The purpose of this study is to understand mineral diagenesis authigenic mineral and the effect of climate on mineral of Pleistocene-Holocene sediment deposits in the Southern Kenya Rift. Lake Magadi unique geologic settings are characterized by extreme alkalinity and high silica activities. The mineralogical analysis was achieved by X-Ray diffraction (XRD) and Scanning Electron Microscopy (SEM...

Future climates are forecast to include greater precipitation variability and more frequent heat waves, but the degree to which the timing of climate variability impacts ecosystems is uncertain. In a temperate, humid grassland, we examined the seasonal impacts of climate variability on 27 y of grass productivity. Drought and high-intensity precipitation reduced grass productivity only during a ...

North Africa experienced dramatic changes in hydrology and vegetation during the late Quaternary driven by insolation-induced shifts of the tropical rain belt and further modulated by millennial-scale droughts and vegetation-climate feedbacks. While most past proxy and modelling studies concentrated on the temporal and spatial dynamics of the last African humid period, little is known about the...

BACKGROUND Maintaining a relative humidity (RH) of less than 50% is one recommendation for reducing numbers of house dust mites and their allergens in homes. OBJECTIVE The purpose of this study was to determine whether, in a humid temperate climate, indoor RH could be sufficiently lowered to control dust mites and their allergens. METHODS During a period spanning 2 humid summers (May 1998 t...

[1] The termination of the Holocene African Humid Period ( 9 to 6 kyr BP) is simulated with a threedimensional global coupled climate model that resolves synoptic variability associated with weather patterns. In the simulation, the potential for ‘‘green’’ and ‘‘desert’’ Sahara states becomes equal between 7.5 and 5.5 thousand years ago, causing the climate system to fluctuate between these stat...

[1] Groundwater is an important component of the hydrologic cycle, and its anomaly will result in variations of soil moisture, water, and energy balances between the land surface and atmosphere, which ultimately influence climate. In this study, we implement a groundwater model into the regional climate model RegCM3, which is called RegCM3_GW, and investigate the effects of water table dynamics...

It is essential to examine the sensitivity of hydrologic responses to climate and landuse change across different physiographic regions in order to formulate sound water management policies for local response to projected global change. This study used the U.S. Geological Survey's Precipitation Runoff Modeling System (PRMS) model to examine the potential impacts of climate and landuse changes o...

introduction in general, loess sediments are one of the most widespread forms of aeolian sediments. during the past few decades, loess stratigraphy studies played key role in the investigation about global climate changes. these sediments are usually yellowish in color and silt makes 70 to 90 percent of its volume. in iran, loesses outcrop are often in northeast part of south caspian sea. the p...

to study the effects of different tillage systems on yield and some characteristic of wheat and also some soil properties in wheat dry land area, six experiments were performed in cold, moderate and semi-warm climatic conditions of kermanshah province in west of iran, in a randomized complete block design with five replications. experimental treatments were consisted of no-tillage, reduced till...