Sensitivity of Mexican water bodies to regional climatic change:three study alternatives applied to remote sensed data of lake patzcuaro

摘要

Historical aerial photography over closed basins enables the observatiion of the lake surfaces at variable water levels and climatic conditions.Thus,the assessment at the landscaps level of subtle variations in inumdated areas depends on a suitable framework for processing histroical imageryy,frequently available at different scales and resolutions.The present parper deals with Lake Patxcuaro as a case study and the application of three analytical procedures to based processing of images and further incorporation into GIS led to three different outputs:topographic map (TM-GIS),photomosaic 1(P_1)and photomosaic 2(P_2).Aerial photographs assemblages were georefference by means of GCP's,86 located by means of INEGI vectorial polygons (P_1),and 40 determined directly at the field by GPS(P_2).In conclusion,TM-GIS lack of photointerpretation for the lake as an image derived from a topographic map:while P_2 involved an unacceptale RMS.P_1 thus became the best option for the caluctiion of areas not only because of the lower RMS associated,but the additional photointerpretation of limnological zones exclusive to aerial photographs.As a background pricture,P_1 also facilitates the analysis of histroical images on a comparative basis.