Leukocyte Esterase. Leukocyte esterase is an enzyme present in most white blood cells (WBCs). A few white blood cells are normally present in urine and usually give a negative chemical test result. When the number of WBCs in urine increases significantly, this screening test will become positive.
Land subsidence occurs when large amounts of groundwater have been withdrawn from certain types of rocks, such as fine-grained sediments. The rock compacts because the water is partly responsible for holding the ground up. When the water is withdrawn, the rocks falls in on itself.
Hydrological drought: This is when there is a deficiency of surface water and ground water supply in a region, often as a result of less precipitation, excessive reliance on surface water for farming, energy and other needs. Hydrological drought does not usually occur at the same time as meteorological drought. In a way, this decline in the quantity and quality of surface and sub-surface water is the effect of meteorological drought. Socioeconomic drought: This condition is when some supply of some goods and services such as energy, food and drinking water are reduced or threatened by changes in meteorological and hydrological conditions.