Interactions between the Eph family of receptor tyrosine kinases, and their ligands, the ephrins, are required for the normal development and maintenance of many patterns of connectivity within the nervous system. Eph receptors and ephrins are expressed widely throughout both the developing and mature nervous system where they function as important regulators of cell migration and axon guidance. The studies presented in this thesis examine the role of one particular member of the Eph receptor family, EphA4, in regulating mechanisms that underlie the development and maintenance of certain neural connections within the nervous system. This thesis demonstrates that the EphA4 receptor is expressed within specific regions of the developing and mature nervous system, some of which are associated with the control of locomotor activity. Consistent with these observations are the locomotor defects exhibited by animals with a targeted disruption of the EphA4 gene. These animals exhibit abnormal bilateral limb movements and have severe disruptions of a number of major axonal pathways. One of these disrupted axonal pathways, the corticospinal tract (CST), is a particularly important mediator of locomotor activity. This thesis reveals that EphA4 is expressed on the axons that comprise the CST. It demonstrates that although EphA4 is not required for the initial development of the CST, repulsive interactions between EphA4-bearing CST axons and ephrinB3, a ligand for EphA4 that is expressed at the midline of the spinal cord, appear to prevent CST axons from aberrantly recrossing the spinal midline during development.

Interactions between the Eph family of receptor tyrosine kinases, and their ligands, the ephrins, are required for the normal development and maintenance of many patterns of connectivity within the nervous system. Eph receptors and ephrins are expressed widely throughout both the developing and mature nervous system where they function as important regulators of cell migration and axon guidance. The studies presented in this thesis examine the role of one particular member of the Eph receptor family, EphA4, in regulating mechanisms that underlie the development and maintenance of certain neural connections within the nervous system. This thesis demonstrates that the EphA4 receptor is expressed within specific regions of the developing and mature nervous system, some of which are associated with the control of locomotor activity. Consistent with these observations are the locomotor defects exhibited by animals with a targeted disruption of the EphA4 gene. These animals exhibit abnormal bilateral limb movements and have severe disruptions of a number of major axonal pathways. One of these disrupted axonal pathways, the corticospinal tract (CST), is a particularly important mediator of locomotor activity. This thesis reveals that EphA4 is expressed on the axons that comprise the CST. It demonstrates that although EphA4 is not required for the initial development of the CST, repulsive interactions between EphA4-bearing CST axons and ephrinB3, a ligand for EphA4 that is expressed at the midline of the spinal cord, appear to prevent CST axons from aberrantly recrossing the spinal midline during development.

Two gigantic landslides in carbonate sequences were studied through a combination of remotely sensed datasets and detailed field investigation. Field investigations supplemented the remote analysis at both sites. The work presents the first detailed documentation of the Seymareh (Saidmarreh) landslide, Zagros Mountains, Iran, which is shown to be the largest known rock avalanche in the world and the largest known landslide of any type on the Earth’s land surface. Volume of the Seymareh rock avalanche (38 Gm³) was previously underestimated by nearly 50 percent. The failure mode was complex planar sliding involving fold-related bedding-parallel shears and local break-through of bedding. The overall dip of the sliding surface was 11°. Lateral release and toe release were provided by tectonically-weakened joints and by break-out likely assisted by fluvial undercutting, respectively. Broad scar morphology and outcrop-scale features indicate the presence of nine discrete sliding surfaces distributed through the failed sequence and define nine stacked plates involved in the detachment. The Valley of the Rocks rock avalanche (1.3 Gm³), Rocky Mountains, Canada is described in detail for the first time and shown to be the largest known rock avalanche in North America as well as the largest known landslide of any type in Canada. The failure mode was simple planar sliding along a bedding-parallel, slightly concave-up surface possibly coinciding with a thrust fault (average dip 25°). Lateral release and toe release were provided by bedding-normal joints and by glacial undercutting, respectively. There is a surprisingly high degree of similarity between the two rock avalanches, despite differences in tectonic and climatic setting.. Similarities and differences between the two gigantic landslides suggest several factors important in volume determination of gigantic landslides in carbonate sequences: 1) extensive contiguous source slope; 2) high degree of structural continuity, especially across slope parallel to strike; 3) a comparatively low failure surface dip; 4) discontinuity-parallel slopes, and subsequent toe undercutting; and 5) hard-over-soft geomechanical contrasts. Comparison with magnitude-mobility relationships for landslides over five orders of magnitude shows that the Seymareh rock avalanche suggests an upper limit for landslide mobility (fahrböschung = ~4°) on the Earth’s continental surface.

