Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Hydrological modelling and degraded land evaluation of a tank cascaded semi arid catchment for bioenergy crop production

Auteur : Rajeswari A,

Université de soutenance : Anna University

Grade : Doctor of Philosophy (PhD) 2017

Résumé
The growing population, urbanization and industrialization result in increased demand for food, water and energy which in turn cause pressure on land, water and energy resources. In order to meet out the demand without stressing on the resources, an integrated approach of land, water and energy nexus has to be made through sustainable resources management. The primary aim of this study is to determine the tank cascaded catchment’s water resource potential and to evaluate the degraded land for crop production, which are the more prevalent issues in the semi-arid regions of South Asia. These issues have to be resolved so that effective planning and management of water and land resources can be made. These can be obtained through simulation of surface and groundwater dynamics in the tank cascaded catchment using physically based deterministic modelling and evaluation of the degraded land for restoring under cultivation with the integrated production of food, fodder and bioenergy. Sindapalli Uppodai a semi-arid tank cascaded sub-basin of Vaippar basin in South Tamil Nadu of India consisting of sixteen tanks linked in the form of cascade has been taken for the study.

Hydrology of a tank cascaded basins in the semi-arid region is unique and different from a catchment without any intervening surface storage structures. Earlier the effects of tanks were being lumped while modelling as it requires extensive data. An attempt has been made in this study to characterize and to simulate the flow process through a tank cascaded system with the application of coupled MIKE SHE and MIKE 11, a fully integrated physically based deterministic and distributed model. With the help of primary and secondary data, the complex integrated model has been set up by coupling MIKE SHE and MIKE 11 model. The semi-arid region’s tank cascaded features and processes of the surface tank cascade system, stream networks, unsaturated and saturated zones were characterized and simulated successfully by the coupled model in an integrated manner. The model simulation has been evaluated through calibration and validation of simulated tank yield and head elevation values of observation wells with that of observed data. Three years from 2009 to 2011 of observed water level data of tanks and observation wells were used for the calibration and validation of the model. The model was calibrated over a period of one normal year from January 2011 to December 2011 and validated for one dry year from January 2009 to December 2009 and for one wet year from January 2010 to December 2010. The error matrix, correlation coefficient and Nash-Sutcliffe coefficient values of calibration and validation process indicate good simulation potential and prediction capability of the coupled model developed for the tank cascaded catchment. The scenario simulation, with and without considering tank cascaded system indicates large difference in the overland flow, ground water levels and recharging pattern in the saturated zone. The scenario simulation confirms the capturing of the effects of tanks by the coupled model and proves the importance of inclusion of surface water bodies as it has great influence on water balance analysis of an integrated modelling.

Présentation et version intégrale (Shodhganga)