Assessment of land use change and crop water requirements in Dong Hung district in the Red River Delta of Vietnam using GIS and satellite imageries

Monitoring land use changes plays crucial role for the management and use of land in a reasonable and effective manner. As land use change is associated with increasingly dynamic socio-economic activities, tracking land use change becomes more difficult with larger amounts of data to be processed. In this study, the modern technology of GIS and Remote Sensing was applied for the assessment of land use change and crop water requirements in Dong Hung district in the Red River Delta of Vietnam. Databases of land use for 2013 and 2018 comprising 2492 and 3473 land parcels with 32 and 36 land use types, respectively, were built from land use map and land use status report. The databases were then used to construct a database of land use change for the period of 2013-2018, which was finally used for land use change assessment. In addition, Landsat-8 OLI data was used to detect land use change for Summer-Autumn and Winter-Spring seasons of 2013 and 2018. Moreover, MODIS satellite data was also used to estimate the crop water requirements for the rice fields for the mentioned seasons in the district. The study revealed that there was a complicated conversion among land use types, but in general agricultural land decreased by 485.9 ha, while non-agricultural land increased by 493.23 ha mainly with the expansion of residential land and land for infrastructure development. Among agricultural land use types, however, only annual cropland, which mostly includes paddy land was narrowed down by nearly 770ha, meanwhile other agricultural land increased. Crop water requirement was found to change slightly during the study period. Although the changes in land use in the study area imply the progress of urbanization, infrastructure improvement and economic restructuring, since Thai Binh province is the heart of the Red River Delta and critically contributes to the rice production in the region, the decline in paddy land is of great concern that should be taken into account for land management and planning of the province and the district.