121 808 THS ,—\ ~.. 7., -. -._. . _. .. - .. -.-—..‘-— n..,.-...- *9-‘*" ’M ,3! new}. "a? A“: ). . '.---'~ - m . . -. , . 1 ~ , ‘1‘ L.’ in: {ti-Zi-"eitfirqw; “‘2 q. 3 a. w‘w; Ha“ ‘u‘ ..... -'..’ h. 'r’. to” “(Lu-H.» ‘ 3 “it a: a? . $.19 v”: {:9 $3 0 This is to certify that the thesis entitled MORPHOLOGIC AND LITHOLOGIC INFLUENCES ON RECHARGE IN A GLACIATED BASIN presented by Mark Alan Petrie has been accepted towards fulfillment of the requirements for Masters degree in Geological Sciences M:ogfl A '~ Apt/1’6”“ MM'Or professor Date @952]; /?57 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution MSU RETURNING MATERIALS: Place in book drop to umumas remove this checkout from .—c—- your record. FINES will be charged if book is returned after the date stamped below. 3 13927199; SEP 2 0 200 CD MORPHOLOGIC AND LITHOLOGIC INFLUENCES ON RECHARGE IN A GLACIATED BASIN By Mark Alan Petrie A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geological Sciences l98h ABSTRACT MORPHOLOGIC AND LITHOLOGIC INFLUENCES ON RECHARGE IN A GLACIATED BASIN BY Mark Alan Petrie Estimates of recharge to the drift are calculated for several sub-basins of the Upper Grand River Basin, using four methods of hydrograph separation. Comparrison with flow duration ratios reveals that the method in which all peak flows are separated out as surface runoff provides the best estimate of recharge. The resulting recharge values range from 3.95 to 5.50 in/yr for a water year of near normal precipitation, and from 2.l0 to 8.32 in/yr for all extremes of yearly precipitation. The above recharge estimates were compared with several morphologic parameters and with basin permeability estimates derived from bore hole data. The comparrisons indicate that basin recharge amounts depend primarily upon surface relief and permeability within the upper five feet of the drift. ACKNOWLEDGEMENTS I would like to thank my committee members for their suggestions and criticisms; Dr. Dave Long for reading my work despite the lack of chemical data, and especially Dr. Del Mokma, for making the it to the defense the day after his daughter Rebecca Ann was born. I owe a great debt to Grahame for his patience and sacrifice (taking valuable time out from sabbatical is no small concession), and for providing support when my enthusiasm waned. Thank you, Billy, for leading me (by the nose) through the abyss of the computer world. And special thanks to Cathy, for helping me maintain my sanity in a world too often conspiring to drive a poor boy wild. TABLE OF CONTENTS LIST OF FIGURES LIST OF TABLES INTRODUCTION THE UPPER GRAND RIVER BASIN BASIN RECHARGE PRECIPITATION RECHARGE VERSUS FLOW DURATION . FACTORS INFLUENCING BASIN RECHARGE BASIN MORPHOLOGY AVERAGE DRIFT PERMEABILITY VEGETATION PRECIPITATION . RELATION BETWEEN BASIN RECHARGE AND BASIN PARAMETERS BASIN MORPHOLOGY AVERAGE DRIFT PERMEABILITY CONCLUSIONS FURTHER WORK APPENDICES APPENDIX A -- MORPHOLOGIC PARAMETERS . APPENDIX B -- SURFACE AREA RATIO ALGORITHM APPENDIX C -- SOIL MANAGEMENT GROUP VALUES BIBLIOGRAPHY . . . . . . . . . . . . . 3] .35 Figure Figure Figure Figure LIST OF FIGURES Study Area Bore Hole Locations Soil Management Group Versus Average Permeability. 0 - 5 Feet (a) Circularity Ratio vs. Basin Recharge. (b) Basin Permeability, 0 - 5 Feet vs. Basin Recharge . . . . . 