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

Accueil du site → Doctorat → Inde → 2014 → Estimation of soil moisture from radar remote Sensing data risat 1 and correlation with ground Based and meteorological observation in western Agro climatic zone of tamil nadu

Tamil Nadu Agricultural University (2014)

Estimation of soil moisture from radar remote Sensing data risat 1 and correlation with ground Based and meteorological observation in western Agro climatic zone of tamil nadu

Khedikar shirish yograj

Titre : Estimation of soil moisture from radar remote Sensing data risat 1 and correlation with ground Based and meteorological observation in western Agro climatic zone of tamil nadu

Auteur : Khedikar shirish yograj

Université de soutenance : Tamil Nadu Agricultural University

Grade : Doctor of Philosophy (PhD) in Agricultural Meteorology and Climatology 2014

Résumé
Soil moisture is most important parameter that determines success or failure of crop. Accurate estimates of surface soil moisture are essential in many research fields, including agriculture, hydrology and meteorology. But due to large spatial and temporal variability in soil moisture point measurements are insufficient to characterize soil moisture at larger scale area and also these gravimetric point sampling method is laborious as well as time consuming. Hence, an attempt has been made to retrieve the soil moisture from RISAT-1 C band microwave data and to compare it with in situ ground moisture in three different locations viz. Annur, Muthur and Nambiyur of Western Agroclimatic Zone of Tamil Nadu for both dry and wet seasons. Satellite images for Annur, Muthur and Nambiyur location was analysed for both horizontal and vertical polarization. Significant correlation seen between observed soil moisture and soil moisture, which is estimated by using RISAT-1 satellite image with horizontal polarization. While no significant correlation found in case of vertical polarization with observed soil moisture. Negative correlation seen between observed soil moisture and backscattering coefficient (σ°) for horizontal polarization (r=-0.319) as well as for vertical polarization (-0.357), indicates that as the moisture content in soil increase the backscattering coefficient (σ°) decreases and vice versa. Backscattering coefficient (σ°) for both horizontal and vertical polarization showing no significant correlation (r = -0.109 and -0.101) with height of ridges (cm). This indicate that backscattering coefficient for both horizontal and vertical polarization are insensitive to surface roughness. The significant correlation (r = -0.212 and -0.200) observed between crop height (cm) and backscattering coefficient (σ°) for both horizontal and vertical polarization. Negative correlation indicates that crop height representing vegetation cover has negative effect on accuracy of estimation of soil parameter from remote sensing. There is linear relationship and good correlation observed between backscattering coefficient (σ˚) and in situ soil moisture (field observations), hence an empirical equation developed for estimation of soil moisture by using backscattering coefficient (σ˚) for both horizontal and vertical polarization. There is a need for better semi-empirical model so that accurate estimation of soil moisture from satellite images can be the reality. These models should first be recalibrated to regional soil surface and vegetation conditions before being generalized. Hence, further research is needed for different locations to confirm the obtained result

Présentation et version intégrale (Shodhganga)

Page publiée le 1er mai 2021