Two gigantic landslides in carbonate sequences were studied through a combination of remotely sensed datasets and detailed field investigation. Field investigations supplemented the remote analysis at both sites. The work presents the first detailed documentation of the Seymareh (Saidmarreh) landslide, Zagros Mountains, Iran, which is shown to be the largest known rock avalanche in the world and the largest known landslide of any type on the Earth’s land surface. Volume of the Seymareh rock avalanche (38 Gm³) was previously underestimated by nearly 50 percent. The failure mode was complex planar sliding involving fold-related bedding-parallel shears and local break-through of bedding. The overall dip of the sliding surface was 11°. Lateral release and toe release were provided by tectonically-weakened joints and by break-out likely assisted by fluvial undercutting, respectively. Broad scar morphology and outcrop-scale features indicate the presence of nine discrete sliding surfaces distributed through the failed sequence and define nine stacked plates involved in the detachment. The Valley of the Rocks rock avalanche (1.3 Gm³), Rocky Mountains, Canada is described in detail for the first time and shown to be the largest known rock avalanche in North America as well as the largest known landslide of any type in Canada. The failure mode was simple planar sliding along a bedding-parallel, slightly concave-up surface possibly coinciding with a thrust fault (average dip 25°). Lateral release and toe release were provided by bedding-normal joints and by glacial undercutting, respectively. There is a surprisingly high degree of similarity between the two rock avalanches, despite differences in tectonic and climatic setting.. Similarities and differences between the two gigantic landslides suggest several factors important in volume determination of gigantic landslides in carbonate sequences: 1) extensive contiguous source slope; 2) high degree of structural continuity, especially across slope parallel to strike; 3) a comparatively low failure surface dip; 4) discontinuity-parallel slopes, and subsequent toe undercutting; and 5) hard-over-soft geomechanical contrasts. Comparison with magnitude-mobility relationships for landslides over five orders of magnitude shows that the Seymareh rock avalanche suggests an upper limit for landslide mobility (fahrböschung = ~4°) on the Earth’s continental surface.

[Truncated abstract] Formation and consolidation of the retinotectal projection during optic nerve regeneration has been associated with two major interlinked processes. Initially, retinal ganglion cell (RGC) axons are guided by molecular guidance cues, such as the Eph receptor tyrosine kinases and their ligands, the ephrins, to their approximately correct location and form a coarse topographic map in the optic tecum. Such axon guidance occurs in the absence of neural activity and is considered to be activity-independent. The second process involves glutamatergic excitation, whereby correctly located connections are strengthened by correlated neural activity, whilst removing inappropriately located ones thereby sharpening the topography.The second process is considered to be activitydependent. Here, a number of experiments were undertaken to further examine the interrelationships of activity-dependent and independent processes with respect to functional outcomes. Two models of optic nerve regeneration were studied. In goldfish, following optic nerve crush, regeneration is successful. … In goldfish, guidance along the medio-lateral tectal axis may occur through preordering of axons prior to entering the tectum via the appropriate medial and lateral brachium, with EphA/ephrin-A then guiding axons over the rostral-caudal axis establishing gross topography. The increase in involvement of NMDA-mediated transmission during the period of activity-dependent refinement consolidated the role of this receptor in synapse plasticity. However what triggers NMDA-mediated activity to increase is still largely unresolved, although as the factors governing receptor trafficking during development and synaptic plasticity become better understood, these can be applied to the period of plasticity associated with regenerating axons. And finally, as GABAergic inhibition appears to suppress activity-dependent refinement, means of overcoming this inhibition through 4 such methods as visual training or pharmacological intervention may have significance for mammalian regeneration.

