UNESCO-HELP BASIN The Alento River Basin Presentation of study areas and results N. Romano and G.B. ChiricoDepartment of Agricultural Engineering - University of Napoli Federico II
RationaleMajor limitations on current studies of modeling hydrologicprocesses and assessing the impacts of landuse and climatechanges are lack of:• good quality observational data and model parameters, especially the soil hydraulic characteristics, to provide a basis for evaluation of hydrologic model performance and reliable scenario construction;• information on how the nature of spatial variability of soils (parameters) and boundary conditions (data) affects hydrologic response over a range of scales;• in-depth understanding of effectiveness of using different modeling tools for soil moisture dynamics (for example, the bucket model vs. the Richards equation); and,• clear identification of the catchment landscape units controlling storm runoff generation, its timing, and mixing dynamics.
The SPERAS project [from the Latin-root verb: speras you expect (something of good)] S oil P rocesses and E co-hydrological R esponse in the A lento river S ystemThe SPERAS Project is viewed as a box, whose contents are contributions from different ongoing projects and various other activities.
soil properties: field and lab investigationsClay soil, with vertic features (vertisols)Large and deep cracks within soil surface duringdry periodsMacropores and roots in the top 40 cm (A-horizon)Almost permanently saturated below 150 cmDeep clay C-horizon 0% 20% 40% 60% 80% 100% Soil layers 0 A (clay) 19 31 51 40 B (clay) Depht(cm) 14 29 57 60 18 25 57 BC (clay) 100 11 29 61 C (clay) Sand Silt Clay
Simultaneousdetermination of soilhydraulic properties usingthe evaporation method.(Romano and Santini, WRR, 1999)
soil properties: field & lab investigation Low saturated hydraulic conductivity of the soil matrix (<0.8 mm/h) High permeability of the A-horizon, through preferential flow-pathsA-horizon Ks>10 mm/hB-horizon Ks<0.8mm/hC-horizon Ks<0.2mm/h Stone-cased well
identifying dominant hydrologic states EGU 2010, ViennaRAIN ETodry period dry wet wet to to period dry wetFlow Wells
surficial soil moisture variabilitySurface soil moisture have been measured according to a25m sample grid in 12 field campaigns. Soil water content map 22/09/06 Soil water content map 29/09/06 Soil water content map 03/11/06Soil water content map 2/03/07 Soil water content map 22/01/07 Soil water content map 08/12/07
surficial soil moisture variability Data N CV KS01/09/06 56 0.257 0.074 0.289 0.148 N positive skewness22/09/06 63 0.342 0.071 0.208 -0.126 N in dry state29/09/06 91 0.359 0.080 0.224 -0.255 NN03/11/06 92 0.334 0.064 0.193 -0.559 N08/12/06 92 0.405 0.066 0.163 -0.572 N22/01/07 91 0.410 0.073 0.177 -0.896 N02/03/07 92 0.408 0.076 0.187 -0.452 N As soil water content is a bounded variable, its16/03/07 91 0.347 0.091 0.261 -0.051 NN skewness decreases10/04/07 78 0.405 0.079 0.196 -0.506 N from positive to negative11/05/07 26 0.379 0.110 0.290 -0.964 N values from dry to wet9/07/07 18 0.207 0.088 0.424 0.508 N periods.12/11/07 92 0.383 0.073 0.191 -0.748 N
surficial soil moisture variability Data N CV L-Ntest Lilliefors test for goodness of fit to a01/09/06 56 0.257 0.074 0.289 0.148 N normal distribution22/09/06 63 0.342 0.071 0.208 -0.126 N at 5% significance level29/09/06 91 0.359 0.080 0.224 -0.255 NN03/11/06 92 0.334 0.064 0.193 -0.559 N non-normal08/12/06 92 0.405 0.066 0.163 -0.572 N distribution in22/01/07 91 0.410 0.073 0.177 -0.896 N transition periods02/03/07 92 0.408 0.076 0.187 -0.452 N16/03/07 91 0.347 0.091 0.261 -0.051 NN10/04/07 78 0.405 0.079 0.196 -0.506 N11/05/07 26 0.379 0.110 0.290 -0.964 N9/07/07 18 0.207 0.088 0.424 0.508 N12/11/07 92 0.383 0.073 0.191 -0.748 N
surficial soil moisture variabilityDuring transition periods, surface soil moisture assumes abimodal distribution as a result of the combination of verticalfluxes and lateral fluxes through preferential flow-paths.
surficial soil moisture variability During transition periods, surface soil moisture assumes a bimodal distribution as a result of the combination of vertical fluxes and lateral fluxes through preferential flow-paths. Soil water content map 29/09/06dry-to-wet
surficial soil moisture variabilityDuring transition periods, surface soil moisture assumes abimodal distribution as a result of the combination of verticalfluxes and lateral fluxes through preferential flow-paths. wet-to-dry
what we have learned (up to now) …• We have identified 4 different periods that characterize the hydrologic response of the hillslope; in each of which there occur different dominant hydrologic processes.• Spatial variability of surficial soil water content shows slightly different statistical features in each of these periods.• This type of investigation can give useful directions when one should build hydrologic models as related to specific objectives of modeling
Space-based earth observation and in-depthanalyses of natural phenomena characterizingenvironmental evolution offer new perspectiveson management of land and water resources. GIS + Earth + Model Observation u z u* z ln k z0m R A R T0 X T m RS C T S (z,t) v(x,y,t)
20 July 2004 24 Oct. 2004 soil, vegetation, and landscape characterization through satellite images
KEY TO PROGRESSAbout the data … : improving our monitoring techniques over a broad range of scales (to measure/infer soil hydraulic properties & fluxes at scales of interest for environmental planning).About the models … : identifying dominant vegetation, soil and topography controls on ecosystem dynamics.Defining new criteria for moving across scales