scholarly journals The paradoxical evolution of runoff in the pastoral Sahel: analysis of the hydrological changes over the Agoufou watershed (Mali) using the KINEROS-2 model

2017 ◽  
Vol 21 (9) ◽  
pp. 4591-4613 ◽  
Author(s):  
Laetitia Gal ◽  
Manuela Grippa ◽  
Pierre Hiernaux ◽  
Léa Pons ◽  
Laurent Kergoat
Keyword(s):  
Soil Properties ◽  
Sandy Soil ◽  
Aerial Photographs ◽  
Rainfall Regime ◽  
Drainage Network ◽  
Surface Hydrology ◽  
The Past ◽  
Annual Discharge ◽  
Changes In Soil Properties

Abstract. In recent decades, the Sahel has witnessed a paradoxical increase in surface water despite a general precipitation decline. This phenomenon, commonly referred to as the Sahelian paradox, is not completely understood yet. The role of cropland expansion due to the increasing food demand by a growing population has been often put forward to explain this situation for the cultivated Sahel. However, this hypothesis does not hold in pastoral areas where the same phenomenon is observed. Several other processes, such as the degradation of natural vegetation following the major droughts of the 1970s and the 1980s, the development of crusted topsoils, the intensification of the rainfall regime and the development of the drainage network, have been suggested to account for this situation. In this paper, a modeling approach is proposed to explore, quantify and rank different processes that could be at play in pastoral Sahel. The kinematic runoff and erosion model (KINEROS-2) is applied to the Agoufou watershed (245 km2), in the Gourma region in Mali, which underwent a significant increase of surface runoff during the last 60 years. Two periods are simulated, the past case (1960–1975) preceding the Sahelian drought and the present case (2000–2015). Surface hydrology and land cover characteristics for these two periods are derived by the analysis of aerial photographs, available in 1956, and high-resolution remote sensing images in 2011. The major changes identified are (1) a partial crusting of isolated dunes, (2) an increase of drainage network density, (3) a marked decrease in vegetation with the nonrecovery of tiger bush and vegetation growing on shallow sandy soils, and (4) important changes in soil properties with the apparition of impervious soils instead of shallow sandy soil. The KINEROS-2 model was parameterized to simulate these changes in combination or independently. The results obtained by this model display a significant increase in annual discharge between the past and the present case (p value < 0.001), which is consistent with observations, despite a slight overestimation of the past discharge. Mean annual discharges are estimated at 0.51  ×  106 m3 (2.1 mm yr−1) and 3.29  ×  106 m3 (13.4 mm yr−1) for past and present, respectively. Changes in soil properties and vegetation cover (tiger bush thickets and grassland on shallow sandy soil) are found to be the main factors causing this increase of simulated runoff, with the drainage network development contributing to a lesser extent but with a positive feedback. These results shed a new light on the Sahelian paradox phenomenon in the absence of land use change and call for further tests in other areas and/or with other models. The synergetic processes highlighted here could play a role in other Sahelian watersheds where runoff increase has been also observed.

scholarly journals Modeling the paradoxical evolution of runoff in pastoral Sahel. The case of the Agoufou watershed, Mali

2016 ◽  
Author(s):  
Laetitia Gal ◽  
Manuela Grippa ◽  
Pierre Hiernaux ◽  
Léa Pons ◽  
Laurent Kergoat
Keyword(s):  
Marked Decrease ◽  
Aerial Photographs ◽  
P Value ◽  
Rainfall Regime ◽  
Drainage Network ◽  
Surface Hydrology ◽  
The Past ◽  
Annual Discharge ◽  
Changes In Soil Properties