There has been widespread interest in corneal biomechanics over recent years, driven largely by the advancements in, and the popularity of refractive surgery techniques and subsequent concerns over their safety. Lately there has been interest into whether crosslinking, which is currently used for the treatment of keratoconus, could be developed as a minimally invasive technique to change the refractive power of the cornea by selectively changing the corneal biomechanics in specific regions to induce a shape change. Successful application of this technique requires a detailed understanding of corneal biomechanics and so far, little is known about the biomechanics of this complex tissue. The current lack of understanding can be mostly attributed to the absence of a suitable measurement technique capable of examining the dynamic behaviour of the cornea under physiological loading conditions. This thesis describes the development of a novel full-field, ex vivo, measurement method incorporating speckle interferometric techniques, to examine the biomechanics of the cornea before and after crosslinking in response to hydrostatic pressure fluctuations representative of those that occur in vivo during the cardiac cycle. The eventual measurement system used for the experiments detailed in this thesis incorporated; an Electronic Speckle Pattern Interferometer (ESPI), a Lateral Shearing Interferometer (LSI) and a fringe projection shape measurement system. The combination of these systems enabled the 3-dimensional components of surface displacement and the 1st derivative of surface displacement to be determined in response to small pressure fluctuations up to 1 mmHg in magnitude. The use of both ESPI and LSI together also enabled the applicability of LSI for measurement of non-flat surfaces to be assessed, and limitations and error sources to be identified throughout this work. To enable the measurement of corneal biomechanics, part of this thesis was concerned with the design of a bespoke loading rig. A chamber was designed that could accommodate tissue of both porcine and human origin. This chamber was linked to a hydraulic loading rig, whereby the cornea could be held at a baseline pressure representative of normal intraocular pressure and small pressure variations could be introduced by the automated vertical movement of the reservoir supplying the chamber. Experiments were conducted on a range of non-biological samples with both flat and curved surface topography, and both uniform and non-uniform mechanical properties, to determine if the measurement configuration was giving the expected measurement data and the loading rig was stable and repeatable. Following experiments on non-biological samples, a range of experiments were conducted on porcine corneas to develop a suitable testing methodology and address some of the challenges associated with corneal measurement, including transparency and hydration instability. During these investigations, a suitable surface coating was identified to generate an adequate return signal from the corneal surface, while not interfering with the response. Alongside this, the natural variation in the response of the cornea was investigated over the total experimental time, and a range of data was presented on corneas before and after crosslinking, which confirmed the suitability of the measurement methods for the assessment of crosslinking. Ultimately, a small sample size of six human corneas were investigated before and after crosslinking in specific topographic locations. From the experiments on human and porcine corneas, full-field maps of surface deformation have been presented, and a compliant region incorporating the peripheral and limbal areas has been identified as being fundamental to the response of the cornea to small pressure fluctuations. In addition to this, the regional effects of crosslinking in four different topographic locations on corneal biomechanics have been evaluated. From this, it has been demonstrated that crosslinking in specific regions in isolation can influence the way the cornea deforms to physiological-scale fluctuations in hydrostatic pressure and this could have implications for refractive correction.

Les océans de la Terre sont stratifiés en densité par les gradients de température et de salinité.L'interaction des courants de marée avec la topographie du fond océanique entraîne donc le rayonnement des ondes de gravité interne dans l'intérieur de l'océan. Ces ondes sont appelées marées internes et leur dissipation due à le déferlement des ondes nonlinéaires joue un rôle important dans le mélange de l'océan abyssal, et donc dans la circulation océanique à la grande échelle.Dans ce contexte, nous étudions la génération des ondes internes par l’oscillation d’objet de différentes géométries simplifiées afin de modéliser le marée barotropique sur la topographie océanique et considérons les effets linéaires et nonlinéaires sur ces ondes résultant d’interactions avec l'objet et entre ces ondes.La contribution relativement nouvelle de cette thèse est l'étude des aspects de flux tridimensionnels qui étaient accessibles avec notre approche expérimentale, et sont généralement difficiles à étudier par modélisation numérique et analytique.Nous étudions d'abord la structure des ondes fundamentale et des harmoniques supérieur pour un sphéroïde oscillant, émettant des ondes divergentes. Les harmoniques supérieures sont générées par l'instabilité non linéaire à la surface de l'objet avec des effets nonlinéaires dans la zone d'intersection des faisceaux fundamentales. Ils peuvent se croiser et se concentrer, donc augmenter d'énergie, et devenir dominant sur les ondes fundamentales. On détermine les structures horizontales des ondes fundamentale et des harmoniques supérieures.Subséquemment, nous considérons les ondes générées par un tore oscillant, qui convergent vers un point focal. En dehors de cette région focale, les résultats expérimentaux et les prédictions théoriques sont en bon accord, mais dans la région focale, l'amplitude de l'onde est