Sustainable land management (SLM) is the key to harmonizing environmental and ecological concernsof society with the economic realities of producing adequate food and fiber of high quality and ensuring abasic minimal ...Sustainable land management (SLM) is the key to harmonizing environmental and ecological concernsof society with the economic realities of producing adequate food and fiber of high quality and ensuring abasic minimal quality of life. The aim of SLM is to maintain the integrity of the biophysical land resourcebase, but it can only be realized if land users understand the impacts of land management options on theirlands but also on other off-site areas and can optimize the socioeconomic and environmental benefits of theirchoice. To facilitate this, the contribution of soil survey organizations would be through the assessment andmonitoring of land quality. Land quality is a measure of the ability of land to perform specific functions and isderived by an integration of soil survey information with other environmental, and if necessary, socioeconomicinformation. The desired reliability influences the operational scale of the assessment. Such an assessmentwould assist in: 1) locating homologous areas for research sites or for transferring technologies; 2) providingthe geographic basis for systems analysis (e.g. by modeling); 3) serving as a basis for local, national andglobal resource assessment and monitoring; 4) providing an ecosystem context for land use, assessments oftemporal and spatial variability, and impact of human interventions; 5) serving as a framework for moredetailed assessment for all levels of interest; and 6) evaluating global issues such as food security, impacts ofclimate change, biodiversity monitoring, and addressing desertification.Based on an evaluation of the progress made in soil resource inventories and considering the demandsof the environment focused world, the paper considers the need for countries to mount such a program. Theauthors believe that this is the next demand of soil science and that we can fulfill our social contract byperiodically providing such information on the state of a nation's land resource.展开更多
In this study, the position of all major rill and gully erosion sites were located using hand held GPS (Global Positioning System) receiver during reconnaissance surveys. Based on severity rating and geopolitical co...In this study, the position of all major rill and gully erosion sites were located using hand held GPS (Global Positioning System) receiver during reconnaissance surveys. Based on severity rating and geopolitical considerations, six of the erosion gully sites were selected for monitoring. Control points were established around each of the gully sites using three Leica 500 dual frequency GPS receivers by method of DGPS (differential GPS) surveys. Detailed topographical survey of the gully sites was carried out using total stations. With the aid of SPOT satellite imageries in combination with total station data and GIS (geographic information system) location maps, contoured maps along with DEM (digital elevation model) were generated using ARCGIS 9.2 software. The morphological parameters of the gullies including depth, width, length and area of the gullies were determined. Volumetric estimate of the amount of soil loss from gully erosion was also carried out. Soil samples were recovered from the gully sites to determine their erodibility and other parameters to be used for soil loss modeling. The result of the studies was used as an indicator for determining the gully initiation point. Slope-area relationship and threshold of gully initiation was established. The minimum volume of soil loss occurred in gully No. 2 (Queen Ede). The minimum AS^2 value was 345 while the maximum was 3,267.展开更多
The safeguarding of Venice and the Venetian lagoon (Italy) from rising water is of great national interest. Besides the normal tidal regime, the effects of an increase in the frequency and intensity of floods in the...The safeguarding of Venice and the Venetian lagoon (Italy) from rising water is of great national interest. Besides the normal tidal regime, the effects of an increase in the frequency and intensity of floods in the lagoon have been accentuated by a reduction in the elevation of the land in respect to the actual average sea level. With the aim of reducing the vulnerability of the lagoon, the Italian Ministry of University and Scientific and Technological Research financed the research project "The geotechnical model of the subsurface for the safeguarding of Venice and its lagoon", to study the compressibility of the lagoon deposits, both by natural causes and as a consequence of overloading with heavy structures. The project involved the construction of a large experimental embankment in the Treporti area of the lagoon, in order to perform a full-scale long-term compression test on the lagoon soils. By using various geomatic and geotechnical monitoring techniques, it was possible to appraise very small vertical movements of the ground induced by the compressibility of the highly heterogeneous silty formations. High-precision data was acquired by means of classical topographic methodologies integrated with continuous GPS (Global Positioning System) measurements. In addition, vertical displacements of the ground were obtained using geotechnical instrumentation. This cross-monitoring approach provided a valuable tool for analyzing both the natural and anthropic causes of settlement.展开更多
In China, some areas with intensive agricultural use are facing serious environmental problems caused by non-point source pollution(NPSP) as a consequence of soil erosion(SE). Until now, simultaneous monitoring of NPS...In China, some areas with intensive agricultural use are facing serious environmental problems caused by non-point source pollution(NPSP) as a consequence of soil erosion(SE). Until now, simultaneous monitoring of NPSP and SE is difficult due to the intertwined effects of crop type, topography and management in these areas. In this study, we developed a new integrated method to simultaneously monitor SE and NPSP in an intensive agricultural area(about 6 000 km2) of Nanjing in eastern China, based on meteorological data,a geographic information system database and soil and water samples, and identified the main factors contributing to NPSP and SE by calculating the NPSP and SE loads in different sub-areas. The levels of soil total nitrogen(TN), total phosphorus(TP), available nitrogen(AN) and available phosphorus(AP) could be used to assess and predict the extent of NPSP and SE status in the study area.The most SE and NPSP loads occurred between April to August. The most seriously affected area in terms of SE and NPSP was the Jiangning District, implying that the effective management of SE and NPSP in this area should be considered as a priority. The sub-regions with higher vegetation coverage contributed to less SE and NPSP, confirming the conclusions of previous studies, namely that vegetation is an effective factor controlling SE and NPSP. Our quantitative method has both high precision and reliability for the simultaneous monitoring of SE and NPSP occurring in intensive agricultural areas.展开更多
