected references-------------------------------------------------- 115 ILLUSTRATIONS Page Figure l. Map showing location of Basin and Range province---------­ 3 2. Schematic sections showing valley types found in the Great Basin--------------------------------------------- 9 3. Sketch showing typical base-flow discharge hydrograph of stream whose discharge is depleted by transpiration of riparian vegetation---------------------------------­ 22 4. Typical hydrograph of well whose water level is affected by transpiration of phreatophytes-------------­ 23 s. Idealized sketch of section perpendicular to river channel, showing changes in position of water table as a result of daily transpiration---------------- 24 CONTENTS v Page Figure 6. Graph for estimating value of Blaney-Criddle coefficient K in determination of \vater use by phreatophytes, in Southwestern United States----------------------------- 27 7-15. Graphs showing-- 7. Variation of evaporation from bare soil with soil type and depth to water table------------- 29 8. Evaporation and seepage from Postoffice Tank, Ariz------------------------------------------- 35 9. Relation of PIE to R/E--------------------------- 38 10. Relation of adjustment coefficient (K) to geologic index (I)----------------------------- 39 11. Relation of R/e to P/e--------------------------- 41 12. Relation of direct runoff to storm rainfall and runoff-curve number---------------------------- 45 13. Relation of runoff-curve number to mean annual runoff expressed as a percentage of mean annual precipitation--------------------------- 45 14. Relations between initial infiltration and runoff-curve numbers--------------------------- 46 15. Relation between storm precipitation, soil- moisture deficiency, and recoverable water on San Nicolas Island----------------------------- 47 16. Idealized diagram of bed and surface configurations in alluvial channels associated with various regimes of flow--------------------------------------------------- 55 17. Graph showing relation of velocity to hydraulic radius for Rio Grande near Bernalillo, N. Mex----------------- 55 18. Sketch showing sectional view through centerline of dual-weir control-------------------------------------- 57 19. Graph showing relation of stream power and median grain size to form of bed roughness-------------------------- 59 TABLES Page Table 1. Hydrologic classification of valleys in the Great Basin---­ 9 2. Monthly percentage of daytime hours of the year for lat 24° to 50° N----------------------------------------­ 26 3. Coefficients for calculating seasonal precipitation factor­ 41 4. Average distribution of daily precipitation at seven desert stations-----------------------------------------­ 45 5. Values of K in the Blaney-Criddle formula for use in computing potential evapotranspiration in Southwestern United States-------------------------------------------­ 51 6. Relation of the Manning roughness coefficient, n, to median grain size in upper regime flow------------------- 59 A SUMMARY OF METHODS FOR THE COLLECTION AND ANALYSIS OF BASIC HYDROLOGIC DATA FOR ARID REGIONS By S. E. Rantz and T. E. Eakin ABSTRACT This report summarizes and discusses current methods of collecting and analyzing the data required for a study of the basic hydrology of arid regions. The fundamental principles behind these methods are no different than those that apply to studies of humid regions, but in arid regions the infrequent occurrence of precipitation, the great variability of the many hydrologic elements, and the inaccessibility of most basins usually make it economically infeasible to use conventional levels of instrumentation. Because of these economic considerations hydrologic studies in arid regions have been commonly of the reconnaissance type; the more costly detailed studies are generally restricted to experimental basins and to those basins that now have major economic significance. A thorough search of the literature and personal communication with workers in the field of arid­ land hydrology provided the basis for this summary of methods used in both reconnaissance and detailed hydrologic studies. The conclusions reached from a consideration of previously reported methods are interspersed in this report where appropriate. 1 2 COLLECTIOli AN,) ANALYSIS, HYDROLOGIC DATA, ARID REGIONS INTRODUCTIOli The use of conventional methods of studying the basic hydrology of humid areas is generally not practical for areas in an arid environment. This is