23 LIST OF TABLES Table l. Recharge (in/yr) And Flow Duration Ratios Table 2. Correlation Coefficients; Recharge Rates Versus Flow Duration Ratios for Water Year l956-57 Table 3. Recharge Rates, Morphologic And Permeability Parameters . . . . . . . . . . . . Table A. I958 Data on Land Use in Michigan . Table 5. Coefficients of Correlation Between Each Parameter and Basin Recharge Table A. Stream Orders For The Sub-basins . . INTRODUCTION Long term recharge to groundwater systems depends on several environmental and physical parameters. These include: I) amount and type of precipitation (Mls, I980), 2) drainage characteristics of the soil (Powell 8 Kirkham, l97h; Baker 5 Mace, I976; Corbett, I979), 3) vegetation cover (Coleman, I953: Bosch 8 Hewlett, I982), A) basin morphology (Gupta, Waymire 8 Wang, I980). and 5) regional geology (Walton, I970; p. 370). The relative influence that these parameters have on recharge, however, is generally poorly understood and has been especially difficult to evaluate for heterogeneous glaciated basins (Walton, I965). The purposes of this paper are; I) to estimate the recharge occurring within several small glaciated basins in south-central Michigan, 2) to quantify two major basin parameters (basin morphology and permeability) for each of these basins, and 3) to determine which of the two parameters has the greater influence on basin recharge. THE UPPER GRAND RIVER BASIN The Upper Grand River Basin lies in the south-central portion of Michigan‘s lower penninsula and covers approximately 2,8h0 square miles (7,356 square km). It is composed of nine sub-basins (Figure I), each of which has slightly varying physical characteristics. In general, the surficial material throughout the Upper Grand River Basin range from nearly flat, clay rich glacial-lake sediments in the north to more hilly morainic and outwash deposits in the south (Martin, I955). The thickness of the drift ranges from 0-50 feet (O-l5 m) in the southern part of the basin to 350-b00 feet (l07-l22 m) in the northern part (Michigan Water Resources Commission, I96I). The uppermost bedrock unit underlying the drift is predominantly the Saginaw Formation (Pennsylvanian: Vanlier et al., I973). It is composed chiefly of interbedded sandstone and shale, with occasional thin beds of limestone and coal. It's thickness ranges from 0 feet in the south to over 500 feet (I52 m) in the north. In the northern half of the basin, low areas on the Saginaw surface contain younger Pennsylvanian sandstones and shales of the Grand River Formation which are up to l25 feet (38 m) thick in places (Kelly, I936). In most areas both the Saginaw and Grand.River Formations are hydraulically connected and act as a single aquifer (Vanlier et al., I973). Near the southern and eastern borders of the basin the Saginaw is completely eroded away, exposing older Mississippian limestones, sandstones and shales. UPPER GRAND WVER BA$N u'oc— long; —u-oo' 4 IF '\ I l. i. u-w— T . .V . -——aru‘ -“ . 3 ' ’ G. \T\ "9%” €in L‘mun Primary, All-wcothlv. Hard Surface _ Secondary, All-weather. Hora Suvtul 3m. Rout. us. Rom Internal. .1 3 3 Interchange Mann av Swamp lmonmncn' Slvnm— \ Gcgmg HO mono a-mo c-m! mun o-nl! —-az-vs' Bum Boundaries Mega! mun-nodul- um“ _ _...— ._._ STATUTE MILE S 1 o r: m: H? “T s o 5 -c is KILOHETERS s 10 I! 30 Figure I. Study Area. BASIN RECHARGE Since changes in groundwater storage tend to be nearly zero (”insignifigant”) when calculated over the course of an entire water year, recharge to an aquifer can be found by separating groundwater runoff (”discharge to the stream”) from total runoff for a water year (Walton, I970; p. I83). This was done for each sub-basin of the Upper Grand River Basin for water years of below-, near- and above normal precipitation (U.S. Dept. Comm., I950-I980). Choosing three years of different inputs to the system allows observation of its response to all extremes. The estimates of recharge were achieved using four different methods of hydrograph separation. The first three, Local Minima (L0), Fixed Interval (FI) and Sliding Interval (SL) are described by Pettyjohn 8 Henning (I979). The fourth, Hand Separation (HA), is based upon a method described by Walton (I970). In all four methods a groundwater runoff curve is drawn under the discharge hydrograph curve: the volume below this line is groundwater runoff and the remainder above it is surface runoff. The results of each hydrograph separation are presented in Table I, together with flow duration ratios calculated for each of the sub-basins. These ratios were obtained using the equations: Q10 5 Q25 ‘1' Q10/90 = -——- Q25/75 = -—- Q90 Q75 where Q10, Q25, Q75 and Q90 are the discharges equalled or exceeded 10, 25, 7S and 90 percent of the time, respectively. PRECIPITATION The calculated recharge for the 9 sub-basins and the overall basin derived from the four separation techniques are shown in Table I for the water years of below-, near-, and above normal precipitation. It is evident fran the data that the recharge estimates vary least among the different separation techniques for the water year of normal precipitation (1956-57). In contrast, the variations IFI recharge estimates for the sub-basins are greatest for both the above- and below normal precipitation years (1955-56 and 1961-62). As expected, recharge values tend to be greatest for the year of above normal precipitation, 1955-1956 (Table I), and are generally least for the year of below normal precipitation (1961-62). In several sub-basins (Jackson, Eaton Rapids, Sloan Creek, Deer Creek, Red Cedar, Lansing and Portland), however, the recharge values from some of the separation techniques are less in the year (fl: normal precipitation (1956-57) than those for the year of below normal precipitation (1961- 62). This may be the result of soil moisture deficit affecting infiltration rates during periods of low precipitation (Bouma, I980; Rao, Tao 8 Rukvichai, 1980). TABLE I. RECHARGE (IN/YR) AND FLOW DURATION RATIOS WATER SEPARATION METHOD RATIOS BASIN YEAR LO FI SL HA 010/90 025/75 l955-56 8.21 8.67 8.70 8.30 2.96 1.63 JACKSON l956-57 9.85 5.90 5.99 5.38 2.06 1.56 1961-62 9.89 5.59 5.61 5.98 2.11 1.50 1955-56 8.32 9.32 9.28 8.99 2.85 1.66 EATON I956-57 9.87 5.59 5.59 5.12 2.32 1.72 RAPIDS 1961-62 5.59 5.78 5.88 5.12 2.60 1.57 1955-56 5.33 5.63 5.98 5.27 9.57 2.11 DEER l956-57 3.09 3.72 3.72 9.19 9.21 2.58 CREEK 1961-62 3.86 9.95 9.99 9.79 9.26 2.07 1955-56 9.60 5.08 9.89 9.81 9.79 3.03 SLOAN l956-57 2.98 3.32 3.90 3.91 6.69 3.90 CREEK 1961-62 2.89 3.53 3.96 3.88 5.61 2.29 1955-56 5.56 7.39 7.33 6.68 9.21 2.01 RED 1956-57 3.95 9.87 9.96 9.72 3.13 2.02 CEDAR 1961-62 9.07 9.28 9.97 9.18 2.62 1.60 1955-56 6.95 8.98 8.92 7.10 3.36 1.78 LANSING 1956-57 9.56 5.99 5.98 9.99 2.67 1.92 1961-62 5.12 5.27 5.90 9.83 2.61 1.55 1955-56 7.29 8.70 8.72 7.99 3.19 1.72 PORTLAND 1956-57 9.77 5.65 5.67 9.98 2.73 1.87 1961-62 5.92 5.61 5.71 5.10 2.95 1.95 1955-56 6.13 8.17 8.23 8.15 3.86 1.90 LOOKING- 1956-57 5.21 6.95 6.92 6.28 3.10 2.09 GLASS 1961-62 9.70 9.85 9.96 9.91 3.79 1.61 1955-56 5.88 8.90 8.98 8.99 5.99 2.58 MAPLE 1956-57 9.35 5.56 5.56 5.99 3.86 2.79 RAPIDS 1961-62 2.10 5.06 5.00 9.91 5.99 1.93 1955-56 7.16 9.09 9.18 7.37 3.59 1.68 IONIA 1956-57 5.50 6.39 6.39 5.19 2.88 1.88 1961-62 9.79 5.90 5.96 9.81 2.71 1.93 Note: l955-56 is the above normal-, I956-57 