deux fois plus grande que près du tore, conduisant à une amplification locale nonlinéaire et à un déferlement des onde pour les grandes amplitudes d'oscillations. En conséquence, la propagation des ondes fundamentales se trouve entravée dans la région focale. L'onde stationnaire se forme alors que de nouvelles ondes sont générées et émises de cette région focale.Un tore plus grand a été testé sur la plate-forme Coriolis pour comparer la focalisation des ondes de gravité internes, inertie-gravité et des ondes inertielles dans un régime faiblement visqueux. En raison de la complexité de la zone focale, une seconde harmonique est observée même quand l'amplitude d'oscillation est faible. Le champ de vorticité verticale des ondes de gravité interne présente une structure dipolaire dans la zone focale, qui se transforme dans le cas tournant en une structure de vortex "Yin-Yang". La structure globale des faisceaux des ondes inertiels est proche de celle pour des ondes de gravité internes, bien q'elle est relativement plus intense. / The Earth's oceans are stratified in density by temperature and salinity gradients.The interaction of tidal currents with ocean bottom topography results therefore in the radiation of internal gravity waves into the ocean interior. These waves are called internal tides and their dissipation owing to nonlinear wave breaking plays an important role in the mixing of the abyssal ocean, and hence in the large-scale ocean circulation.In this context we investigate the generation of internal waves by oscillating objects of different idealized geometries as a model of barotropic flow over ocean topography, and consider linear as well as nonlinear effects on these waves resulting from interactions with the object and from wave--wave interactions.The relatively novel contribution of this thesis is the investigation of three-dimensional flow aspects that were accessible with our experimental approach, and are generally difficult to investigate by numerical and analytical modelling.First we investigate the wave structure of the first and higher harmonics for an oscillating spheroid, emitting diverging waves. Higher harmonics are generated by nonlinear instability at the surface of the object together with nonlinear effects in the zone of intersection of the primary beams. They may intersect and focus, therefore increase in energy, and become dominant over the first harmonic. The horizontal structures of both, first and higher harmonics are determined.We then consider waves generated by an oscillating torus, that are converging to a focal point. Outside this focal region experimental results and theoretical predictions are in good agreement, but in the focal region the wave amplitude is twice as large as it is close to the torus, leading to local nonlinear wave amplification and incipient wave breaking for large oscillation amplitudes. As a result, the propagation of the first harmonic waves is found to be hindered in the focal region. A standing pattern forms, while new waves are generated and emitted away from this focal region.A larger torus has been tested at the Coriolis platform to compare the focusing of internal gravity, inertia--gravity and inertial waves in a low viscous regime. Owing to the complexity of the focal region, a second harmonic is observed even at low oscillation amplitude. The vertical vorticity field of internal gravity waves exhibits a dipolar structure in the focal zone, which transforms in the rotating case into a ``Yin--Yang-shaped'' monopolar vortex structure. The overall structure of the inertial wave beams is close to that for internal gravity waves, though relatively more intense.

The need to construct optimal drape surfaces arises in airborne geophysical surveys where it is necessary to fly a safe distance above the ground and within the performance limits of the aircraft used, but as close as possible to the surface. The problem is formulated as an LP with constraints at every point of a grid covering the area concerned, yielding a very large problem. The objective of the LP is to create as "good" a surface as possible. This formulation is new, as previous methods did not aim to minimise an objective function. If the desired surface has only slope limitations, the resulting drape surface must be constrained in the first derivative. Such a drape surface is readily constructed using the Lifting Algoritlun. It is shown that the Litling Algorithm is both exact and has great speed advantages. Some numerical results confinning exacmcss and speed are presented, as is the algorithm's analogy to a flow network method. An enhanced lifting method with a better order of complexity is also proposed and tested numerically. In most practical situations a drape surface is required which has both first and second derivatives constrained. If only a cut through such a surface is considered, the problem can be solved with relative ease by exploiting its nctwork~Jike structure. This method fonns the basis of one of the preferred heuristics developed later. It was not possible to generalise this method to a full two~dimensional drape surface. A commercially available LP package fares better in finding the optimal solution. Several heuristic methods were examined. first a general heuristic method based on a lifting approach was developed. This was followed by a method using repeated application of the method used for sections (the Alternating One-dimensional Dual Algorithm ["AODA"]). Three heuristics based on thimbles were also designed. Thimbles are caps whose first and second derivatives are acceptable and which are placed over local infeasibilities in the topography The work ends with a chapter comparing the efficiency of various heuristics and comparing the results obtained using a number of test datasets. It was fOLmd that heuristic methods provide acceptable drape surfaces and that the choice lies between speed and accuracy, with a previously designed smoothing method being the fastesl and the AODA the most accurate and quick enough. / Operations Research / D.Phil.

