肯尼亚矿产资源及矿业投资环境分析

肯尼亚是东非第一大经济体,也是非洲东部的重要出海口,战略位置突出。境内矿产资源丰富,有钛铁矿、金、猛、铜等金属矿产,以及纯碱、萤石和重晶石等非金属矿产,主要赋存于太古代绿岩带和莫桑比克构造带上,其中钛铁矿储量全球第五。中肯两国关系稳定,且近年矿业发展迅速,其资源与我国有较强的资源互补性,加之肯尼亚地质工作程度较低,有大部分陆域国土面积尚未进行勘探,具有良好的投资前景。本文在系统梳理肯尼亚主要矿产资源基本情况、矿业开发现状的基础上,深入研判肯尼亚矿业投资环境及主要投资风险与机遇,进而对肯尼亚矿业投资提出建议。     

肯尼亚基图伊地区铜矿地质特征及找矿潜力分析

肯尼亚大地构造位于非洲地块东部,东非裂谷的东支裂谷沿维尔利亚湖东侧贯穿肯尼亚中央高地进入坦桑尼亚境内。基图伊铜矿区处于东非裂谷在肯尼亚段的南东部。主要以近南北向、北西向和近东西向断裂构造为主。铜矿区由于所处构造特殊性,岩浆活动强烈,铜矿主要赋存于斜长角闪片麻岩和花岗片麻岩中,矿体产状与岩石片麻理产状大致一致。主要矿石矿物有孔雀石、蓝铜矿,少量辉铜矿,脉石矿物以碱性长石、斜长石、石英、云母为主,矿石结构主要为放射状变晶结构,矿石构造主要为变胶状构造、块状构造、脉状构造、网脉状构造等。矿体走向延伸长达几十千米,矿体品位较富,铜品位1.0×10-27.5×10-2,矿体厚度较稳定,初步估算铜资源,矿床达大型规模,具有较大的找矿潜力。     

Interannual variability of NDVI and bird species diversity in Kenya

Species richness, or simply the number of species in a given area, is commonly used as an important indicator of biological diversity. Spatial variability in species richness has been postulated to depend upon environmental factors such as climate and climatic variability, which in turn may affect net primary productivity. The Advanced Very High Resolution Radiometer (AVHRR) derived Normalized Difference Vegetation Index (NDVI) has been shown to be correlated with climatic variables including rainfall, actual evapotranspiration and net primary productivity. To determine factors favoring high species richness, we examined the relationship between interannual NDVI variables and species richness of birds at a quarter degree scale (55 × 55 km). Results revealed a strong positive correlation between species richness and maximum average NDVI. Conversely, species richness showed negative correlation with standard deviation of maximum NDVI and the coefficient of variation. Though these relationships are indirect, they apparently operate through the green vegetation cover. Understanding such relationships can help in mapping and monitoring biological diversity, as well as in estimating changes in species richness in response to global climatic change.     

Optical and radar data comparison and integration: Kenya example

The purpose of this study was to evaluate the relative classification accuracies of four land covers/uses in Kenya using spaceborne quad polarization radar from the Japanese ALOS PALSAR system and optical Landsat Thematic Mapper data. Supervised signature extraction and classification (maximum likelihood) was used to classify the different land covers/uses followed by an accuracy assessment. The original four band radar had an overall accuracy of 77%. Variance texture was the most useful of four measures examined and did improve overall accuracy to 80% and improved the producer’s accuracy for urban by almost 25% over the original radar. Landsat provided a higher overall classification accuracy (86%) as compared to radar. The merger of Landsat with the radar texture did not increase overall accuracy but did improve the producer’s accuracy for urban indicated some advantages for sensor integration.     

Evaluating the Accuracy and Effectiveness of Criminal Geographic Profiling Methods: The Case of Dandora,Kenya

Criminal geographic profiling (CGP) prioritizes offender search, extensively reducing the resources expended in criminal investigations. The utility of CGP has, however, remained unclear when variations in environmental characteristics and offense type are introduced. This study evaluates several CGP strategies with data from Dandora, a small but densely populated suburb of Nairobi, Kenya. The research employs error distance and search-cost measures to determine CGP accuracy. Characterized by much shorter journeys to crime than those observed in Western cities, this study discovers significant applicability of CGP strategies in prioritizing offender searches. The negative exponential CGP strategy is identified to generate the most accurate geo-profiles.     

