Classifying Images of Drought-Affected Area Using Deep Belief Network, kNN, and Random Forest Learning Techniques

1. Introduction

Drought is a condition of a land where the rainfall in less than average. This situation thus reduces the groundwater level of the drought affected area. The condition of drought develops cracks in the soil which then lowers the agriculture productivity of the land to zero. It’s a life-fighting situation for human and animals due to lack of water resources which results in poor agricultural output. The general trend is to move away from the drought affected places to some water efficient places. Drought is a natural disaster as it occurs due to climatic conditions which wipes out living beings. Most of the drought comes in the category of temporary droughts rather than the permanent one. Causes of drought include less precipitation which means precipitation methods includes convective, strait-form (Anagnostou, Emmanouil, 2004).and orographic rainfall (Dore et al, 2006). The convective method is the one in which vertical motions are induced that further helps in precipitating in the particular region in no time. On the other hand, while strait-form induces weak upward motion, helps in the long run (Pearce, Penrose, 2002)..These factors are very important for precipitation else the result will be a severe drought. Another reason of drought can be due to the intense reflection of sunlight, high-pressure system, winds with continental air masses which refrain the area from rainfall and the low evapotranspiration worsen the conditions (Paepe, Roland, Rhodes, Jelgersma, 2012). The dry season is also a cause for drought (Wang, Bin, 2006; Boken et al, 2005). If the dry weather occurs in excess it will reduce groundwater and water bodies starts drying up so the living organisms leave that place and go to nearby place. These situations reduce the resources of that place such as plants etc. These plants and living organisms evaporate at a high rate which results in a high amount of loss of water. Even deforestation, over farming (H, excessive irrigation and erosion reduce the ability of the land to hold water. These above reasons result in a shortage of water and hence drought occurs. These activities flow off the top layer of the soil which is the most fertile and the most absorption takes place on that layer of soil which gets prevented. Hence it lowers the groundwater level (Richthofen, Baron, 1882). Due to global warming, the temperature (Smith, B, Katz, 2013) of the planet earth is on the rise, which affects the world temperature. Therefore, the ice caps are melting and the average surface temperature is increasing gradually. This affects the environment and causes uneven effects (Brahic, 2007) across the globe. Some places have heavy rainfall causing a flood and on the other side, some places receive very less rainfall and hence causing drought.

Types of drought are as below,

• 1.

  Meteorological drought occurs, when the primary condition that is precipitation is less than average, for a long time. Regular short duration drought gives birth to this kind. (Palmer, C, 1965).

• 2.

  Agricultural droughts are the one that defers the production of the crop. This occurs due to the human activities and natural soil erosion. (Wang, et al, 2015)

• 3.

  Hydrological drought is the one in which the water bodies starts to get shrink due to less refueling and probably higher usage. This usually brings the condition of low water levels in the nearby areas (Tallaksen, M, Lamen, 2004).