PALSAR wide-area mapping and annual monitoring methodology for Borneo

This paper describes the operational radar mapping processing chain developed and steps taken to produce a provisional wide-area PALSAR forest and land cover map of Borneo for the year 2007, compliant with emerging international standards (CEOS guidelines, FAO LCCS). The methodology is based on the classification of FBS and FBD image pairs. To cover Borneo the equivalent of 554 standard images is required. The final overall accuracy assessment result shows this demonstration map product is in 85.5% full agreement with the independent reference dataset and in 7.8% ‘partial agreement’. Monitoring land cover change on an annual basis requires consistent year-to-year mapping. This implies that the localised and temporal effects of environmental factors on the backscatter level (such as inundation or El Niño drought) and variation due to differing observation dates/cycles (related to change of season) have to be accounted for strip by strip. New concepts for (a) automated intercalibration of radar data, (b) time-consistency and (c) automated adaptation of radar signatures to changing environmental conditions have been evaluated for its usefulness to improve the classification and the consistency of annual monitoring

Using Satellite Data To Improve Land Value Estimations In Bolivia

Precise land valuation is necessary for an efficient allocation of resources at the private level, and territorial planning and provision of public good at the government level. This information can be obtained from real data transactions in limited areas where they occurred, leaving the rest of the land valuation depending on precise estimation models. These estimation models may use sold land characteristics to forecast the value of land with similar characteristics, by using existing data (i.e. returns on land, productivity, surface, soil maps, precipitation data, land use constraints by law, etc.). In many low and middle-income countries this data is scarce, limiting the possibility of developing these models. This information gap may be filled using satellite data. This study uses average biomass production estimations based on satellite data as a proxy for fertility. By using biomass production estimates for Bolivia over a period of 6 years, together with administrative land transaction data and geographical maps including precipitation, average temperature, slope, distance to closest road, to closed local and national markets, we are able to significantly improve previous land price models. This improvement allowed us to develop a land price index to inform farmers about current price trends and expected sale price for their own land

The use of Earth Observation for wetland inventory, assessment and monitoring

The use of Earth Observation (EO) provides Contracting Parties to the Ramsar Convention on Wetlands with new approaches to ensure the wise use and conservation of wetlands at the national and global levels. EO has many applications including the inventory, assessment and monitoring of wetlands. As technology advances, previous limitations of EO will be reduced, and it is anticipated that the use of EO in the management of wetlands will increase. This Ramsar Technical Report aims to provide practitioners with an overview and illustration, through case studies, on the use of EO for implementation of the Convention and the wise use of wetlands more broadly

PALSAR Wide-Area Mapping of Borneo: Methodology and Map Validation

This paper describes the operational radar mapping processing chain developed and steps taken to produce a provisional wide-area PALSAR forest and land cover map covering Borneo for the year 2007, compliant with emerging international standards (CEOS guidelines, FAO LCCS). A Bayesian approach based on (unsupervised) mixture modeling followed by Markov Random Field (MRF) classification has been selected for its suitability and flexibility to deal with a situation where ground truth is sparse and sometimes ambiguous. The methodology is based on the classification of Fine Beam Single (FBS) and Fine Beam Dual (FBD) polarization (path) image pairs. To cover Borneo the equivalent of 554 standard images is required. Qualitative and quantitative validation results and findings are reported. The final overall accuracy assessment result shows the demonstration map product is in 85.5% full agreement with the independent reference dataset and in 7.8% 'partial agreement'. The accuracy achieved is widely considered adequate, a very promising result for a sub-continental high resolution map based on just single-year radar data. Approaches for further improvement of the accuracy of less accurately classified thematic classes such as grassland, cropland and shrubland are suggested. This work has been undertaken in part within the framework of the ALOS Kyoto & Carbon Initiative

Four decades of forest persistence, clearance and logging on Borneo

The native forests of Borneo have been impacted by selective logging, fire, and conversion to plantations at unprecedented scales since industrial-scale extractive industries began in the early 1970s. There is no island-wide documentation of forest clearance or logging since the 1970s. This creates an information gap for conservation planning, especially with regard to selectively logged forests that maintain high conservation potential. Analysing LANDSAT images, we estimate that 75.7% (558,060 km(2)) of Borneo's area (737,188 km(2)) was forested around 1973. Based upon a forest cover map for 2010 derived using ALOS-PALSAR and visually reviewing LANDSAT images, we estimate that the 1973 forest area had declined by 168,493 km(2) (30.2%) in 2010. The highest losses were recorded in Sabah and Kalimantan with 39.5% and 30.7% of their total forest area in 1973 becoming non-forest in 2010, and the lowest in Brunei and Sarawak (8.4%, and 23.1%). We estimate that the combined area planted in industrial oil palm and timber plantations in 2010 was 75,480 km(2), representing 10% of Borneo. We mapped 271,819 km of primary logging roads that were created between 1973 and 2010. The greatest density of logging roads was found in Sarawak, at 0.89 km km(-2), and the lowest density in Brunei, at 0.18 km km(- 2). Analyzing MODIS-based tree cover maps, we estimate that logging operated within 700 m of primary logging roads. Using this distance, we estimate that 266,257 km(2) of 1973 forest cover has been logged. With 389,566 km(2) (52.8%) of the island remaining forested, of which 209,649 km(2) remains intact. There is still hope for biodiversity conservation in Borneo. Protecting logged forests from fire and conversion to plantations is an urgent priority for reducing rates of deforestation in Borneo

Palsar tropical forest and cover mapping, mosaicing and validation, case study Borneo

The production of spatially detailed maps of (very) large areas, and time series of these maps, requires dedicated processing approaches. PALSAR data collection is done in partly overlapping strips or swaths. Since one complete observation cycle of the ALOS satellite is 46 days, adjacent strips, typically, feature differences in acquisition time of several days or weeks. Because of rainfall events, flooding dynamics and incidence angle effects, mosaicing of the backscatter data is tedious. The best approach (which is discussed in this paper) is to make pre-classifications strip by strip and mosaic the strips during the final stage of the classification process. Another challenge is related to the very large volume of the data and, consequently, the need to use computer time in a very efficient way. This problem will be approached by statistical analysis of the data (before classification) to derive appropriate (radar) legends (for each strip) in a highly automated way. In the final mapping stage the legend is made compliant with user needs (based on radar legends of individual strips). This paper shows how mixture modelling and Markov Random Field classification can be utilised for (seamless) mosaicing. New tools are discussed to automate statistical cluster matching between series of adjacent strips. One of the new tools utilises polarimetric data sampling and a new polarimetric decomposition approach. Validation is done with large ground data sets and other reference sets spread over Borneo. The final maps (based on the 2007 FBS and FBD strips) feature high accuracy, large thematic detail with a fair number of forest classes and other land cover classes, and compliance with LCCS and IPCC guidelines. These maps may be of key interest to develop REDD for the humid tropic