Author: PhD Mutua (Rer. nat., Prof. Dr.-Ing. Benedict Mwavu) Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Climate change has continued to impact negatively on water resources globally. For instance, extreme weather conditions especially the drought phenomena have become frequent in Africa. This has prompted water engineers and hydrologists to formulate mitigation and adaptation measures to address these challenges. The frequency of drought event of a defined severity for a defined return period is fundamental in planning, designing, operating and managing water resources systems within a basin. This paper presents an analysis of the hydrological drought frequency for the upper Tana River basin in Kenya using the absolute Stream flow Drought Index (SDI) and modified Gumbel technique. The study used a 41-year (1970-2010) stream flow data and forecasted hydrological droughts for 2, 5, 10, 20, 50, 100, 200, 500 and 1000-year return periods in relation to the selected stream flows. The results provide an overview of drought trends within the river basin and therefore would be very useful in applying drought adaptation policies by water resource managers.
Author: Raphael Muli Wambua Publisher: GRIN Verlag ISBN: 3668917477 Category : Technology & Engineering Languages : en Pages : 245
Book Description
Doctoral Thesis / Dissertation from the year 2016 in the subject Engineering - Civil Engineering, grade: 80.0, Egerton University, course: AGRICULTURAL ENGINEERING, language: English, abstract: Drought is a critical stochastic natural disaster that adversely affects water resources, ecosystems and people. Drought is a condition characterized by scarcity of precipitation and/or water quantity that negatively affects the global, regional and local land-scales. At both global and regional scales, drought frequency and severity have been increasing leading to direct and indirect decline in water resources. Increase in drought severity and frequency in the upper Tana River basin, Kenya, water resources systems have been adversely affected. Timely detection and forecasting of drought is crucial in planning and management of water resources. The main objective of this research was to formulate the most appropriate models for assessment and forecasting of drought using Indices and Artificial Neural Networks (ANNs) for the basin. Hydro-meteorlogical data for the period 1970-2010 at sixteen hydrometric stations was used to test the performance of the indices in forecasting of the future drought at 1, 3, 6, 9, 12, 18 and 24-months lead times, by constructing ANN models with different time delays. Drought conditions at monthly temporal resolution were evaluated using selected drought indices. The occurrence of drought was investigated using non-parametric Man-kendall trend test. Spatial distribution of drought severity was determined using Kriging interpolation techinique. In addition, a standard Nonlinear-Integrated Drought Index (NDI), for drought forecasting in the basin was developed using hydro-meteoroogical data for the river basin. The results of spaial drought show that the south-eastern parts of the basin are more prone to drought risks than the north-western areas. The Mann-Kendall trend test indicates an increasing drought trend in the south-eastern and no trend in north-western areas of the basin. Development of Surface Water Supply Index (SWSI) function, NDI and characteristic curves defining the return period and the probability of different drought magnitudes based on Drought Indices (DIs) was achieved. Drought Severity-Duration-Frequency (SDF) curves were developed. The formulated NDI tool can be adopted for a synchronized assessment and forecasting of all the three operational drought types in the basin. The results can be used in assisting water resources managers for timely detection and forecasting of drought conditions in prioritized planning of drought preparedness and early warning systems.
Author: Tae-Woong Kim Publisher: MDPI ISBN: 3039368060 Category : Technology & Engineering Languages : en Pages : 168
Book Description
This Special Issue is a platform to fill the gaps in drought risk analysis with field experience and expertise. It covers (1) robust index development for effective drought monitoring; (2) risk analysis framework development and early warning systems; (3) impact investigations on hydrological and agricultural sectors; (4) environmental change impact analyses. The articles in the Special Issue cover a wide geographic range, across China, Taiwan, Korea, and the Indo-China peninsula, which covers many contrasting climate conditions. Hence, the results have global implications: the data, analysis/modeling, methodologies, and conclusions lay a solid foundation for enhancing our scientific knowledge of drought mechanisms and relationships to various environmental conditions.
