Abstract/Summary

This working paper presents the findings of research undertaken on land use and land cover (LULC) change in Cambodia, with a focus on water resource development and local livelihoods in Stung Chrey Bak catchment, Kompong Chhnang province. The research aims to provide improved information of LULC to researchers, policy makers, and other stakeholders and was undertaken as one of three research components of the Water Resource Management and Research Capacity Development Programme (WRMRCDP).

This study investigates the interaction between water resources, LULC, and local livelihoods over two decades within an agricultural catchment in the upper and middle sections of Stung Chrey Bak (a tributary of the Tonle Sap) catchment. The time period examined was 1989 to 2008. Research focused on two aspects: i) investigation of the physical characteristics of land cover changes using satellite image classifications; and, ii) interviews and field observations at the local level and qualitative analysis of on the ground changes. Changes in land cover were quantified using satellite remote sensing imagery; however, drivers of changes in land use, including land conversion, were harder to measure through quantitative analysis. The qualitative research aimed not only at understanding changes on the ground, but also the possible reasons or drivers behind such change. By combining qualitative and quantitative research a more comprehensive understanding of change at different spatial locations and across multi-temporal periods was gained.

The results of this research indicate that LULC across the study site has changed considerably over the last two decades. The three satellite image classifications in 1989, 2003 and 2008 suggest that LULC has changed across the majority of the catchment. Fragmentation and a decline in the quality of evergreen forest has occurred in the upstream part of the catchment, though some areas of evergreen forest have been retained in areas which correspond closely with the boundary of the Phnom Aural Wildlife Sanctuary. The field interviews revealed that both quality and quantity of the evergreen forest had declined over the study period within most of the Chrey Bak catchment. Findings also showed a steady decline of remaining secondary forest in the midstream and some upstream areas. Such disturbance is a result of forest encroachment and illegal logging by local people and outsiders1, charcoal production, and commercial agriculture (large scale plantations). The implications of such disturbances must be taken into consideration if sustainable catchment management objectives across the catchment are to be achieved.

Various players have contributed to LULC change across the catchment. Poorly conceived water resource development and agricultural expansion during the Khmer Rouge (KR) period from 1975 to 1979 influenced the patterns of land use and land cover seen today2. The KR, which occupied some areas in the study site until the 1990s, contributed to rapid forest clearing, including the removal of high value timber, particularly in the upstream catchment.

Institutional and organisational changes, including the adoption of the Land Laws in 1992 and 2001, and the Laws on Forestry in 2002 and 2005, have also shaped current land use practices and attitudes towards land and forests. For example, the 1992 Land Law allowed people who cultivated a specific plot for five years or longer to claim ownership of that land. 1 It was unclear who this refers to but may include external operators from as far afield as Phnom Penh. 2 Imagery for the period prior to 1975 showing forest cover and land use was not available at the time of this research. Such claims commonly led to conversion of land from secondary forest to rice fields, the results of which are still evident across the catchment today. In addition, the 2002 Law on Forestry has provided improved security to local communities throughout Cambodia by allowing the government to confiscate land that has otherwise been claimed illegally through land grabbing. Other factors that have influenced LULC change in the catchment include land grabbing, charcoal production, illegal logging and economic land concessions.

Even as irrigation system development played a minor role in agricultural land expansion, the expansion of irrigated land for rice production and other more water intensive agriculture poses a threat to hydrological processes within the catchment, in particular the availability of water resources. The irrigation system is constrained by water availability, but irrigation demand is growing with the potential to create increased competition for water between upstream and downstream users. Concerns over increased competition for water were a key issue raised in the interviews for this research. Changes to land use and land cover have the potential to impact on water availability and quality, limiting the opportunities for more sustainable catchment management.

The key messages of this research are that:

·         Effective methods to assess land use and land cover change in Cambodia are needed to ensure that suitable data is available for sustainable catchment management and monitoring.

·          Land use and land cover change assessment and monitoring need to involve technically sophisticated quantitative methods such as remote sensing; however, these methods alone do not provide a comprehensive tool for measuring land cover change.

·         A combination of quantitative methods such as remote sensing and qualitative methods such as interviews is essential to provide a complete picture of land use and land cover change in Cambodia.

   Key actions that the Cambodian government can take to improve land use and land cover data are:

·         Encourage and invest in the integration of high quality technical quantitative and qualitative approaches using local knowledge and ground truthing to avoid over simplification and to understand local nuances and specificity. Attention should be paid to strengthening local expertise in LCLU change analysis and ensuring quality data.

·         Draw upon the Royal University Phnom Penh (RUPP) and CDRI for the capacities that these institutions have built through this project by using the mixed methods approach to advance knowledge and understanding of LULC change in Cambodia.