NASA has confirmedthat New Orleans and the surround areas are sink at a much higher rate than previously mean . Using airborne radar to represent the charge per unit at which the ground is sink over a period of a few years , they were able to document in fine detail exactly which regions are most at risk , and where provision and building needs to be monitored .
The Earth ’s surface can sink due to a mixture of natural and human being - made reason . The weight of situate deposit can , for example , cause cave in , as can the movement of glaciers and the compaction of shallow sediments . But human being can also influence this appendage by pump out petroleum and gas , or in the example of New Orleans , by the withdrawal of weewee .
The extraction of groundwater and dewatering of the part , in which surface water is remove so as to prevent suffer H2O or saturated ground , is cause the city to sink . This has been exasperatedby the construction of levee , which prevent the natural flesh - up of deposit that counteract the sinking feeling .
The region of Norco is one of the worst affected , sinking 5 centimeters ( 2 in ) per year . NASA / JPL - Caltech , Esri
Thisis most acutein regions upriver along the Mississippi River , specifically the industrial areas of Norco and Michoud , where the ground is sinking by a disturbing 5 centimeter ( 2 column inch ) per year . Other areas of concern were in New Orleans Upper and low ninth Ward , where the remission may be related to the water levels of the Mississippi . Of particular concern is the change in ground level around the levees built to prevent flooding , as they found regions behind the levees sinking by 4 centimetre ( 1.6 inch ) a yr .
The data used by NASA to build up the maps , published in a paper in theJournal of Geophysical Research , was create using NASA ’s Uninhabited airy Vehicle Synthetic Aperture Radar ( UAVSAR ) , which is able to traverse changes in meridian on the Earth ’s surface down to a centimetre difference . This by itself ca n’t tell the research worker what is causing the change in ground level , so they then have to unsnarl all the possible cause , which operate at dissimilar time and place scales .
While the fact that the part is sinking is not new , NASA have highlighted that the degree to which it is hap is much dandy than antecedently thought , and that it could be putting certain region at a much greater risk of flooding , as if there was n’t a big enough one to commence with . It is hoped that the data can be used to attempt to reduce or reverse the settling in the most severely affected expanse , as well as supporter with planning determination for the hereafter .