Le géoradar est une méthode électromagnétique haute fréquence (>10 MHz) utilisé pour caractériser les premiers mètres du sous-sol. Lors de la présence d'une topographie, les données géoradar sont déformées en conséquence. Afin de retrouver la vraie géométrie des réflecteurs, nous avons codés un algorithme de migration prenant en compte la topographie. La méthode est démontrée grâce à un modèle synthétique simple, puis testée avec succès sur des données réelles. Les algorithmes de migration apportent cependant du bruit dans les données. Pour pallier à ce problème, deux méthodes ont été mises en place : la première, inhérente à la migration, permet de réduire l'aliasing dit sur l'opérateur. La deuxième est un filtre ré-interpolant les traces en se basant sur un profil de pendage. Les deux méthodes suppriment un bruit incohérent des données mais dégradent les profils lorsqu'utilisées abusivement. Dans un deuxième chapitre, nous avons appliqués avec succès le géoradar dans un contexte de paléo-sismologie en Mongolie. L'utilisation conjointe de deux fréquences (50 et 500 MHz) ainsi que des comparaisons avec des tranchées a permis d'obtenir des informations complémentaires sur les géométries et les déplacements potentiels le long de deux failles. Dans un dernier chapitre, nous avons appliqués les mesures géoradar sur les dépôts pyroclastiques du volcan Tungurahua en Equateur. A nouveau, l'utilisation jointe de différentes fréquences (250, 500 et 800 MHz) nous permet d'imager efficacement les dépôts. Les unités principales sont mises en évidence avec l'antenne de 250 MHz et les architectures des dépôts sont observables avec les antennes de 500 et 800 MHz. / Georadar is a high frequency (>10MHz) electromagnetic method used to prospect near surface. When a topography is present, GPR images are distorted. To restore the true geometry of reflexions, we coded an migration algorithm which takes the topography into account. The method is first demonstrate on a simple synthetic model, and then succesfully applied on real data. However, migration algorithms bring noise to the data. Two methods have then been tested to avoid and remove it. The first one is inherent to the migration algorithm and reduce what is called operator's aliasing. The second one is a filter re-interpolating traces based on a profile containing the slope. Both methods remove inconsistent noise when used with caution, but decrease their quality when used with excess: reflexions presenting dip are the first to be deteriorated, as well as reflexions below strong topography. In a second chapter, we successfully used GPR in a paleo-sismology context in Mongolia. The use of two frequencies (50 and 500 MHz) as well as comparison with trenches bring complementaries informations on the geometry and possible offset along two faults. In the last chapter, GPR was tested over pyroclastic deposits from the Tungurahua volcano in Ecuador. Again, the combination of several frequencies (250, 500 and 800 MHz) has proven its efficiency. Main units were obvious with the 250 MHz antenna while the inner architecture of deposits was visible with the 500 and 800 MHz antenna.

Submitted by Rafael Marini Paschoaletti Perri dos Santos (rafaelmpps@hotmail.com) on 2017-10-30T19:28:34Z No. of bitstreams: 2 PPGAA_ Dissertação_Rafael Marini PP Santos_2017 (1).pdf: 3014297 bytes, checksum: f71dea6e56def749b21f955b1a8a1ad5 (MD5) Encaminhamento_Dissertação_Rafael Marini dos Santos_PPGAA.pdf: 792545 bytes, checksum: eec6f1001daf58a9614a859a1d455837 (MD5) / Approved for entry into archive by Alini Demarchi (alini@cca.ufscar.br) on 2017-11-30T16:55:11Z (GMT) No. of bitstreams: 2 PPGAA_ Dissertação_Rafael Marini PP Santos_2017 (1).pdf: 3014297 bytes, checksum: f71dea6e56def749b21f955b1a8a1ad5 (MD5) Encaminhamento_Dissertação_Rafael Marini dos Santos_PPGAA.pdf: 792545 bytes, checksum: eec6f1001daf58a9614a859a1d455837 (MD5) / Approved for entry into archive by Alini Demarchi (ri.bar@ufscar.br) on 2018-01-15T18:25:58Z (GMT) No. of bitstreams: 2 PPGAA_ Dissertação_Rafael Marini PP Santos_2017 (1).pdf: 3014297 bytes, checksum: f71dea6e56def749b21f955b1a8a1ad5 (MD5) Encaminhamento_Dissertação_Rafael Marini dos Santos_PPGAA.pdf: 792545 bytes, checksum: eec6f1001daf58a9614a859a1d455837 (MD5) / Made available in DSpace on 2018-02-01T13:31:38Z (GMT). No. of bitstreams: 2 PPGAA_ Dissertação_Rafael Marini PP Santos_2017 (1).pdf: 3014297 bytes, checksum: f71dea6e56def749b21f955b1a8a1ad5 (MD5) Encaminhamento_Dissertação_Rafael Marini dos Santos_PPGAA.pdf: 792545 bytes, checksum: eec6f1001daf58a9614a859a1d455837 (MD5) Previous issue date: 2017-06-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Nowadays, society has a