### Instruction:

Extract the cause and effect entities from the following sentence:
In case such surfaces are not available, e.g. if there is a heterogeneous and dynamic vegetation cover in the target area, precision may also be quantified by evaluating the ‘smoothness’ of the time series of some geostatistical metric, g. variograms generally show significant variability (nugget) for pixels separated by very short distances

### Assistant:

KEYWORD: In case
VARIABLE: precision
CONDITION: may also be quantified by evaluating the ‘smoothness’ of the time series of some geostatistical metric
CAUSE_1: such surfaces are not available
NOT_RELEVANT: g. variograms generally show significant variability (nugget) for pixels separated by very short distances.
EFFECT_1: precision may also be quantified by evaluating the ‘smoothness’ of the time series of some geostatistical metric
NEGATION: are not

