Geoelectrical investigation for aquifer delineation in the semi-arid Chad Basin, Nigeria

2004 ◽  
pp. 279-284
Author(s):  
E Shemang ◽  
A Iliya
Keyword(s):  
Chad Basin ◽  
Semi Arid

scholarly journals Assessment of Drought Characteristics under Changing Climatic Conditions using SPI and SPEI Indices in Semi-Arid Environment of Southeastern Niger

2021 ◽  
pp. 146-157
Author(s):  
Issiaka Issaharou-Matchi ◽  
Habou Rabiou ◽  
Boubacar M. Moussa ◽  
Idrissa Soumana ◽  
Karim Saley ◽  
...  
Keyword(s):  
Climate Change ◽  
Local Level ◽  
Standardized Precipitation Index ◽  
Arid Environment ◽  
Ecological Impacts ◽  
Maximum Temperature ◽  
Lake Chad ◽  
Chad Basin ◽  
Lake Chad Basin ◽  
Semi Arid

In the sahelian zone where 80% of the populations rely on rainfed-agricultural activities for their livelihood, drought episodes had significant socio-economics and ecological impacts. In recent decades, there has been an increase in the intensity, frequency and severity of drought occurrence mainly attributed to climate change. Thus, the main objectives of this study were: i) to understand drought multi-scale patterns and trend; ii) to assess drought duration, frequency and temporal extent over Mainé-soroa and Diffa located in the lake chad basin. To achieve these objectives standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) at 1, 3, 6, 9, 12 and 24-month timescales were employed for the stations of Mainé-soroa and Diffa. Stations’ monthly rainfall, air minimum and maximum temperature spanning 1950-2009 and 1988-2017 respectively for Mainé-soroa and Diffa were used for the analysis. The Mann–kendall trend test was performed and revealed negative SPEI and SPI trends in the station of Mainé-soroa.  Results indicate a significant negative SPI-12 and SPI-24 trend (p-value < 0.05), while no trend was detected in the rest of the time-scale series. The absolute value of declining trend was gradually increasing when SPEI was calculated with more lagged months.  Meanwhile, at the Diffa station both SPEI and SPI showed positive trends. The pettitt's t-test on the SPEI series indicated particularly 1968 as the change point detected for three time scales including spei-9, SPEI-12, and SPEI-24. Drought frequency generally increased in Mainé-soroa over the period of 1950–2009. SPEI appear to be the most powerful tool of monitoring drought in semi-arid environment in the context of climate change. To build resilience to drought and cope with its effects in the area we stress the importance of the establishment of early risk identification and advices framework at local level such study should be extended to lake chad basin.

scholarly journals GEOCHEMICAL FACIES OF THE TURONIAN GONGILA FORMATION, BORNU (CHAD) BASIN, NIGERIA: IMPLICATION FOR PROVENANCE, PALEOCLIMATE AND PALEOWEATHERING CONDITIONS

2018 ◽  
Vol 6 (4) ◽  
pp. 144-156
Author(s):  
B. Shettima ◽  
F. D. Adams ◽  
A. I. Haruna ◽  
A. I. Goro ◽  
M. Bukar
Keyword(s):  
Source Area ◽  
Xrd Analysis ◽  
Igneous Rocks ◽  
Bivariate Model ◽  
Chad Basin ◽  
Geochemical Evaluation ◽  
Chemical Index ◽  
Chemical Index Of Alteration ◽  
Mineralogical Compositions ◽  
Semi Arid

Geochemical evaluation of the Gongila Formation of Bornu (Chad) Basin indicated mineralogical compositions of quartz, feldspar, anatase, gypsum, smectite and kaolinite from XRD analysis. Corresponding major oxides from XRF analysis indicated the dominance of SiO2 with an average of 54.91 wt % followed by Al2O3 with 15.92 wt %. CaO, NaO, K2O, MgO, MnO, Fe2O3 TiO2 and P2O5 occurred with average compositions of 1.87%, 1.02%, 2.15%, 1.17%, 0.06%, 3.04%, 0.03% and 1.52 % respectively. Alteration indexes derivations from these oxides consisting of Chemical Index of Alteration (CIA), Plagioclase Index of Alteration (PIA) and Chemical Index of Weathering (CIW) accounted for a dominantly moderate weathering condition for the formation. Discriminant plots of Fe2O3+MgO versus TiO2 indicated a tectonically passive source area composed of generally intermediate igneous rocks, affirmed by Al2O3 versus TiO2 bivariate model with skewed plot along the granite line. The dominance of smectite suggests prevalence of arid to semi-arid paleoclimatic conditions during the deposition of shales of the Gongila Formation. Intermittent phases of superposed tropical climate are also depicted by the subordinate kaolinite mineralization.

Ferrihydrite dissolution at the root zone of crops under semi-arid condition controls the plant uptake of uranium and arsenic

2020 ◽  
Author(s):  
Arindam Malakar ◽  
Michael Kaiser ◽  
Daniel D. Snow ◽  
Harkamal Walia ◽  
Chittaranjan Ray
Keyword(s):  
Plant Uptake ◽  
Root Zone ◽  
Arid Condition ◽  
Semi Arid

THE CLASSIFICATION OF LAND ACCORDING TO THE DEGREE OF RABBIT INFESTATION IN CENTRAL OTAGO

1987 ◽  
pp. 65-70
Author(s):  
I.G.C. Kerr ◽  
J.M. Williams ◽  
W.D. Ross ◽  
J.M. Pollard
Keyword(s):  
Carrying Capacity ◽  
Mediterranean Climate ◽  
Natural Habitat ◽  
Public Funding ◽  
Soil Survey ◽  
European Rabbit ◽  
Cultural Modification ◽  
Classification Information ◽  
Semi Arid

The European rabbit (Oryctolagus cuniculus) introduced into New Zealand in the 183Os, has consistently flourished in Central Otago, the upper Waitaki, and inland Marlborough, all areas of mediterranean climate. It has proved difficult to manage in these habitats. The 'rabbit problem' is largely confined to 105,000 ha of low producing land mostly in semi arid areas of Central Otago. No field scale modifications of the natural habitat have been successful in limiting rabbit numbers. The costs of control exceed the revenue from the land and continued public funding for control operations appears necessary. A system for classifying land according to the degree of rabbit proneness is described. Soil survey and land classification information for Central Otago is related to the distribution and density of rabbits. This intormation can be used as a basis for defining rabbit carrying capacity and consequent land use constraints and management needs. It is concluded that the natural rabbit carrying capacity of land can be defined by reference to soil survey information and cultural modification to the natural vegetation. Classification of land according to rabbit proneness is proposed as a means of identifying the need for, and allocation of, public funding tor rabbit management. Keywords: Rabbit habitat, rabbit proneness, use of rabbit prone land.

CASE STUDY: Evaluation of Different Cooling Systems in Lactating Heat-Stressed Dairy Cows in a Semi-Arid Environment

2007 ◽  
Vol 23 (5) ◽  
pp. 546-555 ◽  
Author(s):  
R. Burgos ◽  
L.J. Odens ◽  
R.J. Collier ◽  
L.H. Baumgard ◽  
M.J. VanBaale
Keyword(s):  
Dairy Cows ◽  
Arid Environment ◽  
Cooling Systems ◽  
Study Evaluation ◽  
Semi Arid
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