Modeling the contributing factors of desertification and evaluating their relationships to soil degradation process through Geomatic techniques

Abstract

Abstract. Desertification is a prolonged stage of land degradation which converts the productive ecosystem to fragile by three crucial events namely evapotranspiration, rainfall and negative human intrusion. The present study concentrates on identifying the causative factors of desertification namely temperature, wind, rainfall and human pressure, distinguishing the desertified land from degraded land and assessing the way from which the soil degradation process gets accelerated by those factors by employing the datasets such as long term (2001–2011) and short term (2012–2015) Meteorological data and Landsat ETM+ and OLI satellite imageries of crop growing period (June–October) into geostatistical methods and newly proposed remote sensing models which yielded good accuracy with in situ observations (R2 = 0.8). In temperature induced desertified region, the rate of increment of the saline affected region was magnified significantly from 16 to 74 % (2001–2015) due to the presence of native fluoride concentration and extreme temperature event over a period of time. The long term exaggeration of soil moisture stress (19 to 90 %) has been notified in the areas that were susceptible to wind induced desertification, due to high evaporation rate invoked by extreme wind event for a substantial period. Similarly rainfall induced desertified regions have also been experiencing high soil moisture stress (4 to 70 %) because of the insufficient reception of rainfall. High human made soil salinity (36 %), human occupancy (16 %), followed by moisture stress (7 %) are observed in the human affected region because of growing population and improper land management of the already fragile land.

Coupling Cellular Automata With Medalus Assessment for the Desertification Issue

“…s c + is given by the geometric mean of its index s c and the index of its neighbourhood c at time t. However, if the cell c is in a very degraded state and its neighbourhood is in high or degraded state, it keeps its state at time t + 1 and a stress cell changes its state to a superior state. These fundamental rules are explained by these facts: (1) Desertified or very degraded state is almost irreversible in degradation situation [2] [9] and (2) bad climate conditions and human pressures lead to a stress in the exposed land by the degradation process [18]. where Id is identity function, I 3 is range of high state, I 4 range of degraded state and I 5 range of very degraded state in Table 1.…”

Spatial Monitoring of Desertification Extent in Western Iraq using Landsat Images and GIS

“…In a more recent work, Shoba & Ramakrishnan (2016) used geostatistical model with four factors (i.e. temperature, wind, rainfall, and human induced) for assessing the land degradation and desertification.…”

“…The identification of suitable indicators for monitoring desertification at local, regional, and global scales is crucial (Reed et al, 2013). Recently, various studies have been published (Salvati et al, 2013;Symeonakis et al, 2014;Miao et al, 2015;Torres et al, 2015;Xu et al, 2015;Yan & Cai, 2015;Eskandari et al, 2016;Li et al, 2016;Sadeghravesh et al, 2016;Shoba & Ramakrishnan, 2016;Zhang et al, 2016).…”

“…Thus, continued observation is required to monitor the high year‐to‐year variability of dryland ecosystem conditions. Remote sensing is currently the most successful approach for detecting the long‐term desertification process and vegetation changes (Shoba & Ramakrishnan, ). The identification of suitable indicators for monitoring desertification at local, regional, and global scales is crucial (Reed et al ., ).…”

Assessing degradation of floodplain soils in north east Nile Delta, Egypt

“…Therefore, it poses a threat to food security in many countries since it needs efficient management and high costs, which may eventually obligate farmers to abandon the soils (Uchida, 2015). Soil degradation is a complex phenomenon that results from wide changes in soil properties due to natural and/ or anthropic factors (Shoba and Ramakrishnan, 2016). Soil degradation due to anthropic actions is a result of hazards caused by human activities (El-Baroudy and Moghanm, 2014).…”