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Accueil du site → Doctorat → Royaume-Uni → 2002 → Development and application of PARCHED-THIRST : a user-friendly agrohydrological model for improving dryland cropping systems

University of Newcastle upon Tyne (2002)

Development and application of PARCHED-THIRST : a user-friendly agrohydrological model for improving dryland cropping systems

Young, Mark Damion Bede

Titre : Development and application of PARCHED-THIRST : a user-friendly agrohydrological model for improving dryland cropping systems

Auteur : Young, Mark Damion Bede.

Université de soutenance : University of Newcastle upon Tyne

Grade : Doctor of Philosophy (Ph.D.) : 2002

Résumé
The world’s semi-arid areas are typified by rainfall that is both unreliable and, for most of the year, exceeded by potential evaporation. When rainfall does occur, it is often as short duration, high intensity storms that, in many cases, lead to the loss of water, soil and nutrients through runoff. As a result, yields of rainfed crops are low and unreliable. This thesis investigates whether rainwater harvesting (RWH) is capable of improving the performance of rainfed agriculture in Tanzania. RWH is a term that describes a range of techniques that attempt to utilise runoff from one area to improve crop growth on another. Results from experimental effort at five sites in Tanzania, over a period of seven years, suggest that microcatchment and macrocatchment RWH do have potential. However, because experiments are limited in extent in time and space, experimental work alone is insufficient to ensure spatial and temporal transferability of the results. To enhance transferability, the PARCHED-THIRST model was developed. This semi-distributed process-based model is described, and sensitivity analysis and validation results are discussed. It integrates the crop models PARCH and OYZAW with runoff intensity and routing sub-models. It allows the user to quickly and easily conduct computer ’experiments’ to identify optimal RWH strategies for a given situation and assess the risks involved. Recognising the poor use of models outside research, considerable effort was devoted to usability. Firstly, the user-interface was developed iteratively with potential users. Lessons learnt from this process are presented. Secondly, data requirements are minimised by the incorporation of : a climate generator that generates the long-term data necessary for the assessment of sustainability ; and pedotransfer functions that estimate soil hydraulic properties from more readily available soil data such as that from soil survey. These tools are described and tested.

Mots Clés : Rainwater harvesting Agricultural engineering Soil science Hydrology Agricultural engineering Soil science Hydrology

Présentation : EThOS (UK)

Accès au document : Proquest Dissertations & Theses

Page publiée le 4 juin 2009, mise à jour le 19 octobre 2018