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

Accueil du site → Master → Pays Bas → Modelling impact of change in irrigated land on rivers discharge and recharge of lake Urumieh, Iran

International Institute for Geo-Information Science and Earth Observation (ITC) 2003

Modelling impact of change in irrigated land on rivers discharge and recharge of lake Urumieh, Iran

Hesamy, A. (Ali)

Titre : Modelling impact of change in irrigated land on rivers discharge and recharge of lake Urumieh, Iran.

Auteur : Hesamy, A. (Ali)

Etablissement de soutenance : University of Twente International Institute for Geo-Information Science and Earth Observation (ITC)

Grade : Master of Science in Geo-Information Science and Earth Observation 2003

Résumé
In this study the impact of irrigation on rivers discharge and recharge of Urumieh lake was investi- gated. Remote sensing and geographic information systems were used to improve the hydrological knowledge of the study area. The Urumieh lake catchment is located in the northwest part of Iran, which has a moderate cold cli- mate. It has an area of 47200 km 2 . There are more than 30 rivers flowing in the region, feeding the Urumieh lake. Mean annual precipitation of the catchment equals 398 mm, wh ile evaporation equals about 1150 mm ; in addition rivers contributed on average 6-km3 water annually in to the lake. The Miandoab alluvial plain (field area) south east of lake Urumieh covers an area of 1025 km 2 , with a general topographic gradient from th e south and southeast towards lake Urumieh. It has an average annual rainfall over 350 mm, decreasing gradually to 250 mm toward the Lake. There were no significant variations in total amount of precipitation observed from the 14-rainfall station in the Simineh and Zarrineh rivers basin in south part of the lake. Rivers discharge at four gauges was analysed. The result showed a significant decline in one out of four gauges. Also all four gauges revealed a negative sign for the regression. Fluctuation of ground water table was studied for years between 1989 and 2000. The result revealed a 3.9-meter decline in ground water table. It was caused 0.179-km3 volume of water. Land use change was analysed using multiple date landsat thematic imagery for 1989 and 2000. There was 18417-hectare increase in total irrigated area during years between 1989 and 2000. Total amount of water demand for irrigation was cal culated for the study area. There were 0.226-km 3 increases in water demand for irrigation during years of observation. Relation between observed and predicted rivers discharge was investigated. The result revealed that predicted rivers discharge was always cons iderably lower than the observed discharge. Regression analysis on effects of observed rivers discharge and lake level on predicted rivers discharge revealed that the effects of observed discharge and lake level on predicted discharge are highly significant. And the regression accounted for 48.3 % in predicted rivers discharge. Relation between observed and predic ted rivers discharge during the years of observation showed that in case of rise in lake level the difference between predicted rivers discharge and observed rivers dis- charge was reduced

Version intégrale (ITC)

Page publiée le 3 avril 2018, mise à jour le 14 octobre 2018