Abstract. In the last decades the Sahel has witnessed a paradoxical increase in surface water despite a general precipitation decline. This phenomenon, commonly referred to as "the Sahelian paradox", is not completely understood yet. The role of cropland expansion due to the increasing food demand by a growing population has been often put forward to explain this situation for the cultivated Sahel. However, this hypothesis does not hold in pastoral areas where the same phenomenon is observed. Several other processes have been suggested to account for this situation such as the degradation of natural vegetation following the major droughts of the 70ies and the 80ies, the development of crusted top soils, the intensification of the rainfall regime and the development of the drainage network. In this paper, a modeling approach is proposed to quantify and rank the different processes that could be at play in pastoral Sahel. The KINEmatic EROSion model (KINEROS-2) is applied to the Agoufou watershed, in the Gourma region in Mali, which underwent a significant increase of surface runoff during the last 60 years. Two periods are simulated, the "past" case (1960–1975) preceding the Sahelian drought and the "present" case (2000–2015). Surface hydrology and land cover characteristics for these two periods are derived by the analysis of aerial photographs, available in 1956, and high resolution remote sensing images in 2011. The major changes identified are: (1) a partial crusting of isolated dunes, (2) an increase of drainage network density, (3) a marked decrease in vegetation with the non-recovery of tiger bush and vegetation growing on shallow sandy soils and (4) important changes in soil properties with shallow soil being eroded and giving place to impervious soils. These changes were implemented independently and in combination in the KINEROS-2 model. The simulations results show a significant increase of annual discharge between the "past" and the "present" case (p value 

CHANGES IN SOIL PROPERTIES AND EARTHWORM POPULATIONS INDUCED BY LONG-TERM ORGANIC FERTILIZATION OF A SANDY SOIL IN THE VENEZUELAN AMAZONIA

Soil Science ◽  
2004 ◽  
Vol 169 (3) ◽  
pp. 188-194 ◽  
Author(s):  
D. López-Hernández ◽  
Y. Araujo ◽  
A. López ◽  
I. Hernández-Valencia ◽  
C. Hernández
Keyword(s):  
Soil Properties ◽  
Sandy Soil ◽  
Organic Fertilization ◽  
Earthworm Populations ◽  
Changes In Soil Properties

scholarly journals ANÁLISE TEMPORAL DO USO E OCUPAÇÃO DO SOLO NA MICROBACIA HIDROGRÁFICA DO CÓRREGO DA FAZENDA GLÓRIA, MUNICÍPIO DE TAQUARITINGA, SP.

Irriga ◽  
2009 ◽  
Vol 14 (3) ◽  
pp. 314-324 ◽  
Author(s):  
Flavia Mazzer Rodrigues ◽  
Teresa Cristina Tarle Pissara ◽  
Sergio Campos
Keyword(s):  
Native Species ◽  
Environmental Concern ◽  
Aerial Photographs ◽  
Mountain Range ◽  
Drainage Network ◽  
Land Occupation ◽  
Data Analyses ◽  
Citrus Orchards ◽  
Intense Exploitation

análise temporal do uso e ocupação do solo na microbacia hidrográfica do Córrego da Fazenda Glória, município de Taquaritinga, SP.   Flavia Mazzer Rodrigues1; Teresa Cristina Tarlé Pissarra1; Sérgio Campos21Departamento de Engenharia Rural, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP, [email protected] de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP  1 RESUMO  A problemática ambiental assume importante papel, visto a ocupação desordenada do espaço e a intensa exploração dos recursos naturais, levando ao esgotamento e à degradação do meio natural. Para tanto, as técnicas de sensoriamento remoto permitem identificar os agentes modificadores do espaço, reconhecer e mapear, além de estimar a extensão das alterações provocadas pelo homem. Assim o objetivo deste trabalho foi mapear o uso e ocupação do solo para avaliar a  evolução na Bacia Hidrográfica Córrego da Fazenda Glória, Taquaritinga - SP, no período de1983 a2000. Como resultado das análises estereoscópicas nas fotografias aéreas de 2000 e avaliação dos dados nos documentos cartográficos e em campo foram identificados a rede de drenagem, comunidades vegetais naturais e agrícolas. Os resultados permitiram constatar que a classe de cana-de-açúcar tornou-se predominante em 2000, apresentando-se distribuída em áreas relativamente extensas, em detrimento de pomares de citrus e outras culturas. Observou-se também a presença de represas, o que não aparece notadamente nos dados de 1983 e o aumento na área de fragmentos florestais (mata) e das áreas de várzeas no decorrer do período analisado. Áreas recuperadas com reflorestamentos com espécies nativas foram identificadas principalmente ao longo dos córregos e nas nascentes na Serra do Jabuticabal.  UNITERMOS: sensoriamento remoto, cobertura vegetal, mapeamento.  RODRIGUES, F, M.; PISSARRA, T. C. T.;CAMPOS, S. TEMPORAL ANALISES OF THE USE AND OCCUPATION OF THE GROUND IN THE WATERSHED OF THE STREAM OF THE FARM GLÓRIA, TAQUARITINGA, SP.  2 ABSTRACT The role of environmental concern is important due to the disorganized land occupation and intense exploitation of natural resources which lead to the degradation and exhaustion of the environment. Remonte sensing techniques allow identifying, recognizing and mapping areas modifiers besides estimating the extension of alterations made by man. Thus, the objective of this study was to map land use and occupation in order to evaluate the development of the Gloria Farm Stream watershed in Taquaritinga, SP,Brazil, from 1983 to 2000. The drainage network and agricultural and natural vegetation areas were identified by stereoscopic analyses of 2000 aerial photographs and by data analyses of the field and cartographic documents. The results verified that sugarcane became predominat in 2000 and it is distributed in  relatively large areas with detriment to citrus orchards and other crops. The presence of dams, which is not noted in 1983 data, and the increase of forest and natural vegetal fragment areas in the analyzed period was observed. Recovered areas dur to reforestation with native species were identified along the streams and springs of Jabuticabal Mountain Range. KEYWORDS: remote sensing, vegetation cover, mapping. 

