Hydrological recovery

Our analysis focuses on three measures of secondary forest development biomass accumulation, nutrient accumulation, and hydrological recovery. We choose biomass accumulation, because it is the best integrative measure of secondary forest development, it is the basis for estimates of carbon sequestration by secondary forests, and it is the most frequently measured secondary forest parameter. An analysis of nutrient accumulation allows us to examine the commonly held assumption that nutrient shortages limit rates of secondary forest recovery (e.g. Gehring et al. 1999, Tucker et al. 1998). Although hydrological recovery in secondary forests is poorly documented in... 

Solid-wa.ste-filling plan. The specific method of filling will depend on the characteristics of the site, such as the amount of available cover material, the topography, and local hydrology and geology. To assess future development plans, it will be necessary to prepare a detailed plan for the layout of the individual solid-waste cells. On the basis of the characteristics of the site or the method of operation (e.g., gas recovery), it may be necessaiy to incorporate special features for the control of the movement of gases and leachate from the landfill. 

Mishra, S., Parker, J. C., and Kaluarachchi, J. J., 1989b, Analysis of Uncertainty in Predictions of Hydrocarbon Recovery from Spill Sites Journal of Contaminate Hydrology, in review. 

If all of these elements are incorporated into a basic hydrologic flow model, then detailed modelling of the behavior of the leaching system will be possible. The development of such comprehensive models will not only aid in the optimization of solution compositions for the most effective uranium recovery, but will also allow a more realistic environmental impact assessment and corrective measures if required. 

Further support of rapid recovery of hydrological functions in secondary forest comes from the Zona Bragantina, east of Belem. Here, Holscher et al. (1997) used a Bowen ratio approach to measure evapotranspiration in a 2.5-3.5-year-old secondary forest on abandoned crop land, and found an average daily rate (3 9 mm d ) very close to that of mature forests receiving similar amounts of radiation. During the dry season, this secondary forest was absorbing water from below 3 m depth, and therefore had recovered a portion of its deep soil water uptake capacity. 

Evans, C.D., Cullen, J.M., Alewell, C., Kopacek, J., Marchetto, A., Moldan, F., Prechtel,A Rogora, M., Vesely, J., and Wright, R.F. (2001). Recovery from acidification in European surface waters. Hydrology Earth System Science, 5, 283-298. 

Van Sickle, J., Baker, J.R, Simonin, H.A., Baldigo, B.P., Kretser, W.A. and Sharpe, W.F. (1996). Episodic acidification of small streams in the northeastern United States Fish mortality in field bioassays. Ecological Applications, 6, 408-421. Wright, R.F (2003). Predicting recovery of acidified freshwaters in Europe and Canada. Hydrology Earth System Science, 7, 429—430. 

The use of surfactants for remediation of contaminated soils and aquifers has been widely examined. Techniques for remediation are conveniently denoted as in situ and ex situ, where the former refers to treatment of soil or aquifers in place (in the subsurface) and the latter indicates excavation of soil for treatment above ground and pump and treat in the case of aquifers. The literature is quite extensive on surfactant-enhanced subsurface remediation [15] and has relied on the basics of surfactant-based remediation chemistry-physicochemistry-hydrology [16-27]. It was further demonstrated that the recovery and reuse of the surfactant (if applicable), is critical for maintaining the economic feasibility of this remediation technology applied [28],... 

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