描述:
f the earth's
surface.Therefore,it has great benefit for clarifying the mutual action between human
beings and land and their change principles in the historical period when the land use
and the land cover changes are chosen as the study perspective.
描述:
made for economic prosperity. At the same time, some
man-made natural disasters have been paid more and more attentions , so the research on hydraulic
characteristics of the river in recent years has been put on the agenda. Considering the ecological
environment, flood control, pollution prevention and control method, and in view of the perspective of
the urban landscape as well as the national strategic plan for sustainable development, the research the
hydraulic characteristics of river and making river reasonably repair and ecological reconstruction will
become a general trend, because that is a kind of remediation measure for human to be done
unreasonable exploitation, and it also will be the strong protection of river resources and sustainable
model for better using river resources in the future.
描述:
ainly chooses three aspects, the quantity and quality
of farmland, the land system and agricultural technology, to analysis the fact that the land system,
the land utilization patterns and the selection of agricultural technology are constrained by natural
environment and land resources, accordingly reveal the main-land relationship which is influenced
by natural environment. The thesis is composed of four parts.
描述:
ainly chooses three aspects, the quantity and quality
of farmland, the land system and agricultural technology, to analysis the fact that the land system,
the land utilization patterns and the selection of agricultural technology are constrained by natural
environment and land resources, accordingly reveal the main-land relationship which is influenced
by natural environment. The thesis is composed of four parts.
描述:
ium between the grain production
and water resource: the drought and the irrigation area in northeast china, the drought and the
irrigation region in Huanghuaihai area, the drought and the irrigation area in northwest
china.The article analized the characteristic of water using of the main crops and the main
cropping systems, compared the economic benefit of the water-saving planting patterns,
studied the economic benefit, the water-saving benefit and participatory farmers survey
results etc. of the water-saving technologies.