Assessing the aftermath of informal irrigation practices under the arid climate east of Suez Canal using Hyperion and multispectral remote sensing data

Abstract

The study was conducted in El Qantra sharq District of Ismailia Governorate, east of Suez Canal, covering an area of almost 163527 hectares (389194 feddans) as a representative of vast cultivated area in Egypt that is informally irrigated under arid climate. In this study, for getting more accurate mapping results, Hyperion (EO-1) and multispectral (TM8) remote sensing data were used, both acquired in January 2016. Normalized Difference Vegetation Index (NDVI) was extracted from the two types of data for mapping the land cover features. NDVI values of the cropped area with irrigated trees dominated by mango under slightly saline soils ranged from 0.381 to 0 .612 by EO 1 but were from 0. 0.463 to 0.541 by TM8. For the annual cropped area with surface irrigated herbaceous crop dominated by clover in slightly saline soils, the values are 0.343 to 0.381 from EO-1 but are 0.386 to 0.463 from TM8. For areas of other crops in slightly saline soils, the values are 0.034 to 0.150 from EO-1 but are 0.127 to 0.179 from TM8. For the bare areas of slightly to moderately saline, the values are -0.004 to -0.119 from EO-1 but are 0.050 to.127 from TM8.The values of waterlogged area with extremely saline soils ranged from -0.235 to -0.119 by EO-1, while by TM8 they ranged from -0.024 to -0.050. For submerge areas, the values are -0.620 to -0.235 from EO-1 , while are -0.285 to -0.001 from TM8 Pearson’s correlation coefficient between the processed NDVI values from TM8 and EO-1 is strong for scanning the cultivated areas, bare areas of shifting sands and submerged ones,while is moderate for scanning the bare areas of stony soils and the waterlogged areas. For setting up that correlation, the pixel values of TM8 were selected to fit the same sites as of spectral signatures of EO-1that reflected within ranges of NDVI values. It is concluded that use of spectral data from TM8 within those adapted ranges can produce more valid and accurate results concerning the cultivated and deteriorated land. Also, these adapted NDVI values can be manipulated to serve an extrapolation process for later on scanning of other managed land. The frequent availability of TM8 data versus the scarcity and costs of other ones in order to monitor the land degradation within proper systemized dates is an added advantage for the former