Remote Sensing Approach for the Appearance and Disappearance of Oasis Farmland in Kazakhstan.

Oases agriculture is one of the most vulnerable anthropogenic landscapes to climate change and human activates. Central Asia is one of the arid regions highly vulnerable to water scarcity. Located in Central Asia, Kazakhstan is characterized as a semi-arid region which includes dry steppe land in the south. Agriculture carried out in this area is typically oasis farmland with water taken from local rivers used for irrigation. During the former Soviet Union, irrigation projects were widely carried out to expand agricultural land, and large-scale irrigation projects were created in several areas. Therefore, many irrigated farmlands were abandoned due to the collapse of the former Soviet Union. However, China's investment in Kazakhstan agriculture is cultivating once abandoned agricultural land and developing new oases agricultural land. Our study focusses on the vulnerability of oasis agriculture and extract changes in agricultural land for about 30 years from 1989 to the present using Landsat series and Sentinel series and visualized them using RGB color combined techniques. The results show that agricultural land is disappeared or desertified at the Ili River basin and at the foot of the zhongar-Alatau Mountain and that there are several years of fallow even in areas where agriculture is active. Using the Zharkent region in the irrigated alluvial fan of zhongar-Alatau Moun-tain of eastern Kazakhstan as an example, we classify the farm field changing using Landsat TM and Sentilel-2 satellite imagery and identify of vulnerability to the disappearance of oases farmland. China's investment in agriculture could lead to the depletion of water resources in the region.