Overview of study region
The project area focuses on the whole Yongxin County in Heshui
River watershed, Jiangxi Province. This county is located in the western
part of the Jiangxi Province, with an area of 2194.57 km2. Of this total,
cultivated paddy field land cover is 263.27 km2, grassland is
14.52 km2, and vegetable/fruit orchard farm is 13.17 km2 (Huang
et al., 2006). The topography consists mainly of hilly land and mountains,
with the highest lands in the north and south, sloping down to
the central area (Fig. 2). The estimated annual surface water storage is
1760 million m3. Groundwater from two aquifers (alluvial and karst
aquifers) can be used for irrigation. The estimated amount of renewable
groundwater resources in the study area is 286millionm3/year (Huang
et al., 2006).