A review of vegetation indices as applied to Landsat-TM and ETM+ multispectral data is presented. The review focuses on indices that have been developed to produce biophysical information about vegetation biomass/ gre...A review of vegetation indices as applied to Landsat-TM and ETM+ multispectral data is presented. The review focuses on indices that have been developed to produce biophysical information about vegetation biomass/ greenness, moisture and pigments. In addition, a set of biomass/greenness and moisture content indices are tested in a Mediterranean semiarid wetland environment to determine their appropriateness and potential for carrying redundant information. The results indicate that most vegetation indices used for biomass/greenness mapping produce similar information and are statistically well correlated.展开更多
The world population will grow up to 9.8 billion by 2050.The intensification in urban growth will occur on all continents and in all sizes of cities,especially in developing countries,experiencing a greater rising in ...The world population will grow up to 9.8 billion by 2050.The intensification in urban growth will occur on all continents and in all sizes of cities,especially in developing countries,experiencing a greater rising in urban agglomerations of 300,000 to 500,000 people,those of 500,000 to 1 million and those of 1 to 5 million,by 2035.In this way,the demand of soil to host human activities(land take)will increase,mainly affecting soils with greater agricultural potential close to cities,at the same time as the need for food will increase.Land rehabilitation can contribute to human food security,to enhance ecosystem services and,if made by waste Technosols,those are viable as substrate for urban agroforestry systems.Although the references for brownfield reclamation for urban agriculture,adding constructed Technosols and de-sealed soils can recover its ecosystem functions even food supply services and would be the solution in urban areas.展开更多
Reservoirs play an important role in water management and are key elements for water supply.Monitoring is needed in order to guarantee the quantity and quality of stored water.However,this task is sometimes not easy.T...Reservoirs play an important role in water management and are key elements for water supply.Monitoring is needed in order to guarantee the quantity and quality of stored water.However,this task is sometimes not easy.The objective of this study was to develop a procedure for predicting volume of stored water with remote sensing in water bodies under Mediterranean climate conditions.To achieve this objective,multispectral Landsat 7 and 8 images(NASA)were analyzed for the following five reservoirs:La Serena,La Pedrera,Beniarrés,Cubillas and Negratín(Spain).Reservoirs water surface was computed with the spectral angle mapper(SAM)algorithm.After that,cross-validation regression models were computed in order to assess the capability of water surface estimations to predict stored water in each of the reservoirs.The statistical models were trained with Landsat 7 images and were validated by using Landsat 8 images.Our results suggest a good capability of water volume prediction from free satellite imagery derived from surface water estimations.Combining free remote sensing images and open source GIS algorithms can be a very useful tool for water management and an integrated and efficient way to control water storage,especially in low accessible sites.展开更多
文摘A review of vegetation indices as applied to Landsat-TM and ETM+ multispectral data is presented. The review focuses on indices that have been developed to produce biophysical information about vegetation biomass/ greenness, moisture and pigments. In addition, a set of biomass/greenness and moisture content indices are tested in a Mediterranean semiarid wetland environment to determine their appropriateness and potential for carrying redundant information. The results indicate that most vegetation indices used for biomass/greenness mapping produce similar information and are statistically well correlated.
文摘The world population will grow up to 9.8 billion by 2050.The intensification in urban growth will occur on all continents and in all sizes of cities,especially in developing countries,experiencing a greater rising in urban agglomerations of 300,000 to 500,000 people,those of 500,000 to 1 million and those of 1 to 5 million,by 2035.In this way,the demand of soil to host human activities(land take)will increase,mainly affecting soils with greater agricultural potential close to cities,at the same time as the need for food will increase.Land rehabilitation can contribute to human food security,to enhance ecosystem services and,if made by waste Technosols,those are viable as substrate for urban agroforestry systems.Although the references for brownfield reclamation for urban agriculture,adding constructed Technosols and de-sealed soils can recover its ecosystem functions even food supply services and would be the solution in urban areas.
文摘Reservoirs play an important role in water management and are key elements for water supply.Monitoring is needed in order to guarantee the quantity and quality of stored water.However,this task is sometimes not easy.The objective of this study was to develop a procedure for predicting volume of stored water with remote sensing in water bodies under Mediterranean climate conditions.To achieve this objective,multispectral Landsat 7 and 8 images(NASA)were analyzed for the following five reservoirs:La Serena,La Pedrera,Beniarrés,Cubillas and Negratín(Spain).Reservoirs water surface was computed with the spectral angle mapper(SAM)algorithm.After that,cross-validation regression models were computed in order to assess the capability of water surface estimations to predict stored water in each of the reservoirs.The statistical models were trained with Landsat 7 images and were validated by using Landsat 8 images.Our results suggest a good capability of water volume prediction from free satellite imagery derived from surface water estimations.Combining free remote sensing images and open source GIS algorithms can be a very useful tool for water management and an integrated and efficient way to control water storage,especially in low accessible sites.