Author: Kenneth M. Strzepek Publisher: World Bank Publications ISBN: Category : Languages : en Pages : 68
Book Description
This paper summarizes the methods and findings of the hydrological assessment component of the project studying likely impacts of climate change on water resources and agriculture in Africa. The first phase of the study used a version of a conceptual rainfall-runoff model called WatBal (Water Balance) applied to gridded data to simulate changes in soil moisture and runoff across the whole continent of Africa rather than to any particular catchment or water resource system. The model inputs were the climate variables of the 1961-90 climatology and physiological parameters (such as soil properties and land use) derived from global datasets for each of the 0.5 degree latitude/longitude cells across the continent. The primary model output comprised a time series (monthly time step) of simulated runoff for all the grid cells for each of the districts in the countries of interest. The second phase of the study extended the hydrology analyses to update the above hydroclimatic series to the year 2000 using updated input data. To ascertain the possible impacts of climate change within the districts being investigated this study used synthetic or GCM-based climate change scenarios as input to the WatBal model. The WatBal model was used to determine the impact of these different scenarios on runoff and actual evaporation and hence flow in the districts under study. The generated hydroclimatic series and scenario analyses were used as inputs into various Ricardian regressions in other analyses measuring likely impacts of climate change on the agricultural economies of Africa.
Author: Ayugi Brian Odhiambo Publisher: ISBN: 9781636480329 Category : Languages : en Pages : 48
Book Description
Kenya's economy and that of the Great Horn of Africa rely on rain-fed agriculture. Unfortunately, the country is prone to hydrological extremes, mainly drought and floods. The occurrence of drought/flood is associated with not only the destruction of property but with loss of lives. The situation is worsening under the observed reduction in seasonal rainfall and amplified global warming. Characterizing the recent evolution of climate extreme scenarios across localized domains remains an imperative process to adapt tailor suit innovative solutions to drought risks and their impacts. The purpose of this book is aimed at demonstrating the recent changes in droughts/pluvial events over Kenya for planning purposes. The first chapter describes the existing literature on the past work documenting historical occurrences of drought/flood over localized domains or the whole country. Chapter two presents the approaches used to examine the current drought/flood scenarios by illustrating the trend, intensity, severity, and frequency based on the Standardized Evapotranspiration Precipitation Index (SPEI). Chapter three describe the results derived from careful analysis of climate extremes most pronounced over the study region. Lastly, possible conclusions and recommendations are presented in the last chapter. The book is designed as an upper-level undergraduate, graduate, and research text. Authors: Ayugi Brian Odhiambo, Guirong Tan, Niu Ruoyun, Dong Zeyao, Moses Ojara, Lucia Mumo, Hassen Babaousmail, and Victor Ongoma.
Author: Zekâi Şen Publisher: Elsevier ISBN: 0128024224 Category : Science Languages : en Pages : 485
Book Description
Applied Drought Modelling, Prediction, and Mitigation provides a practical guide to new and recent methodologies for drought characterizations, change modeling, down-scaling, and future predictions. The modeling procedures covered by the book include recent advancements in regional drought extent, coverage, intensity, and water deficit predictions, which are increasingly significant given current climate change impacts on water resources. Each modeling procedure is explained theoretically prior to the mathematical derivation, and includes book examples, exercises, and case studies that supplement the applied and practical material, thus making the approaches accessible and applicable to the reader. - Presents new and recent methodologies for drought characterizations, change modeling, down-scaling, and future predictions - Includes online modeling tools to help readers quickly solve drought related problems - Presents methodologies, including drought features (duration, intensity, and magnitude) at any desired risk level - Include case studies from arid and semi-arid regions
Author: Management Association, Information Resources Publisher: IGI Global ISBN: 1668424096 Category : Computers Languages : en Pages : 1575
Book Description
Artificial neural networks (ANNs) present many benefits in analyzing complex data in a proficient manner. As an effective and efficient problem-solving method, ANNs are incredibly useful in many different fields. From education to medicine and banking to engineering, artificial neural networks are a growing phenomenon as more realize the plethora of uses and benefits they provide. Due to their complexity, it is vital for researchers to understand ANN capabilities in various fields. The Research Anthology on Artificial Neural Network Applications covers critical topics related to artificial neural networks and their multitude of applications in a number of diverse areas including medicine, finance, operations research, business, social media, security, and more. Covering everything from the applications and uses of artificial neural networks to deep learning and non-linear problems, this book is ideal for computer scientists, IT specialists, data scientists, technologists, business owners, engineers, government agencies, researchers, academicians, and students, as well as anyone who is interested in learning more about how artificial neural networks can be used across a wide range of fields.