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

A literature review on firms' internationalisation through e-commerce

2019 ◽  
pp. 121-143
Author(s):  
Riccardo Resciniti ◽  
Federica De Vanna
Keyword(s):  
Systematic Review ◽  
Literature Review ◽  
International Business ◽  
Decision Process ◽  
Foreign Markets ◽  
New Markets ◽  
Integrative Framework ◽  
The Past ◽  
The Relationship

The rise of e-commerce has brought considerable changes to the relationship between firms and consumers, especially within international business. Hence, understanding the use of such means for entering foreign markets has become critical for companies. However, the research on this issue is new and so it is important to evaluate what has been studied in the past. In this study, we conduct a systematic review of e-commerce and internationalisation studies to explicate how firms use e-commerce to enter new markets and to export. The studies are classified by theories and methods used in the literature. Moreover, we draw upon the internationalisation decision process (antecedents-modalities-consequences) to propose an integrative framework for understanding the role of e-commerce in internationalisation

Concealment of Illegally Obtained Assets in Nigeria: Revisiting the Role of the Churches in Money Laundering

2020 ◽  
Vol 28 (1) ◽  
pp. 106-121
Author(s):  
Kato Gogo Kingston
Keyword(s):  
Economic Growth ◽  
Money Laundering ◽  
Financial Crime ◽  
The Past ◽  
Key Drivers ◽  
Nigerian Government

Financial crime in Nigeria – including money laundering – is ravaging Nigeria's economic growth. In the past few years, the Nigerian government has made efforts to tackle money laundering by enacting laws and setting up several agencies to enforce the laws. However, there are substantial loopholes in the regulatory and enforcement regimes. This article seeks to unravel the involvement of the churches as key drivers in money laundering crimes in Nigeria. It concludes that the permissive secrecy which enables churches to conceal the names of their financiers and donors breeds criminality on an unimaginable scale.

Provision of Remedies for Violation of Economic, Social and Cultural Rights: A Comparative Study of the United Nations, Inter-American and African Human Rights Systems

2020 ◽  
Vol 28 (2) ◽  
pp. 298-318
Author(s):  
Roman Girma Teshome
Keyword(s):  
Human Rights ◽  
United Nations ◽  
Comparative Study ◽  
Economic Rights ◽  
Regional Monitoring ◽  
Cultural Rights ◽  
The Past ◽  
The United Nations ◽  
To Receive

The effectiveness of human rights adjudicative procedures partly, if not most importantly, hinges upon the adequacy of the remedies they grant and the implementation of those remedies. This assertion also holds water with regard to the international and regional monitoring bodies established to receive individual complaints related to economic, social and cultural rights (hereinafter ‘ESC rights’ or ‘socio-economic rights’). Remedies can serve two major functions: they are meant, first, to rectify the pecuniary and non-pecuniary damage sustained by the particular victim, and second, to resolve systematic problems existing in the state machinery in order to ensure the non-repetition of the act. Hence, the role of remedies is not confined to correcting the past but also shaping the future by providing reforming measures a state has to undertake. The adequacy of remedies awarded by international and regional human rights bodies is also assessed based on these two benchmarks. The present article examines these issues in relation to individual complaint procedures that deal with the violation of ESC rights, with particular reference to the case laws of the three jurisdictions selected for this work, i.e. the United Nations, Inter-American and African Human Rights Systems.

