The depth from extreme points(DEXP)method can be used for estimating source depths and providing a rough image as a starting model for inversion.However,the application of the DEXP method is limited by the lack of pri...The depth from extreme points(DEXP)method can be used for estimating source depths and providing a rough image as a starting model for inversion.However,the application of the DEXP method is limited by the lack of prior information regarding the structural index.Herein,we describe an automatic DEXP method derived from Euler’s Homogeneity equation,and we call it the Euler–DEXP method.We prove that its scaling field is independent of structural indices,and the scaling exponent is a constant for any potential field or its derivative.Therefore,we can simultaneously estimate source depths with diff erent geometries in one DEXP image.The implementation of the Euler–DEXP method is fully automatic.The structural index can be subsequently determined by utilizing the estimated depth.This method has been tested using synthetic cases with single and multiple sources.All estimated solutions are in accordance with theoretical source parameters.We demonstrate the practicability of the Euler–DEXP method with the gravity field data of the Hastings Salt Dome.The results ultimately represent a better understanding of the geometry and depth of the salt dome.展开更多
The values of farmland ecosystem services are composed of several components: provisioning service value, regulating service value, supporting service value and cultural service value, so it is important to make a ful...The values of farmland ecosystem services are composed of several components: provisioning service value, regulating service value, supporting service value and cultural service value, so it is important to make a full assessment of the values of farmland ecosystem services for agriculture and farmland protection. Here, we assessed the values of farmland ecosystem services in Qingdao City in 1997, 2002, 2007, 2012 and 2017 by using various methods(market value method, carbon tax method, afforestation cost method, substitute cost method, equivalent factor method, etc.) based on establishing an assessment index system for the farmland ecosystem services value. The results show that the total yearly value of farmland ecosystem services increased from 499.74× 10~8 Yuan to 681.74× 10~8 Yuan in the period of 1997-2017, and the yearly value of farmland ecosystem services per hectare increased from 6.57× 10~4 Yuan to 9.73× 10~4 Yuan. The product provisioning service, carbon fixation service and oxygen release service, as well as the soil conservation service, are the main farmland ecosystem services, and the proportions of these four ecosystem service values to the total value of farmland ecosystem services in Qingdao City were large and kept increasing. Some countermeasures are put forward to adequately use the indirect service value of the farmland ecosystem and provide improved well-being for humans, such as protecting and wisely using farmland, developing agriculture that is rooted in local conditions, promoting agricultural production efficiency, speeding up construction of modern agriculture gardens, deepening the supply-side structural reform of agriculture, developing agricultural eco-tourism, etc.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.42176186).
文摘The depth from extreme points(DEXP)method can be used for estimating source depths and providing a rough image as a starting model for inversion.However,the application of the DEXP method is limited by the lack of prior information regarding the structural index.Herein,we describe an automatic DEXP method derived from Euler’s Homogeneity equation,and we call it the Euler–DEXP method.We prove that its scaling field is independent of structural indices,and the scaling exponent is a constant for any potential field or its derivative.Therefore,we can simultaneously estimate source depths with diff erent geometries in one DEXP image.The implementation of the Euler–DEXP method is fully automatic.The structural index can be subsequently determined by utilizing the estimated depth.This method has been tested using synthetic cases with single and multiple sources.All estimated solutions are in accordance with theoretical source parameters.We demonstrate the practicability of the Euler–DEXP method with the gravity field data of the Hastings Salt Dome.The results ultimately represent a better understanding of the geometry and depth of the salt dome.
基金The National Key Research and Development Plan of China (2016YFC0503503)The Natural Science Foundation of Shandong Province,China (ZR2016DM11)。
文摘The values of farmland ecosystem services are composed of several components: provisioning service value, regulating service value, supporting service value and cultural service value, so it is important to make a full assessment of the values of farmland ecosystem services for agriculture and farmland protection. Here, we assessed the values of farmland ecosystem services in Qingdao City in 1997, 2002, 2007, 2012 and 2017 by using various methods(market value method, carbon tax method, afforestation cost method, substitute cost method, equivalent factor method, etc.) based on establishing an assessment index system for the farmland ecosystem services value. The results show that the total yearly value of farmland ecosystem services increased from 499.74× 10~8 Yuan to 681.74× 10~8 Yuan in the period of 1997-2017, and the yearly value of farmland ecosystem services per hectare increased from 6.57× 10~4 Yuan to 9.73× 10~4 Yuan. The product provisioning service, carbon fixation service and oxygen release service, as well as the soil conservation service, are the main farmland ecosystem services, and the proportions of these four ecosystem service values to the total value of farmland ecosystem services in Qingdao City were large and kept increasing. Some countermeasures are put forward to adequately use the indirect service value of the farmland ecosystem and provide improved well-being for humans, such as protecting and wisely using farmland, developing agriculture that is rooted in local conditions, promoting agricultural production efficiency, speeding up construction of modern agriculture gardens, deepening the supply-side structural reform of agriculture, developing agricultural eco-tourism, etc.