文摘Sustainable land management (SLM) is the key to harmonizing environmental and ecological concernsof society with the economic realities of producing adequate food and fiber of high quality and ensuring abasic minimal quality of life. The aim of SLM is to maintain the integrity of the biophysical land resourcebase, but it can only be realized if land users understand the impacts of land management options on theirlands but also on other off-site areas and can optimize the socioeconomic and environmental benefits of theirchoice. To facilitate this, the contribution of soil survey organizations would be through the assessment andmonitoring of land quality. Land quality is a measure of the ability of land to perform specific functions and isderived by an integration of soil survey information with other environmental, and if necessary, socioeconomicinformation. The desired reliability influences the operational scale of the assessment. Such an assessmentwould assist in: 1) locating homologous areas for research sites or for transferring technologies; 2) providingthe geographic basis for systems analysis (e.g. by modeling); 3) serving as a basis for local, national andglobal resource assessment and monitoring; 4) providing an ecosystem context for land use, assessments oftemporal and spatial variability, and impact of human interventions; 5) serving as a framework for moredetailed assessment for all levels of interest; and 6) evaluating global issues such as food security, impacts ofclimate change, biodiversity monitoring, and addressing desertification.Based on an evaluation of the progress made in soil resource inventories and considering the demandsof the environment focused world, the paper considers the need for countries to mount such a program. Theauthors believe that this is the next demand of soil science and that we can fulfill our social contract byperiodically providing such information on the state of a nation's land resource.
文摘In this study, the position of all major rill and gully erosion sites were located using hand held GPS (Global Positioning System) receiver during reconnaissance surveys. Based on severity rating and geopolitical considerations, six of the erosion gully sites were selected for monitoring. Control points were established around each of the gully sites using three Leica 500 dual frequency GPS receivers by method of DGPS (differential GPS) surveys. Detailed topographical survey of the gully sites was carried out using total stations. With the aid of SPOT satellite imageries in combination with total station data and GIS (geographic information system) location maps, contoured maps along with DEM (digital elevation model) were generated using ARCGIS 9.2 software. The morphological parameters of the gullies including depth, width, length and area of the gullies were determined. Volumetric estimate of the amount of soil loss from gully erosion was also carried out. Soil samples were recovered from the gully sites to determine their erodibility and other parameters to be used for soil loss modeling. The result of the studies was used as an indicator for determining the gully initiation point. Slope-area relationship and threshold of gully initiation was established. The minimum volume of soil loss occurred in gully No. 2 (Queen Ede). The minimum AS^2 value was 345 while the maximum was 3,267.
文摘The safeguarding of Venice and the Venetian lagoon (Italy) from rising water is of great national interest. Besides the normal tidal regime, the effects of an increase in the frequency and intensity of floods in the lagoon have been accentuated by a reduction in the elevation of the land in respect to the actual average sea level. With the aim of reducing the vulnerability of the lagoon, the Italian Ministry of University and Scientific and Technological Research financed the research project "The geotechnical model of the subsurface for the safeguarding of Venice and its lagoon", to study the compressibility of the lagoon deposits, both by natural causes and as a consequence of overloading with heavy structures. The project involved the construction of a large experimental embankment in the Treporti area of the lagoon, in order to perform a full-scale long-term compression test on the lagoon soils. By using various geomatic and geotechnical monitoring techniques, it was possible to appraise very small vertical movements of the ground induced by the compressibility of the highly heterogeneous silty formations. High-precision data was acquired by means of classical topographic methodologies integrated with continuous GPS (Global Positioning System) measurements. In addition, vertical displacements of the ground were obtained using geotechnical instrumentation. This cross-monitoring approach provided a valuable tool for analyzing both the natural and anthropic causes of settlement.
基金Supported by the State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences(No.0812201210)the National Natural Science Foundation of China(No.41301307)the Knowledge Innovation Program of Chinese Academy of Sciences(No.ISSASIP1114)
文摘In China, some areas with intensive agricultural use are facing serious environmental problems caused by non-point source pollution(NPSP) as a consequence of soil erosion(SE). Until now, simultaneous monitoring of NPSP and SE is difficult due to the intertwined effects of crop type, topography and management in these areas. In this study, we developed a new integrated method to simultaneously monitor SE and NPSP in an intensive agricultural area(about 6 000 km2) of Nanjing in eastern China, based on meteorological data,a geographic information system database and soil and water samples, and identified the main factors contributing to NPSP and SE by calculating the NPSP and SE loads in different sub-areas. The levels of soil total nitrogen(TN), total phosphorus(TP), available nitrogen(AN) and available phosphorus(AP) could be used to assess and predict the extent of NPSP and SE status in the study area.The most SE and NPSP loads occurred between April to August. The most seriously affected area in terms of SE and NPSP was the Jiangning District, implying that the effective management of SE and NPSP in this area should be considered as a priority. The sub-regions with higher vegetation coverage contributed to less SE and NPSP, confirming the conclusions of previous studies, namely that vegetation is an effective factor controlling SE and NPSP. Our quantitative method has both high precision and reliability for the simultaneous monitoring of SE and NPSP occurring in intensive agricultural areas.