Remote sensing and GIS applications are being widely used for various projects relating to natural resource management. Forests are very important national assets for economic, environmental protection, social and cul...Remote sensing and GIS applications are being widely used for various projects relating to natural resource management. Forests are very important national assets for economic, environmental protection, social and cultural values and should be conserved in order to realize all these benefits. Kenya’s forests are rapidly declining due to pressure from increased population, technological innovation, urbanization human development and other land uses. Mau forest is one of the major forests in Kenya that is a catchment area for many Great Rift Valley lakes within the country and faces a lot of destruction. Continued destruction of the Mau forest will cause catastrophic environmental damage, resulting in massive food crises and compromising the livelihoods of millions of Kenyans, and the possible collapse of the tourism industry. The purpose of this research was to investigate the relationship between the increasing rate of deforestation and the reduction of the volumes of water in the neighboring lakes between the years 1989 to 2010. Satellite images from Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced Thematic Mapper (ETM+) were used for the detection of changes in the Mau forest and the dynamics of the neighboring water bodies that included lakes: Naivasha, Baringo, Nakuru, Elementaita and Bogoria. The research showed that from a period of 1989 to 2010 Mau forest has been decreasing due to deforestation and the water bodies have irregular dynamics in that, from 1989 to 2000, there was rise in the volume of water, this is attributed to the El Nino rains experienced in the country during the year 1997 and 1998. But between 2000 and 2010 the volume decreased as the forest is also decreasing. It is recommended that the government creates awareness to sensitize the public on the importance of such forests as catchment areas in Kenya.展开更多
Miyun Reservoir provides more than 70% drinking water resources for Beijing, it is very important that to study the hydrological properties of canopy of water resources protection forests, which to help managing and c...Miyun Reservoir provides more than 70% drinking water resources for Beijing, it is very important that to study the hydrological properties of canopy of water resources protection forests, which to help managing and cultivating the water resources protection forests. In this paper, the stands of Robinia pseudoacacia, Pinus tabulaeformis and Castanea mollissima were studied from 1999 to 2000. The total precipitation amount was 545 mm in the 2 main rain periods from 1999 to 2000, distribution in canopy interception, through_fall and stem_flow in the R.pseudoacacia stand were 97.73 mm, 434.78 mm and 12.49 mm, respectively, that in the P.tabuleaeformis were 131.54 mm, 397.98 mm and 15.48 mm, respectively, and in the C.mollissima stand were 110.73 mm, 422.07 mm and 12.20 mm, respectively. The canopy interception and stem_flow amount of P.tabulaeformis stand, the through_fall amount of R.pseudoacacia stand was the biggest among the three stand respectively. The elements content of N, P, K, Na, Ca, Mg, Fe, Zn, Cu and Mn were monitored for the precipitation, canopy interception, through_fall and stem_flow of the three forest types. The total amount of weighed average content of ten chemical elements in precipitation was 12.001 1 mg5L -1. The sequence of the chemical elements weighted average content of the precipitation is followed: Ca > N > K > Mg > Na > P > Fe > Zn > Cu > Mn. The concentration of chemical elements of through_fall and stem_flow varied in differently for three forest types in comparison with the precipitation’s.展开更多
文摘Remote sensing and GIS applications are being widely used for various projects relating to natural resource management. Forests are very important national assets for economic, environmental protection, social and cultural values and should be conserved in order to realize all these benefits. Kenya’s forests are rapidly declining due to pressure from increased population, technological innovation, urbanization human development and other land uses. Mau forest is one of the major forests in Kenya that is a catchment area for many Great Rift Valley lakes within the country and faces a lot of destruction. Continued destruction of the Mau forest will cause catastrophic environmental damage, resulting in massive food crises and compromising the livelihoods of millions of Kenyans, and the possible collapse of the tourism industry. The purpose of this research was to investigate the relationship between the increasing rate of deforestation and the reduction of the volumes of water in the neighboring lakes between the years 1989 to 2010. Satellite images from Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced Thematic Mapper (ETM+) were used for the detection of changes in the Mau forest and the dynamics of the neighboring water bodies that included lakes: Naivasha, Baringo, Nakuru, Elementaita and Bogoria. The research showed that from a period of 1989 to 2010 Mau forest has been decreasing due to deforestation and the water bodies have irregular dynamics in that, from 1989 to 2000, there was rise in the volume of water, this is attributed to the El Nino rains experienced in the country during the year 1997 and 1998. But between 2000 and 2010 the volume decreased as the forest is also decreasing. It is recommended that the government creates awareness to sensitize the public on the importance of such forests as catchment areas in Kenya.
文摘Miyun Reservoir provides more than 70% drinking water resources for Beijing, it is very important that to study the hydrological properties of canopy of water resources protection forests, which to help managing and cultivating the water resources protection forests. In this paper, the stands of Robinia pseudoacacia, Pinus tabulaeformis and Castanea mollissima were studied from 1999 to 2000. The total precipitation amount was 545 mm in the 2 main rain periods from 1999 to 2000, distribution in canopy interception, through_fall and stem_flow in the R.pseudoacacia stand were 97.73 mm, 434.78 mm and 12.49 mm, respectively, that in the P.tabuleaeformis were 131.54 mm, 397.98 mm and 15.48 mm, respectively, and in the C.mollissima stand were 110.73 mm, 422.07 mm and 12.20 mm, respectively. The canopy interception and stem_flow amount of P.tabulaeformis stand, the through_fall amount of R.pseudoacacia stand was the biggest among the three stand respectively. The elements content of N, P, K, Na, Ca, Mg, Fe, Zn, Cu and Mn were monitored for the precipitation, canopy interception, through_fall and stem_flow of the three forest types. The total amount of weighed average content of ten chemical elements in precipitation was 12.001 1 mg5L -1. The sequence of the chemical elements weighted average content of the precipitation is followed: Ca > N > K > Mg > Na > P > Fe > Zn > Cu > Mn. The concentration of chemical elements of through_fall and stem_flow varied in differently for three forest types in comparison with the precipitation’s.
