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Abstract: This paper presents an overview of a decade (2002-2012) of studies performed on Soil-Plant-Atmosphere processes, in semi-arid areas (Haouz plain, Morocco). In this period, fifteen in-situ experiments on the dominant irrigated crops were performed, controlling the fluxes exchanged between land surface and atmosphere. The results showed that the physically based SVATs (ICARE, SiSPAT and ISBA) provided the best estimates of surface fluxes. For operational purposes, the FAO-56 approach and SAMIR Software (Satellite Monitoring for Irrigation) give a good estimate of evapotranspiration at field and regional scales, respectively. Finally, thermal infrared data were used in conjunction with SVATs to investigate the possibility of estimating the quantity of irrigation water. [Copyright &y& Elsevier]

Abstract: The objective of this study is to evaluate the capability of the two source energy budget (TSEB) to predict daily evapotranspiration over irrigated crops in a semi-arid area. The TSEB model presents particularly interesting skills for seasonal course of daily evapotranspiration regarding the limited number of inputs required with an RMSE of 0.75mm/day (33% on average) with regards to eddy-covariance measurements at least before crop senescence. By contrast, if focusing on a drying/wetting period surrounding a rain event, a lack of model reaction to stress is highlighted that could be a major drawback for irrigation scheduling. [Copyright &y& Elsevier]

A Decision Support System has been set up as the result of a fruitful cooperation between several public and research institutions in the framework of a large cooperation program. The DSS aims to compare spatially and temporally sectorial water demands of the Haouz-Mejjate plain (Morocco) in regard to available surface and groundwater resources. It is composed of a tool for satellite estimation of Agricultural Water Demand (SAMIR), a tool for integrated water resources planning (WEAP) and a groundwater model (MODFLOW) each of them relying on a common Geographical Information System not described here. The DSS is operating on a monthly time scale. Agricultural water demand accounts for about 80 % of the total demand. In areas where groundwater abstraction is difficult to quantify by direct methods, multitemporal remote sensing associated to the FAO methodology is a simple and efficient alternative to estimate Evapotranspiration (ET). In this work, a monthly estimate of ET from irrigated areas is derived from freely available MODIS NDVI for the 2001-2009 period. An important part of the paper deals with the validation of these estimates with eddy covariance flux measurements installed on different irrigated crops of the region. Results are satisfactory with a minus 6.5 % error per year on the monthly time scale. This preprocessing allows to dichotomize irrigated versus non-irrigated areas, and then, to estimate groundwater abstraction in subareas distinguishing by their operating modes: traditional, dam or privately irrigated. A dynamic linkage between MODFLOW and WEAP transfers the results of one model as input data to the other. The model restitutes both spatial and temporal variations in head charges and allows the calculation of the ground water balance. After calibration, piezometric validation is acceptable for the majority of the 21 head control points. [ABSTRACT FROM AUTHOR]