near normal-, and l96l-62 below normal precipitation year. Because of these inconsistancies, recharge values for the years of above- and below normal precipitation were not used in this investigation to define the general relationship between sub-basin physical parameters and sub-basin recharge. Only the water year I956-57 was used in the analysis, because fewer interferences are active during years of near-normal precipitation. RECHARGE VERSUS FLOW DURATION Chow (1969; p. 19-92 to 19-99) has shown that both the discharge hydrograph and the flow duration curve of a basin are closely related. It can be concluded, therefore, that the separation method which is in closest agreement with the flow duration characteristics of a stream probably best reflects the recharge characteristics of a basin. Table 2 lists the correlation coefficients of recharge (in/yr) versus the flow duration ratios 010/90 and 025/75 for all of the sub-basins in the Upper Grand River Basin. It is evident from Table 2 that the recharge values obtained using subroutine L0 correlate much better with flow duration ratios than do the values obtained using the other subroutines. This would suggest that recharge calculated by L0 probably provides the best estimate for recharge within each of the sub-basins. In Table 3, both the amount of groundwater runoff as percent of total runoff and the recharge rate calculated by L0 are shown, for each of the nine sub-basins as well as the whole basin. The basin areas and mean daily discharges are also given. From the data it is evident that Jackson, Eaton Rapids, Lookingglass and lonia sub-basins have generally high recharge rates (9.85 to 5.50 in/yr), while Sloan Creek, Deer Creek and Red Cedar sub-basins have generally low recharge rates (2.98 to 3.95 in/yr). TABLE 2. CORRELATION COEFFICIENTS; RECHARGE RATES VERSUS FLOW DURATION RATIOS FOR WATER YEAR l956-57 SEPARATION RATIO METHOD L0 Fl SL HA 010/90 -.893 -.755 -.761 -.679 025/75 -.811 —.697 -.706 —.589 It appears that the very small drainage areas of Deer Creek and Sloan Creek sub-basins (16.3 and 9.39 sq.mi.) result in artifically low recharge estimates. This is probably because most precipitation enters into the stream channel before it has time to infiltrate. Excluding these two sub-basins, the calculated recharge values in the eight remaining sub-basins range from 3.95 to 5.50 in/yr. Previous investigations have reported similar recharge values: Firouzian (1963) used flow net analysis to calculate an average recharge rate of 9.8 in/yr for the drift in Ingham County (the Lansing metropolitan area lies in the NW corner of the county in Figure I); based on an analog model, Vanlier et al. (1973) estimated 9.0 in/yr of recharge to the drift in Ingham, Eaton and Clinton Counties (these three counties surround the Lansing metropolitan area). 00.0 \}.\0 Hm“. OAZVA .90.“...1 {.23~ 20.9mm ..It|Il6-.|I ~m.~ min no.0 maiwfi. .¢mv r...— A n.1,; Agape: n .32 m2 _ £2 0n..m m0.0n nu. sn.. 0.0 ..> “0.0 x0.0 an.0 mm.0 .n.0 00.0 0n.n n_.n ma.0 .u.0 n.n RR.0 0m.00 n..no R0.a02 a0.n¢\ .uan .nanu mucuc :Znfidpxag .4334 .3 mm_b_4_:¢az.¢ f. ua‘lutelllullu ~q.«m. v.1IlIQIIIIIEIIC|COIIUI mm..~ 1“ In 0 :0 a: Q on.¢ 0%.».0 ¢v.nmc N 37:32»... a zzc 37...: a .m. 1,. m0.0m 0.0m 0n.km 0a.. ~0.~ _m.e 0.0 0.\ 0.0 00.0 mm.0 AR.0 0n.0 no.0 n0.0 m0.0 00.0 00.0 N~.n .- I- 00.0 I- .: na.m m¢.m 00.0 0m.nn «0.0m um.m¢ n.0mu 00.0 0R.0 .nnm 0m.0 m.ou «can; gauzu auuxu 00¢ zcoum gum; Idle... Umoogovamo'e 4:4. «0.1mm. anIIIIOUII‘IIItII-II‘QO|IOJIIIIIIlll‘aIIOIIICIII-UIIOOlo.