土地利用方式对平原-丘陵-湿地交融区水资源的影响

近年来三江平原的平原-丘陵-湿地交融区土地利用方式变化显著,造成地下水水位下降、水资源紧缺等问题,然而揭示该区土地利用方式变化对水资源影响的报道较少,且难于精准描述地表、地下、湿地和绿水等水资源量时空变化。本文联合基于格子波尔兹曼法的分布式TOPMODEL和湿地水流运动模型构建平原-丘陵-湿地交融区水文模型,利用GIS和RS技术,结合地学信息图谱与空间自相关方法,分析了挠力河流域土地利用方式变化及其对水资源量影响。结果表明:根据耕地面积变化和动态度分布得1990—2013年间挠力河流域草地和林地面积变化不大,旱地面积轻微下降;挠力河流域中部与北部区域生产条件优越的未利用地和旱地转为水田;土地利用方式变化对水资源影响由强到弱的顺序为灌溉水田抽取地下水量、绿水储量、径流深、绿水流量、补给地下水量;水稻田不同生育期蒸发量不同,造成了挠力河流域5—6月期间绿水流量增加、绿水储量减少、径流深减少、补给地下水量增加和灌溉水田抽取地下水量增加等趋势,7—8月期间这一增加趋势逐渐减弱,8月后这一趋势结束;水田密集区域绿水流量大,绿水储量和径流深减少,而补给地下水量和灌溉水田抽取地下水量增加。

Influence of Land Use on Water Resources in Plain-Hill-Wetland Blend Area

Land use of plain-hill-wetland blend area in Sanjiang Plain was changed significantly, resulting in the decline of groundwater level and shortage of water resources, while rare research was focused on revealing the effect of land use change on water resources, especially on the temporal and spatial distribution of water resources of surface water and ground water, wetland water and green water. A plain-hill-wetland blend area hydrological model was constructed based on distributed TOPMODEL and wetland flow kinematic model. The land use change and its impact on water resources in Naolihe River Basin was analyzed by using GIS and RS technology, combined with the geo information and spatial autocorrelation method. The results showed that the areas of grassland and woodland in the Naolihe River basin were changed little, while dry land area was decreased slightly according to the change of cultivated land area and dynamic degree distribution between 1990 and 2013;unused land and dry land with advantageous conditions for production was converted to paddy field in the central and northern areas of Naolihe River Basin;The influence of land use change on water resources declined in the order of withdraw water quantity, green water reserves, runoff flow, green water flow, and groundwater recharge;the evaporation capacity of paddy field was different in different rice growth periods, which led to the increase of green water flow, decrease of green water reserves, decrease of runoff flow, increase of groundwater recharge and increase of withdraw water quantity during May and June in Naolihe River Basin. The difference of these items was decreased gradually during July and August, and disappeared after August. Green water flow was increased, green water reserves and runoff flow were decreased, while groundwater recharge and withdraw water quantity were increased in paddy field.