Author: Angel Utset Suastegui Publisher: Nova Science Publishers ISBN: 9781606920336 Category : Climatic changes Languages : en Pages : 0
Book Description
According to climate change assessments, less precipitations and higher temperatures can be expected in the Iberian Peninsula and other Mediterranean zones. Besides, an increment in droughts and other extreme events can be expected as well. Such climatic conditions require an effort to optimise irrigation technologies and to improve water management efficiency. There are currently available water-use and crop-growth simulation models, which can be combined to climate scenarios and weather generators in order to recommend, through many simulations, the most reliable irrigation management. The Preliminary Assessment of the Impacts in Spain due to the Effects of Climate Change and the National Plan for Adaptation to Climate Change recommend the use of such simulation tools in Spanish climate-change impact assessments. Those tools, however, have not been used yet to support irrigation decision-making in our country. In that sense, the EU-funded proposal AGRIDEMA, leaded by Spain, has been addressed to introduce such tools, connecting the tools "providers" from Universities and high-level research centres, with their "users", located in agricultural technological or applied-research centres. AGRIDEMA comprised courses and Pilot Applications of the tools. Local researchers knew in the AGRIDEMA courses how to access to GCM data and seasonal forecasts, they receive also basic knowledge on weather generators, statistical and dynamical downscaling; as well as on available crop models as DSSAT, WOFOST, CROPSYST, SWAP and others. About 20 pilot assessments have been conducted in several European countries during AGRIDEMA, applying the modelling tools in particular cases. The AGRIDEMA results are commented, mentioning particularly the Pilot Assessments that were held in Spain and in the Mediterranean area. Furthermore, several "users" opinion regarding the available climate and crop-growth simulation tools are also pointed out. Those opinions can be used as important feedback by the tools "developers". An illustrative example on how modelling tools can help to manage Sugarbeet irrigation under present and future climate conditions in Spain is also shown. Several future research directions are pointed out, as followed from the shown example and the AGRIDEMA results. Those research directions agree with the actions recommended in the Spanish National Plan for Adaptation to Climate Change, as well as in the European and international guidelines. Stakeholder will adopt climate-change mitigation options only if they realise the reliability of such options on their specific cases. To achieve this, the "users" of the modelling tools must develop local demonstration proposals, aimed to model calibration and validation, etc. Particularly, some demonstration proposals should be aimed to recommend productive and efficient irrigation water management under the adverse climate conditions that Spanish farmers will eventually face in the next years.
Author: Samiha A.H. Ouda Publisher: Springer ISBN: 3319336606 Category : Technology & Engineering Languages : en Pages : 109
Book Description
The book contains suggestion on suitable crop rotations for salt-affected soils to maximize the productivity of lands and water under current climate and under climate change in 2030. This book discusses droughts and water scarcity, which are important issues related to natural phenomena and affected by climate variability and change. It calls for reassessing the prevailing crop structure in Egypt under rain fed irrigation in North Egypt and under surface irrigation in the Nile Delta and Valley. Droughts affect rain fed agriculture, while water scarcity affects irrigated agriculture. The book investigates proposals for improving crop structure in these areas, taking into account the sustainability of water and soil resources. Further, it explores improved management options for crop production in both rain fed and irrigated agriculture. Lastly, it examines suggestions on more rational use of irrigation water in irrigated agriculture to conserve irrigation water under present climate conditions and to help meet the anticipated demand under climate change conditions.
Author: PhD Mutua (Rer. nat., Prof. Dr.-Ing. Benedict Mwavu)
Author: Raphael Muli Wambua
Author: Tae-Woong Kim
Author: Kenneth M. Strzepek
Author: Ayugi Brian Odhiambo
Author: Zekâi Şen
Author: Speed, Robert
Author: Management Association, Information Resources
Author: Angel Utset Suastegui
Author: Samiha A.H. Ouda