Receptions of the Past: Commemoration, Racism, Desire

Somatechnics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 288-303
Author(s):  
Michael Connors Jackman
Keyword(s):  
Critical Point ◽  
Social Relations ◽  
White Privilege ◽  
Body Politic ◽  
The Body ◽  
Race And Racism ◽  
Lesbian And Gay ◽  
The Past ◽  
History Of

This article investigates the ways in which the work of The Body Politic (TBP), the first major lesbian and gay newspaper in Canada, comes to be commemorated in queer publics and how it figures in the memories of those who were involved in producing the paper. In revisiting a critical point in the history of TBP from 1985 when controversy erupted over race and racism within the editorial collective, this discussion considers the role of memory in the reproduction of whiteness and in the rupture of standard narratives about the past. As the controversy continues to haunt contemporary queer activism in Canada, the productive work of memory must be considered an essential aspect of how, when and for what reasons the work of TBP comes to be commemorated. By revisiting the events of 1985 and by sifting through interviews with individuals who contributed to the work of TBP, this article complicates the narrative of TBP as a bluntly racist endeavour whilst questioning the white privilege and racially-charged demands that undergird its commemoration. The work of producing and preserving queer history is a vital means of challenging the intentional and strategic erasure of queer existence, but those who engage in such efforts must remain attentive to the unequal terrain of social relations within which remembering forms its objects.

Vitamin A: dietologist’s position

2020 ◽  
pp. 49-57
Author(s):  
S. V. Orlova ◽  
E. A. Nikitina ◽  
L. I. Karushina ◽  
Yu. A. Pigaryova ◽  
O. E. Pronina
Keyword(s):  
Immune Response ◽  
Urinary Tract ◽  
Gastrointestinal Tract ◽  
Vitamin A ◽  
Developed Countries ◽  
Therapeutic Practice ◽  
The Past ◽  
Increased Risk ◽  
Mucous Membranes

Vitamin A (retinol) is one of the key elements for regulating the immune response and controls the division and differentiation of epithelial cells of the mucous membranes of the bronchopulmonary system, gastrointestinal tract, urinary tract, eyes, etc. Its significance in the context of the COVID‑19 pandemic is difficult to overestimate. However, a number of studies conducted in the past have associated the additional intake of vitamin A with an increased risk of developing cancer, as a result of which vitamin A was practically excluded from therapeutic practice in developed countries. Our review highlights the role of vitamin A in maintaining human health and the latest data on its effect on the development mechanisms of somatic pathology.

Learning Zulu

2016 ◽  
Author(s):  
Mark Sanders
Keyword(s):  
Language Learning ◽  
Cultural History ◽  
South African ◽  
Press Coverage ◽  
African History ◽  
African Culture ◽  
The Past ◽  
Correct Form ◽  
Linguistic Purism

When this book's author began studying Zulu, he was often questioned why he was learning it. This book places the author's endeavors within a wider context to uncover how, in the past 150 years of South African history, Zulu became a battleground for issues of property, possession, and deprivation. The book combines elements of analysis and memoir to explore a complex cultural history. Perceiving that colonial learners of Zulu saw themselves as repairing harm done to Africans by Europeans, the book reveals deeper motives at work in the development of Zulu-language learning—from the emergence of the pidgin Fanagalo among missionaries and traders in the nineteenth century to widespread efforts, in the twentieth and twenty-first centuries, to teach a correct form of Zulu. The book looks at the white appropriation of Zulu language, music, and dance in South African culture, and at the association of Zulu with a martial masculinity. In exploring how Zulu has come to represent what is most properly and powerfully African, the book examines differences in English- and Zulu-language press coverage of an important trial, as well as the role of linguistic purism in xenophobic violence in South Africa. Through one person's efforts to learn the Zulu language, the book explores how a language's history and politics influence all individuals in a multilingual society.

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