Details zur Publikation

Referenztyp Qualifizierungsarbeiten
DOI / URL Link
Titel (primär) Hydrological consequences of land use / Land cover and climatic changes in mesoscale catchments
Autor Samaniego, L.;
Journal / Serie Mitteilungen / Institut für Wasser- und Umweltsystemmodellierung
Erscheinungsjahr 2003
Department CHS;
Heft 118
Sprache englisch;
Keywords Land use/cover; Monte-Carlo-Simulation; Non-parametric-tests; Robust-estimators; Runoff-modelling; Landnutzung; Statistik; Abfluss; Hydrologie
Abstract Many hydrologic studies reported in the literature indicate that observed changes of various characteristics of the water cycle largely depend on the geographic location and the scale at which such a study is carried out. In general, the water cycle of a given basin may be modified due to climatic and/or land use/cover changes. Identifying, however, the causes of the observed variability at the mesoscale is a challenging task because of the lack of data describing the spatial distribution of relevant explanatory variables and the unknown spatial heterogeneity of parameter values. This study proposes a general method that attempts to split the observed variability of a given characteristic of a basin's runoff along the time axis into two independent components, one that is only explained by climatic fluctuations, and a second one that is exclusively explained by land cover changes. The proposed algorithm works as follows. Given a set of explanatory variables, it initially calibrates and assesses the goodness of the fit of as many non-linear models as feasible combinations of these variables exist, then, it estimates the robustness of every model using a cross-validation technique, and finally, it assesses the statistical significance of each explanatory variable employing a permutation test. The optimisation of the parameters of each model is carried out by a generalized reduced gradient algorithm. Finally, the algorithm selects the most robust model as that which best accomplishes simultaneously the following criteria: 1) it should have the least number of variables but explain as much as possible the variance of the sample; 2) it should be robust to outliers (i.e. the minimum cross-validation statistic); and 3) all its variables should be significant at 5% level. Lastly, those hydrological models calibrated for a given set of runoff characteristics were linked with a stochastic land use/cover change model in order to simulate the effects of the hydrological consequences of land use/cover and climatic changes in a mesoscale catchment. The magnitude of these effects was assessed in a probabilistic way by a sequential Monte-Carlo simulation provided four different scenarios which take into account likely developments of macro-climatic and socio-economic conditions relevant for a given study area. The proposed methodology was developed and tested in the upper catchment of the Neckar River covering an area of about 4000 km2; however, its application in other catchments is possible.
ID 5174
dauerhafte UFZ-Verlinkung
Samaniego, L. (2003):
Hydrological consequences of land use / Land cover and climatic changes in mesoscale catchments
Dissertation, Universität Stuttgart
Mitteilungen / Institut für Wasser- und Umweltsystemmodellierung
Universität Stuttgart, Stuttgart, 179 pp.