The major effect of land u on land cover since 1750 has been deforestation of temperate regions. More ret signifit effects of land u include urban sprawl, soil erosion, soil degradation, salinization, aification. Land-u ge together with u of fossil fuels, are the major anthropogenic sources of carbon dioxide, a dominant greenhou gas.
Acc to a report by the United Nations’ Food and Agriculture anisation, land degradation has been exacerbated where there has been an abnce of any land u planning, or of its orderly execution, or the existence of financial al iives that have led to the wrong land u decisions, or one-sided tral planning leading to over-utilization of the land resources—for instanmediate produ at all costs. As a quehe result has often been miry for large gments of the local population aru of valuable ecosystems. Suarroroaches should be replaced by a teique for the planning and ma of land resources that is ied and holistid where land urs are tral. This will ehe long-term quality of the land for human u, the prevention or resolution of social flicts related to land u, and the rvation of ecosystems of high biodiversity value.
土地利用率（land utilization rate）指已利用的土地麵積與土地總麵積之比，一般用百分數（pertage）表示，是反映土地利用程度（land u degree）的數量指標。
衡量土地利用率的主要指標（index）包括：
(1) 農業土地利用率（agricultural land utilization rate）。
(2) 非農業土地利用率(non-agricultural land utilization rate)。指一個地區或農業生產單位非農業用地（包括城鎮居民點、工礦、交通、旅遊、軍事等的占地）占土地總麵積。
(3) 墾殖指數(cultivation index)。
(4) 複種指數(multiple-cropping index)。在土地開發利用過程中，必須在不造成水土流失(water and soil erosion)和破壞生態環境的原則下，將一切可以開發利用的土地資源，因地製宜地加以充分合理的開發利用，以提高土地利用率。