The notion that landscape features have coevolved over time is well known in the Earth sciences. Hydrologists have recently called for a more rigorous connection between emerging spatial patterns of landscape features and the hydrological response of catchments, and have termed this concept catchment coevolution. In this paper we review recent literature on this subject and attempt to synthesize what we have learned into a general framework that would improve predictions of hydrologic change. We first present empirical evidence of the interaction and feedback of landscape evolution and changes in hydrological response. From this review it is clear that the independent drivers of catchment coevolution are climate, geology, and tectonics. We identify common currency that allows comparing the levels of activity of these independent drivers, such that, at least conceptually, we can quantify the rate of evolution or aging. Knowing the hydrologic age of a catchment by itself is not very meaningful without linking age to hydrologic response. Two avenues of investigation have been used to understand the relationship between (differences in) age and hydrological response: (i) one that is based on relating present landscape features to runoff processes that are hypothesized to be responsible for the current fingerprints in the landscape; and (ii) one that takes advantage of an experimental design known as space-for-time substitution. Both methods have yielded significant insights in the hydrologic response of landscapes with different histories. If we want to make accurate predictions of hydrologic change, we will also need to be able to predict how the catchment will further coevolve in association with changes in the activity levels of the drivers (e.g., climate). There is ample evidence in the literature that suggests that whole-system prediction of catchment coevolution is, at least in principle, plausible. With this imperative we outline a research agenda that implements the concepts of catchment coevolution for building a holistic framework toward improving predictions of hydrologic change.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAlbacora Leste, one of the largest Campos Basin deep-water oilfields, was discovered in March of 1986. Oil field development area involves 141km 2 and water depth ranges from 800 to 2000m. In order to exploit the field, 30 horizontal wells -16 producers and 14 injectors -will be connected to an FPSO unit (P-50). Expected total reserves are 565 million barrels of oil.Albacora Leste main reservoirs are Miocene sandstones with high porosity and permeability. The depositional model is interpreted as a complex turbidity system, mainly represented by channels, lobes and overbank facies. Net thickness ranges from 5 to 35m, suggesting horizontal well drilling. After the deposition stage, erosive channels introduced flow barriers that generated different reservoir compartments. These compartments impacted drainage pattern design and were checked through reservoir pressure data after long term pilot well production, log interpretation, and fluid samples analyses. Small gas caps showing different gas/oil contacts were detected all over the field area, introducing an additional challenge for field development.Intensive application of the following technologies was important to make field development technically and economically successful: (1) high quality 3D seismic; (2) image logs and LWD (logging while drilling); (3) long gravelpacked horizontal wells; (4) thermally insulated flowlines, allowing flow assurance for distant satellite wells; and (5) massive sea water injection for sweep, and reservoir pressure maintenance. In order to avoid scale deposition as a result of sea water injection, a Sulphate Removal Unit was installed in the P-50 FPSO.This paper presents the key aspects of the reservoirs, the drainage modeling and design, as well as the strategy adopted during project implementation, in order to overcome main reservoir uncertainties, such as fluid type, connectivity, and net pay, accomplishing at the end a successful project execution.

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