Cyanobacterial toxins in Lake Baringo, Kenya

This paper presents data on the first identification, characterization and quantification of hepatotoxic microcystins and neurotoxic anatoxin-a in water samples of Lake Baringo, Kenya. The shallow turbid Lake Baringo was investigated five times between June 2001 and May 2002. The phytoplankton community was mainly dominated by the cyanobacterium Microcystis aeruginosa. Due to the high turbidity the phytoplankton biomass was low, ranging between 1.5 and 8.2 mg L⁻¹. High mean total phosphorus concentration (1.0 mg L⁻¹) and mean total nitrogen concentration (2.8 mg L⁻¹) typical for hypertrophic lakes were found. Using HPLC technique the hepatotoxins microcystin-LR, -RR and -YR and the neurotoxin anatoxin-a were detected in the water samples. The microcystin concentrations varied from 310 to 19800 μg microcystin-LR equivalents g⁻¹ DW and the anatoxin-a concentration ranged from 270 to 1260 μg g⁻¹ DW. To our knowledge this is the first evidence of cyanobacterial toxins in Lake Baringo.     

Effects of seasonal breeding on productive performance of pastoral goat herds in northern Kenya: a longitudinal analysis of growth in kids and body weight development of does

This paper investigates whether liveweight development of kids and dams can be improved by introducing a seasonal breeding regime in goat herds maintained under pastoral management in northern Kenya. The experimental treatment consisted of six consecutive mating seasons. Traits studied comprise relative growth rates of kids (g kg^−0·75 day⁻¹) from birth until 2 years of age, liveweight development of kids (kg) from birth until 2 years of age, and body weight development (kg) of does over a reproductive cycle of 1 year duration. No systematic effect of mating season on birth weights of kids could be detected, whereas the experiment succeeded in demonstrating that mating season has an impact upon body weight development of kids. The highest average preweaning weight gains were achieved by kids born in the period from October to May, while growth performance was seriously compromised when birth took place at the middle of the long dry season. However, the differences between mating season groups had almost completely disappeared by 1 year of age. The mating season treatment produced marked differences in weight development curves in does. During gestation, does were advantaged when they were mated just prior to the long rainy season, while the largest relative liveweight gains over the entire reproductive cycle were achieved by does mated during the short rains. It is concluded that seasonal breeding does not confer any major advantage in terms of liveweight production of young livestock, except that mating during the short dry season from December to January should be avoided. Similarly, a clear effect on body weights of does at the end of the reproductive cycle could only be observed when mating occurred during this period.     

Stratigraphy of the Koobi Fora Formation (Pliocene and Pleistocene) in the Loiyangalani region of northern Kenya

Tuffaceous marker beds in the Loiyangalani region were previously identified as correlative with similar beds in the Shungura and Koobi Fora Formations of southwestern Ethiopia and northwestern Kenya. Associated sedimentary strata correlate with the Koobi Fora Formation, and include intercalated basalt flows. In the Loiyangalani region the Koobi Fora Formation has a composite thickness of at least 257 m, and records one time interval for which no strata are known in the Koobi Fora region. Four members of the Koobi Fora Formation (Lonyumun, Tulu Bor, Burgi, and KBS) are recognized in the region, and a composite member (Moiti–Lokochot) proposed because the Lokochot Tuff, the formal boundary between the Moiti and Lokochot Members has not been identified. This extends the known geographic area of the Koobi Fora Formation 100 km southward. These strata, together with others, were previously termed ‘Loiyangalani formation (or Formation)’. Deposition in the Loiyangalani region began at about the same time as in the Koobi Fora and Nachukui Formations. Newly named basalts are Kankam (3.2–3.3 Ma), Lenderit (2.02 to 2.18 ± 0.02 Ma), and Balo (1.79 ± 0.02 Ma). We also report K/Ar ages on basalts from Mt. Kulal (2.04 ± 0.02 to 2.40 ± 0.03 Ma) east of the region and from Serima Gorge (0.77 ± 0.01 Ma) south of the study area.     

Heading Households and Heading Businesses: Rural Kenyan Women in the Informal Sector

The dynamics of intra-household economics among sedentary farmers in rural Kenya suggest that women, whether or not they have a male household head, are responsible for providing basic resources to insure the daily survival of household members. Many rural Kenyan women operate small businesses in rural market centers in order to meet these obligations, and many of these women are also heads of their households. This paper examines women's resource bases for establishing and maintaining small-scale businesses. Compared to women who are associated with male-headed households, women who head households have fewer resources for establishing businesses which in turn generate lower earnings. At the same time, these women are almost completely dependent on their businesses for meeting the household's needs.