-luv I Owla 9.: IIlullIllllllillllIl‘UOll'II-I'Illll'llco‘|lllIIIIlt'It‘lIIUIOIIOI'EIIII'IIOI if? mm.mx m0 .omn .«00 manic: 7.0de . mm _ «v... 0.01.33 “1 GUI»? On.— d.m.... «TACO no.0 06.0. mm.~\ ma.x3 .vxq 'CIIIIInn‘oll'II'D'lIIIIIOOIIIIIOIIUIIIIIEIIIOIDIOOIIl'llI-"IlIlullii. ZDfl/Agiq. .IiIIu-IIDIODIIIIIIIIIu Tum: a -- Q r. ~-_~:¢uzzu... 4.3.4:...)q II n51IIOOIIOAIlllolllu ulttd.lltlo 3~ ~43. «aye d:¢+¢:3 35.6.1 fi: 30.. a: .(1 7...: _¢JZO._a 3~ :3. >_ uzcigozuu n: .— {.1 2x0 0. 3—_¢.¢ 23u_¢uz2m~: >Hvzuwscux; ccuxbm Ammzuzuv 4.4.21 waxczuux 31.023: 1.9324 .-:ZDO.¢D pzucau; 2w 0.”: maid—fix.“ TA » 4 a c... 26 at A. 35.330 63.14 2.35.. FACTORS INFLUENCING BASIN RECHARGE BASIN MORPHOLOGY The following morphologic parameters were determined for each sub-basin in the Upper Grand River Basin following the methods described by Morrisawa (I968): stream frequency (Fs), bifurcation ratio (Rb), form ratio (Rf), circularity ratio (Rc), elongation ratio (Re) and relief ratio (Rr). The first two parameters quantify the sub-basin drainage characteristics while the others define the shape. The methods of quantification are briefly discussed in appendix A, and the values of these parameters are shown in Table 3. Note that no stream frequencies or bifurcation ratios are reported for the two smallest sub-basins, Deer Creek and Sloan Creek. 0n the base map scale (Figure l) these sub-basins have no tributaries, which makes these two ratios meaningless. In addition to these, surface roughness was quantified by calculating the ”surface area ratio” (Rs), following the procedure presented in appendix B. While no clear pattern is evident in the morphologic data shown in Table 3, there are some general trends. Stream frequencies are fairly consistant among the sub-basins except for Maple Rapids, which has an unusually high value. Jackson and Red Cedar sub-basins, on the other hand, have relatively low values. The bifurcation ratios also are about the same for each of the sub-basins except for the low value for Jackson sub-basin. In the case of Jackson sub-basin, the low stream frequency value and bifurcation ratio may be related to a high water table which is evidenced by large areas of marshland (Figure l). The high stream frequency value for Maple Rapids sub-basin is probably due to the local low relief (surface area ratio of 1.21), while the low stream frequency for Red Cedar sub-basin probably reflects the trellis drainage pattern related to the parallel Charlotte and Lansing moraines (Martin, 1955). In general, the highest shape parameter values occur in Jackson sub-basin and the lowest in Lookingglass sub-basin. The Portland sub-basin, not the Lookingglass, has the lowest circularity ratio (Rc), which is probably due to the sharp westward bend of the sub-basin boundary near the gaging station at Portland. If this bend were less sharp the Portland sub-basin Rc value would probably increase signifigantly. The surface area ratios (Rs), however, do not follow the same general trend of the shape parameters. The Ionia and Portland sub-basins have high Rs values while the two smallest sub-basins, Deer Creek and Sloan Creek, have the lowest values. AVERAGE DRIFT PERMEABILITY The permeability of the drift underlying each sub-basin in the study area was estimated using the data set of water- and oil well logs shown in Figure 2. This data set is part of a computer file established for the National Coal Resources Data System (NCRDS, 1980), and includes information on thickness- and texture of each drift and 11 UPPER GRAND RIVER BASIN SUB-BASIN BOUNDARY JACKSON 1m 9“,” EA'ON EAP‘DS Em — — _ DEER CREEK ’DCI — SLOAN :REH vs" — ED CEDAR RC1 —...._...._ \ANSI c .a; - _____ annrgann Ian __ __ ‘DO'INGSLA‘SS O I ................ MAPLE RADIOS may — DNIA ‘Dl __ STATUTE MILES 5 0 S I .5 ”- Tad—In" _ 5 a I 20 25 10 as KILOHETERS Figure 2. Bore Hole Locations. 12 bedrock unit penetrated. The drift permeability was estimated from the Iithologies reported in the first 5-, IO- and 15 feet as well as the whole drift thickness reported for each drill hole. Drift Iithologies were grouped into three categories and were assigned a correponding value for permeability; 7.0 in/yr for clay, 38.5 in/yr for sand and clay, and 70.0 in/yr for sand and gravel. These values are based on permeability values used in a finite element model of recharge through the drift in the Lansing metropolitan area (Kehers et al., 1983). This area lies near the center of the Upper Grand River Basin (Figure l). A weighted average permeability for each point was produced by multiplying the thickness of each drift unit in a well by the appropriate permeability value, then adding the results and dividing by the sum of the thicknesses. The resultant values were then summed and divided by the number of wells in the sub-basin to achieve an average sub-basin permeability. The results of these calculations are shown in Table 3 above. To test the validity of the above calculations, county- and township-wide average permeabilities compiled from well data were compared with county- and tdwnship-wide average Soil Management Group (SMG) values. In theory, there should be a definite correlation between these values since SMG reflects soil permeability (Mokma 8 Robertson, 1976). These comparrisons are presented in Figure 3, and the data are tabluated in appendix C. 13 SMG (WITH MUCK) SMG (WITHOUT MUCK) 4.0 35 3O 25 40 35 10 25 O OMMnth. A Eoton Co. 0 Ingham Co. E] Jackson Co. ‘7 Shiowouoo Co. .. + Jackson Co. Townships + + « + §. 4 + + ++ D + + ++ + + T + OVA + I I I I 1 20 30 4O 50 60 q + + ‘ + I + + < + D + + + + + d +- + + + + 1 V + A. + CD 11’} 1 fl 1 T 1 1 20 30 40 50 60 AVERAGE PERMEABILITY, 0-5 FEET Figure 3. Average Permeability, 0 - S (a) Coefficient of Correlation (b) Coefficient of Correlation (INCHES /YEAR) 19 Soil Management Group Versus Feet. +0.653 +0.796 It is evident from the correlation coefficient in Figure 3 (0.653) that the permeability values calculated from well logs are fairly reliable indicators of actual basin permeability. Using the average SMG values which exclude muck soils provides an even better correlation coefficient (0.796). This is probably because none of the wells used to calculate permeability are located in muck soils. Given this good correlation, the lack of data coverage in Figure 2 can be considered insignifigant, because the soil associations reported in county soil surveys are continuous across the boundaries from adequately to inadequately covered areas. This suggests that the calculated permeabilities for these sub-basins (Red Cedar, Lansing, Portland, Maple Rapids and Ionia) represent fairly accurately the whole sub-basin values. VEGETATION There is currently no compiled data on vegetation distribution in the Upper Grand River Basin. However, a qualitative survey of areal photographs of the 9 counties that lie either totally or partially within the Upper Grand River Basin (Table 9) reveals a generally even distribution of forest and pasture. It is therefore reasonable to assume that the broad divisions of vegetation in Table 9 can be extended to the sub-basins. From the