Characterizing suspended sediments from the Piracicaba River Basin by means of k(0)-INAA

The inorganic chemical characterization of suspended sediments is of utmost relevance for the knowledge of the dynamics and movement of chemical elements in the aquatic and wet ecosystems. Despite the complexity of the effective design for studying this ecological compartment, this work has tested a procedure for analyzing suspended sediments by instrumental neutron activation analysis, k(0) method (k(0)-INAA). The chemical elements As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, Fig, K, La, Mo, Na, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Yb and Zn were quantified in the suspended sediment compartment by means of k(0)-INAA. When compared with World Average for rivers, high mass fractions of Fe (222,900 mg/kg), Ba (4990 mg/kg), Zn (1350 mg/kg), Cr (646 mg/kg), Co (74.5 mg/kg), Br (113 mg/kg) and Mo (31.9 mg/kg) were quantified in suspended sediments from the Piracicaba River, the Piracicamirim Stream and the Marins Stream. Results of the principal component analysis for standardized chemical element mass fractions indicated an intricate correlation among chemical elements evaluated, as a response of the contribution of natural and anthropogenic sources of chemical elements for ecosystems. (C) 2010 Elsevier B.V. All rights reserved.

Land Use and Climate Change Impacts on the Hydrology of the Upper Mara River Basin, Kenya: Results of a Modeling Study to Support Better Resource Management

Some of the most valued natural and cultural landscapes on Earth lie in river basins that are poorly gauged and have incomplete historical climate and runoff records. The Mara River Basin of East Africa is such a basin. It hosts the internationally renowned Mara-Serengeti landscape as well as a rich mixture of indigenous cultures. The Mara River is the sole source of surface water to the landscape during the dry season and periods of drought. During recent years, the flow of the Mara River has become increasingly erratic, especially in the upper reaches, and resource managers are hampered by a lack of understanding of the relative influence of different sources of flow alteration. Uncertainties about the impacts of future climate change compound the challenges. We applied the Soil Water Assessment Tool (SWAT) to investigate the response of the headwater hydrology of the Mara River to scenarios of continued land use change and projected climate change. Under the data-scarce conditions of the basin, model performance was improved using satellite-based estimated rainfall data, which may also improve the usefulness of runoff models in other parts of East Africa. The results of the analysis indicate that any further conversion of forests to agriculture and grassland in the basin headwaters is likely to reduce dry season flows and increase peak flows, leading to greater water scarcity at critical times of the year and exacerbating erosion on hillslopes. Most climate change projections for the region call for modest and seasonally variable increases in precipitation (5–10 %) accompanied by increases in temperature (2.5–3.5 °C). Simulated runoff responses to climate change scenarios were non-linear and suggest the basin is highly vulnerable under low (−3 %) and high (+25 %) extremes of projected precipitation changes, but under median projections (+7 %) there is little impact on annual water yields or mean discharge. Modest increases in precipitation are partitioned largely to increased evapotranspiration. Overall, model results support the existing efforts of Mara water resource managers to protect headwater forests and indicate that additional emphasis should be placed on improving land management practices that enhance infiltration and aquifer recharge as part of a wider program of climate change adaptation.

PLANT ACCUMULATIONS ALONG THE ITANHAEM RIVER BASIN, SOUTHERN COAST OF SAO PAULO STATE, BRAZIL

Examination of the mechanisms involved in the construction of present-day vegetative deposits along coastal waterways has made it possible to establish depositional patterns that can be compared with those found in similar environments in geologic time. These patterns include not only the composition and transport of the debris but also an estimation of the time involved in its deposition. Six sites with active deposits of plant macrodebris in the coastal basin of the Itanhaem River, Sao Paulo State, Brazil, were used in the study. In the central portion of the basin, the interior coastal plain is covered with restinga forest (dense, wet tropical forest of low altitudes), while the lower portion consists of mangrove swamps. The coast reflects anthropogenic intervention, and only a few scattered remnants of precolonization dune vegetation remain. The results after three years of study suggest that the accumulation of plant macrodebris in the middle and lower portions of the basin is parautochthonous, since only the leaves of genera typical of the restinga forest and mangrove swamp, respectively, were found. Along the coast the accumulations involved a mixture of parautochthonous and allochthonous elements. On the levee of the Branco River and within the mangrove swamp, deposition was slow, and many of the elements decayed quickly; such accumulations show little potential for preservation and eventual fossilization. A different site, however, reveals the rapid deposition of thick layers of plant debris, presumably associated with storms, and these accumulations are preserved for long periods, constituting good candidates for possible fossilization.

Missouri River basin condensed tabulation of river mileage and drainage areas /

Cover title.

Salinity control in Colorado River basin [microform] : hearing before the Subcommittee on Department Operations, Research, and Foreign Agriculture of the Committee, House of Representatives, Ninety-seventh Congress, first session, June 10, 1981.

"Serial no. 97-L."

Lower Des Plaines River basin : an inventory of the region's resources /

"A project of the Critical Trends Assessment Program."

The Cache River Basin : an inventory of the region's resources /

This is a product of the Critical Trends Assessment Program (CTAP) and the Ecosystems Program of the Illinois Dept. of Natural Resources (DNR). Both are funded largely through Conservation 2000, a six-year State of Illinois initiative to enhance nature protection and outdoor recreation by reversing the decline of the state's ecosystems. Conservation 2000 is the culmination of recommendations from CTAP, the Illinois Conservation Congress, and Governor Edgar's Water Resources Land Use Priorities Task Force.--T.p. verso.

The DuPage River basin : an inventory of the region's resources.

"February 2001."

The Embarras River basin : an inventory of the region's resources /

"A product of the Critical Trends Assessment Program (CTAP) and the Ecosystems Program of the Illinois Department of Natural Resources (IDNR)."

The Kaskaskia River Basin : an inventory of the region's resources.

"January 2001"

The Kishwaukee River Basin : an inventory of the region's resources /

"A product of the Critical Trends Assessment Program (CTAP) and the Ecosystems Program of the Illinois Dept. of Natural Resources (DNR)"--P. [2] of cover.

The lower Rock River basin : an inventory of the region's resources /

"A project of the Critical Trends Assessment Program."

The Mackinaw River Basin : an inventory of the region's resources / [Susan L. Post].

"A product of the Critical Trends Assessment Program (CTAP) and the Ecosystems Program of the Illinois Dept. of Natural Resources (DNR)"--P. [2] of cover.

The Spoon River basin : an inventory of the region's resources 1998 /

"A product of the Critical Trends Assessment Program (CTAP) and the Ecosystems Program of the Illinois Department of Natural Resources (IDNR)--P. [2] of cover.