challenge to deal with sustainable water use. High demand and water contamination, environmental degradation and the unpredictability of climate changes are some water insecurity causes. Riparian forests maintenance offers water ecosystems services, but in some cases the riparian ecosystem is in a degraded condition that require human intervention actions for forest restoration. In this way, geotechnologies help us to infer about physical landscape characteristics where watershed is a basic unity for environmental planning. This study aimed to identify important hydrologically areas of Consulta stream watershed and Retiro stream watershed and propose priorities areas for forest restoration and sustainable agricultural destination. The two watersheds are the main sources of public water supply in the city of Bebedouro (Brazil). It is hypothesized that the limits established by Brazilian forest law (BFL) riparian buffers zones may not fully guarantee the two watersheds riparian areas protection. It was assumed that the forest community plays an important role in the attenuation of chemical elements and sediments, and that is essential that there is a disruption of potentially polluting activities near riparian areas. It was used in the study images from orbital sensors spatial resolution 30 m and 90 m and topographical map 1:50.000 for obtaining and processing elevations data and land use in geographic information system (GIS), and environmental legislation. The results allowed to characterize the watersheds that are surrounding and presented similarities in their physical parameters (basin form, drainage density, channel length, and others) and the Topographic Wetness Index (TWI) class distribution, slope class, landscape elements and land use. Three scenarios of priority areas for forest restoration were generated. It was observed that the priority areas are distributed close to the drainage channel of watersheds and are partially related to required areas by BFL. It can be concluded that in the three scenarios established the BFL may not be sufficient for the full protection of riparian sites and the adopted methodology proved to be efficient for guiding water resources management actions at larges scales. / Resolver conflitos relacionados ao uso da água é um desafio para a sociedade atual. Dentre os fatores que preocupam a segurança hídrica destacam-se a crescente demanda de consumo, a contaminação dos mananciais, a degradação de áreas naturais e a imprevisibilidade das mudanças climáticas que resultam em períodos irregulares de secas e estiagens. As matas ripárias oferecem funções importantes para os serviços ecossistêmicos de provisão hídrica, mas em algumas regiões encontram-se degradadas e com baixa resiliência, necessitando de ações de restauração florestal. As geotecnologias permitem inferir as características físicas da paisagem e a microbacia hidrográfica (MBH) é uma unidade básica para o planejamento ambiental. Este trabalho teve por objetivo identificar áreas hidrologicamente importantes nas MBHs do Córrego da Consulta e do Córrego do Retiro, de abastecimento público do município de Bebedouro (SP), e propor áreas prioritárias para a restauração florestal e manejo diferenciado. A hipótese é que as áreas de preservação permanente (APPs) de 30 m não são suficientes para abranger por completo as áreas ripárias destas MBHs. Considerou-se a eficiência da comunidade florestal em atenuar agentes químicos, sedimentos e a necessidade de interrupção de atividades potencialmente poluidoras próximas às áreas ripárias. Foram utilizadas imagens orbitais com resoluções espaciais de 30 m e 90 m, carta topográfica em escala 1:50.000 para obtenção e processamento de dados de elevação e uso e ocupação dos solos em sistema de informações geográficas (SIG), e legislação ambiental pertinente. Os resultados permitiram caracterizar as duas MBHs que são circunvizinhas e apresentaram semelhanças nos seus parâmetros físicos (fator de forma de bacia, densidade de drenagem, comprimento de canais, entre outros), na distribuição das classes do índice topográfico de umidade (ITU), de classes de declividade, de elementos de paisagem e de uso e ocupação dos solos. Foram gerados três cenários de áreas prioritárias para a restauração florestal. Observou-se que as áreas prioritárias para a restauração florestal e manejo diferenciado estão distribuídas próximas ao canal de drenagem das MBHs e estão relacionadas às APPs. Conclui-se que, nos três cenários estabelecidos, as APPs não são suficientes para a integral proteção de locais de caráter ripário e a metodologia adotada se mostrou eficiente para apontar ações de gestão de recursos hídricos em escalas maiores.