data in Table 9 it is evident that, in each of the counties (and thus in each sub-basin), 2/3 of the area is generally cropland, 1/9 is forest and pasture, and the remainder is urban land, water, marsh land and others (U.S. Soil Conservation Service, 1968). Although Montcalm and Ionia counties show slightly more than 25% forest and pasture, most of this occurs outside the study area. It appears, therefore, that vegetation, being generally similar among sub-basins, has little effect on basin recharge and can be considered insignifigant in this study. PRECIPITATION The recharge rates estimated by hydrograph separation seem to indicate that recharge and precipitation vary directly. As was previously noted, however (page 5), there are several inconsistancies in the data (Table I) that make an assessment of the true relationship between precipitation and recharge difficult to accomplish with any degree of certainty. TABLE 9. 1958 DATA ON LAND USE IN MICHIGAN* (1) PERCENT OF COUNTY TOTAL THOUSANDS FOREST, (2) (3) COUNTY OF ACRES CROP PASTURE URBAN OTHER Clinton “365.99 72.0 16.6 9.1 7.3 Eaton 362.88 63.2 23.2 5.5 8.1 Gratiot 362.29 70.5 20.9 3.0 5.6 Ingham 357.76 61.6 15.9 10.8 11.7 Ionia 368.00 55.9 32.0 3.1 9.5 Jackson 951.20 99.3 20.0 9.8 20.9 Livingston 365.99 98.9 23.9 6.9 21.3 Montcalm 955.68 56.9 36.1 1.6 5.9 Shiawassee 395.60 69.7 18.9 5.5 6.9 * After The Michigan Conservation Needs Inventory Of 1968 (U.S. Soil Conservation Service, 1968). Notes: I. The acreage listed excludes water bodies in excess of 90 acres and river reaches over 1/8 mile wide. 2. Includes cities and built-up areas, roads and highways. 3. Includes rural homesteads, farmsteads, farm roads, feed lots, ditches and banks, fence and hedge rows, small water bodies (see no. I above), marshes, strip mines, gravel pits, borrow land, etc. 17 RELATION BETWEEN BASIN RECHARGE AND BASIN PARAMETERS The correlation coefficients between basin recharge and the various basin parameters discussed below are presented in Table 5. All the correlations were made both including and excluding the data for Jackson sub-basin, because of the anomalous behavior exhibited by that sub-basin. This odd behavior is probably due to a high water table in the sub-basin (Figure I), which acts as an impermeable layer near the surface. Because the high water table modifies the stream hydrograph to a shape normally associated with “flashy“ streams, the hydrograph separations result in estimates of base flow that are lower than the probable actual amounts. A combination of two factors are proposed to maintain this high water table. First, the hydraulic gradient in this sub-basin is probably directed from the Saginaw sandstone into the overlying more permeable sand and gravel drift (Michigan Water Resources Commission, 1961). In addition, the locally thin drift cover further limits the amount of infiltration into the drift aquifer. BASIN MORPHOLOGY The correlation coefficients between morphologic parameters and recharge, listed in Table 5, are extremely low for all but the the circularity ratios (-.856 and -.918) and surface area ratios (0.859 18 TABLE 5. COEFFICIENTS OF CORRELATION BETWEEN EACH PARAMETER AND BASIN RECHARGE WITH WITHOUT PARAMETER JACKSON VALUES JACKSON VALUES STREAM FREQUENCY 0.169 0.229 BIFURCATION RATIO 0.118 0.220 FORM RATIO -.185 0.075 CIRCULARITY RATIO -.856 -.918 ELONGATION RATIO -.119 0.021 RELIEF RATIO -.905 0.310 SURFACE AREA RATIO 0.859 0.859 AVERAGE PERMEABILITY 0 - 5 FEET 0.568 0.728 AVERAGE PERMEABILITY 0 - 10 FEET 0.509 0.665 AVERAGE PERMEABILITY 0 - 15 FEET 0.399 0.989 AVERAGE PERMEABILITY WHOLE DRIFT 0.205 0.103 19 and 0.859). This suggests that none of the morphologic parameters except these two influence sub-basin recharge to any appreciable degree. This is to be expected, since the surface glacial deposits in the study area are too young (13,000 - 15,000 years old; Farrand 8 Eschman, 1979) for an equilibrium to have been established in the drainage system (Leopold et al., 1969; p. 923-926). The nearly perfect relationship between sub-basin values of circularity ratio (Rc) and recharge, however, seems anomalous when compared with the poor correlations between recharge and the other shape parameters. A low Rc value can result from either an elongated (less circular) basin shape, or an irregular (highly incised) basin perimeter, or both. If the low Rc is due more to elongation, basin recharge would be relatively low, because the short overland travel path from the perimeter to the stream channel would allow less time for water to infiltrate before reaching the stream. The exact opposite is seen in the sub-basin values; as Rc decreases, recharge increases. Basin shape, therefore, can not be the cause of the good correlation between Rc and recharge. This conclusion is also supported by the lack of any clear relation between the other shape parameters and recharge, especially the elongation ratios, which show coefficients of correlation with recharge of -.119 and +.021. The ratio Rs measures surface irregularity, not the general surface slope. Thus the correlation between Rs and recharge is positive: as relief increases, opportunities for ponding of water increase, causing increased recharge. In addition, as surface irregularity increases the basin perimeter should become more 20 irregular, resulting in lower Rc values. Comparrison of Rs with Rc shows correlation coefficients of -0.625 and -0.699. which seems to support this contention. It is sub-basin relief, therefore, not sub-basin shape that causes the strong relationship between sub-basin circularity ratios and sub-basin recharge. This means that the relief ratios, which show a poor correlation with recharge (-.905 and +.3IO), do not accurately indicate the sub-basin surface relief at all. Rather, they indicate only the general slope from sub-basin perimeter to the sub-basin outlet. It is the surface area ratio that quantifies sub-basin relief in this area, and, to some extent, the circularity ratio. A third morphologic parameter, sub-basin size, also appears to influence recharge rates. In the case of the two smallest sub-basins, Deer Creek and Sloan Creek, the calculated recharge values are considerably lower than the value for Red Cedar sub-basin, in which they both lie. Precipitation falling on these small sub-basins reaches the stream channel very quickly, both over the surface and as interflow through the soil, and so has less time to infiltrate. It is possible that the lower than expected recharge value estimated for Jackson sub-basin is due, not to the high water table, but to a relatively small sub-basin area. This does not seem likely, however, since the next largest sub-basin, the Lookingglass, is essentially the same size, yet it has the second highest recharge rate (Table 3). 21 Figure 9. (a) Circularity Ratio vs. Basin Recharge. (b) Basin Permeability, 0 - 5 Feet vs. Basin Recharge. (JK is the Jackson sub-basin value.) (a) Coefficient of Correlation = -0.856 with JK, -0.9l8 without JK. (b) Coefficient of Correlation = +0.568 with JK, +0.728 without JK. 22 +Jk 116 I4 T O_._.HE._._.:m