Sign up
Knowledge base

Parametric Coherence Analysis for InVEST Model

Models

WaterProof makes use of the flow, sediment, phosphorus and nitrogen information consolidated in the GEMS-GLORI database, which is based on the works of Meybeck & Ragu, (2012).

In the GEMS-GLORI database, a total of 923 monitoring points were found around the world. In total, 244 points were filtered for flow, 205 points for suspended sediment concentration, 111 for nitrogen concentration and 26 for phosphorous concentrations.

Análisis de coherencia paramétrica para modelo InVEST (1)

With the help of the digital hydro-shed elevation model, the definition of the watersheds with closure points recorded by the GEMS-GLORI database was carried out (Meybeck & Ragu, 2012). The accumulation threshold used for the definition is the same as that used for the evaluation of the models (20 accumulation cells). The number of regions per model in which the coherence analysis could be performed is listed below.

  • SWY 56/56 regions
  • AWY 44/56 regions
  • SDR 41/56 regions
  • NDR-N 39/56 regions
  • NDR-P 12/56 reg regions ions

Given that the monitoring points of the GEMS-GLORI database do not have a presence in all the 56 regions in which the planet earth was segmented for the purposes of WaterProof, it was necessary to carry out a process of parametric regionalization. For this, the K-means algorithm was used, which uses groups of closest mean values ​​(K-means) and the choice of a random center with a specific probability. The points (initial centroids) are obtained using a specific probability that minimizes the inertia squared (Manochandar et al., 2020). The basic principle of the K-means formulation is to divide a sample of “η” observations into “k” cluster with the highest possible homogeneity, for this the K-means algorithm aims to choose the centroids that minimize the inertia squared.

Bibliography

  1. What is InVEST? NATURAL CAPITAL PROJECT 2020

    InVEST is a suite of free, open-source software models used to map and value the goods and services from nature that sustain and fulfill human life.

  2. Análisis de coherencia paramétrica para modelos InVEST JNogales. TNC 2020

    In line with the scope established for the development of the Waterproof, the current document aims to present the parametric coherence exercise carried out for the InVEST models, which constitute the biophysical calculation engine of the Waterproof. parameters of the models, then presents the methodological scheme used for the coherence analysis, and then presents the results obtained. Subsequently, the regionalization scheme adopted for the transfer of data to the regions with absence of information is presented and, finally, the way in which some RIOS parameters were identified is presented. It is very important to bear in mind that what is stated in this document does not correspond to a strict calibration and validation exercise of the InVEST models. The exercise should be understood as an adjustment so that the response of the models is in a coherent order of magnitude in relation to the region of the world where the analysis is being carried out within the Waterproof.

References

Back to top